Guide Book Fourth Annual Indiana Geologic Field Conference

The Mississippian-Pennsylvanian unconformity is the most pronounced and extensive break in the Paleozoic rocks of the Eastern Interior Basin. During the long erosional interval Mississippian beds were truncated and a topographic surface of considerable relief was developed. Pennsylvanian sediments rest on Upper Chester beds in southwestern Indiana, on Meremacian limestones in midwestern Indiana and on Osagian and upper Devonian beds in northwestern Indiana. Outcrops selected for the 1950 Field Conference show the Mississippian-Pennsylvanian unconformity and the stratigraphy along the unconformity in michvestern Indiana. Basal Pennsylvanian beds will be seen resting on Lower Chester, Ste. Genevieve, St. Louis, Salem, Harrodsburg, and Borden rocks representing a truncation of approximately 260 feet of sediments

Stratigraphy of Three Wells in Sullivan and Vigo Counties, Indiana

Indiana Geological Survey Report of Progress 2Recent oil discoveries have stimulated drilling activity in Sullivan and Vigo counties. The discovery well of the Wilfred Pool, Siepman No. 1 well, was completed in August, 1948. Since then, approximately 80 test wells have been drilled in these two counties. Three new pools have been opened in the Devonian limesto ne, Wilfred and Marts in Sullivan County, and Spring Hill in Vigo County. Additional wells have been drilled in three old pools, Riley and Prairie Creek in Vigo County, and Siosi on the Sullivan-Vigo county line. This report is written in response to requests for immediate information on the Devonian formations and the possible Devonian pay zones in this area. The purpose of this paper is to make available to the public some of the geologic information now being assembled. As the present study of the subsurface Devonian is still in progress, correlations are tentative. The report includes sort descriptions of the Pennsylvanian and Mississippian beds and detailed sections of the Devonian formations in three wells in Sullivan and Vigo counties. The wells are; Riggs No.1, by Felmont Corporation, sec. 36, T. 8 N., R. 9 W., a Sullivan County wildcat; Leon Wallace No. 2, by F. B. Cline, sec. 30, T. 9 N., R. 8 W., Wilfred Pool, Sullivan County; and R. B. Campbell No. 1, by Sage and Farley, sec. 24, T. 11 N., R. 8 W., Riley Pool, Vigo County. These particular wells were selected because they penetrate the entire Devonian section. The Riggs No. 1 well and the Campbell No. 1 well were cabletool tests into the Trenton, and the Wallace No. 2 well was a rotary test that penetrated 361 feet of the Silurian rocks. The three wells are aligned in a north -south direction (Fig. 1) and show lithologic changes in the Devonian formations. The conclusions given in the paper are also based on information from many other wells in the Sullivan and Vigo county area.Indiana Department of Conservatio

Stratigraphy Along Mississippian-Pennsylvanian Unconformity of Western Indiana

Indiana Geological Survey Guidebook 4The Mississippian-Pennsylvanian unconformity is the most pronounced and extensive break in the Paleozoic rocks of the Eastern Interior Basin. During the long erosional interval Mississippian beds were truncated and a topographic surface of considerable relief was developed. Pennsylvanian sediments rest on Upper Chester beds in southwestern Indiana, on Meremacian limestones in midwestern Indiana and on Osagian and upper Devonian beds in northwestern Indiana. Outcrops selected for the 1950 Field Conference show the Mississippian-Pennsylvanian unconformity and the stratigraphy along the unconformity in midwestern Indiana. Basal Pennsylvanian beds will be seen resting on Lower Chester, Ste. Genevieve, St. Louis, Salem, Harrodsburg, and Borden rocks representing a truncation approximately 260 feet of sediments. This conference was planned to observe and discuss problems associated with a portion of the Mississippian-Pennsylvanian unconformity. Mississippian stratigraphy will be emphasized, and special attention will be given to the old Mississippian topography and to the lithology of the basal Pennsylvanian beds. We hope that discussion combined with actual field observation will be of mutual benefit.Department of Geology, Indiana University; Indiana Division of Geology; Indiana Department of Conservatio

Correlation of the Waldron and Mississinewa Formations

Indiana Geological Survey Bulletin 3Silurian and Devonian outcrops of Indiana are divided roughly into two areas, northern and southeastern Indiana. The bedrock of the northern area is largely covered by glacial drift, whereas the bedrock of the southeastern area is well exposed. These two areas are separated by an intervening zone which is blanketed completely by glacial drift. Although accurate and detailed work has been done on the Silurian and Devonian outcrops of the state, the formations of the two areas have never been correlated. The Silurian and Devonian formations in Indiana dip off the Cincinnati and Kankakee Arches into the Michigan Basin and the Eastern Interior Basin. The formations are difficult to trace in subsurface studies, because they are composed of a series of gradational limestones, dolomites, and calcareous siltstones. The surface formations have not been recognized in the subsurface strata. Some of the subsurface beds cannot be correlated with the outcropping beds, because additional sediments deposited in the basin do not appear on the arches. The Silurian-Devonian contact lacks identifying characteristics over much of the area, and, for this reason, many subsurface reports have considered both systems as one unit. The writers believe that accurate determinations of thickening, thinning, and pinching-out of the Silurian and Devonian formations on the flanks of the arches would be of great assistance in future prospecting for oil. These two problems, the geology of the arches and the geology of the basins, go hand in hand. Additional subsurface correlation studies are needed to clarify the Silurian and Devonian stratigraphy of Indiana.Indiana Department of Conservatio

Silurian Formations and Reef Sturctures of Northern Indiana

Indiana Geological Survey Guidebook 3In response to popular demand, the Silurian formations and associated reef structures of northern Indiana were chosen as the subject for the 1949 Field Conference. The numerous quaquaversal structures in the Niagaran of northern Indiana were long the subject of controversies and objects of mystery until, in 1927, Cumings and Shrock showed conclusively that they are ancient coral and stromatoporoid reefs. In the past few years, interest in reefs, recent and ancient, has been revived. The vast number of soundings taken in coral reef lagoons during the war and recent studies in connection with the Bikini atom bomb tests have shed much new light on present day reefs, and recent oil field discoveries associated with reef structures have stimulated much interest and study of the Paleozoic reefs. The conference has been planned to provide group observation and to promote group discussion of Niagaran reefs. Silurian stratigraphy is emphasized and special attention is given to lithology of reef core, reef flank, and inter-reef strata, as well as to the effect of reef structure on the overlying Devonian rocks. We hope that discussion combined with actual field examples will be of mutual benefit. This opportunity to become better acquainted and to exchange ideas is the most important part of the program.Department of Geology, Indiana University; Indiana Division of Geology; Indiana Department of Conservatio

Upper and Middle Mississippian Formations of Southern Indiana

Indiana Geological Survey Guidebook 2This field trip was organized to observe and discuss outcrop of Upper and Middle Mississippian age in Indiana. These formations are of special economic interest because the greater part of petroleum, agricultural limestone, road metal, and building stone in Indiana is produced from this rock series. The stratigraphy of the Indiana Chester formations is emphasized because of the wide divergence of opinion held upon their correlation with the subsurface formations of the Illinois Basin and the outcrops of similar age in the states surrounding the basin. The problems of time correlation by fossil evidence and of lithologic correlation by sedimentation units will be discussed. We hope that discussion combined with actual field examples of the Indiana section will provide a better understanding of the Chester correlation problems to all conference members. This opportunity to become better acquainted and to exchange ideas is the most important part of the program.Department of Geology, Indiana University; Indiana Division of Geology; Indiana Department of Conservatio