Results 11 to 20 of about 8,217 (293)

Chemostratigraphy of Neoproterozoic carbonates: implications for ‘blind dating’ [PDF]

open access: yesTerra Nova, 2001
The δ13Ccarb and 87Sr/86Sr secular variations in Neoproteozoic seawater have been used for the purpose of ‘isotope stratigraphy’ but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for ‘blind dating’.
Melezhik, V.A.   +3 more
openaire   +4 more sources

Large Igneous Province Record Through Time and Implications for Secular Environmental Changes and Geological Time‐Scale Boundaries

open access: yesGeophysical Monograph Series, Page 1-26., 2021

Exploring the links between Large Igneous Provinces and dramatic environmental impact

An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Richard E. Ernst   +8 more
wiley  

+8 more sources

Chemostratigraphy of the Pliensbachian, Puesto Araya Formation (Neuquén Basin, Argentina) [PDF]

open access: yesGeologica Acta, 2005
In a preliminary attempt to establish an isotope stratigraphy, strontium, carbon and oxygen isotope ratios were determined from marine biogenic carbonates of Pliensbachian age, in the context of scheme of local ammonite Zones correlatable to the European
Susana A. Valencio   +4 more
doaj   +6 more sources

Localized and Transient Oxygenation of Shallow Oceans of Southwestern Laurentia at the Ediacaran-Cambrian Boundary. [PDF]

open access: yesGeobiology
ABSTRACT The Ediacaran–Cambrian boundary, which precedes one of the most significant biotic diversification events in Earth's history, is associated with a global negative carbon isotope excursion termed the BAsal Cambrian carbon isotope Excursion (BACE).
Chanchai W   +6 more
europepmc   +2 more sources

An integrative biostratigraphic, chemostratigraphic, and sequence stratigraphic perspective of the Ordovician–Silurian boundary on Anticosti Island (Canada) [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
Anticosti Island, Canada, has long been recognized as an exceptional Ordovician–Silurian boundary succession with the potential to serve as one of the best records of climatic, oceanographic, and biological events associated with the Late Ordovician ...
Joshua B. Zimmt   +10 more
doaj   +1 more source

Integration of Darriwilian (Middle Ordovician) δ13Corg chemostratigraphy with graptolite biostratigraphy in the classical Röstånga area in northwestern Scania (southern Sweden) [PDF]

open access: yesEstonian Journal of Earth Sciences, 2020
The largely covered Middle Ordovician succession in the classic geological Röstånga area in northwestern Scania has not been studied for some 80 years.
Stig M. Bergström   +4 more
doaj   +1 more source

Ordovician climate changes in the northern subtropics: The δ18O record from the Tunguska Basin, Siberia [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
Oxygen isotopes from bioapatite (conodonts) have been used for several decades to reconstruct the Palaeozoic climate history. During the Ordovician, conodont-based δ18Ophos studies have revealed a general cooling trend throughout the system.
Peep Männik   +2 more
doaj   +1 more source

Searching for the Ordovician–Silurian boundary in Estonia, Latvia and Lithuania [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
The present study focuses on determining the position of the lower boundary of the Silurian System in the eastern Baltic region. To achieve this, we conducted a comprehensive analysis of stable isotopic curves, combined with previously published data on ...
Tõnu Meidla, Olle Hints, Leho Ainsaar
doaj   +1 more source

Age of the Ordovician sedimentary succession in Lumparn Bay, Åland Islands, Finland [PDF]

open access: yesEstonian Journal of Earth Sciences, 2023
Depression of the ancient Lumparn meteorite impact structure in the Åland Islands is partly infilled with the lower Palaeozoic sediments, lying presently below sea level. The Cambrian and Ordovician sedimentary cover is distributed in the area of 15 km2,
Leho Ainsaar, Tõnu Meidla
doaj   +1 more source

Late Cenomanian-Turonian isotopic stratigraphy in the chalk of the Paris Basin (France): a reference section between the Tethyan and Boreal realms

open access: yesBSGF - Earth Sciences Bulletin, 2021
A chemostratigraphic study (δ13C and δ18O) of the Late Cenomanian and Turonian chalk succession from the “Craie 701” Poigny borehole (near Provins in the Paris Basin, France) provides new high-resolution stable carbon and oxygen isotope data. Correlation
Le Callonnec Laurence   +3 more
doaj   +1 more source

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