Results 61 to 70 of about 36,250 (203)

The Ultramafic Belts [PDF]

, 2013
One petrological approach to upper mantle studies is to determine which ultramafic rocks represent mantle material. Ultramafic rocks occur in a variety of field and petrographic associations: in recent reviews, Wyllie [1967b, 1968] outlined eleven petrographic associations, some with subdivisions.
openaire   +2 more sources

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

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

Partitioning of Major and Trace Elements in a Stand of the Nickel Hyperaccumulator Rinorea cf. bengalensis in Borneo

Ecological Research, Volume 41, Issue 3, May 2026.
Rinorea cf. bengalensis is a tropical nickel hyperaccumulator plant that can be dominant in forests locally. We investigated the partitioning of major and trace elements in a stand of R. cf. bengalensis in Borneo. Hyperaccumulators have a large impact on the cycling of Ni and other elements in their ecosystem. ABSTRACT Rinorea cf.
Philip Nti Nkrumah, Amelia Corzo‐Remigio, Sukaibin Sumail, Guillaume Echevarria, Peter D. Erskine, Antony van der Ent   +5 more
wiley   +1 more source

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

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

Ages of the Pliocene-Pleistocene Alexandra and Ngatutura Volcanics, western North Island, New Zealand, and some geological implications [PDF]

, 1989
The Alexandra and Ngatutura Volcanics are the two southernmost of the Pliocene-Quaternary volcanic fields of western and northern North Island, New Zealand, northwest of Taupo Volcanic Zone TVZ.
Briggs, Roger M., Itaya, T., Keane, A.J., Lowe, David J.   +3 more
core   +2 more sources

Characterizing the Unique Chemical Imprint of On‐Axis, Lower‐Temperature Hydrothermal Flow to the Deep Ocean (Southern East Pacific Rise, 16.5°–18.0°S)

Geophysical Research Letters, Volume 53, Issue 7, 16 April 2026.
Abstract In addition to high‐temperature vents, lower‐temperature flow (LTF) (<300°C) is abundant along mid‐ocean ridges and contributes globally‐important fluxes of heat and water along with largely‐unconstrained geochemical influences on the ocean. We examined the impact of on‐axis LTF on the chemical composition of the overlying water column (<40 m ...
Laura E. Moore, Randelle M. Bundy, Joseph A. Resing, Scott White, Tamara Baumberger, Peter N. Sedwick, Nathaniel J. Buck, Anson M. Antriasian, Isaac Keohane, Bettina M. Sohst, Sharon L. Walker, Christopher R. German   +11 more
wiley   +1 more source

Terrestrial analogs and thermal models for Martian flood lavas [PDF]

, 2000
The recent flood lavas on Mars appear to have a characteristic “platy-ridged” surface morphology different from that inferred for most terrestrial continental flood basalt flows.
A. S. McEwen, Arya, Bird, Booth, Cattermole, Crisp, Crisp, Davies, Edgett, Edgett, Fink, Glaze, Goncharov, Greeley, Greeley, Greeley, Harmon, Harmon, Hartmann, Hartmann, Hartmann, Hill, Hon, Hooper, Hulme, Jakobsson, Jerram, Keszthelyi, Keszthelyi, Keszthelyi, Keszthelyi, Keszthelyi, Keszthelyi, Kilburn, L. Keszthelyi, Macdonald, Macdougall, Malin, Mangan, Martin, McEwen, McEwen, McEwen, McEwen, Mouginis-Mark, Muhleman, Oskarsson, Peterson, Pieri, Plescia, Reidel, Rowland, Sakimoto, Sakimoto, Scott, Scott, Self, Self, Shaw, Smith, Spence, Steingrímsson, Stephenson, Swanson, T. Thordarson, Theilig, Thorarinsson, Thordarson, Thordarson, Thordarson, Tolan, Wadge, Walker, Ward, Wilson, Wilson, Woods, Zielinski   +77 more
core   +1 more source

A First Quantification of Plant Endemism in the Manica Highlands (Zimbabwe–Mozambique) and the Significance of Open Habitats

Ecology and Evolution, Volume 16, Issue 4, April 2026.
We present here the first quantitative assessment of plant endemics from the Manica Highlands (Zimbabwe‐Mozambique), totalling 216 taxa, representing over 9% of the estimated total flora. A major finding is that 173 (80%) endemic taxa are principally or entirely confined to open montane habitats such as grassland, bare rock, crags and scrub or dwarf ...
Jonathan Timberlake, Vincent Ralph Clark
wiley   +1 more source