A study of core samples from Baffin Bay indicates that gravel and coarse sand occur in all parts of the bay. Fragments in this size range are considered to have been transported into the area by floating ice. This coarse-grained sediment is rich in granitic detritus, but samples from an area within approximately 200 km of the Canadian coast also contain limestone fragments. The distribution of limestone fragments on the bottom coincides closely with the track of the Baffin Land current, in which icebergs originating in areas of limestone outcrop move southward through the bay. The distribution of limestone detritus in subbottom samples, however, suggests that the Baffin Land current has in the past flowed over a wider area than it does at present.

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The Knoxville 1°x2° quadrangle spans the Southern Blue Ridge physiographic province at its widest point from eastern Tennessee across western North Carolina to the northwest corner of South Carolina. The quadrangle also contains small parts of the Valley and Ridge province in Tennessee and the Piedmont province in North and South Carolina. Bedrock in the Valley and Ridge consists of unmetamorphosed, folded and thrust-faulted Paleozoic miogeoclinal sedimentary rocks ranging in age from Cambrian to Mississippian. The Blue Ridge is a complex of stacked thrust sheets divided into three parts: (1) a west flank underlain by rocks of the Late Proterozoic and Early Cambrian Chilhowee Group and slightly metamorphosed Late Proterozoic Ocoee Supergroup west of the Green brier fault; (2) a central part containing crystalline basement of Middle Proterozoic age (Grenville), Ocoee Supergroup rocks east of the Greenbrier fault, and rocks of the Murphy belt; and (3) an east flank containing the Helen, Tallulah Falls, and Richard Russell thrust sheets and the amphibolitic basement complex. All of the east flank thrust sheets contain polydeformed and metamorphosed sedimentary and igneous rocks of mostly Proterozoic age. The Blue Ridge is separated by the Brevard fault zone from a large area of rocks of the Inner Piedmont to the east, which contains the Six Mile thrust sheet and the Chauga-Walhalla thrust complex. All of these rocks are also polydeformed and metamorphosed sedimentary and igneous rocks. The Inner Piedmont rocks in this area occupy both the Piedmont and part of the Blue Ridge physiographic provinces. The intensity of deformation and metamorphism increases from west to east in the Blue Ridge. The west flank is mostly chlorite grade or relatively unmetamor phosed, and the central part of the Blue Ridge is mostly staurolite, garnet, or biotite grade, although sillimanite grade rocks occur along the eastern part of the central Blue Ridge in the vicinity of the leading edge of the Hayesvil Ie fault. The east flank of the Blue Ridge and much of the Inner Piedmont are at kyanite or silli manite grade of Manuscript approved for publication February 22, 1991. Description of the Area 3 Figure 3: Knoxville 1º x 2º quadrangle showing available 7 ½-min topographic maps. and Hiawassee Rivers, all tributaries of the Tennessee River. The Piedmont and eastern slopes of the Blue Ridge are drained to the east by many tributaries of the Catawba,

Carbonate rocks consisting of micritic phosphorite, reefoid conglomerate, and calcarenite were dredged from a seamount on Ayes Swell at 13°30 ' N, 63~I0 ' W. The petrology of these rocks was investigated by optical, chemical, X-ray diffraction, and electron microprobe techniques in order to study the effects of diagenesis.Samples of micritic phosphorite were dense and hard, contained Oligocene-Miocene foraminiferal remains, and were composed dominantly of microcrystalline carbonate-apatite. The phosphorite was obtained from the slopes of the seamount at 620 to 730 m. It is considered to have formed as a result of replacement of an original calcareous ooze by phosphorous from sea water, according to mechanisms proposed by Kazakov (1937) and Ames (1959).Conglomerate composed of highly altered, reefoid detritus and containing fossils of probable Pleistocene to early Holocene age was collected in the depth range of 340 to 455 m. Etched and embayed calcareous structures show that the rock has been partially replaced by a microcrystalline matrix of carbonate-apatite and iron/manganese oxides, in which dolomite euhedra occur abundantly. Epitaxial rims of dolomite crystals around algal detritus suggest that fragments of high-magnesium calcite may have served as local nuclei for the development of dolomite within the rock. Because of its intimate association with Fe/Mn oxides, it does not appear likely" that the dolomite formed at shallow depths in this open-ocean, unrestricted environment.Very coarse, porous calcarenite composed dominantly of unabraded foraminiferal tests and molluscan fragments and cemented by fibrous, high-magnesium calcite were collected from the top of the seamount, at 340 m. Abundant pelagic forms, uninverted aragonite grains, and the scarcity of shallow-water forms suggest that this rock has not been exposed to the effects of atmospheric water. Cementation has therefore probably taken place below sea level.A paragenesis involving changes in water depth over the seamount is proposed to explain the origin of these different rock types.