Results 91 to 100 of about 21,944 (246)

A neoproterozoic age for the chromitite and gabbro of the Tapo Ultramafic Massif, Eastern Cordillera, Central Peru, and its tectonic implications [PDF]

, 2011
The ultramafic-mafic rocks of the Tapo Complex are exposed in the Eastern Cordillera of the Central Peruvian Andes. This complex is composed of serpentinised peridotites and metabasites with some podiform chromitite lenses and chromite disseminations and
Amaral, Baldo, Castroviejo, Castroviejo, Cawood, Chew, Colombo C.G. Tassinari, Dalmayrac, Dalziel, Eurico Pereira, Fuck, Irvine, Jorge Acosta, Jose F. Rodrigues, Le Maitre, Ludwig, Megard, Palme, Pearce, Pedrosa-Soares, Ramos, Ramos, Ramos, Ricardo Castroviejo, Sato, Steiger   +25 more
core   +3 more sources

Determining impact angle from the spatial distribution of shock metamorphism: A case study of the Gosses Bluff (Tnorala) impact structure, Australia

Meteoritics &Planetary Science, EarlyView.
Abstract The majority of planetary impacts occur at oblique angles. Impact structures on Earth are commonly eroded or buried, rendering the identification of the direction and angle of impact—using methods such as asymmetries in ejecta distribution, surface topographic expression, central uplift structure, and geophysical anomalies—challenging. In this
Eloise E. Matthews, Auriol S. P. Rae, Thomas Kenkmann, Nicholas E. Timms, Aaron J. Cavosie, Marian B. Holness   +5 more
wiley   +1 more source

Detrital zircon and apatite (U‐Th)/He geochronology of intercalated baked sediments: a new approach to dating young basalt flows [PDF]

, 2011
Simple numerical models suggest that many basaltic lava flows should sufficiently heat the sediments beneath them to reset (U‐Th)/He systematics in detrital zircon and apatite.
Aciego, Aciego, Aciego, Blackburn, Blondes, Bristow, Dungan, Dungan, Farley, Farley, Flowers, Frances J. Cooper, Gardés, Gautheron, Hon, Hourigan, Jaeger, Kelley, Kip V. Hodges, Lipman, Lipman, Matthijs C. van Soest, McDougall, Min, Nasdala, Reiners, Schildgen, Schildgen, Self, Shuster, Vermeesch, Vermeesch, Wendt   +32 more
core   +2 more sources

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

SHRIMP U-Pb zircon dating on Nyainqentanglha granite in central Lhasa block

Chinese Science Bulletin, 2004
The Nyainqentanglha granite, a batholith with an area of 1500 km2 in the central Lhasa block, comprises mainly medium-fine-grained biotite monzonitic granite and medium-coarse-grained biotite monzonitic granite. Their contact relationship suggests that the medium-fine-grained biotite monzonitic granite was crystallized earlier than the medium-coarse ...
Qisheng Liu, Zhenhan Wu, Daogong Hu, Peisheng Ye, Wan Jiang, Yanbin Wang, Hancheng Zhang   +6 more
openaire   +2 more sources

Magmatic record of India-Asia collision [PDF]

, 2015
This work was financially co-supported by Chinese Academy of Sciences (XDB03010301) and other Chinese funding agencies (Project 973: 2011CB403102 and 2015CB452604; NSFC projects: 41225006, 41273044, and 41472061).New geochronological and geochemical data
Cawood, Peter Anthony, Chung, Sun-Lin, Liu, Sheng-Ao, Mo, Xuan-Xue, Niu, Yaoling, Wang, Qing, Wu, Fu-Yuan, Zhao, Zhi-Dan, Zhu, Di-Cheng   +8 more
core   +1 more source

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

Meteoritics &Planetary Science, EarlyView.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska, Sanna Alwmark, Mikael Calner, Sylvain Richoz, Jens Ormö, Erik Sturkell, Carl Alwmark   +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

Confirming the impact origin of the São Miguel do Tapuio structure, northeastern Brazil

Meteoritics &Planetary Science, EarlyView.
Abstract The São Miguel do Tapuio structure (SMT) is a remarkable, nearcircular feature of about 21 km diameter, centered at 5°37.6′ S, 41°23.3′ W in Piauí state, northeastern Brazil. The structure is located within the sedimentary strata of the Paleozoic–Mesozoic Parnaíba Basin and predominantly comprises sandstones of the Devonian Pimenteiras and ...
Alvaro Penteado Crósta, Neivaldo Araújo de Castro, Marcos Alberto Rodrigues Vasconcelos, Airton Natanael Coelho Dias, Ludovic Ferrière, Wolf Uwe Reimold, Ana Maria Góes, Jackson Alves Martins, Liliana Sayuri Osako, Raimundo Mariano Gomes Castelo Branco   +9 more
wiley   +1 more source

Turning Trash Into Treasure: Extracting Meaning From Discordant Data via a Dedicated Application

Geochemistry, Geophysics, Geosystems
Zircon U–Pb geochronology is a vital tool for dating geological events, but interpreting discordant zircon ages—often the result of Pb loss due to fluid‐rock interactions—remains challenging.
Lucy M. Mathieson, C. L. Kirkland, M. L. Daggitt   +2 more
doaj   +1 more source