Results 71 to 80 of about 1,682 (219)

Downcurrent variation in submarine channel‐fill architecture from the shelf to upper slope

Sedimentology, EarlyView.
ABSTRACT The transition between the shelf and the upper slope is often considered an area of sediment bypass, where steeper gradients increase flow velocities and maintain particles in suspension. In addition to transferring sediments into deeper basins, upper‐slope areas can also host channelised submarine deposits.
Moreno Pizzutto, Fabrizio Felletti, Adam McArthur, Mattia Marini, George Pantopoulos, Daniele Invernizzi, Chiara Zuffetti   +6 more
wiley   +1 more source

DEPLETED SSZ TYPE MANTLE PERIDOTITES IN PROTEROZOIC EASTERN SAYAN OPHIOLITES IN SIBERIA

Геодинамика и тектонофизика, 2017
N.L. Dobretsov et al. [1985] first described the rock complexes in Eastern Sayan as ophiolites. Ophiolites formed in Dunzhugur island arc and were obducted onto Gargan block, a Neoarchean crystalline basement of the Tuva-Mongolian Massif (TMM), as a ...
Kuo-Lung Wang, Zhuyin Chu, M. A. Gornova, S. Dril, V. A. Belyaev, Kuan-Yu Lin, S. Y. O’Reilly   +6 more
doaj   +1 more source

Salt Range Formation of Pakistan Preserves Unique Record of Volcanic Fertilization During the Ediacaran Shuram Excursion

Terra Nova, EarlyView.
ABSTRACT Thin, discontinuous, organic‐rich oil shale beds in the siliciclastic‐evaporitic Salt Range Formation (SRF) of Pakistan are of approximate Neoproterozoic to Cambrian age based on stratigraphic constraints. The beds are enriched (26–43 wt.% total organic carbon, TOC) in aliphatic organic matter (OM) of low thermal maturity despite their ...
Paul C. Hackley, Ryan J. McAleer, Jay M. Thompson, Brett J. Valentine, Imran Khan   +4 more
wiley   +1 more source

Laser Raman Spectroscopic Study and LA-ICP-MS U-Pb Dating of Zircons from the Badaling Granitic Complex

Yankuang ceshi, 2016
Alpha dose matrix effect is the discrepancy of ablation rate and down-hole fractionation induced by the difference of crystal damage degree (alpha dose) between standard zircons and sample zircons. It has been proved to be the cause of systematic bias of
WANG Jia-song, XU Ya-wen, PENG Li-na, LI Guo-zhan   +3 more
doaj   +1 more source

U–Pb Dating of Cambrian Magmatism in the Pinerolo‐Sanfront Unit, Dora‐Maira Massif (Western Alps)

Terra Nova, EarlyView.
ABSTRACT The Pinerolo‐Sanfront Unit (PSU), the structurally lowest tectonic unit of the Dora‐Maira Massif (Western Alps), has been regarded as a monocyclic unit composed of Permo‐Carboniferous sediments and Permian granitoids that were metamorphosed during the Alpine orogeny.
Francesco De Cesari, Davide Dana, Salvatore Iaccarino, Chiara Montomoli, Alberto Corno, Daniela Rubatto, Rodolfo Carosi   +6 more
wiley   +1 more source

Rare Earth Element Potential in the Araí Rift Metavolcanic, Central Brazil: Gamma‐Ray Signatures, Mineralogy and Exploration Implications

Terra Nova, EarlyView.
ABSTRACT Although central Brazil hosts significant ion‐adsorption rare earth element (REE) deposits associated with A‐type granites, their coeval volcanic counterparts have been largely overlooked as exploration targets. This study demonstrates that acidic metavolcanic rocks of the Araí Group share strong radiometric, geochemical and mineralogical ...
Yuri Ribeiro, Nilson Francisquini Botelho, Valmir da Silva Souza, Diego Guilherme da Costa Gomes   +3 more
wiley   +1 more source

Multi‐Mineral Geochronology Across the Neoproterozoic Brasília Nappe Stack: Constraints on Thermal Resetting and Metamorphic Architecture

Terra Nova, EarlyView.
ABSTRACT The Southern Brasília Orogen formed during Western Gondwana's final assembly and comprises nappe systems piled against the São Francisco Craton. We present new rutile U–Pb ages from the lowermost Canastra Group (> 2.2 Ga) and the uppermost Carrancas Group (~560 Ma), integrated with published zircon, monazite, garnet, and mica ages from the ...
Rodrigo Irineu Cerri, Alex J. Choupina A. Silva, Tamiris Pagotti Gonçalves Pinto, Rodrigo Prudente de Melo, George Luiz Luvizotto, Regiane Andrade Fumes, Fabrício de Andrade Caxito, Renato Moraes   +7 more
wiley   +1 more source

Zircon: The Metamorphic Mineral

Reviews in Mineralogy and Geochemistry, 2017
A mineral that forms under conditions as variable as diagenesis to deep subduction, melt crystallization to low temperature alteration, and that retains information on time, temperature, trace element and isotopic signatures is bound to be a useful petrogenetic tool. The variety of conditions under which zircon forms and reacts during metamorphism is a
openaire   +3 more sources

The polyphase Belokurikhinsky granite massif, Gorny Altai: isotope-geochemical study of zircon

Записки Горного института
Based on the isotopic-geochemical analyses of zircons from granites of the Belokurikhinsky massif in the Gorny Altai using the U-Pb method, the ages of three intrusion phases have been determined for the first time: the age of the first phase refers to ...
Sergey G. Skublov, Ekaterina V. Levashova, Maria E. Mamykina, Nikolay I. Gusev, Anatoliy I. Gusev   +4 more
doaj  

Fixed Points of Zircon Automorphisms

Order, 2008
A zircon is a poset in which every principal order ideal is finite and equipped with a so-called special matching. We prove that the subposet induced by the fixed points of any automorphism of a zircon is itself a zircon. This provides a natural context in which to view recent results on Bruhat orders on twisted involutions in Coxeter groups.
openaire   +4 more sources