Gray-white quartzite main content.

Gray-white quartzite

Gray-white quartz_HERO

Exhibition Text

This quartzite formed in a riverbed, as indicated by the well-developed cross-bedding (sedimentary layers at angles to the main horizontal layers). Its buff to gray color is typical of the oldest rocks of the Huronian Supergroup. The color suggests deposition when the atmosphere contained no free oxygen. 

AMNH collection

For Educators

Topic: Earth Science

Subtopic: Atmosphere

Keywords: Geology, Stratigraphic--Huronian, Quartzite, Oxygen, Atmosphere, Paleoclimatology

Audience: General