Results 71 to 80 of about 28,608 (299)

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

Geological Journal, EarlyView.
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, Md. Sazzadur Rahman, Gao Pin, M. Santosh, Wataru Fujisaki, Sam Uthup, Prince Mandingaisa   +6 more
wiley   +1 more source

Late Precambrian U-Pb titanite age for peak regional metamorphism and deformation (Knoydartian orogeny) in the western Moine, Scotland [PDF]

, 2003
There has been controversy over the number and timing of orogenies in the Precambrian Moine block in the Scottish Caledonides since the earliest radiometric dating in the 1960s. This work challenges a recent hypothesis, that this sector of the Laurentian
Evans, J.A., Tanner, P.W.G.
core   +1 more source

The lowermost last‐glacial equilibrium line altitude in the Taiwanese Central Mountain Range and its implications for the palaeoclimate and the tropospheric moisture transport in East Asia

Journal of Quaternary Science, EarlyView.
Abstract The high mountains of Taiwan provide a unique location for Quaternary palaeoclimate research in East Asia and the north‐western Pacific. This study applies geomorphological field mapping and rock surface exposure dating with paired (10Be/26Al) in situ‐produced terrestrial cosmogenic nuclides to identify and date glacial landforms and boulders ...
Robert Hebenstreit, Jacob Hardt, Margot Böse   +2 more
wiley   +1 more source

Geochemistry and petrogenesis of the Kolah-Ghazi granitoid assemblage, south of Esfahan

Journal of Economic Geology, 2018
Introduction The Kolah-Ghazi granitoid assemblage is located in the south of Esfahan and in the Sanandaj-Sirjan magmatic-metamorphic zone. The Sanandaj-Sirjan zone is extended for 1500 km from Sirjan in the southeast to Sanandaj in the northwest of Iran
Jamshid Ahmadian, Hajar Gholamian, Ali Khan Nasr Esfahani, Maryam Honarmand   +3 more
doaj   +1 more source

Anomalously old biotite ⁴⁰Ar/³⁹Ar ages in the NW Himalaya [PDF]

, 2017
Biotite 40Ar/39Ar ages older than corresponding muscovite 40Ar/39Ar ages, contrary to the diffusion properties of these minerals, are common in the Himalaya and other metamorphic regions.
Grujic, Djordje, Kleeberg, Reinhard, Pfänder, Jörg, Ratschbacher, Lothar, Sperner, Blanka, Stübner, Konstanze, Warren, Clare   +6 more
core   +1 more source

Raman Study of the Slobodka Ordinary Chondrite

Journal of Raman Spectroscopy, EarlyView.
The texture and mineral chemistry of Slobodka are most consistent with L4 chondrites, exhibiting strong shock metamorphism characteristic of shock stage S4, including irregular and planar fractures, undulatory extinction, and mosaicism in olivine, pyroxene, and plagioclase.
M. Simopoulou, I. Baziotis, L. Ferrière, J. Hu, C. Sanchez‐Valle, P. N. Gamaletsos, D. Palles, J. Berndt, C. Ma, S. Klemme, P. D. Asimow   +10 more
wiley   +1 more source

Assessing Thermal Maturity of the Pendência Formation (Potiguar Basin) Using Vitrinite Reflectance and Raman Spectroscopy

Journal of Raman Spectroscopy, EarlyView.
Palynofacies assemblages from the onshore Potiguar Basin display a wide thermal maturity range, with vitrinite reflectance (%Ro) values of 0.46–2.72 measured from nine samples at depths of 1059–4443 m. A strong correlation exists between %Ro and Raman parameters, specifically the G‐band's full width at half maximum.
Gabriel A. Barberes, Dalva A. L. Almeida, Flávia C. Marques, Julliana F. Alves, Paulo H. M. Toledo, Rafael de Oliveira, Lenize F. Maia, Linus Pauling F. Peixoto, Antonio Carlos Sant'Ana, Celly M. S. Izumi, Gustavo F. S. Andrade, Dorval C. Dias Filho, Taissa R. Menezes, Delano M. Ibanez, Luiz Fernando C. de Oliveira   +14 more
wiley   +1 more source

Problems of the Metamorphic and Igneous Rocks of the Mojave Desert [PDF]

, 1954
The Mojave Desert region, as defined by Baker (1911, pp. 335-336), is the region of desert plains, mountains, and valleys comprising the extreme southwestern portion of the Great Basin (fig. 1).
McCulloh, Thane H.
core  

Provenance history of a Late Triassic-Jurassic Gondwana margin forearc basin, Murihiku Terrane, North Island, New Zealand: petrographic and geochemical constraints [PDF]

, 2004
The Murihiku Terrane in the North Island was a forearc basin adjacent to a volcanic arc along the eastern margin of Gondwana during the Mesozoic. The rocks that infill the basin are mainly volcaniclastic sandstones and mudstones, often turbiditic, with ...
Briggs, Roger M., Middleton, Matthew P., Nelson, Campbell S.   +2 more
core   +2 more sources

Integration of Physics‐Based and Data‐Driven Approaches for Landslide Susceptibility Assessment

International Journal for Numerical and Analytical Methods in Geomechanics, EarlyView.
ABSTRACT Rainfall‐triggered landslides pose a significant threat to communities and infrastructure around the world. Various data‐driven and machine learning (ML) based algorithms have been applied to assess landslide susceptibility. However, purely data‐driven methods are affected by issues such as uncertainty in the selection of landslide ...
Yi Han, Shabnam J. Semnani
wiley   +1 more source