Depositional Environments of Mississippian Newman Limestone in Northeastern Tennessee
Steven C. Beckman, Daniel A. Textoris
The Mississippian Newman Limestone of Hancock and Claiborne Counties, Tennessee, is a carbonate sequence that was deposited on a low-energy carbonate ramp in a subsiding basin. It includes the type area of the Newman. Twelve carbonate microfacies, with varying amounts of siliciclastic mud rock interbedded, are recognized: micrite, biomicrite, oosparite, dolomite, biopelmicrite, intrasparite, pelmicrite, oomicrite, intramicrite, pelsparite, biosparite, and biopelsparite. The microfacies represent deposition in the intertidal and shallow subtidal environments of varying depths and energies. The intertidal environments can be divided into higher and lower subenvironments. The shallow subtidal environments can be divided into three subenvironments: restricted marine, normal m rine, and high-energy shoals. The carbonates underwent a number of diagenetic changes including micritization, cementation, silicification, dolomitization, compaction, stylolitization, fracturing, and solution.
The Newman Limestone was deposited during a regional transgression. The sequence was interrupted by a minor regression marked by a reddish silty micrite unit. As defined here, the top of the Newman is capped by a transitional carbonate-shale unit, separating it from the Pennington Formation. The renewed siliciclastic influx represented by the Pennington was caused by uplift of an eastern source area.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.