Abstract A Marcellus-Burket/Geneseo field trip in the Appalachian Valley and Ridge features both brittle and ductile structures. The degree to which these structures have developed depends on both lithology, which is a function of the stratigraphic architecture of the Devonian Appalachian Basin and position relative to the foreland during the Alleghanian Orogeny. Joints are best developed in the black shales and the units immediately above with the J 2 joint set most prominent in the Brallier Formation just above the Burket/Geneseo Formation. Faults are seen in the form of cleavage duplexes and bedding-parallel slip accompanying flexural-slip folding. Cleavage duplexes are found in the Marcellus whereas bedding-parallel slip is more common in the overlying Mahantango Formation and further up the section in the Brallier Formation. Layer-parallel shortening decreases from greater than 50% to approximately 10% when crossing the Jacks Mountain–Berwick Anticline structural front from the hinterland portion to the foreland portion of the Valley and Ridge. Disjunctive cleavage, the primary mechanism for layer-parallel shortening, is best developed in carbonates whereas pencil cleavage is best developed in shales.

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 Upper Devonian Foreknobs Formation is a series of sandstones and siltstones that outcrops in the central Appalachian Basin from Pennsylvania south into Virginia and West Virginia. The Foreknobs Formation is generally regarded as the delta slope portion of the Catskill clastic wedge (= Catskill delta) occurring between the dark marine lithologies of the underlying Brallier and Scherr Formations and the younger fluvial red beds and conglomerates of the overlying Hampshire Formation. Progradational and retrogradational pulses of the clastic wedge are recorded in the alternating siltstones and sandstones before grading into nonmarine lithologies at its top. Well-preserved fossils are very abundant within the Foreknobs Formation. They have aided in locating the Frasnian-Famennian Stage boundary and have provided important information regarding its namesake extinction event. The progradation of the clastic wedge during Foreknobs Formation deposition allowed for both shallow- and deep-water environments to exist up to and across the Frasnian-Famennian boundary, which may have contributed to some uncertainty in correlating the lithostratigraphic position of the boundary with the biostratigraphic signature of the extinction event.