Question

what is the composition and thickness f the crust, mantle, outer core, inner core

Answer 1

Here are the approximate compositions and thicknesses of Earth’s main radial layers (values are averages/ranges):

1) Crust
- Thickness:
- Oceanic crust: ~5–10 km (typical ~7 km)
- Continental crust: ~20–70 km (typical ~30–50 km)
- Overall range: ~5–70 km
- Composition: solid, silica-rich rocks
- Continental: felsic/granitic rocks (quartz, K/Na-feldspar, mica) — relatively high Si and Al
- Oceanic: mafic/basaltic rocks (basalt/gabbro, olivine, pyroxene, plagioclase) — richer in Fe, Mg, Ca
- Typical densities: ~2.6–3.0 g/cm3

2) Mantle
- Thickness: ~2,890 km (extends from base of crust/Moho down to the core–mantle boundary at ~2,890 km depth)
- Composition: predominantly ultramafic silicate rocks (peridotite) made of olivine, pyroxenes, and garnet in the upper parts; at greater depth phases change to bridgmanite (silicate perovskite) and ferropericlase in the lower mantle
- Physical state: mostly solid but convects on geologic timescales; includes rigid lithospheric mantle and weaker asthenosphere
- Typical densities: ~3.3–5.6 g/cm3 (increasing with depth)

3) Outer core
- Thickness: ~2,260 km (from ~2,890 km to ~5,150 km depth)
- Composition: molten (liquid) iron–nickel alloy with some lighter elements (e.g., sulfur, oxygen, silicon, possibly hydrogen or carbon)
- Role: convecting liquid generating Earth’s magnetic field (dynamo)
- Typical densities: ~9.9–12.2 g/cm3

4) Inner core
- Thickness (radius): ~1,220 km (inner core radius ≈ 1,220 km; extends from ~5,150 km depth to Earth’s center at ~6,371 km)
- Composition: primarily solid iron with significant nickel and small amounts of lighter elements
- Physical state: solid (high pressure keeps it solid despite very high temperatures); shows seismic anisotropy
- Typical densities: ~12.8–13.1 g/cm3

All numbers are approximate; precise values come from seismology, high-pressure experiments, and geophysical inference. If you want a diagram, a table comparing exact depths, densities, and major elements, or sources for these numbers, I can provide that.