Evidence record

What is inside the Earth?

Every sentence on the exploration belongs to at least one claim below. Each says what kind of statement it is, what it rests on, what the evidence does not establish, and how far it was checked. Nothing here is a score, and none of it is a verdict on a belief or a theory.

Last checked 24 September 2026.

Source checked: 34
Partly checked: 19
Presented as open: 4
A judgement, not a fact: 4

If something here is wrong, misquoted, out of date or unfair, write to support@unknownoceans.com and give the claim number, which does not change.

What the question takes for granted

A scientific question about a place nobody can visit. The page separates what the seismic record fixes (the layers) from what it leaves open (composition, the two large structures above the core, how much water the mantle holds), and says where a few samples break the rule that everything below the crust is inferred.

The Earth has a layered interior that earthquake waves can resolve
Established
Crust, mantle, liquid outer core and solid inner core are read from how earthquake waves bend, reflect and slow, and whether shear waves pass through.
Seismic velocities can tell us what the deep interior is made of
Contested
They fix structure well and composition less well: the same average velocity profile has been fitted by different mineral mixtures, and slow regions can be read as hotter or as chemically different.

How the question is labelled

Claim: Earth’s interior

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: Inside Earth

Kind: Framing. Signposting. It asserts nothing a source could check.

The question

Claim: The deepest hole ever drilled did not get through the crust.

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep WellIntroduction, first paragraph; history section
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: the world’s deepest scientific well, which reached a record depth of 12.262 m
Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep Wellhistory section
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: it made it possible to penetrate 12262 meters deep into the Earth’s crust
Supports
The Interior of the EarthThe Crust
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: a Soviet hole on the Kola Peninsula has been drilled to a depth of 12 kilometers, but drilling expense increases enormously with depth, and Moho penetration is not likely very soon

What this does not establish

The record is for depth, as the 2021 anniversary paper gives it: “12262 m, which has not been surpassed so far”.

Later work looked for

Crossref, 2021 on, "Kola superdeep borehole": studies of its cores and its history, nothing reporting a deeper hole.

Claim 3 · checked 24 September 2026 · AI-assisted audit

Claim: What we know about the inside of this planet comes mostly from earthquake waves passing through it, read against laboratory experiments.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

The same source lists the other evidence: surface rocks, the Earth’s motions, gravity, the magnetic field and heat flow.

Supports
The Interior of the EarthIntroduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: Our current information comes from studies of the paths and characteristics of earthquake waves travelling through the Earth, as well as from laboratory experiments on surface minerals and rocks at high pressure and temperature.

Later work looked for

How the field works; not a finding later work revises.

Corrected

24 September 2026. Previously: “Everything we know about the inside of this planet is inferred from waves passing through it.” Overstated. The USGS lists laboratory experiments, gravity, magnetism and heat flow beside seismology, and the page itself reports a diamond inclusion and a drilled mantle section.

Claim 4 · checked 24 September 2026 · AI-assisted audit

Claim: Mantle rock lies under the crust and has been sampled where tectonics lifted it to the surface or where a piece came up inside a diamond,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
A long section of serpentinized depleted mantle peridotiteIntroduction, second paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: limited accessibility as the mantle is normally covered by crust. Mantle sections of ophiolites are an exception ... Abyssal peridotites, exposed locally by tectonic processes along slow- and ultraslow-spreading mid-ocean ridges and transform faults
Supports
Hydrous mantle transition zone indicated by ringwoodite included within diamondfirst paragraph and abstract, last sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Measurement
The source reads: we find ringwoodite included in a diamond from Juína, Brazil. ... The finding also indicates that some kimberlites must have their primary sources in this deep mantle region.

What this does not establish

Nobody has published a list of every route; this follows from how the 2024 paper describes access to the mantle, with eruptions added from the diamond study, which was read as an abstract.

Later work looked for

Crossref, 2024 on, "Atlantis Massif Expedition 399 mantle peridotite": follow-up studies of the same core, nothing that changes how the mantle has been reached.

Corrected

24 September 2026. Previously: “Nobody has ever sampled the mantle in place,” Stated as an absolute that no read source makes. The 2024 drilling paper says how the mantle has been reached, which is the claim the page can carry.

24 September 2026. Previously: “Mantle rock has been sampled only where tectonics lifted it to the surface or an eruption carried it up,” The sources read give tectonic exposure and one inclusion that came up in a diamond; none says an eruption carries mantle rock up or that these are the only ways it is sampled.

Claim 5 · checked 24 September 2026 · AI-assisted audit

Claim: and two continent-sized structures near the core have no agreed explanation.

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantleabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Review of the field
The source reads: However, the origin and composition of the anomalous provinces is uncertain.
Supports
Moon-forming impactor as a source of Earth’s basal mantle anomaliesabstract, first sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Model
The source reads: Seismic images of Earth’s interior have revealed two continent-sized anomalies with low seismic velocities

Claim 6 · checked 24 September 2026 · AI-assisted audit

Claim: The Kola Superdeep Borehole in north-western Russia reached 12,262 metres in 1990,

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep Wellsite description and history section, p. 231
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: SG -3 was started in the northwestern part of the Kola Peninsula ... In 1990, the maximum depth was reached – 12262 m, which has not been surpassed so far.

Corrected

24 September 2026. Previously: “The Kola Superdeep Borehole in north-western Russia reached about 12.3 kilometres” The source gives the depth to the metre and the year; the page now does.

Claim 7 · checked 24 September 2026 · AI-assisted audit

Claim: in rock that was hotter than expected and kept caving in,

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep Welldrilling technology section, p. 232, and the section on borehole conditions
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: Drilling became more difficult, and the borehole took on an oval shape, many caverns appeared, and accidents became more frequent. ... led to collapse of the borehole walls
Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep Wellgeological results, p. 235
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: significantly higher than expected ... the real temperature in the borehole at a depth of 10 km reached 180
The same passage gives 212 degrees at about 12 km against an assumed 120.

Corrected

24 September 2026. Previously: “before conditions made further drilling impractical.” The source names the conditions and says the work ended because funding was cut, not because the rock made it impossible.

Claim 8 · checked 24 September 2026 · AI-assisted audit

Claim: and drilling stopped in 1992 when the funding ran out.

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep Wellhistory section, p. 231
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: However, a drastic reduction in funding made it impossible to continue the work. Drilling was stopped in 1992.

Claim 9 · checked 24 September 2026 · AI-assisted audit

Claim: That is less than half the average thickness of continental crust, and about 0.2% of the way to the centre.

Kind: Present-day figure. A count, survey or report finding, as the named source gives it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inside the Earth (This Dynamic Earth)first and second paragraphs
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The thickness of the crust beneath continents is much more variable but averages about 30 km
Supports
Inside the Earth (This Dynamic Earth)first paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: about 12,750 kilometers (km) in diameter

What this does not establish

Arithmetic on the USGS figures: 12.262 km against an average crust of about 30 km, and against a radius of about 6,375 km.

Later work looked for

Reference figures for the crust and the radius; not a finding later work revises.

Corrected

24 September 2026. Previously: “That is roughly a third of the way through continental crust,” No cited source gave a crustal thickness. Against the USGS average of about 30 km the hole is about two fifths of the way, so the page says less than half.

Claim 10 · checked 24 September 2026 · AI-assisted audit

Claim: Nearly everything below that is known indirectly.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from claims 4 and 5: the exceptions are pieces of the mantle brought up by tectonics or eruptions, like the diamond in claim 24.

Corrected

24 September 2026. Previously: “Everything below that is known indirectly.” The page itself reports a mantle sample carried up in a diamond, which is direct evidence.

Claim 11 · checked 24 September 2026 · AI-assisted audit

What seismic waves reveal

Claim: What seismic waves reveal

Kind: Framing. Signposting. It asserts nothing a source could check.

The layered structure is well established

Claim: The layered structure is well established

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
The Interior of the EarthIntroduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The planet Earth is made up of three main shells: the very thin, brittle crust, the mantle, and the core; the mantle and core are each divided into two parts.

Later work looked for

A settled result; later seismology refines layers within it and has not revised it.

Claim 13 · checked 24 September 2026 · AI-assisted audit

Claim: Seismic waves from earthquakes refract, reflect and change speed at boundaries inside the Earth.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
The Interior of the EarthFigure 2 caption
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The paths curve because the different rock types found at different depths change the speed at which the waves travel.
Supports
The Interior of the EarthThe Crust
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: it can be detected by a sharp increase downward in the speed of earthquake waves there

Later work looked for

How the method works; not a finding later work revises.

Claim 14 · checked 24 September 2026 · AI-assisted audit

Claim: Reading those arrivals at stations worldwide gives a layered model: crust, mantle, liquid outer core, solid inner core.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
The Interior of the EarthThe Core
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The inner core is considered to be solid because of the behavior of P and S waves passing through it.
Supports
Inside the Earth (This Dynamic Earth)fourth paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: a 2,200 km-thick liquid outer core and a 1,250 km-thick solid inner core

Later work looked for

A settled result; not something later work has revised.

Claim 15 · checked 24 September 2026 · AI-assisted audit

Claim: The inner core was proposed in 1936 by the Danish seismologist Inge Lehmann from an analysis of P-wave data

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inge Lehmann's paper: P'(1936)p. 262, opening
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Review of the field
The source reads: In 1936, the Danish seismologist Inge Lehmann ... suggested from the analysis of P-wave data that the Earth must have an inner core

Claim 16 · checked 24 September 2026 · AI-assisted audit

Claim: inside the core, she wrote, “there is an inner core in which the velocity is larger than in the outer one”

Kind: Quotes a source. The words of a named text, checked against the source.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inge Lehmann's paper: P'(1936)p. 262, epigraph quoting Lehmann (1936)
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Primary text
The source reads: inside the core there is an inner core in which the velocity is larger than in the outer one

What this does not establish

Quoted from Lehmann’s 1936 paper as the Episodes article reproduces it; the 1936 publication itself was not read.

Claim 17 · checked 24 September 2026 · AI-assisted audit

Claim: A reference model built from those arrival times, ak135, supplies the travel times the International Seismological Centre uses to locate earthquakes.

Kind: Present-day figure. A count, survey or report finding, as the named source gives it.
Review: Source checked. The cited passage was read, and it says this.

Supports
AK135 Travel Time Tablesintroduction page
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Model
The source reads: The ak135 velocity model is designed to provide a good fit to a wide variety of seismic phases ... The details of the construction procedure are described in ... Constraints on seismic velocities in the Earth from travel times
Supports
ISC Locatormain features of the location algorithm
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: uses of all IASPEI standard phases with a valid ak135 travel time prediction

Later work looked for

The ISC page records a new locator version in July 2025 with unchanged documentation; nothing that replaces ak135 there.

Corrected

24 September 2026. Previously: “The model is constrained by thousands of earthquakes recorded at thousands of stations, and is accurate enough to be used for locating events and for nuclear test monitoring.” No cited source gave the counts or the monitoring use. The replacement names one model and one documented use.

Claim 18 · checked 24 September 2026 · AI-assisted audit

The core generates the magnetic field

Claim: The core generates the magnetic field

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Reversals: Magnetic Fliptechnical description
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The source of the magnetic field is the iron-rich liquid outer core of the Earth.

Later work looked for

A settled result; not something later work has revised.

Claim 19 · checked 24 September 2026 · AI-assisted audit

Claim: Convection in the liquid iron outer core, combined with Earth’s rotation, sustains the magnetic field by dynamo action.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
Reversals: Magnetic Fliptechnical description
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: This liquid moves in complex ways as a result of the convection of the heat deep within the core and of the rotation of the planet.
Supports
Reversals: Magnetic Fliptechnical description
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: The motion of this metal fluid across existing magnetic field lines of force produces electrical currents and these, in turn, generate more magnetic field.

Later work looked for

How the dynamo works in outline; not a finding later work revises.

Claim 20 · checked 24 September 2026 · AI-assisted audit

Claim: The field has reversed polarity many times, recorded in the magnetisation of seafloor basalt,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Reversals: Magnetic FlipHow often do reversals occur?
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: the Earth’s magnetic field has undergone numerous reversals of polarity. We can see this in the magnetic patterns found in volcanic rocks, especially those recovered from the ocean floors.
Supports
Developing the theory (This Dynamic Earth)Seafloor spreading and recycling of oceanic crust
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: the oceanic crust now came to be appreciated as a natural "tape recording" of the history of the reversals in the Earth’s magnetic field

Later work looked for

A settled result; later work refines the reversal timescale, not the fact.

Claim 21 · checked 24 September 2026 · AI-assisted audit

Claim: and the striped pattern those reversals left became one of the main lines of evidence for plate tectonics.

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
Developing the theory (This Dynamic Earth)opening paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: four major scientific developments spurred the formulation of the plate-tectonics theory: (1) demonstration of the ruggedness and youth of the ocean floor; (2) confirmation of repeated reversals of the Earth magnetic field in the geologic past
Supports
Developing the theory (This Dynamic Earth)Seafloor spreading and recycling of oceanic crust
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: By explaining both the zebralike magnetic striping and the construction of the mid-ocean ridge system, the seafloor spreading hypothesis quickly gained converts

Corrected

24 September 2026. Previously: “which is also how plate tectonics was confirmed.” The USGS names striping as one of four developments behind the theory, not as the confirmation. The cited page, Inside the Earth, says nothing about it; the chapter that does is now cited.

Claim 22 · checked 24 September 2026 · AI-assisted audit

There is water inside the mantle

Claim: There is water inside the mantle

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
The role of water in Earth’s mantleIntroduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: Extensive studies have agreed that the transition zone is a major water reservoir, but the water storage in the lower mantle is poorly constrained.

Later work looked for

Crossref, 2020 on, "water content mantle transition zone electrical conductivity": regional studies that find water in the transition zone; nothing that removes it.

Claim 23 · checked 24 September 2026 · AI-assisted audit

Claim: A diamond from Brazil was found to contain an inclusion of ringwoodite carrying roughly one percent water by weight,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Hydrous mantle transition zone indicated by ringwoodite included within diamondabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Measurement
The source reads: X-ray diffraction, Raman and infrared spectroscopic evidence for the inclusion of water-rich ringwoodite in diamond from Juína, Brazil, indicates that, at least locally, the Earth’s transition zone is hydrous to about 1 weight per cent.
Supports
The role of water in Earth’s mantleWater in the transition zone
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: hydrous ringwoodite, namely spinel type of Mg2SiO4 containing water up to 1 wt.% [21], have been discovered as inclusions in diamonds

What this does not establish

One inclusion in one diamond. The 2014 paper was read as its abstract and first paragraph only.

Later work looked for

Crossref, 2015 on, "ringwoodite inclusion diamond water transition zone": laboratory work on water in ringwoodite; nothing that revises the finding.

Claim 24 · checked 24 September 2026 · AI-assisted audit

Claim: direct evidence that the mantle transition zone is hydrous, at least locally.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Hydrous mantle transition zone indicated by ringwoodite included within diamondfirst paragraph
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Measurement
The source reads: is direct evidence that, at least locally, the transition zone is hydrous, to about 1 weight per cent
Supports
The role of water in Earth’s mantleWater in the transition zone
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: These observations suggest that the mantle transition zone is wet locally.

What this does not establish

Local. How much of the transition zone is wet is claim 43.

Later work looked for

Crossref, 2015 on, "ringwoodite inclusion diamond water transition zone": nothing that revises it.

Corrected

24 September 2026. Previously: “providing direct physical evidence that the mantle transition zone is hydrous.” The paper says “at least locally”, and the page had dropped the qualifier.

Claim 25 · checked 24 September 2026 · AI-assisted audit

Claim: Nobody went down for it: it came up inside the diamond, and the authors infer that some kimberlite magmas come from that deep.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Hydrous mantle transition zone indicated by ringwoodite included within diamondfirst paragraph and abstract, last sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Measurement
The source reads: we find ringwoodite included in a diamond from Juína, Brazil. ... The finding also indicates that some kimberlites must have their primary sources in this deep mantle region.

What this does not establish

Read as the abstract only.

Corrected

24 September 2026. Previously: “The sample arrived at the surface by accident, carried up in a volcanic pipe.” The abstract says what the paper infers about kimberlites; "by accident" and the pipe were not in what was read.

Claim 26 · checked 24 September 2026 · AI-assisted audit

The structures nobody can identify

Claim: The structures nobody can identify

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Section title. It fits the two large provinces above the core (claims 29 to 31) most closely; the inner core and the water budget in the same section are measured but disputed.

Claim 27 · checked 24 September 2026 · AI-assisted audit

What the two enormous structures above the core are

Claim: What the two enormous structures above the core are

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: Beneath Africa and beneath the Pacific sit continent-sized regions where seismic waves travel unusually slowly.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
The presence of ancient subducted oceanic crust contributes to seismic anomalies in Large Low Shear Velocity ProvincesMain text, first paragraph, and the reference to Garnero and others 2016
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: These seismic anomalies are observed beneath Africa and the Pacific and extend thousands of kilometers horizontally and hundreds of kilometers vertically above the CMB region ... Continent-sized anomalous zones with low seismic velocity at the base of Earth's mantle
Context
Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantlestandfirst
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Review of the field
The source reads: Two large zones through which seismic waves travel unusually slowly are found at the base of Earth’s mantle.

What this does not establish

The provinces are seen in seismic velocity models; how sharp their edges are and what they are made of is argued (claims 30 and 31). The Garnero review, read as its abstract, is context: the 2025 paper, read in full, carries the claim.

Later work looked for

Crossref, 2021 on, "large low shear velocity provinces origin": the provinces are imaged in every recent study found; their cause is argued (claim 31).

Corrected

24 September 2026. Previously: “where seismic waves slow down markedly” The typical anomaly is a few per cent; the review’s own wording is “unusually slowly”. No source for Africa and the Pacific was cited, and one is now.

Claim 29 · checked 24 September 2026 · AI-assisted audit

Claim: They are real, they are large, and their composition and origin are debated:

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Context
Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantleabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Review of the field
The source reads: However, the origin and composition of the anomalous provinces is uncertain.
Supports
The presence of ancient subducted oceanic crust contributes to seismic anomalies in Large Low Shear Velocity ProvincesMain text, first paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: However, the possibility of a combination of thermal and chemical factors still cannot be fully ruled out.
Supports
The presence of ancient subducted oceanic crust contributes to seismic anomalies in Large Low Shear Velocity ProvincesDiscussion of the primordial hypothesis
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: there are alternative explanations for such a cause

What this does not establish

The Garnero review, read as its abstract, is context; the 2025 paper, read in full, carries the claim, and argues for one side of the debate it describes.

Claim 30 · checked 24 September 2026 · AI-assisted audit

Claim: proposals range from piles of ancient subducted oceanic crust to primordial material that never mixed, to the remains of an early planetary collision.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
The presence of ancient subducted oceanic crust contributes to seismic anomalies in Large Low Shear Velocity ProvincesHypothesis section, first sentence
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: suggests that their origin is attributed to the long-term accumulation of ancient subducted oceanic crust in the lowermost mantle
Supports
Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantleabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Review of the field
The source reads: potentially partly composed of subducted or primordial material, and have therefore been termed thermochemical piles
Supports
Moon-forming impactor as a source of Earth’s basal mantle anomaliesabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: LLVPs may represent buried relics of Theia mantle material (TMM) that was preserved in proto-Earth’s mantle after the Moon-forming giant impact

What this does not establish

The Garnero review and the Yuan paper were read as abstracts. Each proposal is argued by its authors; none is established.

How the inner core behaves

Claim: How the inner core behaves

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: The inner core appears to turn at a slightly different rate from the rest of the planet, and the difference changes over decades.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inner core backtracking by seismic waveform change reversalsabstract and introduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: has been inferred to rotate relative to the surface of Earth or change over years to decades based on changes in seismograms from repeating earthquakes and explosions ... The inferred rate of super-rotation has settled to about 0.05–0.15° per year
Qualifies
Annual-scale variability in both the rotation rate and near surface of Earth’s inner coreabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: We thus resolve the long-standing debate on whether temporal variability in PKIKP waves results from rotation or more local action near the inner-core boundary: it is tentatively both.

What this does not establish

Rotation is an inference from changing waveforms. Part of the change may be the inner core’s surface deforming, which is claim 39.

Later work looked for

Crossref, 2024 on, "inner core rotation seismic": Vidale and others (2025) find non-rotational change as well; page updated.

Corrected

24 September 2026. Previously: “The inner core turns at a slightly different rate” The papers describe the rotation as inferred, and a 2025 study attributes part of the signal to deformation.

Claim 33 · checked 24 September 2026 · AI-assisted audit

Claim: It is read from repeating earthquakes whose waves should travel the same path twice,

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inner core backtracking by seismic waveform change reversalsabstract
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: The matching waveforms reveal times at which the inner core re-occupies the same position, relative to the mantle, as it did at some time in the past.
Context
Multidecadal variation of the Earth’s inner-core rotationabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: This rotation has been inferred from temporal changes between repeated seismic waves that should traverse the same path through the inner core.

Claim 34 · checked 24 September 2026 · AI-assisted audit

Claim: and two groups reading South Sandwich Islands earthquakes recorded in northern North America agree that the rotation has lately been turning back

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Multidecadal variation of the Earth’s inner-core rotationabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: We compared this recent pattern to the Alaskan seismic records of South Sandwich Islands doublets going back to 1964 and it seems to be associated with a gradual turning-back of the inner core relative to the mantle
Supports
Inner core backtracking by seismic waveform change reversalsabstract and Discussion
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: 121 earthquakes between 1991 and 2023 in the South Sandwich Islands ... recorded on the medium-aperture arrays in northern North America ... Our measurements confirm the general trend, which had been controversial, and extend the observation period several more years, confirm a reversal and show asymmetry

What this does not establish

Yang and Song was read as its abstract.

Corrected

24 September 2026. Previously: “two groups working the same South Sandwich Islands events recorded on the same northern arrays” Yang and Song used Alaskan records and paths worldwide; Wang and colleagues used arrays in Alaska and Canada. The regions match; "the same events on the same arrays" was more than the abstracts show.

Claim 35 · checked 24 September 2026 · AI-assisted audit

Claim: and differ on what it is part of.

Kind: Disputed. A contested point, where the page reports a side or the disagreement.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Inner core backtracking by seismic waveform change reversalsabstract, last sentence
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: The resolved different rates of forward and backward motion suggest that new models will be necessary for the dynamics between the inner core, outer core and mantle.
Supports
Multidecadal variation of the Earth’s inner-core rotationabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: as a part of an approximately seven-decade oscillation

What this does not establish

Yang and Song was read as its abstract.

Claim: One reads a pause and a reversal inside an oscillation of about seven decades.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Multidecadal variation of the Earth’s inner-core rotationabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: This globally consistent pattern suggests that differential inner-core rotation has recently paused.

What this does not establish

Read as the abstract.

Claim 37 · checked 24 September 2026 · AI-assisted audit

Claim: The other tracks a super-rotation from 2003 to 2008 and then a return along the same path, two to three times slower, through 2023.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
Inner core backtracking by seismic waveform change reversalsabstract
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: the inner core gradually super-rotated from 2003 to 2008, and then from 2008 to 2023 sub-rotated two to three times more slowly back through the same path

Claim 38 · checked 24 September 2026 · AI-assisted audit

Claim: That group later found that some of the change comes from the inner core’s surface deforming, and proposes, tentatively, that it both turns and changes shape.

Kind: Hypothesis. A proposed explanation, not an established one.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Annual-scale variability in both the rotation rate and near surface of Earth’s inner coreabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Earth and its record · Observational study: associations, not causes
The source reads: Here we extend this set of repeating earthquakes ... revealing non-rotational changes at YKA but not ILAR between 2004 and 2008. We propose that these changes originate in the shallow inner core ... it is tentatively both. The changes near the inner-core boundary most likely result from viscous deformation

What this does not establish

Read as the abstract. The non-rotational change was seen at one of the two arrays, and the authors call their resolution tentative.

Later work looked for

This is the newer work; nothing later found.

Corrected

24 September 2026. Previously: “” Added from the currency search: the 2025 follow-up changes what the rotation signal is taken to be.

Claim 39 · checked 24 September 2026 · AI-assisted audit

How much water is down there in total

Claim: How much water is down there in total

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: A review of the geophysical estimates puts about four hundredths of an ocean’s worth in the upper mantle, between a fifth of an ocean and a whole one in the transition zone, and less than two oceans in the lower mantle.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
The role of water in Earth’s mantleIntroduction; Table 1
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: The water contents summarized in Table 1 indicate that the upper mantle, mantle transition zone and lower mantle contain 0.04, 0.2–1 and <2 oceans of water, respectively.

Later work looked for

Crossref, 2020 on, "water content mantle transition zone electrical conductivity": new regional estimates; no newer global budget found.

Claim 41 · checked 24 September 2026 · AI-assisted audit

Claim: It also says which of those numbers to trust: that the transition zone is a major reservoir is agreed, and the lower mantle is poorly constrained.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
The role of water in Earth’s mantleIntroduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: Extensive studies have agreed that the transition zone is a major water reservoir, but the water storage in the lower mantle is poorly constrained.

Claim 42 · checked 24 September 2026 · AI-assisted audit

Claim: Each figure extrapolates electrical-conductivity and seismic measurements from particular regions across a whole layer, and the transition-zone range assumes that about 30 per cent of it is wet.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
The role of water in Earth’s mantleTable 1
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: 0.2∼1 Ocean mass ... (assuming Wet TZ 30% ... Dry TZ 70%)
Supports
The role of water in Earth’s mantleIntroduction
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Review of the field
The source reads: Reliable estimation of global water contents in the mantle is obtained by geophysical observations, since other procedures may represent the water contents in local regions

Corrected

24 September 2026. Previously: “Each figure is a handful of samples and laboratory measurements extrapolated across a layer, and the layer with no samples is the one with the widest range.” The review’s table is built from geophysical observations, which it prefers to samples precisely because samples are local.

Claim 43 · checked 24 September 2026 · AI-assisted audit

What inference cannot settle

Claim: What inference cannot settle

Kind: Framing. Signposting. It asserts nothing a source could check.

What the deep interior is made of, precisely

Claim: What the deep interior is made of, precisely

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Computational support for a pyrolitic lower mantle containing ferric ironabstract, first sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: The composition of the Earth’s lower mantle is not well constrained.

Claim 45 · checked 24 September 2026 · AI-assisted audit

Claim: Composition is inferred by matching seismic velocities against laboratory measurements and calculations for candidate minerals under extreme pressure.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Source checked. The cited passage was read, and it says this.

Supports
The Interior of the EarthThe Core, last paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Reference work
The source reads: Scientists are continuing to refine the chemical and mineral composition of the Earth’s interior by laboratory experiments
Context
A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity dataabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Physical systems · Experiment
The source reads: Accurate knowledge of sound velocities in the lower-mantle minerals under relevant high-pressure, high-temperature conditions is essential in constraining the mineralogy and chemical composition using seismological observations

Later work looked for

How the method works; not a finding later work revises.

Claim 46 · checked 24 September 2026 · AI-assisted audit

Claim: The same average profile has been matched by different mixtures:

Kind: Disputed. A contested point, where the page reports a side or the disagreement.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Computational support for a pyrolitic lower mantle containing ferric ironabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: As a result, different compositional models for the Earth’s lower mantle have been proposed ... an intermediate volume fraction (about 8:2) consistent with a pyrolitic composition can reproduce the reference velocities and densities

What this does not establish

Both papers were read as abstracts.

Claim: one group’s measurements pointed to a lower mantle more than 93 per cent perovskite by volume, another group’s calculations to a mantle of one composition from top to bottom.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity dataabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Physical systems · Experiment
The source reads: The mineralogical model that provides the best fit to a global seismic velocity profile indicates that perovskite constitutes more than 93 per cent by volume of the lower mantle
Supports
Computational support for a pyrolitic lower mantle containing ferric ironabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: Our findings support a uniform chemical composition throughout the present-day mantle, which we suggest is the result of whole-mantle convection.

What this does not establish

Both papers read as abstracts. One is laboratory measurement, the other calculation; neither is a sample of the lower mantle.

Corrected

24 September 2026. Previously: “one group’s measurements pointed to a lower mantle more than 93 per cent perovskite, another group’s calculations to a mantle of one composition from top to bottom.” Murakami and others give the figure by volume; without the unit it could be read as by mass.

Claim 48 · checked 24 September 2026 · AI-assisted audit

How far down life extends

Claim: How far down life extends

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: Microbes have been recovered from about 2.5 kilometres below the sea floor,

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floorabstract
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan.
Supports
Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floorsubmitted manuscript, results, first paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: We detected intact microbial cells throughout the entire drilled sediment core down to the deepest sample at 2,458 mbsf.
2,458 metres below the sea floor is about 2.5 km.

What this does not establish

One drill site, off Japan. Cell numbers at that depth were very low, about 10 to 1,000 per cubic centimetre. The full text read is the authors’ submitted manuscript, not the published version.

Later work looked for

Crossref, 2019 on, "temperature limits deep subseafloor life": Heuer and others (2020) sample hotter sediment at shallower depth; no deeper recovery found.

Corrected

24 September 2026. Previously: “Microorganisms have been recovered from kilometres below the surface, in rock and in ocean sediment, living at extremely low metabolic rates.” The only citation was a continental biomass paper that carries neither the ocean sediment nor the metabolic rates. Each part now has its source.

Claim 50 · checked 24 September 2026 · AI-assisted audit

Claim: and the rock beneath the continents is estimated to hold 2 to 6 × 10²⁹ cells.

Kind: Present-day figure. A count, survey or report finding, as the named source gives it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
The biomass and biodiversity of the continental subsurfaceabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Review of the field
The source reads: we estimated that the continental subsurface hosts 2 to 6 × 10^29 cells

What this does not establish

A compilation estimate, read as the abstract.

Later work looked for

Crossref, 2019 on, "temperature limits deep subseafloor life": nothing found that revises the continental estimate.

Claim 51 · checked 24 September 2026 · AI-assisted audit

Claim: Cells in these settings break down food ten thousand to a million times more slowly than microbes in a rich laboratory culture.

Kind: What the field holds. The settled view of a field, as a review, a consensus statement or a reference work gives it. Not one study.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Microbial life under extreme energy limitationabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Review of the field
The source reads: Microbial cells in these very stable and oligotrophic settings catabolize 10⁴- to 10⁶-fold more slowly than model organisms in nutrient-rich cultures

What this does not establish

A review, read as its abstract.

Later work looked for

Crossref, 2019 on, "temperature limits deep subseafloor life": a 2020 review of physiological limits (Orsi and others) was found and not read; nothing read revises it.

Claim 52 · checked 24 September 2026 · AI-assisted audit

Claim: Temperature is taken to set the lower limit, and it is not a clean line:

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Temperature limits to deep subseafloor life in the Nankai Trough subduction zonetitle and abstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: Temperature limits to deep subseafloor life in the Nankai Trough subduction zone. ... Above 45°C, populated zones alternate with zones up to 192 meters thick where microbes were undetectable.
Context
The biomass and biodiversity of the continental subsurfaceabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Review of the field
The source reads: Based on considerations of global heat flow, surface temperature, depth and lithology

What this does not establish

Read as abstracts.

Corrected

24 September 2026. Previously: “The lower limit is set by temperature,” Stated as settled and uncited. The 2020 Nankai Trough study shows what the temperature limit looks like in one place.

Claim 53 · checked 24 September 2026 · AI-assisted audit

Claim: in the Nankai Trough, vegetative cells fall a hundredfold above 45°C, yet hyperthermophiles are active at 100 to 120°C.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Temperature limits to deep subseafloor life in the Nankai Trough subduction zoneabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: Above 45°C, concentrations of vegetative cells drop two orders of magnitude
Supports
Temperature limits to deep subseafloor life in the Nankai Trough subduction zoneabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: In 100° to 120°C sediments, isotopic evidence and increased cell concentrations demonstrate the activity of acetate-degrading hyperthermophiles.

What this does not establish

One site, sampled to 1.2 km; read as the abstract.

Later work looked for

Crossref, 2019 on, "temperature limits deep subseafloor life": this is the most recent direct study found.

Claim 54 · checked 24 September 2026 · AI-assisted audit

Claim: Where exactly that limit falls has not been established.

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Temperature limits to deep subseafloor life in the Nankai Trough subduction zoneabstract, last sentence
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Research in microbes · Observational study: associations, not causes
The source reads: Above 45°C, populated zones alternate with zones up to 192 meters thick where microbes were undetectable.

Claim 55 · checked 24 September 2026 · AI-assisted audit

How the whole system started

Claim: How the whole system started

Kind: Framing. Signposting. It asserts nothing a source could check.

Claim: The core formed early, within about the first 30 million years of the Solar System on the evidence of hafnium and tungsten isotopes.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Rapid accretion and early core formation on asteroids and the terrestrial planets from Hf–W chronometryabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · Artefacts and sites · Measurement
The source reads: the (182)Hf-to-(182)W decay is ideally suited for dating core formation in planetary bodies. ... We conclude that core formation in the terrestrial planets and the formation of the Moon must have occurred during the first approximately 30 million years of the life of the Solar System.

What this does not establish

Read as the abstract, which notes that an earlier study had put core formation at 60 million years or later. The age depends on the meteorite values used as reference.

Later work looked for

Crossref, 2017 on, "Hf-W timing core formation Earth": later papers model how metal and silicate equilibrated, found and not read; nothing read moves the date.

Corrected

24 September 2026. Previously: “The core formed early, and the details of how iron separated and descended, and how much of the early history is preserved rather than erased by convection, remain unresolved.” Uncited. The timing and the open question now have sources; the clause on how iron descended, which no read source carried, was removed.

Claim 57 · checked 24 September 2026 · AI-assisted audit

Claim: How much of the planet’s earliest makeup survives in the mantle is an open question,

Kind: Open question. Something the page says is not known.
Review: Presented as open. The page says this is unresolved, and the review found that it is.

Supports
Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basaltsabstract, first sentence
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: How much of Earth’s compositional variation dates to processes that occurred during planet formation remains an unanswered question.

Claim 58 · checked 24 September 2026 · AI-assisted audit

Claim: though some modern lavas carry tungsten signatures from domains formed in the first 50 million years or so.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basaltsabstract
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: were created during the first ~50 million years of solar system history, indicating that portions of the mantle that formed during Earth’s primary accretionary period have survived to the present
Supports
Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basaltsauthor manuscript, main text, first paragraphs
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: in Phanerozoic flood basalts from Baffin Bay and the Ontong Java Plateau, some of which range ... to the highest ever measured in terrestrial rocks.

What this does not establish

The lavas are Phanerozoic flood basalts from Baffin Bay and the Ontong Java Plateau, which the paper’s title calls modern. The full text read is the authors’ manuscript, not the published version.

Later work looked for

Europe PMC: Mundl and others (2017, Science) report tungsten-182 variation in present-day ocean island basalts; consistent, abstract only.

Claim 59 · checked 24 September 2026 · AI-assisted audit

Two ideas worth watching

Claim: Two ideas worth watching

Kind: Framing. Signposting. It asserts nothing a source could check.

The anomalies are the remains of another planet

Claim: The anomalies are the remains of another planet

Kind: Hypothesis. A proposed explanation, not an established one.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Moon-forming impactor as a source of Earth’s basal mantle anomaliesabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: The LLVPs may, thus, be a natural consequence of the Moon-forming giant impact.

What this does not establish

A heading in the section of possibilities. The paper says “may”; claim 64 says it is not established.

Claim 61 · checked 24 September 2026 · AI-assisted audit

Claim: One proposal identifies the low-velocity provinces with material from the body that struck the early Earth and formed the Moon, fragments that sank and never mixed.

Kind: Hypothesis. A proposed explanation, not an established one.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Moon-forming impactor as a source of Earth’s basal mantle anomaliesabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: dense TMM blobs with a size of tens of kilometres after the impact can later sink and accumulate into LLVP-like thermochemical piles atop Earth’s core and survive to the present day

What this does not establish

Simulations show a route, not that it happened. Rival explanations are in claim 31.

Later work looked for

Crossref, 2020 on, "Moon-forming impactor basal mantle anomalies": a 2025 follow-up by Yuan on debris survival, title only; nothing that settles it.

Claim 62 · checked 24 September 2026 · AI-assisted audit

Claim: It comes from impact and mantle-convection simulations, which show that it could have happened,

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Partly checked. Only part of the source could be read. What was not read is listed.

Supports
Moon-forming impactor as a source of Earth’s basal mantle anomaliesabstract
Cited · Link answered, 19 October 2026 · Abstract only, 24 September 2026 · A simulation · Model
The source reads: Our canonical giant-impact simulations show that a fraction of Theia’s mantle could have been delivered to proto-Earth’s solid lower mantle. ... Our mantle convection models show that dense TMM blobs with a size of tens of kilometres after the impact can later sink and accumulate into LLVP-like thermochemical piles

What this does not establish

Read as the abstract.

Corrected

24 September 2026. Previously: “It is a striking hypothesis, it is taken seriously,” The proposal had no cited source and "taken seriously" is not something a source states. The 2023 paper is now cited, and the page says what kind of evidence it is.

Claim 63 · checked 24 September 2026 · AI-assisted audit

Claim: and it is not established.

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

Follows from the paper’s own “may” (claim 61) and from the rival explanations in claim 31.

Claim 64 · checked 24 September 2026 · AI-assisted audit

We will eventually drill into the mantle

Claim: We will eventually drill into the mantle

Kind: This page’s reading. A judgement the page makes from the evidence. Others read it differently.
Review: A judgement, not a fact. Reviewed for whether it is fairly put and follows from the checked claims. No source can confirm it.

A heading in the section of possibilities: a prediction, not a finding. The passage below it says what has been drilled so far.

Claim 65 · checked 24 September 2026 · AI-assisted audit

Claim: Reaching the mantle by drilling through thin oceanic crust has been the goal since Project Mohole was proposed to the US National Science Foundation in the late 1950s.

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
History of scientific ocean drilling, from Project Mohole to the end of IODP1961: Project MoHole
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: Project Mohole , a concept proposed to the U.S. National Science Foundation, considered the feasibility of drilling through the geological boundary identified by an abrupt change in rock physical parameters (Mohorovičić discontinuity)
Supports
The 50th Anniversary of the Start of Drilling the Kola Superdeep WellUS Ocean Drilling Program section
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: In 1958, the Mohol superdeep drilling program appeared in the United States.

Corrected

24 September 2026. Previously: “has been the goal since Project Mohole put it to the American National Science Foundation in 1961, and it has come closer with each generation of drilling vessels.” The IODP page dates the CUSS I drilling to 1961, not the proposal, which the Kola paper puts in 1958. "Come closer" was not in any source.

Claim 66 · checked 24 September 2026 · AI-assisted audit

Claim: In 1961 its platform, CUSS I, was held on target in a strong current, and drilling from a ship became feasible.

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
History of scientific ocean drilling, from Project Mohole to the end of IODP1961: Project MoHole
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: In 1961 when dynamic positioning was successfully used to keep the drilling platform CUSS I on target in strong current, scientific drilling took root as a feasible technology

Claim 67 · checked 24 September 2026 · AI-assisted audit

Claim: The last of the programmes that followed ran from October 2013 to September 2024,

Kind: Historical claim. A statement about the past that historical evidence can test.
Review: Source checked. The cited passage was read, and it says this.

Supports
History of scientific ocean drilling, from Project Mohole to the end of IODP2013-2024 entry
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Texts · Reference work
The source reads: The IODP partners continued their collaboration via the International Ocean Discovery Program (IODP) between October 2013 and September 2024.

Claim 68 · checked 24 September 2026 · AI-assisted audit

Claim: and in 2023 it drilled the deepest hole yet into oceanic mantle rock: 1,268 metres of serpentinised peridotite from the Atlantis Massif, more than six times the previous record, altered by hydrothermal fluid over its whole depth.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
A long section of serpentinized depleted mantle peridotiteDrilling a mantle peridotite section at Atlantis Massif
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: We recovered a 1268 m long section of serpentinized oceanic mantle peridotite, interleaved with thin gabbroic intrusions, from Atlantis Massif ... International Ocean Discovery Program (IODP) Expedition 399 (April-June 2023) targeted Site
Supports
A long section of serpentinized depleted mantle peridotiteFig. S3 caption
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: Hole U1601C is more than six times as deep as the previous record in serpentinized peridotite.
Supports
A long section of serpentinized depleted mantle peridotiteabstract
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: Extensive hydrothermal fluid-rock interaction is recorded across the full depth of the core

Later work looked for

Crossref, 2024 on, "Atlantis Massif Expedition 399 mantle peridotite": follow-up petrology; nothing deeper.

Corrected

24 September 2026. Previously: “The programme that ran those expeditions ran from October 2013 to September 2024, and its last years produced the longest section of mantle rock anyone has drilled:” The paper claims a record for oceanic mantle rock, not for any mantle rock anywhere; the comparison with the previous record is now given.

Claim 69 · checked 24 September 2026 · AI-assisted audit

Claim: Faulting had already lifted that mantle to the sea floor, so the drill did not have to pass through the crust.

Kind: Observation. Something measured or seen, as the named source reports it.
Review: Source checked. The cited passage was read, and it says this.

Supports
A long section of serpentinized depleted mantle peridotiteDrilling a mantle peridotite section at Atlantis Massif, and the section on the orientation of the core
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: Along the south wall of the massif, detachment faulting exhumed serpentinized mantle rocks with minor gabbroic intrusions ... a 1268 m deep hole (U1601C), recovering predominantly serpentinized mantle peridotites with subordinate gabbro ... Exhumation of Atlantis Massif and our recovered core section was accommodated by fault-block rotation

Later work looked for

Crossref, 2024 on, "Atlantis Massif Expedition 399 mantle peridotite": follow-up petrology of the same core; nothing that changes how it was exhumed.

Corrected

24 September 2026. Previously: “” Added so the passage does not read as though the drilling went through the crust to the mantle.

Claim 70 · checked 24 September 2026 · AI-assisted audit

Claim: Only drilling gives a continuous, oriented section of the mantle rather than loose pieces.

Kind: What scholars argue. A report of what specialists argue, or where they disagree.
Review: Source checked. The cited passage was read, and it says this.

Supports
A long section of serpentinized depleted mantle peridotiteIntroduction, second paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: Only drilling of abyssal peridotite provides a continuous and oriented record of the upper mantle.
Supports
A long section of serpentinized depleted mantle peridotiteIntroduction, second paragraph
Cited · Link answered, 19 October 2026 · Read in full, 24 September 2026 · Earth and its record · Measurement
The source reads: the vast majority of these rocks have been obtained by dredging

Corrected

24 September 2026. Previously: “It remains the only route to a sample that is not a fragment carried up by something else.” The rock drilled at Atlantis Massif had itself been carried up by faulting. The paper’s own claim is about continuity and orientation.

Claim 71 · checked 24 September 2026 · AI-assisted audit

What was read

The 50th Anniversary of the Start of Drilling the Kola Superdeep WellLobanov, Chicherov and Sharov, Arctic and North 44 · Journal PDF, Arctic and North 44 (2021), pages 224 to 239, English textRead in full, 24 September 2026 · Copyright; quoted brieflyThe authors are Lobanov, Chicherov and Sharov; the page had named "Kalashnikov and others" and a slightly different title.
Inside the Earth (This Dynamic Earth)U.S. Geological Survey · pubs.usgs.gov, This Dynamic Earth, page last modified 11 July 2025Read in full, 24 September 2026 · Public domain (US Government work)
Inge Lehmann's paper: P'(1936)Martina Kölbl-Ebert, Episodes 24.4, pages 262 to 267 · Publisher PDF via the Crossref text-mining link (pdf.medrang.co.kr), Episodes 24(4), 2001Read in full, 24 September 2026 · CC BY-NCThe author is Martina Kölbl-Ebert; the page had named Bruce A. Bolt, whom the paper cites.
Multidecadal variation of the Earth’s inner-core rotationYang and Song, Nature Geoscience 16 · Abstract on nature.com; the article is closedAbstract only, 24 September 2026 · Copyright; quoted briefly
Inner core backtracking by seismic waveform change reversalsWang, Vidale and others, Nature 631 · Europe PMC full text, PMC11236701Read in full, 24 September 2026 · CC BY 4.0Supplementary tables were not read.
The role of water in Earth’s mantleOhtani, National Science Review 7 · Europe PMC full text, PMC8288861Read in full, 24 September 2026 · CC BY 4.0
Hydrous mantle transition zone indicated by ringwoodite included within diamondNature · Abstract and first paragraph from the nature.com description; the article is closed and the DESY repository copy did not loadAbstract only, 24 September 2026 · Copyright; quoted briefly
Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantleNature Geoscience · Abstract on nature.com; the review is closedAbstract only, 24 September 2026 · Copyright; quoted briefly
The biomass and biodiversity of the continental subsurfaceNature Geoscience · Abstract on nature.com; the article is closedAbstract only, 24 September 2026 · Copyright; quoted briefly
History of scientific ocean drilling, from Project Mohole to the end of IODPInternational Ocean Discovery Program · iodp.org/about-iodp/historyRead in full, 24 September 2026 · Copyright; quoted briefly
A long section of serpentinized depleted mantle peridotiteLissenberg and others, Science 385 · Accepted manuscript, White Rose Research Online eprint 227502, with supplementary figuresRead in full, 24 September 2026 · Copyright; author manuscript; quoted briefly
The Interior of the EarthU.S. Geological Survey, general interest publication · pubs.usgs.gov/gip/interior, general interest publicationRead in full, 24 September 2026 · Public domain (US Government work)An older general-interest publication. Used for what the methods are and for the layered model, not for any recent figure.
Developing the theory (This Dynamic Earth)U.S. Geological Survey · pubs.usgs.gov, This Dynamic Earth, "Developing the theory"Read in full, 24 September 2026 · Public domain (US Government work)
Reversals: Magnetic FlipBritish Geological Survey, Geomagnetism · geomag.bgs.ac.uk education page, including its technical sectionRead in full, 24 September 2026 · Copyright; quoted briefly
AK135 Travel Time TablesB. L. N. Kennett, Research School of Earth Sciences, Australian National University · Research School of Earth Sciences, ANU, ak135 introduction pageRead in full, 24 September 2026 · Copyright; quoted briefly
ISC LocatorInternational Seismological Centre · isc.ac.uk ISC Locator pageRead in full, 24 September 2026 · Copyright; quoted brieflyThe locator documentation PDF was not read; the page itself states the ak135 dependence.
Annual-scale variability in both the rotation rate and near surface of Earth’s inner coreVidale, Wang and others, Nature Geoscience 18 · Abstract on nature.com; the article is closedAbstract only, 24 September 2026 · Copyright; quoted briefly
The presence of ancient subducted oceanic crust contributes to seismic anomalies in Large Low Shear Velocity ProvincesKrymarys, Murakami and others, Communications Earth & Environment 6 · nature.com open-access HTMLRead in full, 24 September 2026 · CC BY 4.0Main text read; the supplementary information was not.
Moon-forming impactor as a source of Earth’s basal mantle anomaliesYuan and others, Nature 623 · Abstract on nature.com and Europe PMC (PMID 37914947)Abstract only, 24 September 2026 · Copyright; quoted briefly
A perovskitic lower mantle inferred from high-pressure, high-temperature sound velocity dataMurakami and others, Nature 485 · Europe PMC abstract (PMID 22552097)Abstract only, 24 September 2026 · Copyright; quoted briefly
Computational support for a pyrolitic lower mantle containing ferric ironWang, Tsuchiya and Hase, Nature Geoscience 8 · Abstract and first paragraph on nature.comAbstract only, 24 September 2026 · Copyright; quoted briefly
Exploring deep microbial life in coal-bearing sediment down to ~2.5 km below the ocean floorInagaki and others, Science · Submitted manuscript of 6 May 2015, University of Aberdeen repository (AURA, hdl 2164/5437), read in full; the published abstract (Europe PMC, PMID 26206933) was read firstRead in full, 24 September 2026 · Repository copy; licence not stated; quoted brieflyThe submitted version gives the coal-bed depths as about 1.9 to 2.5 km where the published abstract says 1.5 to 2.5 km.
Microbial life under extreme energy limitationHoehler and Jørgensen, Nature Reviews Microbiology · Europe PMC abstract (PMID 23321532)Abstract only, 24 September 2026 · Copyright; quoted briefly
Temperature limits to deep subseafloor life in the Nankai Trough subduction zoneHeuer and others, Science · Europe PMC abstract (PMID 33273103)Abstract only, 24 September 2026 · Copyright; quoted briefly
Rapid accretion and early core formation on asteroids and the terrestrial planets from Hf–W chronometryKleine and others, Nature 418 · Europe PMC abstract (PMID 12198541)Abstract only, 24 September 2026 · Copyright; quoted briefly
Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basaltsRizo and others, Science 352 · Author manuscript, University of Maryland repository (DRUM, doi 10.13016/ijjb-aex3), read in full; the published abstract (Europe PMC, PMID 27174983) was read firstRead in full, 24 September 2026 · Repository copy; licence not stated; quoted briefly