Exam 9: Precambrian Earth and Life History the Proterozoic Eon

A conglomerate that is formed by glacial processes is called ____.

Orogens are belts of igneous and metamorphic rocks formed by the collisions of cratons.

Fortunately for life, oxygen levels in the atmosphere have been stable over Earth's history.

The three basic divisions of an ophiolite sequence are ____.

The process by which Rodinia broke apart was ____.

The multicelled fauna of the Neoproterozoic is known from all continents except Antarctica, and is collectively referred to as the ____________________.

Mineral diversity increased after the Great Oxygenation event.

Sedimentary rocks made up of alternating thin layers of chert and iron minerals, mostly the iron oxides such as hematite and magnetite, are called ____.

When did the present style of plate tectonics develop?

What evidence indicates oxygen started accumulating in the atmosphere and oceans during the Proterozoic? How does this evidence support the accumulation of oxygen?

Sandstone-carbonate-shale assemblages are characteristic of the early continental rifting phase of the Wilson cycle.

The ____________________ orogen is the earliest mountain-building event that documents a complete ____________________ cycle of opening and closing ocean basins.

A landmass in the Precambrian made up of North America, Greenland, parts of northwestern Scotland, and perhaps some of the Baltic shield of Scandinavia was ____.

Orogens are characterized by ____.

Eukaryotic cells have a nucleus and other internal structures.

The transition from single to multicelled organisms may have started with the specialization of cells in colonies.

Most basement rock formed during the Archean and Proterozoic eons.

The ____________________ ____________________ hypothesis states that widespread glaciers covered Earth and froze the seas during the Proterozoic.

Asia is classified as a supercontinent because it contains more land area than any other continent.

____________________ ____________________ ____________________ are alternating layers of chert and iron oxide minerals that formed in shallow marine environments 2.3-2.5 bya.