Results 81 to 90 of about 1,938 (228)

New SHRIMP ages for Ladakh and Karakoram Batholiths - inherited zircons indicate involvement of older crust

Himalayan Journal of Sciences, 1970
DOI = 10.3126/hjs.v5i7.1230 Himalayan Journal of Sciences Vol.5(7) (Special Issue) 2008 p ...
G Lister, TR Ireland, M Forster, L White, T Ahmad   +4 more
openaire   +2 more sources

Contrasting sources of Late Paleozoic rhyolite magma in the Polish Lowlands:evidence from U–Pb ages and Hf and O isotope composition in zircon [PDF]

, 2018
The Polish Lowlands, located southwest of the Teisseyre–Tornquist Zone, within Trans-European Suture Zone, were affected by bimodal, but dominantly rhyolitic, magmatism during the Late Paleozoic.
Michael Wiedenbeck, Słodczyk, Elżbieta, Elżbieta Słodczyk, Bruno Dhuime, Breitkreuz, Christoph, Glynn, Sarah, Slodczyk, Elzbieta, Pietranik, Anna, Anna Pietranik, Christoph Breitkreuz, Wiedenbeck, Michael, Sarah Glynn, Dhuime, Bruno   +12 more
core   +1 more source

Araguainha Dome, Brazil: A polygonal impact structure due to a complex pre‐impact regional structural framework

Meteoritics &Planetary Science, EarlyView.
Abstract We investigated the structural framework of the north–northwestern Paraná Basin in Brazil to test whether the pre‐impact structures in this region may have had any influence on the first‐order formation and morphostructure of the Araguainha impact structure (AIS).
Renato B. Bernardes, Wolf U. Reimold, Roger L. Gibson, Julia B. Curto Ma, Adolfo B. Silva, Natalia Hauser   +5 more
wiley   +1 more source

Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure

Meteoritics &Planetary Science, EarlyView.
Abstract Hummeln is a simple impact structure located in south‐eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln‐1 with a focus on impact metamorphism and the impact process.
S. Alwmark, J. Granbom, P. Ahlberg, M. Calner, S. Richoz, K. J. Gajewska, W. R. Hyde, K. Ljung, C. Alwmark   +8 more
wiley   +1 more source

Effect of chemical abrasion of zircon on SIMS U–Pb, δ¹⁸O, trace element, and LA-ICPMS trace element and Lu–Hf isotopic analyses [PDF]

Geochronology
This study assesses the effect of chemical abrasion on in situ mass spectrometric isotopic and elemental analyses in zircon. Chemical abrasion improves the U–Pb systematics of SIMS (secondary ion mass spectrometry) analyses of reference zircons, while ...
C. Kooymans, C. W. Magee Jr., K. Waltenberg, N. J. Evans, S. Bodorkos, Y. Amelin, Y. Amelin, S. L. Kamo, T. Ireland, T. Ireland   +9 more
doaj   +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
Tanner, P.W.G., Evans, J.A.
core  

Impact‐diagnostic criteria for use in confirming a meteorite impact origin of terrestrial geological structures: Recommendations by the Impact Cratering Committee of the Meteoritical Society

Meteoritics &Planetary Science, EarlyView.
Abstract The framework of the Impact Cratering Committee (ICC) of the Meteoritical Society was approved in 2020, with the first committee members appointed in 2023. The ICC has a mandate to (1) approve, maintain, and update a database of confirmed terrestrial meteorite impact structures, (2) define and regularly update the criteria used for ...
A. J. Cavosie, S. Alwmark, D. Baratoux, G. Consolmagno, L. Ferrière, S. Goderis, N. Hauser, T. Kenkmann, C. Koeberl, G. R. Osinski, A. E. Pickersgill, M. Schönbächler   +11 more
wiley   +1 more source

Zircon U–Pb geochronology of paragneisses and biotite [PDF]

, 2008
Sensitive high-resolution ion microprobe U–Th–Pb age determinations on detrital and inherited zircon from the E ´ vora Massif (SW Iberian Massif, Portugal) provide direct evidence for the provenance of the Ossa–Morena Ediacaran basins (Se´rie Negra) and ...
Chichorro, Martim, Silva, Jose B., Pereira, M. Francisco, Williams, Ian S.   +3 more
core  

Geochemical investigation of impactites from the Boltysh impact structure and possible relationship to early Danian sediments from the Umbria–Marche Basin, Italy

Meteoritics &Planetary Science, EarlyView.
Abstract Within the Danian Scaglia Rossa Formation appears a regionally correlatable horizon cutting across multiple sections and outcrops within the Umbria–Marche Basin of NE Italy, where it is intercalated with uniform pelagic carbonate successions. This horizon is called “ALE layer” and has tentatively been interpreted as a fine‐grained volcanic ash.
Toni Schulz, Sophia Wernitznig, Christian Koeberl, Bérengère Mougel, Alessandro Montanari, Frédéric Moynier   +5 more
wiley   +1 more source

Natural Resources and Political Patronage in Africa: An Ethnicity Level Analysis

Review of Development Economics, EarlyView.
ABSTRACT We investigate the effect of resource discoveries on ethnicity‐level political patronage in Africa using a large geospatial dataset of 254 ethnic groups in 15 countries over the period 1960–2004. We find that the first (or single first) resource discovery in a virgin ethnic homeland increases the share of cabinet posts of that ethnicity.
Sambit Bhattacharyya, Nemera Mamo
wiley   +1 more source