Geo Notes

Super Position

Oldest on the bottom youngest on the top 

Original Horizontality

Gravity causing sediments to be deposited horizontally

Principle of Lateral Continuity

Sediments accumulate as continuous sheet in a given region

Principle of Inclusion

 If a rock has an inclusion, the inclusion is older

Baked Contacts

Igneous intrusion is older than surrounding rocks

Hadean Eon

Formation of geosphere, atmosphere, oceans, and Biosphere

Archean Eon

“Age of Bacteria” Oldest rocks found on planet, final cooling stage, formed crust, all life unicellular

Proterozoic Eon

Most diamonds formed, oldest sed. rock, cyanobacteria(Photosynthesis), 1st multicellular organisms

Cambrian Period

1st abundant skeletons, lots of soft bodied critters and arthropods

Ordovician

echinoderms, 1st vertebrates, Acadian Mountains formed

Silurian period

Early land plants, heavy colonial life,

Devonian Period

1st insect fossils, 1st forest, 1st amphibians

Mississippian Period

1st reptiles, Appalachian Mountains

Triassic Period

Pangea breaks up, earliest dinosaurs and mammals

Jurassic Period

Diversification of dinosaurs, First flight

Cretaceous Period

 Extreme specialization of Dinosaurs, 1st flowering plants

Cenozoic Era

Age of mammals

Palogene

 Early primates, birds, horses, and camels, formation of Himalayas, Ice at poles

Neogene

Mammals become huge and specialize

Holocene

Human age

Convergence

plates move together

Divergence

plates move apart

Transform

 plates that move horizontally past each other

Stress

Force Applied

Strain

Deformation that occurs

Elastic Limit

Stress>Strain

Results of Brittle Behavior

Faults/Fractures

Where brittle behavior occurs

At depths less than 15-20 km

Ductile Behavior Results?

Folding

Where ductile behavior occurs?

At depths lest than 15 km