Results 51 to 60 of about 2,007 (165)

Research Progress on Re-Os Isotopes Application in Dating and Paleoenvironmental Interpretation during the Neoproterozoic to Early Cambrian Periods

open access: yesYankuang ceshi, 2016
The Neoproterozoic to Early Cambrian period is a very important era in the history of earth evolution. Research on stratigraphic framework, paleo-oceanography, palaro-atmospheric, and paleoclimatology are focuses of international geosciences.
WANG Fu-liang   +7 more
doaj   +1 more source

Geochemical and Seismic Constraints on the Role of Mud Diapirs in Petroleum Migration and Accumulation in the Recôncavo Basin, NE Brazil

open access: yesJournal of Petroleum Geology, Volume 49, Issue 2, Page 433-447, April 2026.
ABSTRACT In the Recôncavo Basin, Northeast of Brazil, mud diapirs have been reported for decades, but their role within the basin's petroleum system remains poorly constrained. Here, we combine 2D seismic interpretation, field observations, and organic geochemical analyses of rocks and oil seeps to investigate the relationship between diapirism and ...
Cora Mattos   +3 more
wiley   +1 more source

MINERALOGY AND ZIRCON AGE OF CARBONATITES OF THE SREDNYAYA ZIMA COMPLEX (EASTERN SAYAN)

open access: yesГеодинамика и тектонофизика
The Srednyaya Zima alkaline-ultramafic carbonatite complex is located in the Eastern Sayan and is a part of the area of manifestation of Neoproterozoic rare-metal alkaline-carbonatite magmatism along the southern and southeastern margins of the Siberian ...
I. R. Prokopyev   +5 more
doaj   +1 more source

3D inversion of the Sichuan Basin magnetic anomaly in South China and its geological significance

open access: yesEarth, Planets and Space, 2020
The Sichuan Basin magnetic anomaly is the most striking regional aeromagnetic anomaly in South China. It is characterized by a continuous large-scale linear magnetic anomaly and contains long-wavelength constituents which could still be detected on ...
Jie Wang   +6 more
doaj   +1 more source

Exploring the Gravimetric and Geochronological Links in Ancient Terranes of the São Francisco Craton and Borborema Province, NE‐Brazil

open access: yesTerra Nova, Volume 38, Issue 2, Page 77-86, April 2026.
ABSTRACT Deep crustal fragments and structural lineaments identified through satellite gravity data provide evidence for the extension of the reworked ancient basement of the Central African Block into the northern São Francisco Craton and southern Borborema Province.
Douglas Teixeira Martins   +3 more
wiley   +1 more source

Cryogenian Glacial Erosion and Tectonics as Agents of Crustal Recycling

open access: yesTerra Nova, Volume 38, Issue 2, Page 87-96, April 2026.
ABSTRACT Zircon preserves evidence of recycling processes that link surface environments to the mantle. Combined δ18O‐εHf in zircon fingerprints magmatic sources and tracks how crustal material is reworked over time. We apply statistical analyses to a global compilation that apparently resolves shifts in zircon U–Pb, δ18O, and Lu‐Hf data spanning the ...
M. Seraine   +9 more
wiley   +1 more source

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

open access: yesTerra Nova, Volume 38, Issue 2, Page 97-105, April 2026.
ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito   +4 more
wiley   +1 more source

Neoarchean Arc Magmatism and Crust Recycling in the Northern Marginal Zone of the Limpopo Complex, Zimbabwe: New Insights From Zircon U‐Pb‐Hf Isotopes of a Charnockite Suite

open access: yesGeological Journal, Volume 61, Issue 3, Page 566-592, March 2026.
Charnockites with 2691–2607 Ma magmatic ages from the NMZ show arc‐magmatic geochemical signatures. They correspond to the lower‐crustal equivalent of the Chilimanzi Suite Granite in the Zimbabwe Craton. Lu‐Hf isotopic data of magmatic zircons show negative εHf(t) values (−11.18 to −2.20) with TDMC ages of 3699–3158 Ma, suggesting their protolith ...
Toshiaki Tsunogae   +6 more
wiley   +1 more source

Provenance of the sedimentary rocks of the Bom Jardim Group (Neoproterozoic, Southern Brazil): Evidence from petrography, geochemistry and neodymium isotopes

open access: yesLatin American Journal of Sedimentology and Basin Analysis
Provenance studies are helpful in reconstructing the tectonic, climatic and geographic setting of terrigenous sedimentary basins. The primary controls on the composition of detrital sedimentary rocks are the composition, climate and relief conditions of ...
André Weissheimer de Borba   +4 more
doaj  

The first animals: ca. 760-million-year-old sponge-like fossils from Namibia

open access: yesSouth African Journal of Science, 2012
One of the most profound events in biospheric evolution was the emergence of animals, which is thought to have occurred some 600-650 Ma. Here we report on the discovery of phosphatised body fossils that we interpret as ancient sponge-like fossils and ...
C. Brain   +9 more
doaj  

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