Results 91 to 100 of about 31,753 (257)

Provenance of Ordovician and Devonian sandstones from southern Peru and northern Bolivia - U-Pb and Lu-Hf isotope evidence of detrital zircons and its implications for the geodynamic evolution of the Western Gondwana margin (14° - 17° S) [PDF]

, 2009
In an attempt to trace the provenance of sedimentary detritus and to gain information on the crustal evolution of the Early Paleozoic western Gondwana margin (14°-17°S) we applied a combined in situ U-Pb and Lu-Hf LA-ICP-MS isotope analysis on detrital ...
Bahlburg, Heinrich, Berndt, Jasper, Carlotto, Victor, Gerdes, Axel, Kooijman, Ellen, Reimann, Cornelia R.   +5 more
core  

Surface roughness, stainability, and translucency of an additively manufactured interim resin reinforced with a commercially available ceramic composite concentrate after coffee thermal cycling

Journal of Prosthodontics, EarlyView.
Abstract Purpose To compare the surface roughness (Ra), stainability, and translucency of a ceramic composite concentrate‐reinforced interim resin with its corresponding non‐reinforced formulation and with a ceramic‐filled resin indicated for definitive use after coffee thermal cycling.
Mustafa Borga Donmez, Nicolas Michel Rotter, Gabriela Panca Sabatini, Almira Ada Diken Türksayar, Hyung‐In Yoon, Burak Yilmaz   +5 more
wiley   +1 more source

Zircon dissolution in a ductile shear zone, Monte Rosa granite gneiss, northern Italy [PDF]

, 2008
The sizes, distributions and shapes of zircon grains within variably deformed granite gneiss from the western Alps have been studied. Zircon shows numerous indicators of a metamorphic response in both the host gneiss and a 5 cm wide continuous ductile ...
Dal Piaz, Engi, Ewing, Hanchar, Hunziker, J. C. Martin, Keller, Kretz, Liati, Moller, Pawlig, Rubin, T. J. Dempster, Varva, Z. K. Shipton   +14 more
core   +1 more source

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

Zircons from Syros, Cyclades, Greece—Recrystallization and Mobilization of Zircon During High-Pressure Metamorphism [PDF]

, 2017
Zircons were studied from high-pressure/low-temperature metamorphosed meta-igneous lithologies from Syros. These rocks carry several zircon generations related to each other by dissolution-reprecipitation processes. One generation is pristine zircon that
BALLHAUS, CHRIS, KENNEDY, ALLEN K., LAGOS, MARKUS, TOMASCHEK, FRANK, VILLA, IGOR M.   +4 more
core  

Vertical profiling of shock attenuation at the Rochechouart impact structure, France

Meteoritics &Planetary Science, EarlyView.
Abstract Rochechouart, south‐west France, is a complex impact structure. Here, we present the first report of shock barometry of quartz from what are likely parautochthonous basement units at depth, based on samples from the 2017 C.I.R.I.R drilling campaign. The crystallographic orientations of 725 sets of PDFs in 512 quartz grains in samples from four
P. Struzynska, S. Alwmark, C. Alwmark, M. H. Poelchau, P. Lambert   +4 more
wiley   +1 more source

Detrital zircon U–Pb ages and Hf isotope analyses of modern and Quaternary sediments in China: A new dataset with preliminary analysis

Geoscience Data Journal
Developments of detrital zircon geochronology have resulted in an explosion of publications that report or discuss detrital zircon data. Combined detrital zircon U–Pb ages with Hf isotope analyses from modern and Quaternary sediments have been widely ...
Xiyun Chen, Ping Wang, Hongsen Xie, Longchen Zhu, Xia Liao, Xinggong Kong   +5 more
doaj   +1 more source

Columbite-Group Minerals from New York Pegmatites: Insights from Isotopic and Geochemical Analyses

Geosciences, 2018
Columbite crystals from niobium-yttrium-fluorine (NYF) pegmatites lacking zircon or containing metamict cyrtolite were analyzed for major and minor elements (Electron Microprobe (EMP)), trace elements (Laser Ablation-Inductively Coupled Plasma-Mass ...
Marian V. Lupulescu, Jeffrey R. Chiarenzelli, Mark E. Pecha, Jared W. Singer, Sean P. Regan   +4 more
doaj   +1 more source

Deconvolving the pre-Himalayan Indian margin – tales of crustal growth and destruction [PDF]

, 2018
The metamorphic core of the Himalaya is composed of Indian cratonic rocks with two distinct crustal affinities that are defined by radiogenic isotopic geochemistry and detrital zircon age spectra.
Ahmad, Ali, Ali, Ali, Ali, Ali, Ali, Amato, Aoki, Be’eri-Shlevin, Be’eri-Shlevin, Blades, Botev, Cawood, Cawood, Cawood, Chen, Chen, Clift, Collins, Collins, Cui, DeCelles, DeCelles, Ding, Dyck, Gansser, Ge, Gehrels, Gehrels, Griffin, Guynn, Gürsu, Han, Hassanzadeh, Hawkesworth, Hopkinson, Horstwood, Hu, Hu, Huang, Iizuka, Iizuka, Isozaki, Kaur, Kay, Keppie, Kohn, Le Fort, Le Fort, Lee, Li, Li, Li, Li, Li, Li, Long, Long, Martin, Martin, McQuarrie, McQuarrie, Merdith, Morag, Morag, Mottram, Myrow, Myrow, Myrow, Nowell, Pan, Parrish, Richards, Roberts, Roberts, Robinson, Robinson, Scholl, Searle, Shen, Shu, Singh, Sláma, Song, Spakman, Spencer, Spencer, Spencer, Spencer, Spencer, Stern, Stern, Su, Tate, Thimm, Thomas, Veevers, von Huene, Wang, Wang, Wang, Wang, Wang, Wang, Wang, Wang, Wang, Wang, Wang, Webb, Webb, Woodhead, Woodhead, Yakymchuk, Yan, Yao, Yao, Yao, Yao, Yao, Yin, Yu, Yu, Yu, Yu, Zhang, Zhang, Zhou, Zhou, Zhu, Zhu, Zou   +132 more
core   +4 more sources

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