Nashville Dome Research Articles

Cambrian to Holocene Structural and Burial History of Nashville Dome

About 14,000 ft (4,270 m) of strata covered basement over the present crest of the Nashville dome by the end of the Paleozoic (calculated by estimating the geothermal gradient, and using temperatures of veins in Stones River Group and Knox Dolomite). At least 7,500 ft (2,290 m) of post-Devonian strata have been removed by subsequent erosion. Estimates of other erosional episodes include 350 ft (107 m) of upper Knox (during the Middle Ordovician) and 500 ft (152 m) of Devonian-Ordovician (during the Late Devonian). Mesozoic to Holocene uplift was at least 6,350 ft (1,940 m), 1,500 ft or 460 m (25%) of which occurred in the latest 100 m.y. and 450 ft or 140 m (7%) during the latest 2 m.y., a rate ranging from about 15 ft/m.y. (4.6 m/m.y.) for the longer term to over 225 ft/ .y. (70 m/m.y.) in the Pleistocene to Holocene. Earliest structure of the area was a series of elongate basins, probably rifts synchronous with Reelfoot rift to the west. Uplifts trending N10°E moved about 40 mi (65 km) westward during the Middle Ordovician. These may relate to similar trending (and moving) Appalachian orogenic events. A change to uplifts trending N50°E (parallel to strikes of Appalachian thrusts) occurred in the Late Ordovician and continued to the Devonian; this may reflect a similar Late Ordovician change in the orientation of Appalachian tectonism. In the interval from post-Mississippian to Late Cretaceous, the dome curved westward to join the Pascola arch in response to Ouachita activity.

Appalachian thrusting, lithospheric flexure, and the Paleozoic stratigraphy of the Eastern Interior of North America

The Appalachian Basin is interpreted to be a multistage foreland basin developed by lithospheric downwarp under the loads of successive Taconic, Acadian, and Alleghanian overthrusts in the adjacent Appalachian Mountains. By quantifying this model we show how the stratigraphic record of the foreland basin can be used to constrain the timing, areal distribution, and thickness of the orogenic overthrusts. The cumulative present-day thickness of these allochthonous units is suggested to range from 4 to 18 km with the greatest thickness in the vicinity of Pennsylvania and Virginia. These model load thicknesses compare favourably with those implied by the COCORP seismic profile across the southern Appalachians and Atlantic Coastal Plain. We further suggest that, for reasons of isostatic balance, these thick overthrusts are likely to rest on the old Cambro-Ordovician continental margin, a conclusion also in keeping with, but independent of, COCORP results. The distribution of model loads is qualitatively correlative with observed patterns of regional Bouguer gravity anomalies but we have not as yet attempted quantitative gravity calculations.Flexural interactions between the Appalachian Basin and the contemporaneous intracratonic Michigan and Illinois basins produced the interbasinal Kankakee, Findlay–Algonquin, and Cincinnati arches as well as the Jessamine and Nashville domes. These arches and domes existed in fluctuating submergent and emergent conditions, alternately yoking together and decoupling the foreland basin and one or both of the intracratonic basins. The location and magnitude of Appalachian overthrusting and the lithosphere's rheological behaviour are the primary controls on arch development. The most satisfactory stratigraphic results are achieved using a lithospheric model with a temperature-dependent Maxwell viscoelastic rheology. In such a lithosphere the lower regions relax load-induced stress on time scales of 1–200 Ma but the upper regions are too viscous to flow on time scales less than the age of the Earth.We propose no explanation for the initiation of subsidence in the intracratonic Michigan and Illinois basins. Nevertheless, we show that the sediment record of these basins is likely to have been substantially modified by the influence of Appalachian overthrusts. This influence should be removed before attempting to interpret the sedimentary record of the intracratonic basins in terms of a basin-initiating mechanism.Viscoelastic relaxation is shown to provide a natural explanation for the unconformities that bound Sloss' sedimentary sequences in those parts of the basins well removed from the overthrusts. The onset and termination of erosion that created the unconformities correlate with the termination and initiation, respectively, of overthrust episodes. Sloss' sequences are seen as marking intervals of major orogenic overthrusting in the Appalachians. Insofar as the periods of thrusting are a consequence of worldwide plate tectonic reorganization, the stratigraphic sequences may have worldwide synchroneity but they are shown to have a more immediate local tectonic origin.

Tectonic History of Mississippi Embayment and Surrounding Areas: ABSTRACT

Recently published U.S. Geological Survey gravity and magnetic maps constitute powerful tools for interpreting the tectonic nature and history of the northern part of the Mississippi embayment. Perhaps the most striking feature of the maps is a set of alternating, roughly coincident gravity and magnetic anomalies that bear northeastward and extend from the northwestern edge of the embayment to Alabama. Positive anomalies in this set are viewed, using the model of McKensie, as zones of stretching, thinning, and subsidence of the continental lithosphere. Gradients between positive and negative anomalies may mark the position of listric faults, which blocked out grabens and horsts within the basement rocks, forming a low-relief crustal mosaic. This mosaic was jostled by the Ouachita collision during the Late Pennsylvanian. A horst on the northwestern flank of the embayment was pushed slightly northeastward and uplifted at its northeastern end to form the Pascola arch. Potential field maps provide no evidence that the Pascola arch connected the Ozark and Nashville domes. Older structures athwart the region trend of the mosaic, such as the Ste. Genevieve and Rough Creek faults, were reactivated as thrust faults up on their southern sides. In the Early Permian, alkalic dikes were intruded in the region of the Illinois Mineral District providing the earliest evidence of a lens of low velocity mantle rock beneath the embayment. Radiometric dates suggest alkalic igneous activity peaked in the Cretaceous. In this scenario, the Reelfoot region evolved from a broad complex graben to a true rift during the late Paleozoic. Mesozoic igneous events and present seismicity suggest that the Reelfoot is not a dying rift; it is instead being born. End_of_Article - Last_Page 1460------------

Plants of Devonian-Mississippian Black Shales, Eastern Interior, U.S.A.: ABSTRACT

Macrofossils of the New Albany shale and equivalents of Late Devonian of Early Mississippian age in the east-central United States are known from three main floras or assemblages. One is almost entirely composed of Callixylon logs, slabs, End_Page 444------------------------------ and slivers, presumed to be driftwood permineralized after burial. Callixylon fossils are most abundant in the upper part of the Clegg Creek Member of the New Albany shale ()Famennian) and equivalent strata in western New York, Ohio, and contiguous areas, perhaps because these Progymnosperms reached the zenith of their development at that time. They also occur sporadically throughout the New Albany shale and equivalent strata. The principal geographic concentration of Callixylon is in western New York, principally in marine sediments, and on the west side of the Cincinnati arch. Callixylon is also sparsely and sporadically distributed in nearly all areas of outcrop of the Devonian black shales including the New Albany, Antrim, Kettle Point, and Ohio shales, and is found in Kinderhooki n age shales from Illinois and Tennessee. A second, and later, flora consists principally of permineralized wood pieces (phosphatized free-wood or concretions) of stems, rachises, petioles, and possibly even mid-veins of pinnules of diverse members of the Lycopsida, Sphenopsida, Cladoxylales, Coenopteridales, Progymnospermae, and Pteridospermae. A few of these disjunct pieces have been reconstructed into more complete plants known from the Catskill delta in western New York, Pennsylvania, and West Virginia. The principal concentration of these stem and petiolar segments is in the Falling Run Member of Sanderson Formation of the New Albany shale on the west side of the Cincinnati arch in southern Indiana and Kentucky, and in central Kentucky in the low saddle between the Cincinnati arch proper and its southward extension as th Nashville dome. This abundant distribution of minute stem axes and other such small plat fragments strongly suggests the source of these palnts to be a nearby island (Cincinnatia?). Alternatively, it is proposed that they have been concentrated by currents on a very shallow choal on or near a structurally positive submarine rise of the Cincinnati arch, or by floating algal mats in which the waterworn wood and leaf fragments became enmeshed as flotsam near some shore and were transported by these mats to more distant sites before the disintegration of the mats. The third type of macrofossil palnt assemblage is constituted of Foerstia. These plants are considered to be algal in origin and indicate no clear relationship either to distance from shore or depth of water. The main concentration is in middle and lower New Albany shale and equivalents. It is also found sparingly in West Virginia and Michigan and much farther west (one specimen from the Exshaw shale of Montana). End_of_Article - Last_Page 445------------

Dolomitization of Brassfield Formation: ABSTRACT

The Brassfield Formation (Lower Silurian), which crops out in southwestern Ohio, through parts of Indiana and Kentucky, to western Tennessee, is a transgressive sequence consisting of interbedded shales, limestones, and dolostones. Shales dominate the eastern edge of the outcrop, whereas carbonate sediments are characteristic of the western and southern exposures. A detailed study of outcrops in southwestern Ohio shows that two separate dolomitizing processes have altered the rocks. Elsewhere, the Brassfield Formation appears to be dolomitized by a single process. In southwestern Ohio, initial dolomitization was restricted to the basal Belfast Member and probably occurred penecontemporaneously in a supratidal environment similar to a modern sabkha. Dolomite in the Belfast member occurs as small (10 to 40 µm), cloudy, anhedral crystals. Thinly laminated sediments with a few gypsym casts are characteristic of this unit. Regional dolomitization was a later diagenetic event related to the formation of a freshwater and seawater mixing zone beneath a landmass created by upwarping of the Cincinnati arch and Nashville and Ozark domes. Intensity of dolomitization in the outcrop belt is controlled by the proximity of the original carbonate sediments to the source of dolomitizing fluids in the mixing zone. The Brassfield is undolomitized away from these structural highs. Dolomite from this portion of the formation is typically large (> 10µm), limpid, euhedral rhombs replacing bioclasts and sparry calcite cement. This Dorag type of dolomitization suggests the presence of landmasses in the areas of the Cincinnati arch and the Ozark and Nashville domes during the time of dolomitization of the Brassfield Formation. End_of_Article - Last_Page 638------------

Regional Patterns of Woodbine-Tuscaloosa, Northern Coastal Region: ABSTRACT

The Tuscaloosa can be understood best as a boundary phenomenon. Sands of this trend were deposited along the demarcation between two distinct tectonic elements. Also, these sands were superposed upon one of the greatest sedimentary breaks of northern coastal areas, i.e., the angular unconformity which separates Comanche and Gulf (Cretaceous) Series. Basic crustal differences produced a marked correspondence between Mesozoic tectonic and physiographic features. The boundary between the Mesozoic shelf and the central Gulf subbasin constituted a structurally controlled shelf break which remained constant in position through the major part of the Mesozoic Era. The shelf was an exceptionally broad feature where sea End_Page 1552------------------------------ level changes effected migration of depositional environments. Such migrations were evidently cyclic in nature, i.e., they comprise a repetitive series of transgressive-inundative-regressive sequences. Retreat of Mesozoic shorelines, and inception of active erosion of former depositional areas, was commonly anticipated by the gulfward migration of lithotopes. An example of this is seen in the upward increase in grain size and clastic ratio in strata below the sub-Gulfian unconformity. Thus, in some areas of east Texas, the Buda Limestone is succeeded upward by the Maness Shale, which is then succeeded by sands of the upper member of the Tyler Formation. The sub-Gulfian unconformity constitutes regionally the most useful means for determining the Gulf and Comanche Series boundary. Accordingly, strata deposited immediately before culmination of the South Tyler regression are assigned to the Washita Group. Strata deposited immediately after the beginning of Woodbine-Tuscaloos transgression are assigned to the Woodbine Stage. Consequently, some lower sands along the lower Tuscaloosa fairway could be latest Comanche regressive deposits. Fluviatile deposits have been described in the lower Tuscaloosa Formation near the inland edge of the Toledo Bend flexure. The presence of continental facies, within such a short distance of the Mesozoic shelf break, indicates that the shoreline previously had migrated almost completely across the Mesozoic shelf by the end of Washita deposition. The fluviatile deposits grade upward into finer grained strata of the middle Tuscaloosa Formation, thereby suggesting increasing distance of transport and deepening of waters. The upward change from the fine-grained middle Tuscaloosa to the coarse-grained strata of the upper Tuscaloosa suggests the gulfward spread of shallow-water conditions. Accordingly, the lower, middle, and upper Tuscaloosa divisions are interpreted to represent, respectiv ly, the transgressive, inundative, and regressive phases of the Woodbine-Tuscaloosa depositional cycle. An interesting phenomenon of inland areas was the opening of the Mississippi embayment. During this event, Gulf-related deposition spread inland across a series of basin-concentric, Paleozoic elements inland from the Ouachita deformed belt. These elements included a linear trend of fore-basins and a trend of large foreland uplifts. The embayment first extended northward across the Black Warrior basin, then across a saddlelike feature between the Nashville dome and the Pascola arch (i.e., the buried southeastern extension of the Ozark uplift). Coarse clastics were supplied to the Tuscaloosa by Paleozoic formations, such as the Fort Payne Chert, which cropped out on nearby structures. The embayment axis has since migrated progressively westward to its present position near the course of the Mississippi River. Indicated reserves along the lower Tuscaloosa fairway seem impressive. Furthermore, the fairway opens up whole new types of Mesozoic reservoirs, those deposited along the Mesozoic slope. Since this trend defines the gulfward edge of the Mesozoic shelf, it permits the study of a complete suite of shelf facies and the definition of a new frame of reference for stratigraphic and environmental studies. End_of_Article - Last_Page 1553------------

Late Middle and early Late Ordovician history of the Cincinnati arch province, central Kentucky to central Tennessee

Six limestone classes occur in the Ordovician strata from Lexington, Kentucky, to Nashville, Tennessee. Sediments that make up classes 1 through 4 were deposited in “open” epicontinental marine environments, whereas classes 5 and 6 reflect more “restricted” environments. These classes were used to calculate relative mechanical energy and depth indices for a defined time-stratigraphic interval. The base of this interval is a bentonite bed that occurs near the base of the Brannon Member of the Lexington Limestone, and the top is defined by a major change in the relative abundance of platform conodonts. Relative mechanical energy and depth contours intersect the present axis of the Cincinnati arch at a high angle, which suggests that a continuous arch was not present. Shoal environments existed in the Lexington area and northeast of the present Nashville dome. These shoals correspond to the positions of the Lexington and Nashville domes or precursors to these domes which were present during the defined time interval. Paleobathymetric contours parallel east- and south-trending normal faults that are present in and south of the Lexington, Kentucky, area. This suggests that these faults were active during late Middle Ordovician time and were partly responsible for creating the bathymetric relief necessary for higher-energy carbonate sediments to accumulate. Deeper-water environments between the two shoal areas reflect the presence of the Rome trough. The general bathymetric trend for these strata is one of submergence.

Developments in East-Central States in 1977

Oil production in Illinois, Indiana, Kentucky, and Tennessee in 1977 totaled 38,399,000 bbl, down 1.5% from 1976. Gas production in Kentucky was 61 Bcf, a decline of 7.9%; gas production in the other states is insignificant. Oil and gas drilling tests numbered 2,962, down 4% from 1976. Exploratory tests totaled 1,041, up 6.1%; 246 (23.6%) were successful. Tennessee had 244 oil and gas tests in 1977, up 13.5% from 1976. The number of exploratory wells increased 5.5%; development drilling increased 76%. The success ratio for both categories improved slightly. No tests were drilled west of the axis of the Nashville dome. Scott, Fentress, and Morgan Counties continued to be the most active. Footage for all 1977 tests totaled 401,544, of which 267,497 ft was exploratory. Carbonate rocks of Mississippian age, especially the Fort Payne and Monteagle limestones, continued as the important pay zones in 1977 exploratory drilling. Shallow Mississippian gas pays in northern Cumberland Plateau counties are attracting increasing attention. In 1977 a single deep test was drilled in eastern Coffee County and was plugged after reaching total depth in a Cambrian(?) arkosic sandstone, but details have not been released. Crude oil production in Tennessee in 1977 was 819,655 bbl, an increase of 36.9%. Illinois had 1,105 oil and gas tests in 1977, down 15.8% from 1976. Exploratory tests numbered 241, down 2.4%, and were 17.4% successful. Footage drilled, including service wells, totaled 3,114,384, down 5.8%. Testing of the Salem Limestone (Valmeyeran) highlighted drilling activity in Illinois. Salem production was discovered in 9 fields. Keenville field, Wayne County, was outstanding; 42 Salem wells, with average initial production of 161 BOPD, were completed in the field in 1977; Salem production is about 3,600 ft deep. Less important, but significant, was the testing of the Ullin Limestone immediately below the Salem; Ullin production was discovered in 9 fields. Most of the Salem and Ullin activity centered in Wayne and Clay Counties. More than half of all the oil and gas tests we t to the Salem or deeper; 6 unsuccessful tests were drilled to depths greater than 6,000 ft. Despite the contributions of deeper drilling, crude oil production in Illinois in 1977 was only 25,608,000 bbl, down 2.5% from 1976. Indiana had 608 oil and gas tests, up 22.1% from 1976. Exploratory drilling increased from 196 wells to 279 and development drilling, from 290 wells to 329. Exploratory footage totaled 630,340--159,333 ft were successful. Exploratory wells were 24.0% successful. Development of Salem Limestone reservoirs in Gibson and Knox Counties contributed much to drilling activity. Interest in deeper strata is indicated by the 94 deeper pool tests drilled in 1977 (21.3% successful) as compared with 29 in 1976. The search for oil in the deeper strata of the Union-Bowman Consolidated field in Knox, Gibson, and Pike Counties found production in the St. Louis, Salem, and Harrodsburg Limestones. Interest in the deeper Mississippian rocks in southwestern Indiana is expected to continue during 1978. A si nificant new-field discovery was Vollmer field, Knox County, in August; the discovery well had an initial daily oil production of 42 bbl/hr and settled production of 600 BOPD from an oolitic break in the Ste. Genevieve Limestone; average initial production of the 12 oil wells reported by year end was 177 BOPD. Estimated oil production in Indiana in 1977 was 5,400,000 bbl, up 770,000 bbl from 1976. In Kentucky 1,005 oil and gas tests were drilled in 1977, down from 1,073 in 1976. The 365 exploratory tests, down from 373 in 1976, resulted in 51 oil wells and 22 gas wells, a success of 20.0%. Development wells were 60.6% successful, resulting in 262 oil wells and 126 gas wells. Discoveries consisted of 6 fields, 10 new-pool wildcat successes, 10 deeper pools, 20 shallower pools, and 27 extensions. A discovery in western Kentucky, an extension to Cadiz field in Trigg County, had an initial production of 100 Mcf from New Albany Shale; apparently the Devonian shale in this area, although thin compared with that in the Big Sandy gas field in eastern Kentucky, can be commercially productive. In Webster County, a deep test was dry in the Cambrian at 15,200 ft TD. Crude oil production in Kentucky in 1977 was 6,571,000 bbl, down 12.2% from 1976.

Seismic characteristics of southeast Missouri as indicated by a regional telemetered microearthquake array

abstract A regional microearthquake network has been established in the New Madrid seismic zone to study better the seismic characteristics of this region. The network consists of 16 stations distributed on the borders of and within the head of the Mississippi embayment. The network has a location sensitivity for all earthquakes of mb ≧ 1 occurring within the network. A total of 330 earthquakes has been located within a 1.5° by 1.5° area inside the array during the first 21 months of operation. The spatial distribution of these hypocenters has identified for the first time in this region the existence of linear seismically active zones, corresponding presumably to seismically active faults. Several of these trend N40°E, parallel to the axis of the embayment. Others trend NW; these latter are parallel to and possibly are related to the crest of the Pascola arch which joins the Ozark uplift to the Nashville dome. The linear dimensions of the features identified thus far vary in length from about 25 km to about 100 km. The b value as determined by the number of earthquakes located thus far is about 0.8.

Developments in East-Central States in 1973

Total oil production in Illinois, Indiana, Kentucky, and Tennessee in 1973 was 45 million bbl, down 11.9% from 1972. Tennessee had a very slight increase; all the other states had decreases. Gas production in Kentucky was 69.7 Bcf in 1973, down 7%. Gas production in the other states is not significant. A total of 1,524 oil and gas tests was drilled in 1973, down 11.4% from 1972. Exploratory tests totaled 565, only 4 tests fewer than in 1972. Of these, 85 (15%) were successful. Tennessee had 98 oil and gas tests in 1973, up 4.6% from 1972. The number of exploratory tests was down 1.5%; development wells were up 18.5%. Total footage for all tests was 141,950, of which 97,282 ft was exploratory. Much of the activity was concentrated in Scott, Morgan, and Fentress Counties. Three oil fields, 4 gas fields, 2 oil pools, and 5 extensions (2 oil, 3 gas) were discovered in 1973. A dry 4,875-ft basement test was drilled in Macon County. A basement test is drilling in DeKalb County, and a projected Copper Ridge test in Smith County is shut down at 3,380 ft. Leasing activity increased markedly on the east flank of the Nashville dome. Primary deep objectives in Tennessee are probably the lower Knox and pre-Knox Cambrian sedimentary rocks, and shallower objectives are th upper Knox, Trenton, and Mississippian carbonate rocks. Crude-oil production in Tennessee in 1973 was 201,000 bbl, up 1.5%. Illinois had 556 oil and gas tests in 1973, down 7.8% from 1972. Exploratory tests were up 29.8%, from 151 in 1972 to 196 in 1973. Development wells were down 20.4%. Total footage drilled in oil and gas tests and service wells was 1,446,083, up 3.3% from 1972. Three oil fields, 11 extensions, 4 new-pool wildcats, and 7 new-pay zones in existing fields were discovered. The main focus of exploration was in southwestern Illinois in the Marion and Washington Counties area. Silurian reef production was the principal objective there, but several Trenton tests also were drilled. Nashville field in Washington County was the most significant discovery in 1973. Production is from a Silurian reef. Reserves in the field are estimated at more than 1 million bbl. Silurian reefs and Cambrian-Ordov cian strata are expected to be targets of exploration in 1974. Crude-oil production in Illinois in 1973 was 30,669,000 bbl, down 12.1%. Indiana had 139 exploratory wells (8 more than in 1972) and 100 development wells in 1973. Exploratory tests resulted in 14 (10.1%) successes. Seven oil fields, 3 gas fields, and 6 oil pools were discovered (2 of the new fields resulted from workovers, not included in AAPG-CSD statistics). The discovery well of Westphalia South, one of the most promising of the new fields, was completed in December for an initial daily production of 384 bbl. Production is from the Ste. Genevieve Limestone. The trap appears to be stratigraphic rather than structural. Exploratory activity was concentrated in the belt of known Silurian reefs. Three counties within this area (Daviess, Greene, and Knox) accounted for more than half of the exploratory tests in the state. Exploration in 1974 is expected to f llow the trend of recent years. Silurian reefs, Knox erosional remnants at the Lower Ordovician-Middle Ordovician unconformity in eastern Indiana, and the Middle Ordovician (Trenton) of northern Indiana are expected to be targets. Estimated production in Indiana in 1973 was 5,400,000 bbl, down 730,000 bbl from 1972. A total of 631 oil and gas tests was drilled in Kentucky in 1973. Of 164 exploratory tests drilled, 34 were successful (20.7%). The exploratory successes included 8 fields, 20 deeper or shallower pools, and 6 extensions. Intensive leasing in many parts of Kentucky reflected an interest in deeper Paleozoic strata. Geophysical activity may have reached an all-time high in all parts of the Commonwealth. In Johnson County, a Precambrian test reached a new depth record of 14,566 ft. Other deep wells in 1973 included a 10,000-ft Tomstown test and a 5,877-ft Knox test, both in Johnson County, and a 4,584-ft Copper Ridge test in Morgan County. A Knox test was nearing completion in Logan County. Crude-oil production in Kentucky in 1973 was 8,686,854 bbl, down about 1 million bbl from 1972. Gas production was 69,737,007 Mcf, down about 5 Bcf.

Regional Paleozoic Stratigraphy in Mississippi Between Ouachita and Appalachian Mountains

Paleozoic rocks beneath the Mesozoic Gulf coastal plain beds in Mississippi are in the transition area from the Appalachian Mountain system in Alabama to the Ouachita Mountain system in Arkansas. Strata ranging in age from Cambrian to Pennsylvanian aggregate more than 15,000 ft in thickness in the Black Warrior basin of northern Mississippi and in the Central Mississippi deformed belt. The oldest rock penetrated is cherty dolostone of the Knox Group. The age and composition of the basement are unknown. The Ordovician and Silurian of northeastern Mississippi are mainly carbonate rocks along the southwestern edge of a widespread lower Paleozoic carbonate facies that extends from the Alabama Appalachians northwestward beyond the Nashville dome. A tongue of sandstone and mudstone in the Upper Ordovician of northeastern Mississippi is evidently the distal part of the regional Sequatchie clastic wedge which was derived from the Appalachian area of southern Tennessee. Toward the west across central Mississippi, eastward-pinching tongues of black shale in the Ordovician and Silurian suggest gradation to the Ouachita black shale facies. The Arkansas Novaculite of Devonian-Early Mississippian age extends from the Ouachita Mountains across northern Mississippi. In northeastern Mississippi, the Mississippian-Pennsylvanian sequence is dominated by a thick northeastwardly regressive wedge of shallow-water clastic rocks. The lower part of the clastic sequence grades northeastward to the Mississippian limestone facies in Alabama. The basal Pottsville quartz-pebble conglomerate descends stratigraphically westward across Mississippi, and the higher Pottsville in eastern Mississippi is cyclical carbonaceous shale, sandstone, and coal. The probable Mississippian-Pennsylvanian section of western Mississippi includes dark-colored chert and siliceous shale which are comparable to rocks of the Ouachita facies. Evidently the lower Paleozoic carbonate facies of eastern Mississippi grades westward to the Ouachita dark-colored shale facies and the upper Paleozoic shallow-water regressive clastic facies grades westward to the deep-water clastic facies of the Ouachitas. Both facies changes apparently trend north-northwest across central Mississippi; possibly the facies boundaries formed along a steep shelf edge at the western margin of a relatively shallow platform in eastern Mississippi.

Mesozoic and Cenozoic Physiographic Development of the Lower Tennessee River: In Terms of the Dynamic Equilibrium Concept

The Tennessee River is regarded as a trans-Appalachian river that formed on a coastal plain of Pennsylvanian sediments, probably early in the Mesozoic. The river may have had an initial consequent course close to its present course, and lateral migration southward off of the Nashville dome is postulated as the mechanism for entrapment of the river in Sequatchie Valley. Paleozoic strata presently exposed were overlapped by Upper Cretaceous deposits, and under the concept of dynamic equilibrium of landscapes it is concluded that precursors of the Highland Rim, Cumberland Escarpment, and Cumberland Plateau were in existence in Late Cretaceous time.

Quantitative Analysis of Ordovician and Younger Structural

The Nashville Dome, a swelling on the Cincinnati arch, crosses Tennessee and curves westward to join a buried connection with the Ozark dome at the edge of the Mississippi Embayment. Swelling of the Nashville dome is known from Early Ordovician until mid-Tertiary, and it is likely that both earlier and later movements occurred. Total cumulative swelling since Early Ordovician is about 850 feet. Of this, about 100 feet occurred after burial of the Knox Dolomite and before deposition of the Middle Ordovician Nashville Group; 200 feet from late in the Middle Ordovician until deposition of the Chattanooga Shale (Upper Devonian); 250 feet from Chattanooga until earliest Pennsylvanian; 100 feet sometime before Middle Cretaceous; and 150 feet after Middle Cretaceous and probably after middle Eocene.

Stratigraphy and Geologic History of Middle Ordovician Rocks of Central Tennessee*

Research Article| April 01, 1962 Stratigraphy and Geologic History of Middle Ordovician Rocks of Central Tennessee* CHARLES W WILSON, Jr. CHARLES W WILSON, Jr. Vanderbilt University and Tennessee Division of Geology, Nashville, Tennessee Search for other works by this author on: GSW Google Scholar Author and Article Information CHARLES W WILSON, Jr. Vanderbilt University and Tennessee Division of Geology, Nashville, Tennessee Publisher: Geological Society of America Received: 10 Oct 1960 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1962, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1962) 73 (4): 481–504. https://doi.org/10.1130/0016-7606(1962)73[481:SAGHOM]2.0.CO;2 Article history Received: 10 Oct 1960 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation CHARLES W WILSON; Stratigraphy and Geologic History of Middle Ordovician Rocks of Central Tennessee*. GSA Bulletin 1962;; 73 (4): 481–504. doi: https://doi.org/10.1130/0016-7606(1962)73[481:SAGHOM]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The major facies of the Nashville and Maysville groups (Middle and Upper Ordovician) in Central Tennessee are Laminated argillaceous limestone to the west and limestone with varying amounts of silt to the east; Granular phosphatic limestone and Dove-colored limestone lie between the western and eastern facies. The distribution of these four rock types was controlled by activity of the Cincinnati arch.Typical of the regional history was the pattern of deposition of the various lithologies in the Bigby-Cannon Limestone. During deposition of this formation a relatively deep sea to the west received mud and sand from the west to form the western Laminated argillaceous limestone; a relatively shallow sea to the east received normal limy ooze with varying amounts of silt. Between these two provinces was a north-south belt of shallow water—the Central Tennessee Bank—which was the expression of the Cincinnati arch, and which for short periods of time was above sea level to form a north-south strip of mud and sand. The great concentration of organisms on the western part of this bank resulted in in situ reef detritus and the limy phosphatic “sand” of the fore-reef slope off the bank, which together formed the Granular phosphatic limestone. The eastern part of the bank was a tide-level shelf-lagoon in which fine limy ooze accumulated to form the Dove-colored limestone.During the deposition of the Hermitage Formation there were three uplifts of the then narrow Cincinnati arch. During deposition of the Bigby-Cannon Limestone the arch remained high. At the beginning of deposition of the Catheys Limestone the arch was low, but it was uplifted for a short period of time during early Catheys deposition. Uplifts were recurrent during deposition of the Leipers, and the arch at this time was a broad domal bulge—the Nashville dome. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Tuscaloosa Formation in Tennessee

Late Cretaceous Tuscaloosa Formation occurs as discontinuous remnants that cap many of the ridges in the Western Highland Rim. Typically the formation consists of well-rounded, poorly sorted chert gravel which is trimodal in size distribution. The gravel fraction (mode 15 to 40+ mm) consists of Devonian and Mississippian chert and a small percentage of sandstone pebbles. The medium sand fraction (mode 0.5 mm) consists mainly of angular to well-rounded chert grains developed by attrition during transport. Well-rounded and frosted quartz grains also are present. The fine fraction (mode 0.15 mm) consists of clay, authi-genic (?) mica, and quartz. At its eastern limit the Tuscaloosa is locally well sorted and contains quartz pebbles and a large proportion of quartz sand. Also present in the same area are well-sorted, heavy-mineral-bearing sands and bimodal (0.04, 0.2 mm) siltstone, which contains sand-sized pellet aggregates and fragmentary plant fossils. The finest fraction (less than 0.044 mm) of both eastern and western facies of the Tuscaloosa consists of 60-80 per cent quartz, 5-30 per cent kaolin, and 5-30 per cent montmorillonite, all of which are present in Devonian and Mississippian bedrock. Minor exotic constituents include volcanic(?) glass and heavy minerals. The Mississippian chert gravel in the Tuscaloosa is of local origin, but the Devonian chert was transported from a western source. Other components from a western source are sandstone pebbles and frosted sand grains, both of which probably were derived from Cambrian or Ordovician formations that cropped out on the Pascola arch, an eastward-sloping extension of the Ozark dome. Quartz pebbles, heavy minerals, and some of the angular quartz sand present at the eastern edge of the Tuscaloosa may have been derived from Pennsylvanian sandstone and conglomerates that cropped out north and south of the Pascola arch. Most of the Tuscaloosa Formation is believed to be of nonmarine origin, deposited on the eastward-sloping flank of the Pascola arch. The eastern facies of the Tuscaloosa is believed to be partly marine in origin, the exotic components having been swept in by longshore currents. During deposition of the Tuscaloosa, the Ozark dome and the Cincinnati arch were connected by the Pascola arch, which is now deeply buried beneath the Mississippi Embayment, At that time the Pascola arch stood structurally about 3000 feet higher than at present, and its structural shape and dimensions were comparable to the present Nashville dome. During deposition of the Tuscaloosa the Nashville dome was structurally about 1000 feet lower than at present, and its crest probably was submerged beneath the sea.

Late Cretaceous and Subsequent Structural Development of the Northern Mississippi Embayment Area

During early Late Cretaceous the area of the northern Mississippi Embayment was occupied by a structural and topographic dome standing nearly 1000 feet above sea level. Rocks as old as Cambrian were exposed on its crest. Downwarping of the dome, which commenced in Late Cretaceous time, resulted in the development of the Mississippi Embayment syncline, now filled with sediments of Cretaceous, Paleocene, and Eocene age. The flanks of the Mississippi Embayment syncline slope uniformly about 30 feet per mile. Most of the bending occurred near the synclinal axis, which generally follows the present course of the Mississippi River. Faults cutting the Paleozoic basement and, in some areas, extending upward into the overlying younger rocks resulted from superposition of the narrow synclinal bend across the now-buried structural high. Adjustment also probably occurred by faulting of Paleozoic rocks along the Tennessee River, where the eastern flank of the syncline was bent downward. As a result of structural movements during the Cretaceous and later periods, the old dome has been depressed beneath the Mississippi Embayment and now forms the Pascola arch connecting the Ozark and Nashville domes.

Lithofacies Map of Lower Mississippian Clastics of Eastern and East-Central United States

In order to synthesize some of the newer data on the lower Mississippian Kinderhook and Osage Series in Pennsylvania, Ohio, Indiana, Kentucky, West Virginia, Virginia, Tennessee, Georgia, and Alabama, lithofacies and isopach maps were prepared from approximately two hundred surface and subsurface sections compiled from the literature. Lobes of coarser terrigenous sediment dominate the interval mapped. These deltas, first noted by Pepper et al. (1954, pl. 13) for Kinderhook time, are shown by lithofacies analysis to have lasted through Osage time as well. The directions of transport within the six sandy lobes shown on the lithofacies map were: westward in Pennsylvania, northwestward in Virginia and West Virginia, southward in Ohio, and westward in Indiana. The whole of the central and eastern United States was covered during Lower Mississippian time by terrigenous sediment which was derived from sources north and east of the Appalachian basin and also from low islands within the area of the present Nashville dome and Cincinnati arch.

Geology of Two Recent Deep Tests in Kentucky and Tennessee: ABSTRACT

In 1946-1947 two deep tests, one on the Cincinnati arch in Kentucky, and one on the Nashville dome in Tennessee, were the first wells to penetrate the entire sedimentary section in this geologic province. The California Company's A. R. Spears No. 1, located 1.7 miles northwest of McKinney, Lincoln County, Kentucky, reached the total depth of 6,117 feet, stopping in rhyolite porphyry, probably pre-Cambrian in age. This test was drilled on a local anticline on the south plunge of the Cincinnati End_Page 304------------------------------ arch. Starting in the lower part of the Tate formation of the upper Ordovician, the well penetrated 418 feet of argillaceous limestones and shales of upper Ordovician, Maysville, Eden, and Cynthiana groups; 191 feet of middle Ordovician, Lexington limestone; 651 feet of lower Ordovician, Wells Creek dolomite; 2,936 feet Cambro-Ordovician dolomite probably more or less equivalent to the Knox dolomite group of Tennessee; 137 feet of Cambrian limestone and dolomite with minor amounts of gray shale tentatively correlated with the Maynardville limestone; 739 feet of Cambrian reddish brown and gray shales with some fossil fragments, and gray interbedded siltstones, considered to be in part correlative of the Nolichucky formation; 615 feet of quartzitic sandstone with intercalated green and ray shales and siltstones that may be middle or lower Cambrian in age; 25 feet of Cambrian or pre-Cambrian limestone, the lower part containing pebbles of rhyolite; and 356 of rhyolite porphyry, probably pre-Cambrian in age. The California Company's E. W. Beeler No. 1, located 1/3 mile southwest of Campbellsville, Giles County, Tennessee, reached the total depth of 5,750 feet, stopping in granite, probably pre-Cambrian in age. This well is on a prominent local closure on the southwestern extension of the axis of the Nashville dome. Starting in limestone of the Carters formation of the middle Ordovician, this well penetrated 660 feet of middle Ordovician, Black River-Stones River limestone; 69 feet of lower Ordovician, Wells Creek dolomite; 4,571 feet of Cambro-Ordovician dolomite probably correlative of the Knox and Bibb-Ketona-Brierfield groups; 338 feet of Cambrian calcareous and shaly dolomite; 77 feet of quartzite and quartzitic sandstone, Cambrian or pre-Cambrian in age; and 45 feet of granite. End_of_Article - Last_Page 305------------

CHANNELS AND CHANNEL-FILLING SEDIMENTS OF RICHMOND AGE IN SOUTH-CENTRAL TENNESSEE

Research Article| August 01, 1948 CHANNELS AND CHANNEL-FILLING SEDIMENTS OF RICHMOND AGE IN SOUTH-CENTRAL TENNESSEE CHARLES W WILSON, JR. CHARLES W WILSON, JR. VANDERBILT UNIVERSITY, NASHVILLE 4, TENN. Search for other works by this author on: GSW Google Scholar Author and Article Information CHARLES W WILSON, JR. VANDERBILT UNIVERSITY, NASHVILLE 4, TENN. Publisher: Geological Society of America Received: 31 Mar 1947 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1948, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1948) 59 (8): 733–766. https://doi.org/10.1130/0016-7606(1948)59[733:CACSOR]2.0.CO;2 Article history Received: 31 Mar 1947 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation CHARLES W WILSON; CHANNELS AND CHANNEL-FILLING SEDIMENTS OF RICHMOND AGE IN SOUTH-CENTRAL TENNESSEE. GSA Bulletin 1948;; 59 (8): 733–766. doi: https://doi.org/10.1130/0016-7606(1948)59[733:CACSOR]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract During the post-Maysville, pre-Richmond interval a stream flowing southeastward on the southeastern flank of the Nashville dome cut the Pulaski Channel in Giles and Lincoln counties, Tennessee, for a known length of 32 miles with average width of 1500 feet and depth of 100 feet. During Richmond time this channel was filled with clastic sediments brought in from the southeast by the advancing Richmond sea. About 75 feet of Lower shale and Conglomeratic sandstone was deposited during the first, or estuarine, phase. Lenses of Lower limestone conglomerate consisting of pebbles and cobbles of older underlying limestone in a matrix of sandstone were deposited during this phase. The second, or marine, phase began when the Richmond sea invaded the region and submerged the channel now three-quarters filled with estuarine sediments. Along the submerged channel a total of 70 feet of Upper limestone conglomerate, Upper shale, and Sandstone member of the Mannie shale was deposited contemporary with the accumulation of about 45 feet of normal Richmond over the surrounding region, consisting of Fernvale formation, Mannie shale, and Sandstone member of the Mannie shale. The Upper limestone conglomerate, which is equivalent to the Fernvale limestone member, was deposited upon the upper slopes of the channel and upon the top of the Lower shale. The submerged channel was filled flush with the surrounding sea floor by the Upper, or Mannie, shale.At the same time the Fayetteville Channel in Lincoln County underwent a similar history, but the sediments filling this channel are too poorly preserved to permit satisfactory investigation and interpretation except by analogy with the Pulaski Channel. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Structure of Central Tennessee

During the past 10 years many surface and subsurface elevations have been accumulated from several key horizons within that part of Tennessee between Cumberland Plateau on the east and the western valley of Tennessee River on the west. From these data structural contour maps have been compiled on the top of the Chattanooga shale (Kinderhook group of the Mississippian system), on the Pencil Cave horizon (metabentonite bed near the top of the Black River group of the Ordovician system), and on the top of the Knox dolomite group (Cambro-Ordovician system). These maps show the structural configuration of these horizons and permit a study of comparative structure. This comparative study is supplemented by an isopach map of central Tennessee, showing the variations in thickness of the interval between the Chattanooga shale and the Pencil Cave. From these maps many critical facts may be inferred regarding the structural history of the Nashville dome.