Geology and Earth History Lecture Notes

These flashcards cover major geological events, volcanoes, rock types, and the evolution of early life based on the provided lecture notes.

What are the four major land masses that broke apart at the beginning of the Cambrian period?

Antarctica, Gondwana, Siberia, Baltica.

What supercontinent did the continents reassemble into during the late Paleozoic era?

Pangea.

What are the three Paleozoic mountain-building events that occurred in North America?

Taconic (Ordovician), Avalonian (Devonian), and Appalachian/Alleghanian/Hercynian (Carboniferous/Permian).

What is the significance of the Siberian Traps in Earth's history?

They are associated with the largest extinction event and contain the largest fossil record.

What classifies the explosiveness of volcanic eruptions?

Magma composition (mafic low viscosity, felsic high viscosity) and volatile content (especially water content).

What are the main types of volcanoes?

Shield volcanoes, stratovolcanoes, and calderas.

What is tephra?

Volcanic ejecta classified by size, including bombs, pumice, and ash.

What are the three types of rock stress?

Compressional, extensional, and isotropic.

What are the three types of folds in rocks?

Anticline, syncline, and monocline.

What is Uniformitarianism?

The concept that the present is key to understanding the past and that geological processes occur at observable rates.

What are unconformities in geology?

Discontinuities in sedimentary records that represent gaps in geological time.

What are the main types of metamorphism?

Regional metamorphism and contact metamorphism.

What are index minerals?

Minerals that are used to indicate specific temperature and pressure conditions during metamorphism.

What was the composition of the Earth's first atmosphere?

Nitrogen (N2), carbon dioxide (CO2), and hydrogen sulfide (H2S).

What geological evidence indicates the age of the Earth's oldest rocks?

The Acasta Gneiss, which is 4.0 billion years old.

What significant life forms emerged during the Paleozoic era?

Jawed fishes, amphibians, and the first reptiles.