Results 1 to 10 of about 4,673,798 (343)
Petroleum Exploration and Development, 2021 Based on the lithologies, sedimentary structures, graptolite zones, inorganic geochemical characteristics, electrical data of 110 shale gas wells in southern Sichuan Basin and the mineral quantitative analysis technology of scanning electron microscope ...
Yiqing ZHU +8 more
doaj +5 more sources
Stage boundaries, global stratigraphy, and the time scale: towards a simplification [PDF]
Carnets de Géologie, 2004 This paper examines four facets of stratigraphic terminology and usage considered faulty and proposes corrective measures. The four perfectible areas are: (1) The system of dual nomenclature requiring discrete terminologies for the superpositional and ...
Thierry Jacques +3 more
doaj +6 more sources
Rivista Italiana di Paleontologia e Stratigrafia, 1998 A refined subdivision, based on fusulinids, of the Moscovian stage in southwestern Darvaz is proposed. Seven local zones, three in the Lower Moscovian substage and four in the Upper Moscovian substage were established, based on investigations of three ...
ERNST JA. LEVEN
doaj +5 more sources
Belemnite-based strontium, carbon and oxygen isotope stratigraphy of the type area of the Maastrichtian Stage [PDF]
Netherlands Journal of Geosciences - Geologie en Mijnbouw, 2011 AbstractBelemnitellid cephalopods from the Maastrichtian stratotype area (southeast Netherlands) are shown to be comparatively well preserved. Although partial diagenetic alteration has been observed, micromilling techniques have permitted the extraction of pristine belemnite calcite, suitable for the reconstruction of strontium (Sr), oxygen (O) and ...
Hubert Vonhof +7 more
semanticscholar +6 more sources
Trans-Atlantic dinoflagellate cyst stratigraphy across the Cenomanian–Turonian (Cretaceous) Stage boundary [PDF]
Journal of Micropalaeontology, 2000 Abstract. The principal palynological proxy for the Cenomanian–Turonian Stage boundary, the top of consistent/common Litosphaeridium siphoniphorum (a dinoflagellate cyst), occurs in Greenhorn Bed 73 at the international stratotype section, west of Pueblo, Colorado, USA.
Paul Dodsworth
semanticscholar +6 more sources
Astronomical calibration of the Toarcian Stage: Implications for sequence stratigraphy and duration of the early Toarcian OAE [PDF]
Earth and Planetary Science Letters, 2013 The Toarcian Oceanic Anoxic Event (T-OAE) of the early Jurassic period involves one of the largest perturbations of the carbon cycle in the past 250 Ma, recorded by a pronounced negative carbon-isotope excursion (CIE). Numerous studies have focused on potential causes of the T-OAE and CIE, but are hampered by an uncertain timescale.
Slah Boulila +6 more
semanticscholar +6 more sources
The Stratigraphy and Fauna of the Hackberry Stage of the Upper Devonian [PDF]
, 1925 C. L. FENTON, Mildred Fenton
semanticscholar +4 more sources
Foraminiferal stratigraphy of raised marine deposits, representing isotope stage 5, Prins Karls Forland, western Svalbard [PDF]
Polar Research, 1998 Two raised marine sequences from Prins Karls Forland, western Svalbard, interpreted to have been deposited during part of isotope substage 5e (Eemian) and substage 5a, were studied for foraminifera content. Time constraints are given by 14C ages, infrared stimulated luminescence age estimates and amino acid ratios in subfossil marine molluscs.
Helene Bergsten +2 more
semanticscholar +6 more sources
Integrated stratigraphy of the Waitakian‐Otaian Stage boundary stratotype, Early Miocene, New Zealand [PDF]
New Zealand Journal of Geology and Geophysics, 1999 Abstract The base of the type section of the Otaian Stage at Bluecliffs, South Canterbury, is recognised as the stratotype for the boundary between the Waitakian and Otaian Stages. Principal problems with the boundary are the restriction of existing bioevent proxies to shelf and upper slope environments and its uncertain age. These topics are addressed
Hugh E. G. Morgans +7 more
semanticscholar +5 more sources
Progress, Problems and Prospects on the Stratigraphy and Correlation of the Kungurian Stage, Early Permian (Cisuralian) Series [PDF]
Acta Geologica Sinica - English Edition, 2011 Abstract:The Kungurian Stage is one of the three remaining stages of the Permian that is not yet defined at the base by a Global Stratotype Section and Point (GSSP). The candidate section at the Yuryuzan' River in the Urals yields few conodonts, and contains non‐marine sediments near the boundary. The search for a suitable, continuous marine succession
Yue Wang +5 more
openalex +3 more sources