Quaternary Period - 2.5 million years ago (man)
Tertiary Period - 65 million years ago (grazing and carnivorous mammals)
Cretaceous Period - 136 million years ago (primates, flowering plants)
Jurassic Period - 195 million years ago (birds)
Triassic Period - 225 million years ago (dinosaurs, mammals)
Permian Period - 280 million years ago
Carboniferous Pennsylvanian Period - 320 million years ago (reptiles)
Carboniferous Mississippian Period - 345 million years ago (fern forests)
Devonian Period - 395 million years ago (amphibians, insects)
Silurian Period - 430 million years ago (vascular land plants)
Ordovician Period - 500 million years ago (fish)
Cambrian Period - 570 million years ago (shellfish)
Precambrian Era (algae, cells)
Formation of the Earth - 4.65 billion years ago
Igneous: made of molten material (magma, which comes to the surface as lava)
Falsic (contains feldspar and quartz)
Grantie: contains large quartz and feldspar particles
Rhyloite: small-grain granite
Mafic (contains magnesium and iron)
Gabbro: contains large pyroxene and olivine crystals
Basalt: the most common volcanic rock
Metamorphic: rocks that have been changed by high temperature or pressure
Mica: minerals aligned perpendicular to maximum pressure
Slate: fine, thin layers caused by foliation at low pressure
Schist: coarse foliation at medium pressure
Gneiss: very coarse foliation at high pressure
Sedimentary: rocks formed when loose fragments harden
Clastic: form from broken fragments of current rocks
Sandstone: made from sand
Shale: made from mud
Chemical: formed when minerals precipitate from solution; evaporites
Gypsum: used in plaster and wallboard
Halite: used in table salt
Organic: made from animal and plant remains
Limestone: made from calcium carbonate of coral and shellfish skeletons
Coal: made from swamp plant remains
Iron pyrites FeS2
Rock salt NaCl
Epsom salts MgSO4*7H2O
Steel: iron and 0.8% carbon and 0.5% manganese
Brass: copper and zinc
Bronze: copper and tin
Amalgams: include mercury
Aristotle's student Theophrastus wrote an essay about stones.
Georgius Agricola (Saxon, 1556) wrote De Re Metallica.
James Ussher (English, 1600s) estimated from the Bible that the Earth is 6000 years old.
Comte de Buffon (French, 1700s) estimated from iron ball cooling rates that the Earth is 75,000 years old.
James Hutton (English, 1700s) formulated uniformitarian theory, and is known as the father of geology.
Charles Lyell (Scottish, 1800s) advocated uniformitarianism and wrote Principles of Geology.
Georges Cuvier (French, 1800s) advocated catastrophism.
Alfred Wegener (German, 1912) proposed Continental Drift and the Pangaea supercontinent, which split
into Laurasia and Gondwanaland.
Eduard Seuss (Austrian, 1900s) named Gondwanaland.
Vine and Matthews (British, 1900s) proposed their magnetic stripes hypothesis.
J. Tuzo Wilson (Canadian) and Jason Morgan (American) proposed plate tectonics in the 1960s, saying that
lithosphere plates move over less rigid asthenosphere and sink at subduction zones.
The Law of Superposition states that more recent fossils are in layers of Earth closer to the surface.
Stratigraphy is the study of the Earth's crust, and biostratigraphy studies it through fossils.