Results 61 to 70 of about 36,744 (239)

New Permo-Carboniferous geochemical data from central Thailand: implication for a volcanic arc model [PDF]

, 1991
Current ideas and models of geotectonic reconstructions of Southeast Asia are reviewed and new data on Late Carboniferous through Middle Permian tuffites and sills from central Thailand are presented in the light of the problems of Southeast Asian ...
Altermann, Altermann, Altermann, Amstutz, Barr, Barr, Baum, Beccaluva, Buffetaut, Bunopas, Bunopas, Bunopas, Burret, Burton, Cobbing, Cooper, Damm, De Witt, Dickins, ESCAP, Fontaine, Garson, Gatinsky, Grant, Hahn, Haile, Helmcke, Helmcke, Helmcke, Ingavat-Helmcke, Macdonald, Macdonald, Macdonald, Macdonald, McElhinny, Metcalfe, Metcalfe, Metcalfe, Mitchell, Miyashiro, Miyashiro, Rao, Schermerhorn, Sengör, Shervais, Stauffer, Stauffer, Stauffer, Stöcklin, Thanasuthipitak, Tozer, Waterhouse, Wielchowsky, Winchester, Winkel, Wladyslaw Altermann, Wood, Zanettin   +57 more
core   +1 more source

Release of potassium from rock powder by the yeast Torulaspora globosa

Brazilian Archives of Biology and Technology, 2012
The alteration of minerals in rocks and the availability of elements for plant nutrition require long periods of time, and microorganisms are thought to induce the release of potassium and phosphate from rocks.
Márcia Maria Rosa-Magri, Simoni Helena Avansini, Maria Leonor Lopes-Assad, Sâmia Maria Tauk-Tornisielo, Sandra Regina Ceccato-Antonini   +4 more
doaj   +1 more source

Massive production of abiotic methane during subduction evidenced in metamorphosed ophicarbonates from the Italian Alps

Nature Communications, 2017
Alteration of ultramafic rocks plays a role in hydrocarbon production, but little is known about this process at depth. Here, the authors provide evidence that alteration of carbonated ultramafic rocks at high-pressures are an important source of abiotic
Alberto Vitale Brovarone, Isabelle Martinez, Agnès Elmaleh, Roberto Compagnoni, Carine Chaduteau, Cristiano Ferraris, Imène Esteve   +6 more
doaj   +1 more source

Asteroidal differentiation processes deduced from ultramafic achondrite ureilite meteorites [PDF]

, 2006
Ureilite meteorites are partial melt residues of an asteroid-sized object. They record the differentiation process that transformed many asteroids during the earliest stages of solar system ...
Downes, H., Franchi, I.A., Hudon, P., Mittlefehldt, D.W., Romanek, C.S.   +4 more
core   +1 more source

Olivine-chrome-spinel equilibrium in chromitites and ultramafites of Rai-Iz massif, Polar Urals

Литосфера, 2016
Olivine and chrome-spinel compositions from chromitites and ore-bearing metamorphosed ultramafic rocks of Rai-Iz massif were compared. It was established that olivine and spinel ferruginosity are directly proportional and increase monotonically from ...
P. B. Shirjaev, N. V. Vakhrusheva
doaj   +2 more sources

Baddeleyite and zircon U-Pb ages of the ultramafic rocks in Chigu Tso area, Southeastern Tibet and their constraints on the timing of Comei Large Igneous Province

China Geology, 2020
: A suite of ultramafic and mafic rocks developed in the Chigu Tso area, eastern Tethyan Himalaya. Baddeleyite and zircon U-Pb ages acquired by SIMS and LA-ICP-MS from olivine pyroxenite rocks in the Chigu Tso area are 138.9±3.0 Ma and 139.0±1.9 Ma ...
Ya-ying Wang, Ling-sen Zeng, Ling-hao Zhao, Li-e Gao, Jia-hao Gao, Zhao-ping Hu, Hai-tao Wang, Guang-xu Li, Ying-long Di, Yu Shen, Qian Xu   +10 more
doaj   +1 more source

Ultramafic Melt Viscosity: A Model

Earth and Planetary Science Letters
A non-Arrhenian model for the Newtonian viscosity (η) of ultramafic melts is presented. The model predicts the viscosity of ultramafic melts as a function of temperature (T), pressure (P), H2O content and for a range of melt compositions (70 < Mg# < 100).
James K. Russell, Kai-Uwe Hess, Donald B. Dingwell   +2 more
openaire   +1 more source

Loess Studies in Aotearoa New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Loess in Aotearoa New Zealand (ANZ) has been studied since its first documented recognition (on Banks Peninsula) in 1878 by Julius von Haast. A decade later, John Hardcastle revealed that southern ANZ loess was both glacial in origin and contained signals of past climates.
Brent V. Alloway, David J. Lowe, Bradley J. Pillans, Peter C. Almond, Alan S. Palmer   +4 more
wiley   +1 more source

Oxygen isotope geochemistry of the second HSDP core [PDF]

, 2003
Oxygen isotope ratios were measured in olivine phenocrysts (~1 mm diameter), olivine microphenocrysts (generally ~100–200 µm diameter), glass, and/or matrix from 89 samples collected from depths down to 3079.7 m in the second, and main, HSDP core (HSDP-2)
Eiler, John M., Kitchen, Nami E., Wang, Zhengrong   +2 more
core   +1 more source

Progressively Fenitised Schist and Carbonatitic Clasts From a Metasomatic Aureole Beneath the Alkalic Dunedin Volcano, Otago, New Zealand

New Zealand Journal of Geology and Geophysics, Volume 69, Issue 2, June 2026.
Clasts of albite‐porphyroblastic quartzofeldspathic schist, derived from the Otago Schist basement, occur within the Port Chalmers Breccia, a diatreme at the centre of the Dunedin stratovolcano, New Zealand. Schists have undergone varying degrees of replacement reactions (at temperatures of 300° to >500°C) producing hornfelses, with Ca‐ and K‐enriched ...
Alan F. Cooper
wiley   +1 more source