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C. L. Rice

Publications and source records attributed to C. L. Rice.

10 recordsLinked to original sources
USGS1994

The Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy

The Middle Pennsylvanian Fire Clay tonstein, mostly kaolinite and minor accessory minerals, is an altered and lithified volcanic ash preserved as a thin, isochronous layer associated with the Fire Clay coal bed. Seven samples of the tonstein, taken along a 300-km traverse of the central Appalachian basin, contain cogenetic phenocrysts and trapped silicate-melt inclusions of a rhyolitic magma. The phenocrysts include beta-form quartz, apatite, zircon, sanidine, pyroxene, amphibole, monazite, garnet, biotite, and various sulfides. An inherited component of the zircons (determined from U-Pb isotope analyses) provides evidence that the source of the Fire Clay ash was Middle Proterozoic (Grenvillian) continental crust inboard of the active North American margin. 40 Ar/ 39 Ar plateau ages of seven sanidine samples from the tonstein have a mean age of 310.9 ± 0.8 Ma, which suggests that it is the product of a single, large-volume, high-silica, rhyolitic eruption possibly associated with one of the Hercynian granitic plutons in the Piedmont. Biostratigraphic analyses correlate the Fire Clay coal bed with a position just below the top of the Trace Creek Member of the Atoka Formation in the North American Midcontinent and near the Westphalian B-C boundary in western Europe.

Kentucky, Tennessee, Virginia, West Virginia↗
USGS1985

Terrestrial vs. marine depositional model—A new assessment of subsurface Lower Pennsylvanian rocks of southwestern Virginia

A reinterpretation of the origin of subsurface rocks in southwestern Virginia and southeastern Kentucky suggests that, contrary to commonly accepted ideas, the Mississippian-Pennsylvanian Systemic boundary is an unconformity and the Lower Pennsylvanian quartz arenite sequences were deposited in a fluvial environment. Because Pennsylvanian strata of the Pocahontas and Lee Formations appear to have been deposited at the same time in adjacent valleys, the Pocahontas, which generally has been considered to be older and to underlie the Lee, is considered here to be equivalent to the basal part of the Middlesboro Member of the Lee Formation.

Geology↗