ROCKS ASSOCIATED WITH THE MISSISSIPPIAN-PENNSYLVANIAN UNCONFORMITY IN SOUTHWESTERN INDIANA Indiana Department of Conservation GEOLOGICAL SURVEY Field Conference Guidebook No. 9 1957 STATE OF INDIANA Harold W. Handley, Governor DEPARTMENT OF CONSERVATION E. Kenneth Marlin, Director GEOLOGICAL SURVEY Charles F. Deiss, State Geologist Bloomington ______________________________________________________________________________________ Field Conference Guidebook No. 9 ______________________________________________________________________________________ ROCKS ASSOCIATED WITH THE MISSISSIPPIAN-PENNSYLVANIAN UNCONFORMITY IN SOUTHWESTERN INDIANA CONFERENCE SPONSORED BY Geological Survey, Indiana Department of Conservation and Department of Geology, Indiana University, October 4, 5, and 6, 1957 CONFERENCE COMMITTEE Henry H. Gray, Chairman; T. A. Dawson; Duncan J. McGregor; T. G. Perry; and William J. Wayne Printed by authority of the State of Indiana BLOOMINGTON, INDIANA October 1957 ______________________________________________________________________________________ For sale by Geological Survey, Indiana Department of Conservation, Bloomington, Indiana Price $1.00 This page intentionally blank CONTENTS 3 Page Page Introduction ---------------------------------------5 Glossary of rock-type terms ---------------------32 Physiography ----------------------------------5 Literature cited ------------------------------------33 Paleozoic stratigraphy ------------------------5 Postconference road logs ------------------------35 Geomorphic history ---------------------------7 No. 1. State Route 37 north to Paoli --------------------------------35 Economic geology ----------------------------7 No. 2. State Route 64 and Itinerary --------------------------------------------8 U. S. 460 east to New Albany--------------35 Saturday, October 5, 1957; No. 3. State Routes 37 and 66 Stops 1-7 -------------------------------------8 south to Cannelton ------------------------- 38 Sunday, October 6, 1957; No. 4. State Route 64 west to Stops 8-10 ---------------------------------- 25 Mt. Carmel, Ill. ----------------------------- 40 ILLUSTRATIONS Facing Page Plate 1. Map of field conference area showing physiographic units ---------------------------------------6 2. Generalized columnar section of upper Mississippian and lower Pennsylvanian rocks exposed in field conference area ----------------------------------------8 3. Evolution of stratigraphic nomenclature in the Chester series in Indiana ----------------------------------------------------------------------------------------- -10 4. Railroad cut at National Gypsum Co. plant near Shoals (Stop 3)----------------------------------14 Page Figure 1. Profile of west side of railroad cut at National Gypsum Co. plant near Shoals (Stop 3) ---------------------------------------------------------------------- 14 2. Profile of quarry wall at abandoned Martin County Highway Department quarry (Stop 5) -------------------------------------------------------------------- 20 3. Profile of northwest side of cut along Southern Railroad 1 mile west of Taswell (Stop 10) -------------------------------------------------------------- 30 This page intentionally blank ROCKS ASSOCIATED WITH THE MISSISSIPPIAN- PENNSYLVANIAN UNCONFORMITY IN SOUTHWESTERN INDIANA INTRODUCTION land area that has been maturely dissected so that By Duncan J. McGregor, T. G. Perry, local relief is fairly great. Steep bluffs and local and William J. Wayne structural plains result from erosion of an alternating series of massive sandstones, shales, and limestones, The purpose of this field conference is to Karst valleys are common along the east edge of the acquaint participants with strata that are as -sociated upland, where tributary creeks disappear into with the Mississippian-Pennsylva- nian swallow holes in inliers of Ste. Genevieve unconformity in southwestern Indiana. Criteria limestone. Most of the spectacular caverns of which aid in distinguishing between Mansfield strata Indiana and Kentucky are found along the east edge of Pottsville (early Pennsyl- vanian) age and clastic of this physiographic unit. formations of Chester (late Mississippian) age will re ceive consid -erable attention in discussions at evening meetings and on PALEOZOIC STRATIGRAPHY the outcrop. Inspection of limestone and sandstone quarries will afford an insight into the economic products of Chester and Mansfield rocks. Chester rocks in Indiana crop out in a Participants may collect fossils at many o f the stops. northwestward -trending belt that extends from the Ohio River to the vicinity of Greencastle in central Putnam County, a distance of approximately 125 PHYSIOGRAPHY miles. The width of the Chester outcrop belt in southern Indiana approximates 40 miles, extending from west-central Harrison County to just east of The area that will be traversed during this field Cannelton in Perry County. The Chester outcrop conference lies outside the glaciated part of Indiana, area narrows gradually northward and is less than 10 within the physiographic province Interior Low miles wide near its northern extremity in sout h- Plateau by Fenneman(1938, p. 411-448). central Putnam County. Perry and Smith (in press) The eastern part of the conference area belongs have delineated the areal distribution of lower, to the Highland Rim section of the Interior Low middle, and upper Chester rocks in Indiana. As Plateau (Fenneman, 1938, p. 425-427). The western Chester rocks have a low regional westerly and part of the Highland Rim section in Indiana is southwesterly dip of approximately 25 to 30 feet per underlain by lime -stones of middle Mississippia n mile and underlie the highly dissected topography of age and is characterized by a topography of their outcrop area. sinkh oles and relatively low relief. This subdivision Chester rocks have a unique location in was named the Mitchell plain by Beede (1911, p. the stratigraphic column because of their position 95) and later defined more completely by Malott between dominantly calcarceous strata of Meramec (1922, p. 94-98). Underground drainage is one of the (middle Mississippian) age and rocks of the typifying features of the Mitchell plain, and few Pennsylvanian system which consist largely of streams that rise or east of it cross it without clastic materials (pl. 2). In contrast with the disappearing into cavernous routes. Only deeply underlying limestones of Meramec age and the entrenched water courses, such as the East Fork of overlying dominantly clastic rocks of Pennsylvanian White River, cross the sinkhole plain as surface age, the most striking feature of the Chester series is streams. The ragged, dissected Chester escarpment the repeated alternation of fossilferous marine upheld by sandstones and shales of the Chester limestone and generally unfossilferous clastic series, forms the eastern boundary of the Shawnee formations. Chester limestones characteristically section of the Interior Low Plateau (Fenneman, maintain their lithologic individuality throughout 1938, p. 434-440). The eastern part of the Shawnee their outcrop area; Chester clastic formations, which section is called the Crawford upland (Malott, 1922, include shale, siltstone, and fine-grained sandstone, p. 98-102). The Crawford upland is a high­ commonly display abrupt lateral and vertical var­ 6 ROCKS ASSOCIATED WITH THE MISSISSIPPIAN-PENNSYLVANIAN UNCONFORMITY iations in lithology. Because of lithologic variability Crossbedded fine-grained light yellow-brown of Cheater clastic rocks, they are identified in the sandstones, wavy-bedded very fine-grained gray field mainly by their stratigraphic position with sandstones thinly interbedded with gray shales, and respect to Chester limestones. gray shales that locally are slightly carbonaceous Stratigraphic names in the Chester series used in and micaceous are the dominant rock types. In this guidebook (pl. 3) are essentially those evolved addition, the Mansfield contains thin local coal beds, through the work of Malott (1919, 1925, 1952, and thin dis continuous clay beds, and local deposits of Esarey, Malott, and Bieberman, 1948). Specific pebble conglomerate and conglomeratic sandstone. lithologic terms have been dropped from some Various types of ironstone occur in many places names and replaced with the term formation, in line throughout the formation, and near the top some thin with a suggestion by Gray and Perry (1956), because limestone beds are encountered. Mansfield rocks many of these formations are heterogeneous and the show striking lateral and vertical lithologic single term sandstone is not descriptive of, for variations of both regional and local nature. example, the Sample formation. The most conspicuous regional unconformity in The name Bethel formation is here used in place the bedrock of Indiana separates the Mississippian of Mooretown sandstone (pl. 3). Cor-relation of the system from the Pennsylvanian. Malott (1951, p. Mooretown with the Bethel been generally accepted 239-246) has dis cussed the regional aspects of this for some time, and Bethel has the advantage of unconformity. Pre-Pennsylvanian erosion has priority and wider usage. Furthermore, the name removed progressively older Cheater forma tions at Mooretown is incorrectly spelle d and refers to a increasing distances north of the Ohio River. For village that no longer exists, and the formation is not this reason, upper Chester strata are absent north of dominantly sandstone and is not completely exposed the town of Shoals in Mar tin County,