Results 41 to 50 of about 9,495 (248)

Peixe Zircon as a Quality Control Reference Material in U‐Pb Geochronology by LA‐ICP‐MS

Geostandards and Geoanalytical Research, EarlyView.
Key Points Peixe#0 zircon was characterised for U‐Pb geochronology using CA‐ID‐TIMS, SIMS and a long‐term LA‐ICP‐MS data set. The consistent results establish Peixe#0 as a reference material for U‐Pb quality control. Trace element heterogeneity requires careful, CL‐guided spot selection.
Margareth Sugano Navarro, Erica Martini Tonetto, Elson P. Oliveira, Mauricio Ibañez‐Mejia, Cristina Talavera, Neal J. McNaughton, Jacinta Enzweiler, Michael Wiedenbeck   +7 more
wiley   +1 more source

Petrogenesis of the Kanker Granites From the Bastar Craton: Implications for Crustal Growth and Evolution During the Archean-Proterozoic Transition

Frontiers in Earth Science, 2020
Archean-Proterozoic boundary represents a significant transitional phase in the Earth's history. Bastar Craton is one of the major Archean cratons in the Indian subcontinent with voluminous granites, supracrustal rocks, and tectonic belts.
Ajay Dev Asokan, R. Elangovan, Neeraj Vishwakarma, K. R. Hari, M. Ram Mohan   +4 more
doaj   +1 more source

Timing of Metamorphism and Deformation in the Neoarchean Quetico Metasedimentary Belt, Superior Craton, Constrained by Garnet Trace‐Element Mapping and Lu–Hf Geochronology

Journal of Metamorphic Geology, EarlyView.
ABSTRACT The Quetico subprovince of the Superior Province is among the largest metasedimentary belts globally and provides evidence of tectonic processes at play during the final stages of Archean cratonization. Although previous studies have shown that deformation and metamorphism of the 2.7‐Ga turbiditic protolith resulted in regional subvertical ...
Adrian G. Rehm, Antoine Godet, Doug Tinkham, Carl Guilmette, Matthijs A. Smit   +4 more
wiley   +1 more source

The effect of early diagenetic processes on the quantification of fossil micrometeorite abundance and flux in the geological record

Meteoritics &Planetary Science, EarlyView.
Abstract Fossil micrometeorites (MMs) recovered from lithified sedimentary rocks, particularly iron‐rich (I‐type) cosmic spherules (CSs) provide valuable insights into past dust‐forming events. Their abundances, when combined with estimates of local sedimentation rates can be used to reconstruct the flux of extraterrestrial dust.
Isabelle S. Mattia, Matthew J. Genge, Martin D. Suttle   +2 more
wiley   +1 more source

Komatiites From Mantle Transition Zone Plumes

Frontiers in Earth Science, 2020
During the Archean, episodic volcanism commonly included both plume- and arc-type magmatism, raising the issue of a possible link between “bottom up” and “top down” geodynamic processes.
Derek Wyman
doaj   +1 more source

Examining Archean methanotrophy [PDF]

Earth and Planetary Science Letters, 2016
The carbon isotope ratios preserved in sedimentary rocks can be used to fingerprint ancient metabolisms. Organic carbon in Late Archean samples stands out from that of other intervals with unusually low δ^(13)C values (∼−45 to −60‰). It was hypothesized that these light compositions record ecosystem-wide methane cycling and methanotrophy, either of the
Slotznick, Sarah P., Fischer, Woodward W.   +1 more
openaire   +2 more sources

Petrography and mineral chemistry of Northeast Africa 053—A remnant of Martian crystal mush

Meteoritics &Planetary Science, EarlyView.
Abstract In Earth's igneous systems, crystal mushes, crystal‐rich frameworks permeated by silicate melt, represent a common and fundamental stage in the evolution of magma bodies. However, whether crystal mushes occur within Martian igneous systems and play a comparable role is unknown. Here, we present a comprehensive petrography and mineral chemistry
Xhonatan Shehaj, Eleonora Ammannito, Giovanni Pratesi   +2 more
wiley   +1 more source

The Medicine Hat Block and the Early Paleoproterozoic Assembly of Western Laurentia

Geosciences, 2020
The accretion of the Wyoming, Hearne, and Superior Provinces to form the Archean core of western Laurentia occurred rapidly in the Paleoproterozoic. Missing from Hoffman’s (1988) original rapid aggregation model was the Medicine Hat block (MHB).
Jennifer N. Gifford, Shawn J. Malone, Paul A. Mueller   +2 more
doaj   +1 more source

Microbial Endolithic Community at Meteor Crater

Meteoritics &Planetary Science, EarlyView.
Abstract Postimpact recovery and evolution in response to climate changes produced a modern ecosystem at Meteor Crater dominated by a grassland and woodland of piñon and juniper, which has been used to evaluate floral and megafaunal consequences of impact cratering during the Phanerozoic Eon of complex life.
David A. Kring, Charles S. Cockell
wiley   +1 more source

Paleomagnetism of the Great Dyke of the Kola Peninsula (2.68 Ga): New Evidence of Ultra-Low Paleointensity of the Earth’s Magnetic Field in the Late Archean

Учёные записки Казанского университета: Серия Естественные науки
Giant mafic dykes are the key markers of the Earth’s evolution in the Precambrian and have been the subject of extensive research. This article presents the results of the paleomagnetic, rock-magnetic, and paleointensity Banc studies of the Great Dyke of
V. V. Shcherbakova, R. V. Veselovskiy, G. V. Zhidkov, N. A. Aphinogenova, A. V. Samsonov, A. V. Stepanova, M. A. Smirnov   +6 more
doaj   +1 more source