Earth’s metallic core treated as a compositional unit. Nothing from it has ever been sampled; its composition is inferred from density, from seismology, and from meteorites.
SchematicBulk Earth, bulk silicate Earth, the crust and the upper continental crust are four different volumes, and therefore four different compositions. The core holds most of Earth’s iron, so a figure for one is not a figure for another.Full description of this figure
Concentric shells drawn to scale from Lithoen’s recorded layer thicknesses. The outermost line is the crust. The shell within it is the mantle; mantle and crust together are bulk silicate Earth. Inside those lie the outer and inner core. Bulk Earth is everything, core included. The upper continental crust is only the outermost sampled part of the continental portion of the crust. Because the core holds most of Earth’s iron and its siderophile elements, bulk Earth and bulk silicate Earth are compositions of two different volumes rather than two estimates of one.
Original Lithoen diagram · LITHOEN-ORIGINAL
Classification
scope
core
How this record is known
1
Interpretation
Reached by reasoning from evidence, or produced by a named model.
1 of 1 claims on this page cite at least one registered source. Counts describe how each statement is known, not how likely it is to be true.
What Lithoen records
Each claim states how it is known and cites its evidence.
InferredMetallic iron–nickel; composition inferred, never sampled.
The core is metallic — an iron–nickel alloy — and nearly twice as dense as the mantle. No sample of it exists; its composition is inferred from density, from the behaviour of seismic waves, and from meteorites.
method: Density and seismic constraints combined with meteorite compositions.
Evidence support: Supported by the cited evidence· 2 sources, multiple sources, independence unknown
