Geologic timescale

What are all the periods from the paleozoic and mesozoic eras (acronym)

Cambrian Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous

The precambrian

the hadean, archaean and proterozoic eons. before complex life.

what is the hadean period known for?

oldest minerals (zircons). hellish, volcanic environment. “magma ocean.” heavy space bombardment→ moon is created

what is the archaen period known for?

cold surface. oldest known rocks (canadian Gneiss, greenland pillow basalts show evidence for liquid water) and oldest known

stromatolites

archaen fossils. simplest form of modern carbon-based life. the only life for 2 billion years

what is the proterozoic period known for?

“before complex life.” great oxidation event, snowball earth.

the great oxidation event

caused by photosynthetic bacteria. caused a mass extinction of anaerobic microbes. at first all the oxygen was used up forming BIFs

BIFs

alternating layers of silica and iron oxide from the proterozoic eon. formed from precipitated ions of dissolved O2 and Fe in seawater

how did snowball earth happen?

less greenhouse gas in the atmosphere (from photosynthesis) led to global cooling. albedo effect continued it

how did snowball earth end?

continued plate tectonics and volcanism. CO2 rose and caused greenhouse effect

Albedo effect

based on absorption/reflection of solar energy. higher when theres more ice. more land/sea= more sun absorbed by earth= low albedo. more ice= more sun reflected back = high albedo

The phanerozoic eon (known for? holds what eras?)

complex life and mass extinctions. holds the paleozoic, mesozoic and cenozoic eras

Paleozoic eon (known for? periods in it?)

age of trilobites. periods: Cambrian Ordovician Silurian Devonian Carboniferous Permian

What is the cambrian period known for?

explosion of life. warm tropical sea. good time to be a trilobite.

what is the permian period known for?

Pangea, arid dry climate. less coastline. not a great time to be alive. Mass extinction ends the period and era.

permian extinction

wiped out 95% marine animals and 70% land animals. likely caused by unliveable climate on pangea, and glaciation/volcanism

what is the mesozoic era known for?

age of dinosaurs. holds the Triassic, Jurassic and Cretaceous periods.

K/pg extinction

at the end of the cretaceous period. 75% of all species wiped out including all non-avian dinos. likely caused by massive asteroid impact

what is the Cenozoic era known for

“age of mammals.” holds the paleogene, neogene and quaternary periods. we are currently in it.

steps to mining

1. find ore

2. assess viability (profit analysis, consultation etc)

3. build a mine/extract ore

4. manage waste rock + tailings

fossil fuels

come from the remains of dead organisms. carbon rich and combustible. non renewable.