Results 211 to 220 of about 2,124,047 (278)

Integrated assessment of thermal maturity of the Upper Ordovician–Lower Silurian Wufeng–Longmaxi shale in Sichuan Basin, China

Marine and Petroleum Geology, 2019
The Wufeng-Longmaxi marine shale of the Upper Ordovician (O3w)-Lower Silurian (S1l) is the main source rock and target for shale gas exploration in Sichuan Basin, China.
Ye Wang, N. Qiu, Tenger Borjigin, B. Shen, Xiaomin Xie, Zhongliang Ma, Chaojin Lu, Yunfeng Yang, Liu Yang, Lijun Cheng, G. Fang, Yue Cui   +11 more
semanticscholar   +1 more source

Crinoids from the Upper Ashgill (Upper Ordovician) of Wales

Journal of Paleontology, 1993
A collection of small crinoids and crinoid debris from the Ashgill (Rawtheyan?) of Cnwce, near St. Clears, Dyfed, southwest Wales includes numerous crowns ofAithriocrinus strahanin. gen. and sp. incertae familiae, an indeterminate 10–armed camerate(?) and an indeterminate multiple-armed camerate.Aithriocrinus strahaniwas previously considered to be a ...
Stephen K. Donovan, Cornelis J. Veltkamp
openaire   +1 more source

Upper Ordovician sequences of western Estonia

Palaeogeography, Palaeoclimatology, Palaeoecology, 2004
Abstract The Upper Ordovician (uppermost Caradoc-Ashgill) section of western Estonia consists of a series of seven open-shelf carbonate sequences. Depositional facies grade laterally through a series of shelf-to-basin facies belts: grain-supported facies (shallow shelf), mixed facies (middle shelf), mud-supported facies (deep shelf and slope) and ...
Mark T Harris, Peter M Sheehan, Leho Ainsaar, Linda Hints, Peep Männik, Jaak Nõlvak, Madis Rubel   +6 more
openaire   +1 more source

Symbiosis of conulariids with trepostome bryozoans in the Upper Ordovician of Estonia (Baltica)

Palaeogeography, Palaeoclimatology, Palaeoecology, 2019
The trepostome bryozoans Diplotrypa abnormis, D. bicornis, D. petropolitana, Esthoniopora communis, E. subsphaerica, Mesotrypa excentrica, M. expressa, M.
O. Vinn, A. Ernst, Mark A. Wilson, U. Toom   +3 more
semanticscholar   +1 more source

Kope Formation (Upper Ordovician): Ohio and Kentucky

Science, 1964
Eden-like strata near Maysville, Kentucky, may be correlated with the Eden and lower Fairview formations of Cincinnati. To avoid the name Eden, which has stadial connotation, these rocks are included in the Kope formation, defined as medium-bedded limy shales (mean clastic ratio, 2.5 to 3.8) resting conformably between shaly Point Pleasant limestones ...
M P, Weiss, W C, Sweet
openaire   +2 more sources

Pore structure characterization of different lithofacies in marine shale: A case study of the Upper Ordovician Wufeng-Lower Silurian Longmaxi formation in the Sichuan Basin, SW China

Journal of Natural Gas Science and Engineering, 2018
Pore structure has distinct features in different shale lithofacies. This paper presents a case study of the Upper Ordovician Wufeng-Lower Silurian Longmaxi formation in southeast Sichuan Basin to fully describe the characteristics of shale pore ...
Lanyu Wu, Yangbo Lu, Shu Jiang, Yongchao Lu, Xiaofeng Liu, Haiyan Hu   +5 more
semanticscholar   +1 more source

The American Upper Ordovician Standard: XIII A Revised Time-Stratigraphic Classification of North American Upper Middle and Upper Ordovician Rocks

Geological Society of America Bulletin, 1971
Correlations, based on conodonts, between the Lexington, Kope and Clays Ferry Formations of the Cincinnati Region (Ohio, Kentucky, Indiana) and formations of the Trenton Group of New York and Ontario indicate that the base of the typical Edenian Stage and the top of the typical Shermanian Stage are at essentially the same biostratigraphic level. Hence,
W. C. SWEET, S. M. BERGSTRÖM
openaire   +2 more sources

Multi-proxy analysis of organic matter accumulation in the Upper Ordovician–Lower Silurian black shale on the Upper Yangtze Platform, south China

Marine and Petroleum Geology, 2019
There is no doubt that organic matter plays an important role in shale gas accumulation and storage. Thus, successful evaluation and production strategies of organic-rich shale deposits require an understanding of the range of factors that contribute to ...
Xiaoqi Wang, Yanming Zhu, G. Lash, Yang Wang   +3 more
semanticscholar   +1 more source

Relationship between the origin of organic-rich shale and geological events of the Upper Ordovician-Lower Silurian in the Upper Yangtze area

Marine and Petroleum Geology, 2019
Based on detailed sedimentological observations and geochemical analyses, four geological events have been identified, and a genetic depositional model has been established within a sequence stratigraphic framework.
Lanyu Wu, Yongchao Lu, Shu Jiang, Xiaofeng Liu, Zhanhong Liu, Yangbo Lu   +5 more
semanticscholar   +1 more source

Genesis, modification, and preservation of complex Upper Ordovician hardgrounds: Implications for sequence stratigraphy and the Great Ordovician Biodiversification Event

Palaeogeography, Palaeoclimatology, Palaeoecology, 2019
Hardgrounds from the Upper Ordovician strata of eastern Laurentia exhibit a wide range of morphologies, though the development of their complex surface topographies remains poorly understood.
T. Paton, C. Brett, George E. Kampouris
semanticscholar   +1 more source