Phosphorite and other apatite-bearing sedimentary rocks in the Precambrian of northern Michigan
Circular
746
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Abstract
Phosphatic pebbles are widespread in basal units of the Marquette Range Supergroup (Precambrian X) in the central part of the Upper Peninsula of Michigan. At one locality, a conglomeratic bed about 15 m thick averages about 15 percent P2O5, and many thinner beds are of comparable grade. This occurrence is believed to be the richest sedimentary phosphate deposit known in the Precambrian of the United States, as well as one of the oldest. Although outcrops are generally scarce, similar material has been found at four other localities in the Upper Peninsula of Michigan.
Study Area
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Phosphorite and other apatite-bearing sedimentary rocks in the Precambrian of northern Michigan |
| Series title | Circular |
| Series number | 746 |
| DOI | 10.3133/cir746 |
| Year Published | 1976 |
| Language | English |
| Publisher | U.S. Geological Survey, |
| Description | iii, 6 p. |
| Country | United States |
| State | Michigan |
| Google Analytic Metrics | Metrics page |