Lecture_Exam_2__Stratigraphy__Early_Atmosphere__and_Paleozoic

neptunism

The theory that all rocks were precipitated out of a single primordial ocean.

uniformitarianism

The geological principle stating that the same processes that operate today also operated in the past.

stratigraphy

The study of rock layers and layering, which geologists use to understand Earth's history.

unconformities

Gaps in the rock record where either no rocks were deposited or existing rocks were eroded away.

transgressions

Periods when sea level rises, causing shorelines to move inland.

regressions

Periods when sea level falls, causing shorelines to move seaward.

biostratigraphy

A branch of stratigraphy that uses fossils to identify and correlate the age of rock layers.

stromatolites

Layered structures formed by colonies of cyanobacteria, important for early oxygen production.

paleomagnetism

The study of the magnetic properties of rocks to determine the historical positioning of continents.

Kaskaskia Sequence

A major transgression sequence during the Mid-Devonian to Mississippian, known for its thick carbonate layers.

Absaroka Sequence

The last major transgression onto the North American craton, which marked a shift towards land-based environments.

Permian-Triassic extinction

The most severe mass extinction event in Earth's history, leading to the disappearance of about 90% of marine species.

photosynthesis

The process by which organisms like plants and algae convert carbon dioxide and water into energy, releasing oxygen.

photochemical dissociation

The process by which sunlight breaks down water vapor, releasing oxygen into the atmosphere.

Eerie Miller experiment

A laboratory simulation that created amino acids, suggesting pathways for the origin of life.