In 1839, the Silurian System Was Defined Primarily on the Basis

question 24

Multiple Choice

In 1839, the Silurian System was defined primarily on the basis of

• A) the nature of sedimentary rocks lying directly upon ancient crystalline rocks.
• B) seven distinct fossil mammalian faunas of the Paris Basin.
• C) expansion of glaciers at the south pole, which was related to a mass extinction.
• D) trilobites, brachiopods, and crinoids, and as well as corals that formed small reefs.

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Definitions:

Average Total Cost

The total cost of production divided by the quantity of output produced; it includes both fixed and variable costs.

Long-Run Equilibrium

Long-run equilibrium occurs when an economy's resources are fully employed and the output and input markets are in balance, with no external forces causing disruption.

Market Price

The current price at which a good or service can be bought or sold in a marketplace.

Social Learning Theory

A theory that suggests people can learn new behaviors by observing others and the outcomes of those behaviors.