the.com/petrology
the science that reads rocks like diaries written over billions of years.
means Petrology is the branch of geology that studies the origin, composition, structure, and classification of rocks.
from From the Greek 'petra,' meaning rock or stone — the same root that named the apostle Peter, 'the rock' — joined to '-logy,' from 'logos,' meaning word, reason, or study. So literally 'the study of rock.' The 'petra' root also crops up in 'petrify' (to turn to stone) and, by way of 'petroleum,' in 'rock-oil.' The word is a 19th-century scientific coinage, assembled like most '-ology' terms during the age when geology was busy giving itself a formal vocabulary.
- thin sections
- Rocks sliced to 0.03mm so light passes through
- three families
- Igneous, sedimentary, metamorphic — every rock's identity
- pressure clues
- Mineral crystals record ancient depths and temperatures
- polarized vision
- Minerals flash rainbow colors under crossed light
- deep time
- Some studied rocks predate Earth's continents
apollo 11 moon rocks — 3.8 billion year old basalt samples from the moon's mare tranquillitatis, collected july 1969
yellowstone geothermal system — active rhyolite and geyserite formations in wyoming showing real-time mineral precipitation and alteration
grace cathedral pavement — san francisco's famous labyrinth built with dark and light stone specimens studied for metamorphic textures