Results 71 to 80 of about 40,674 (250)

Size and Composition of the MORB+OIB Mantle Reservoir

Geochemistry, Geophysics, Geosystems, 2022
Most efforts to characterize the size and composition of the mantle that complements the continental crust have assumed that the mid‐ocean ridge basalt (MORB) source is the incompatible‐element depleted residue of continental crust extraction. The use of
A. W. Hofmann, C. Class, S. L. Goldstein
doaj   +1 more source

Geochemical characteristics of geothermal and hot spring gases in Beijing and Zhangjiakou Bohai fault zone

Frontiers in Earth Science, 2022
The Beijing and Zhangjiakou-Bohai Fault Zone is a group of NW-W orderly active fault zones with high seismic activity and abundant geothermal resources since the Cenozoic.
Mingbo Yang, Guiping Liu, Zhe Liu, Jingchen Ma, Liwu Li, Zhiguo Wang, Peixue Hua, Lantian Xing, Xiaoru Sun, Kongyan Han, Bowen Cui, Xiaodong Wu   +11 more
doaj   +1 more source

Trace element geochemistry of peridotites from the Izu-Bonin-Mariana Forearc, Leg 125

, 1992
Trace element analyses (first-series transition elements, Ti, Rb, Sr, Zr, Y, Nb, and REE) were carried out on whole rocks and minerals from 10 peridotite samples from both Conical Seamount in the Mariana forearc and Torishima Forearc Seamount in the Izu ...
Ingram, G., Johnson, K. T. M., Parkinson, I. J., Pearce, J. A., Thirlwall, M. F.   +4 more
core   +1 more source

Sr-Nd isotope geochemistry of the early Precambrian sub-alkaline mafic igneous rocks from the southern Bastar craton, Central India [PDF]

, 2009
Sr–Nd isotope data are reported for the early Precambrian sub-alkaline mafic igneous rocks of the southern Bastar craton, central India. These mafic rocks are mostly dykes but there are a few volcanic exposures.
BL Weaver, DA Papanastassiou, DJ DePaolo, F Kalsbeek, G Sarkar, Gulab C. Gautam, H Crookshank, HC Halls, J Blichert-Toft, JE French, JE French, JJW Rogers, JJW Rogers, M Anand, M Ramakrishnan, NM Evensen, Rajesh K. Srivastava, RCO Gill, RE Ernst, RE Ernst, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RK Srivastava, RL Rudnick, Rob M. Ellam, RP Hall, RW Maitre Le, SA Drury, SL Goldstein, SM Naqvi, SR Taylor, TE Krough, TN Irvine, V Rajamani   +39 more
core   +1 more source

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

Meteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis, L. Ferrière, C. Ma, J. Hu, D. Palles, P. D. Asimow   +5 more
wiley   +1 more source

Long-term memory of subduction processes in the lithospheric mantle: evidence from the geochemistry of basic dykes in the Gardar Province of South Greenland [PDF]

, 2002
The rift-related magmas of the Proterozoic Gardar Igneous Province were emplaced across the contact between the South Greenland Archaean craton and the Palaeoproterozoic Ketilidian mobile belt.
Ellam, R.M., Goodenough, K.M., Upton, B.G.J.   +2 more
core   +2 more sources

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Microspherules Formed by Lightning Strikes

Meteoritics &Planetary Science, EarlyView.
Abstract Natural microspherules are formed by high‐temperature processes and are present throughout the geologic record to the present day. We report the discovery of large numbers of microspherules recovered from a rock pavement in the Pilbara region, Western Australia.
M. R. Boyd, M. J. Genge, A. G. Tomkins
wiley   +1 more source

Theoretical petrology [PDF]

, 1979
The central issues in petrology have remained remarkably unchanged in the last 50 years. In igneous petrology, the focus is on understanding the nature and cause of diversity in igneous rocks: on identifying primary magma types and constraints on the ...
Stolper, Edward
core   +1 more source

Polymict melt‐bearing breccia dikes in the Morokweng impact structure formed by slip‐induced mechanical mixing of pseudotachylite and cataclasite along large‐displacement impact faults

Meteoritics &Planetary Science, EarlyView.
Abstract A core drilled through shocked and faulted Archean granitoid gneisses and dolerites in the eroded peak ring of the 70–80 km diameter Morokweng impact structure intersects multiple centimeter‐ to meter‐wide clastic‐matrix breccias containing a polymict clast population of lithic and mineral clasts and altered, millimeter‐ to centimeter ‐size ...
Roger L. Gibson, S'lindile S. Wela, Leonidas C. Vonopartis, Marco A. G. Andreoli   +3 more
wiley   +1 more source