Exam 19: Precambrian Earth and Life History

Granite-gneiss complexes are typical in what age of rocks?

Pegmatites are associated with ____ rocks and contain ____, ____, and ____.

Organisms are composed of many elements. Which is the least abundant of these?

What do the Ediacaran fauna represent, and why are they important?

A complete _____ involves rifting of a continent and the opening of an ocean basin with passive continental margins on both sides.

What are small molecules composed of multiple amino acids called?

The boundaries of subunits or smaller cratons within the shield are based on topographic expression of different rock types.

A(n)_____ is a linear or arcuate deformation belt in which many of the rocks have been metamorphosed by intruded magma.

The rate of plate motion was probably slowest in the Archean Eon.

What are heterotrophic organisms?

Early gases that had begun to accumulate around Earth during the Early Archean were lost because of a lack of a(n)____________________.

The prevailing model for the formation of greenstone beds in the Archean is ____.

_____ sequences provide evidence for convergent plate boundaries from Neoarchean and Paleoproterozoic rocks.

The Archean atmosphere can best be described as ____.

Sandstone-carbonate-shale assemblages were deposited along _______ continental margins during the Proterozoic.

Outgassing and ____ are probable sources for Earth's early water vapor.

What is the first supercontinent recognized with some certainty, and when did it begin fragmenting?

What term describes molecules that are intermediate between inorganic compounds and living organisms?

_______________ is an informal term that encompasses all geologic time from 4.6 to 4.0 billion years ago.

What does the appearance of red beds in the geologic record indicate about the atmosphere?