The carbon, now: bituminous coal pressed in a seam 2.0 km down.

depth

2 000 m

pressure

49.1 MPa

temperature

65 °C

the plate has carried it

 

heat through each square metre

 

the sky, 2 km overhead

 

the carbon

 

view: heroreset viewenginemore

Drag to turn it. Pinch or scroll to come closer. Tap a crystal, the coal or a glow.

• quartz SiO₂ · Mohs 7 · trigonal · 2.65 g/cm³ · the sandstone's grains and the granite's glass
• calcite CaCO₃ · Mohs 3 · trigonal · 2.71 g/cm³ · the limestone, fizzes in acid
• pyrite FeS₂ · Mohs 6–6.5 · cubic · 5.0 g/cm³ · grows in the coal where sulfur meets iron
• muscovite KAl₂(AlSi₃O₁₀)(OH)₂ · Mohs 2.5 · monoclinic · 2.8 g/cm³ · the shale's glittering flakes
• orthoclase KAlSi₃O₈ · Mohs 6 · monoclinic · 2.56 g/cm³ · the granite's pink feldspar
• almandine Fe₃Al₂(SiO₄)₃ · Mohs 7.5 · cubic · 4.3 g/cm³ · garnet in the basement

Not to scale: the glows are drawn large. Geotherm 25 °C/km from 15 °C; heat flow 65 mW/m²; rock 2 500 kg/m³; plate speed 5 cm a year. The pale motes trace pore water's path, not its speed.