Olentangy Shale Research Articles

CONODONTS FROM THE UPPER OLENTANGY SHALE (UPPER DEVONIAN, CENTRAL OHIO) AND STRATIGRAPHY ACROSS THE FRASNIAN–FAMENNIAN BOUNDARY

Abstract The Upper Olentangy Shale of Ohio, a green pyritic shale interbedded with thin dark gray shale beds, disconformably overlies the lithologically similar Middle Devonian Lower Olentangy Shale. The muds were deposited in a quiet offshore environment on the distal margin of the Appalachian Basin during the Late Frasnian through Early Famennian. The Upper Olentangy Shale contains abundant and diverse conodonts of MN Zone 13 and the Middle triangularis Zone. The Frasnian-Famennian boundary is 4–8 cm below the base of the Huron Shale at the Olentangy Shale type section in Delaware, Ohio. The boundary interval is a green shale containing a mixed highest Frasnian (e.g., Palmatolepis bogartensis, P. linguiformis) and lowest Famennian (e.g., P. delicatula, P. subperlobata, P. triangularis) conodont fauna. An ash horizon, pyritic bed, finely laminated dark shale, and a thin green-blue shale comprise the upper 3 cm of the Olentangy, and contain a conodont fauna indicative of the Middle triangularis Zone.

Conodonts from the Upper Olentangy Shale (Upper Devonian, central Ohio) and stratigraphy across the Frasnian-Famennian Boundary

The Upper Olentangy Shale of Ohio, a green pyritic shale interbedded with thin dark gray shale beds, disconformably overlies the lithologically similar Middle Devonian Lower Olentangy Shale. The muds were deposited in a quiet offshore environment on the distal margin of the Appalachian Basin during the Late Frasnian through Early Famennian. The Upper Olentangy Shale contains abundant and diverse conodonts of MN Zone 13 and the Middle triangularis Zone. The Frasnian-Famennian boundary is 4-8 cm below the base of the Huron Shale at the Olentangy Shale type section in Delaware, Ohio. The boundary interval is a green shale containing a mixed highest Frasnian (e.g., Palmatolepis bogartensis, P. linguiformis) and lowest Famennian (e.g., P. delicatula, P. subperlobata, P. triangularis) conodont fauna. An ash horizon, pyritic bed, finely laminated dark shale, and a thin green-blue shale comprise the upper 3 cm of the Olentangy, and contain a conodont fauna indicative of the Middle triangularis Zone.

Organic Geochemistry and Oil-Source Correlations, Paleozoic of Ohio

Routine analytical methods and new kerogen-kerogen pyrolyzate techniques used for detailed petroleum geochemical studies permit the correlation of oils to their respective source rocks in Ohio. In the Paleozoic section, four good to excellent source units were identified: the Mississippian Sunbury Shale, the Devonian Ohio Shale and Olentangy Shale, and the shales of the Ordovician Point Pleasant Formation. These marine shales are dominantly oil-prone, with maturation levels that span the immature to peak oil-generation range. No source rocks examined exceeded an Ro of 1.0-1.1% (or equivalent). The reservoired oils in Ohio are mostly supermature, based on normal alkanes, pristane/n-C17 to phytane/n-C18 ratios, low asphaltene and sulfur contents, and high paraffin indices. Three basic oil groups were identified using oil characterization procedures: group 1 consists of Cambrian, Ordovician, and some Silurian oils; group 2 consists of some Silurian, Devonian, one Mississippian, and some Pennsylvanian oils; and group 3 consists of oil from the Mississippian Berea sandstone. Oil-source rock correlation techniques permitted the assignment of probable source rocks to each oil group. Group 1 oil was probably derived from the Point Pleasant shales, group 2 oil was derived from the Ohio Shale and Olentangy Shale, and group 3 oil came from the Sunbury Shale. Because the supermature oils in Ohio occur in reservoirs with maturities generally under 0.8% Ro, the oils would have had to migrate from deep within the Appalachian basin. Migration could have followed fracture zones, unconformities, or extensive and permeable units such as the Silurian Clinton sands.

Determination of Organic-Matter Content of Appalachian Devonian Shales from Gamma-Ray Logs

The organic-matter content of the Devonian shale of the Appalachian basin is important for assessing the natural-gas resources of these rocks, and patterns of organic-matter distribution convey information on sedimentary processes and depositional environment. In most of the western part of the Appalachian basin the organic-matter content of the Devonian shale can be estimated from gamma-ray wire-line logs using the equation: ^phgro = (^ggrB - ^ggr)/1.378A, where ^phgro is the organic-matter content of the shale (fractional volume), ^ggr the gamma-ray intensity (API units), ^ggrB the gamma-ray intensity if no organic matter is present (API units), and A the slope of the crossplot of gamma-ray intensity and formation density (API units/(g/cm3)). The quantities A and ^ggrB vary regionally and are mapped using data from gamma-ray and formation-density wire-line logs. Organic-matter contents estimated using this equation are compared with organic-matter contents determined from direct laboratory analyses of organic carbon for 74 intervals of varying thickness from 12 widely separated wells. The organic-matter content of these intervals ranges from near zero to about 20% by volume. Excluding the Cleveland Member of the Ohio Shale and the lower part of the Olentangy Shale, the distribution of the differences between volume-percent organic-matter content determined from core samples and estimated from gamma-ray logs has a mean of 0.44% and a standard deviation of 1.98%, which indicates that the accuracy of the gamma-ray method is adequate for most geologic applications. The gamma-ray intensity of the Cleveland Member of the Ohio Shale and the lower pa t of the Olentangy Shale is anomalously low compared to other Devonian shales of similar richness, so that organic-matter content computed for each of these units from gamma-ray logs is likely to be too low. Wire-line methods for estimating organic-matter content have the advantages of economy, readily available sources of data, and continuous sampling of the vertically heterogenous shale section. The gamma-ray log, in particular, is commonly run in the Devonian shale, its response characteristics are well known, and the cumulative pool of gamma-ray logs forms a large and geographically broad data base. The quantitative computation of organic-matter content from gamma-ray logs should be of practical value in studies of the Appalachian Devonian shale. The general approach described here may also be applicable to other formations with physical and geochemical characteristics similar to the Appalachian Devonian shale.

UPPER DEVONIAN CORRELATIONS IN WESTERN UTAH AND EASTERN NEVADA

From the Devils Gate limestone, Pilot shale, and Pinyon Peak limestone of the eastern Great Basin, the writers have obtained 54 species of 28 conodont genera. Species of the genus Palmatolepis can be used in refined Devonian correlation and classification with the standard stages based on ammonoid genera in Europe. Three distinct assemblage zones, designated A, B, and C, are classified as Upper Manticoceras, uppermost Manticoceras or Lower Cheiloceras and Upper Cheiloceras or Lower Platyclymenia, respectively. The upper part of the Devils Gate can be correlated with the lower and middle Pilot and the upper Pinyon Peak. Zone A, present in these formations, can be correlated with zone II of the Houy formation in Texas, the Independence shale and its equivalents in Iowa and Illinois, the Olentangy shale of Ohio, and the lower part of the Perrysburg formation and its equivalents in western New York and northern Pennsylvania. Zones B and C, present in the middle-lower and middle part of the Pilot and upper part of the Devils Gate and Pinyon Peak, can be correlated with zone III of the Texas Houy formation, the Grassy Creek shale and its equivalents in Illinois and Iowa, and other sections in the mid-continent and eastern United States including the Huron member of the Ohio shale of Ohio and Kentucky and the middle and upper part of the Perrysburg formation in New York and Pennsylvania.

Age of Arkansas Novaculite

The Arkansas novaculite crops out in the Ouachita Mountains of Arkansas and Oklahoma and, with the exception of conodonts, apparently lacks fossils useful in determining its age and correlatives. The best section is at Caddo Gap, Montgomery County, Arkansas, where the formation is 940 feet thick and its three divisions (lower, middle, and upper) are cleanly exposed--except for 80 feet of the middle division. Practically all of the conodonts reported on are from serial collections made at Caddo Gap. Because these conodonts are preserved as molds, latex impressions were made of many specimens to aid in their identification. The lower division is 466 feet thick and consists chiefly of nearly white novaculite. No fossils were collected though a previous investigator reported finding a fragmentary brachiopod in southeastern Oklahoma. This fossil--identified as Leptocoelia flabellites and generally accepted as evidence for dating the lower division--was examined and is considered to be too poorly preserved to warrant identification. On lithologic grounds and stratigraphic position, the lower division is correlated with the Camden chert of Tennessee, the Penters chert of Arkansas, and the Pinetop chert of Oklahoma; these formations are classified as Lower or Middle Devonian. The middle division is 347 feet thick. Its lower 318.5 feet consist chiefly of dark gray and greenish gray shales interbedded with dark gray novaculites whereas its upper 28 feet consist of thin, light brown and greenish gray shale and novaculite beds that are separated from the underlying ones by a 0.5-foot thick, dark gray, minutely pebbled, novaculite conglomerate. The beds below the conglomerate are placed in the Upper Devonian; the conglomerate and overlying beds are assigned to the Lower Mississippian (Kinderhook). No fossils were found in the lowermost 163 feet of the middle division; this interval is placed in the Upper Devonian on lithologic grounds even though the basal part may be slightly older. Two Upper Devonian conodont faunal zones have been recognized. The lower zone s represented by a single lot obtained 184 feet below the top of the middle division. The specifically recognizable conodonts of this zone are similar to those in the Olentangy shale of Ohio. One of the species is definitely present in a faunal zone of the Sweetland Creek shale of Iowa; it may also be present in the Dunkirk shale of New York. The higher zone ranges throughout a known interval of 93.5 feet, or 46.5-140 feet below the top of the middle division; this conodont fauna probably ranges upward through another 18 feet of beds to the base of the aforementioned conglomerate. The identifiable conodonts of the zone suggest correlation with the Huron shale of northern Ohio; the lower Ohio shale of central and southern Ohio; the Antrim shale of Michigan; a part of the middle division o the New Albany shale of Indiana; a part of the Chattanooga shale of Kentucky, Tennessee, Georgia, and Alabama; and a part of the Woodford chert of Oklahoma. Lower Mississippian (Kinderhook) conodonts are present in the topmost 28.5 feet of the middle division. The fauna gradually changes throughout this interval. The lowermost beds contain fossils that suggest correlation with the Bushberg sandstone member of the Sulphur Springs formation of Missouri, the Hannibal shale of Missouri, the Sunbury shale of Ohio, the basal Orangeville shale of northern Ohio, and the very uppermost beds of the New Albany shale of Indiana. Beds slightly higher in the section contain conodonts of lower Chouteau age whereas those located 11.5-17.5 feet below the top of the middle division contain several specim ns of Gnathodus punctatus and Polygnathus radina. These two fossils are known only from beds of Chouteau age and suggest an alignment with the Chappel limestone of Texas and the Welden limestone of Oklahoma. The upper division is 127 feet thick and consists of nearly white, granular novaculite. No fossils were collected at Caddo Gap but a small undescribed fauna was obtained near Hatton in west-central Arkansas. An upper Kinderhook or Osage age is suggested because Chouteau conodonts are present in the topmost beds of the underlying middle division whereas Meramec conodonts are present in the basal beds of the overlying Stanley shale. The upper division is present only in the southern outcrop belt of the Arkansas novaculite; it has not been recognized north or west of McCurtain County, Oklahoma.

NEW ALBANY SHALE

Research Article| September 01, 1946 NEW ALBANY SHALE GUY CAMPBELL GUY CAMPBELL LEXINGTON, INDIANA Search for other works by this author on: GSW Google Scholar Author and Article Information GUY CAMPBELL LEXINGTON, INDIANA Publisher: Geological Society of America Received: 17 May 1945 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1946, 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 (1946) 57 (9): 829–908. https://doi.org/10.1130/0016-7606(1946)57[829:NAS]2.0.CO;2 Article history Received: 17 May 1945 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 GUY CAMPBELL; NEW ALBANY SHALE. GSA Bulletin 1946;; 57 (9): 829–908. doi: https://doi.org/10.1130/0016-7606(1946)57[829:NAS]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 New Albany shale in Indiana consists of the Devonian Blocher and Blackiston formations (90 feet thick) and the Mississippian Sanderson, Underwood, and Henryville formations (11 feet thick). This classification is based on floral and faunal content. The Underwood contains a Hamburg oölite fauna. These divisions continue through Kentucky, Ohio, and Tennessee. In eastern Kentucky the Trousdale, a correlate of the Blocher, is underlain by the Tully Portwood formation, which contains three coeval facies; the Underwood and Henryville are replaced by the Bedford and Sunbury. In Ohio the Blackiston was contemporaneous with the Chagrin, and the Sanderson is equivalent to the Cleveland as restricted. The Olentangy shale is basal Blackiston and Upper Devonian in age. The Chattanooga in central Tennessee contains equivalents of all the Indiana New Albany divisions. New names are proposed for some of the Chattanooga beds. The Hardin sandstone is basal Devonian; the Mississippian basal bed is the Bransford sandstone. Beds classed as Maury occur in the Chattanooga and as basal New Providence and Fort Payne. The New Providence and Fort Payne overlie the Chattanooga disconformably. The Blackiston and Sanderson are represented in Alabama. 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.

The age and fossils of the Olentangy shale of central Ohio

The age and fossils of the Olentangy shale of central Ohio

The Fauna of the Typical Olentangy Shale

The typical outcrops of the Olentangy shale occur in central Ohio, and the term was originally confined to the formation in that area. Megascopic and microscopic fossils recently found in the Olentangy seem to tie it definitely to other more widely distributed deposits of the same stratigraphic position and to confirm its assigned place in the Middle Devonian.

A New Coral from the Olentangy Shale of Ontario

Through the kindness of Irving G. Reimann, curator of geology, Buffalo Museum of Science, the writer has been able to study a new species of tetracoral from the Oletangy shale of Ontario, belonging to a genus which is represented by only four or five known species in the Devonian of North America. This genus, Homalophyllum, was erected by Simpsont in 1900 for Zaphrentoid tetracorals in which the corallum is flattened on the side of the greatest cruvature. As a result of this flattening the shape of the corallum becomes slipper-like, and Grove2 later suggested that the term calceoloid (Latin calceolus-a little shoe) be used for this type of coral. As genotype Simpson selected Zaphrentis ungula Rominger from the Onondaga limestone. He pointed out that in the flattened corallum these corals re-semble the genus Calceola, but did not mention the additional important fact that they lacked the operculum characteristic of Calceola and allied genera.

The Olentangy Shale in Southern Ohio

This paper contains an account of the distribution and characteristics of the blue shale at the base of the Devonian system from Greenfield, Highland County, Ohio, to the Ohio River. Evidence is presented to show that this blue shale belongs to the same formation as the Olentangy shale of central Ohio, that it is local in its occurrence in southern Ohio, and that it rests disconformably on the underlying limestones and lies conformably beneath the Ohio shale, into which it grades in some localities. The field evidence supports the interpretation of Grabau that the Olentangy shale is a basal phase of the Ohio shale and that it is Upper Devonian in age.

Age and Stratigraphic Relations of the Olentangy Shale of Central Ohio, with Remarks on the Prout Limestone and So-Called Olentangy Shales of Northern Ohio

Age and Stratigraphic Relations of the Olentangy Shale of Central Ohio, with Remarks on the Prout Limestone and So-Called Olentangy Shales of Northern Ohio

The Relationships of the Olentangy Shale and Associated Devonian Deposits of Northern Ohio

In the flat glaciated region to the south and east of Sandusky there are few outcrops of the older rocks. The drainage is mostly by small, weak streams which have not yet had time to erode extensive valleys, and railroads have not been compelled to cut deeply in order to establish their grades. About seven miles south of Sandusky, however, where the land is a little higher than in the city and the mantle rock is exceedingly thin, some of the creeks have exposed small sections of bedrock which are somewhat exaggerated by a considerable local dip. Two of the more important of these are to be found along Plum and Pipe creeks. These sections have been discussed elsewhere,2 but a recent study of the region has added some valuable facts to those formerly given and has made it possible to correlate this Ohio Hamilton with the Devonian deposits of the same age to the north of Lake Erie. Plum Creek heads about nine miles southeast of Sandusky and flows, in a general northerly direction, to the lake. At a point about two miles east-northeast of Prout station, on the Baltimore & Ohio Railroad, it cuts into Huron shale, and a little farther north into the Hamilton beds, exposing the following section: