Results 171 to 180 of about 34,326 (336)

P‐T‐t‐d Evolution of Low‐Grade Metamorphic Xenotime, Eastern Alps (Austria)

open access: yesTerra Nova, EarlyView.
ABSTRACT In situ LA‐ICP‐MS U‐Pb dating of xenotime was used to establish the age of low‐grade metamorphism in Permian metasediments of the Austroalpine Unit (Eastern Alps, Austria). Complexly zoned xenotime in chloritoid‐bearing metasedimentary samples possesses distinct MREE‐rich domains. In the eastern sample, this domain yielded a date of c. 135 Ma,
M. S. Hollinetz   +4 more
wiley   +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, EarlyView.
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, EarlyView.
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, EarlyView.
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

Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone

open access: yesTerra Nova, EarlyView.
ABSTRACT Two giant porphyry copper deposits in the Southern Central Andes formed during the Miocene–Pliocene transition when a bend in the subducting Juan de Fernández hotspot chain jammed in the mantle transition zone, causing mega‐scale slab‐kinking. This geometry implies mechanical resistance that caused East–West compression and eventually a thrust‐
Nipaporn Nakrong   +5 more
wiley   +1 more source

Long‐Term Storage of Meteoric Water in the Variscan Basement: Stable Isotope Constraints (δD–δ18O)

open access: yesTerra Nova, EarlyView.
ABSTRACT F‐Ba‐Pb‐Zn (±Ag) deposits near the unconformity between the Armorican and Aquitaine basins formed by mixing surface waters and brines with fluid ascending from the basement. To better constrain the source of this fluid and the conditions of mixing, we analyzed the hydrogen (δDwater) and oxygen (δ18Owater) isotopic composition of water trapped ...
Loïc Bouat   +2 more
wiley   +1 more source

Carbon and strontium isotope ratios shed new light on the paleobiology and collapse of Theropithecus, a primate experiment in graminivory

open access: yesPalaeogeography, Palaeoclimatology, Palaeoecology, 2021
Luke D. Fannin   +8 more
semanticscholar   +1 more source

Dating C/S Structures in Syntectonic Granites by In Situ Rb‐Sr Analyses on Muscovite

open access: yesTerra Nova, EarlyView.
ABSTRACT The interplay of crystallisation, deformation and fluid–rock interactions makes deciphering geochronological information complex in syntectonic granites. In this study, we apply in situ Rb‐Sr analyses to selected samples from the Questembert Variscan syntectonic granite in Western France, which was emplaced along the South Armorican Shear Zone
Philippe Boulvais, Romain Tartèse
wiley   +1 more source

Home - About - Disclaimer - Privacy