Pegmatites,which Often Occur in Dikes,are Unusual Among Shallow Intrusive Rocks

question 48

Multiple Choice

Pegmatites,which often occur in dikes,are unusual among shallow intrusive rocks in that they ________.

• A)possess porphyritic texture
• B)possess exceptionally coarse grains
• C)are mineralogically identical to the extrusive rock basalt
• D)are glassy,cooling so rapidly that crystals do not have time to form

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Definitions:

Pure Competition

A market structure characterized by a large number of small firms, identical products sold by all firms, no barriers to entry or exit, and perfect information among buyers and sellers.

Monopolistic Competition

A market structure characterized by many competitors selling products that are substitutes but differentiated from one another by branding or quality.

Entry Barriers

Conditions that prevent new competitors from easily entering an industry or area of business.

Large Number

A subjective term indicating a quantity significantly above what is considered average or standard.