词条 | Needmore Shale |
释义 |
| name = Needmore Formation | image = | caption = | type = sedimentary | age = Emsian[1] | period = Emsian | prilithology = shale | otherlithology = | namedfor = Needmore, Pennsylvania | namedby = Willard and Cleaves, 1939[2] | region = Appalachian Mountains | country = United States | coordinates = | unitof = | subunits = | underlies = Marcellus Shale and Millboro Shale | overlies = Oriskany Formation | thickness = | extent = Maryland, Pennsylvania, Virginia, and West Virginia | area = | map = | map_caption = }} The Devonian Needmore Formation or Needmore Shale is a mapped bedrock unit in Pennsylvania, Maryland, Virginia, and West Virginia. DescriptionThe Needmore Formation was originally described by Willard and Cleaves in 1939 as a dark- to medium-gray limy shale, based on exposures in southern Fulton County, Pennsylvania. They considered it part of the Onondaga Group.[2] DeWitt and Colton (1964) described the Needmore as "soft calcareous medium dark-brownish-gray and greenish-gray shale and mudrock...and soft, slightly calcareous very fissile brownish-black shale" that is not resistant to weathering. They estimated its thickness in their study area (southern Bedford County, Pennsylvania, and most of Allegany County, Maryland) as approximately 150 feet.[3] FossilsDeWitt and Colton (1964) identified brachiopods (Coelospira acutiplicata, Eodevonaria arcuata), trilobites (Phacops cristata), and ostracods (Favulella favulosa) in the Needmore.[3] Notable ExposuresType locality is between Needmore and Warfordsburg in southern Fulton County, Pennsylvania. AgeRelative age dating places the Needmore in the middle Devonian. References1. ^[https://vtechworks.lib.vt.edu/bitstream/handle/10919/19078/Read%20and%20Eriksson.pdf?sequence=1 Paleozoic Sedimentary Successions of the Virginia Valley & Ridge and Plateau] {{Chronostratigraphy of Maryland}}{{Chronostratigraphy of Pennsylvania}}{{Chronostratigraphy of Virginia}}{{Stratigraphic column of West Virginia}}{{Maryland-geologic-formation-stub}}2. ^1 Willard, Bradford, and Cleaves, A.B., 1939, Ordovician-Silurian relations in Pennsylvania: Geological Society of America Bulletin, v. 50, no. 7, p. 1165-1198. 3. ^1 deWitt, W. Jr., and Colton, G. W., 1964, Bedrock geology of the Evitts Creek and Pattersons Creek Quadrangles, Maryland, Pennsylvania, and West Virginia: U.S. Geological Surveys Bull. 1179, pl 1 and 2. 11 : Limestone formations of the United States|Devonian System of North America|Devonian geology of Pennsylvania|Devonian Maryland|Devonian geology of Virginia|Devonian West Virginia|Geologic formations of Pennsylvania|Geologic formations of Maryland|Geologic formations of Virginia|Geologic formations of West Virginia|Emsian |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。