ABSTRACT Data from 33 locations were utilized in a stratigraphic study of the Early Mississippian Grainger Formation and related units in northeast Tennessee. Isopach maps, stratigraphic cross sections, and lithologic trends indicate the Grainger Formation was deposited in four deltaic lobes: Monroe, Rock Haven, Hancock, and Grainger-Borden. Each is in a separate outcrop belt: Chilhowie Mountain, Clinch Mountain, Newman Ridge, and Cumberland Mountain. The Monroe lobe is the eastern and southernmost of the lobes. Within it, the Grainger Formation is thicker and coarser than in the other locales. It is underlain by gray and black shale; the gray shale is a probable nearshore gray version of the usually greenish Maury Formation. The Greasy Cove Formation, a heterogeneous unit of sandstone, shale, red beds, and limestone, overlies the Grainger Formation and occupies the stratigraphic position of the Maccrady Formation and Newman Limestone in outcrop belts to the northwest. The Greasy Cove Formation is recognized only in the Monroe lobe. In the Rock Haven lobe, both the Grainger Formation and Chattanooga Shale are divisible into mappable members. The Chattanooga Shale consists of an upper Big Stone Gap Member, a middle Brallier Member, and a lower Millboro Member. The Chattanooga Shale locally is 600+ m thick. The Grainger Formation in the Rock Haven lobe is divisible into three newly named members: an upper Hayters Sandstone member, a middle Greendale member, and a basal Bean Station member. The Alumwell glauconite zone, within the upper part of the Greendale member, is also new. The center of the zone approximates a time line and is a key stratigraphic horizon. All Grainger members and the Alumwell glauconite are traceable into the Price Formation of southwest Virginia. In the Rock Haven lobe, the Chattanooga Shale, Grainger Formation, and Maccrady Formation were deposited in a subsiding trough; subsidence began in the Givetian and perhaps in the Eifelian, caused by a migrating peripheral bulge generated by Neoacadian deformation in the Carolina Piedmont. Highlands created by the deformation were the eastern sediment source for the Chattanooga, Grainger, and Maccrady formations in this lobe. Sediment for the Hancock and Grainger-Borden lobes originated from northerly sources. In the Hancock lobe, the Chattanooga Shale and Grainger Formation are thinner, and the Grainger Formation has increased shale content to the south. Paleocurrent data indicate a north-south current flow. The Hancock lobe is likely a southern extension of the Price delta system in southwest Virginia. The Grainger-Borden lobe is the southern terminus of the Borden delta system of Kentucky. Both the Chattanooga Shale and Grainger Formation thin to the south and southeast. The Floyds Knob glauconite bed was deposited during a pause in sediment delivery and separates the Fort Payne Chert from the underlying Grainger Formation as a distinct sedimentary unit. The Fort Payne Chert overlaps the Grainger Formation from a deeper southern basin where the dolostone and chert have little or no interbedded shale. The overlap does not interfinger with the Grainger Formation. The Fort Payne Chert becomes thinner as it progresses northward, finally passing into the Muldraugh Formation in Kentucky. It also made a minor incursion eastward into the western margin of the Hancock lobe, where some chert(y) beds occur at the Maccrady position.

Abstract The recent development of unconventional oil and natural gas resources in the United States builds upon many decades of research, which included resource assessment and the development of well completion and extraction technology. The Eastern Gas Shales Project, funded by the U.S. Department of Energy in the 1980s, investigated the gas potential of organic-rich, Devonian black shales in the Appalachian, Michigan, and Illinois basins. One of these eastern shales is the Middle Devonian Marcellus Shale, which has been extensively developed for natural gas and natural gas liquids since 2007. The Marcellus is one of the basal units in a thick Devonian shale sedimentary sequence in the Appalachian basin. The Marcellus rests on the Onondaga Limestone throughout most of the basin, or on the time-equivalent Needmore Shale in the southeastern parts of the basin. Another basal unit, the Huntersville Chert, underlies the Marcellus in the southern part of the basin. The Devonian section is compressed to the south, and the Marcellus Shale, along with several overlying units, grades into the age-equivalent Millboro Shale in Virginia. The Marcellus-Millboro interval is far from a uniform slab of black rock. This field trip will examine a number of natural and engineered exposures in the vicinity of the West Virginia–Virginia state line, where participants will have the opportunity to view a variety of sedimentary facies within the shale itself, sedimentary structures, tectonic structures, fossils, overlying and underlying formations, volcaniclastic ash beds, and to view a basaltic intrusion.