Cretaceous and Tertiary subsurface geology - The stratigraphy, paleontology, and sedimentology of three deep test wells on the Eastern Shore of Maryland
1948, Anderson, J.L.
This study of the Tertiary and Cretaceous Subsurface Geology of the Coastal Plain sediments of Maryland resulted from the drilling of three deep test wells for oil and gas on the Eastern Shore. Though sporadic test wells for oil and gas had been drilled in the Coastal Plain region of Maryland and in Western Maryland before, the explorations carried out by three major oil companies, the Ohio Oil Company, the Socony-Vacuum Oil Company, and the Standard Oil Company of New Jersey, during the years 1943 to 1946 were the first to utilize the most modern methods and techniques in oil-finding.
The Salisbury well and the Berlin well were drilled down to and into the basement complex, affording two complete sections of the Coastal Plain formations. The Ocean City well stopped just short of reaching the basement complex. The Salisbury well was the first one drilled. Since it was cored continuously from the depth of 1000 feet to the bottom at 5568 feet, this well furnished the most complete and accurate section. The core samples were supplemented by ditch samples over the entire depth. These samples and cores were given to the Department of Geology, Mines and Water Resources. Before the investigation of these samples was completed, the Berlin well was drilled to a depth of 7178 feet. Samples from this well, consisting of ditch samples over the entire depth and cores from a number of depths, were also given to the Department of Geology, Mines and Water Resources, providing a second complete geologic section of the subsurface of the Eastern Shore. The Ocean City well was drilled to a depth of 7710 feet before the investigation of the samples and the correlations of the first two wells were completed. The scope of the study was enlarged by the acquisition of ditch samples over the entire depth and side-wall core samples from this well, which provided a third geologic section of the subsurface of the Eastern Shore complete almost to the basement complex.
The investigation was carried out under the direction of Dr. Judson L. Anderson, Associate Professor of Geology at The Johns Hopkins University, who has had twelve years experience in all phases of petroleum geology. Dr. Anderson made a thorough analysis of the physical character of the sediments, determined their mineralogic content, interpreted and correlated the stratigraphy of the three geologic sections, and discussed their oil and gas possibilities. Dr. Robert M. Overbeck, Ground Water Geologist of the Department of Geology, Mines and Water Resources, participated in the physical analysis and sedimentary petrography of the samples from the Ocean City well and contributed to the interpretations from his knowledge of the subsurface geology of Eastern Shore water wells.
These materials offered such an unparalleled opportunity to advance the knowledge of the Cretaceous and Tertiary stratigraphy and paleontology of Maryland that Dr. John B. Reeside, Jr., Geologist in Charge of Paleontology and Stratigraphy of the United States Geological Survey, very generously arranged to have the fossils determined by the foremost paleontologic specialists of the United States Geological Survey. The Cretaceous mollusks were determined by Dr. Lloyd W. Stephenson, with the exception of a new fauna encountered in the Ocean City well which was described by Dr. Harold E. Vokes, who is also Professor of Geology at The Johns Hopkins University. The Tertiary mollusks were determined by Dr. Julia A. Gardner. The forams were determined by Dr. Joseph A. Cushman, who is also director of the Cushman Laboratory for Foraminiferal Research. A previous comprehensive study of the forams from the outcrop of the Maryland Miocene by Ann Dorsey (Mrs. Arthur W. Clapp) was utilized by Dr. Cushman and made available as a part of this report. The diatoms were studied by Mr. Kenneth E. Lohman and the ostracods by Mr. Frederick M. Swain.
Comprehensive reports on the stratigraphy and paleontology of the Tertiary and Cretaceous formations of the Maryland Coastal Plain were published years ago by the Maryland Geological Survey. They comprise a two-volume report on the Miocene in 1904, a report on the Eocene in 1901, a two-volume report on the Upper Cretaceous in 1916, and a report on the Lower Cretaceous in 1911. These reports concern the outcrops of the formations, and the correlations are based almost entirely on the macrofossils. The work was done before micropaleontology had been developed as an important basis for correlation, before sedimentary petrology had come into general use in stratigraphic interpretation, and before the needs of petroleum geology had turned the attention of geologists to subsurface investigations. This report serves, therefore, to supplement and make more complete the scope of these earlier systematic volumes.
An adjunct to this report and a further contribution to the knowledge of the Eocene stratigraphy of Maryland is an investigation by Dr. Elaine Shifflett of Eocene Stratigraphy and Foraminifera of the Aquia Formation, made in the Geological Laboratory of The Johns Hopkins University and published as Bulletin 3 of the Department of Geology, Mines and Water Resources.
To all of the above-named paleontologists, the Department of Geology, Mines and Water Resources is indebted for their valuable contributions to the completeness of this report.
-Joseph T. Singewald, Jr., Director