Results 41 to 50 of about 29,339 (247)

Geochemistry of beryl varieties: comparative analysis and visualization of analytical data by principal component analysis (PCA) and t-distributed stochastic neighbor embedding (t-SNE)

Записки Горного института, 2022
A study of the trace element composition of beryl varieties (469 SIMS analyses) was carried out. Red beryls are distinguished by a higher content of Ni, Sc, Mn, Fe, Ti, Cs, Rb, K, and B and lower content of Na and water.
Sergey G. Skublov, Aleksandra K. Gavrilchik, Aleksey V. Berezin   +2 more
doaj   +1 more source

Rhenium-osmium geochronology and geochemistry of ancient lacustrine sedimentary and petroleum systems [PDF]

, 2013
The Re-Os geochronometer is a valuable tool able to provide precise depositional ages of marine organic-rich sedimentary rocks as well as the generation age of hydrocarbons. In addition, Os isotopes afford vital insights into seawater Os fluctuations and
CUMMING, VIVIEN,MARY
core  

History of geochronology in Queensland

, 2008
This article is an individual and necessarily brief overview of the history of geochronology in Queensland with emphasis on the contributions of scientists and technicians who played major roles in the implementation of the geochronology facilities at ...
Golding, Suzanne D.
core   +1 more source

Morphological plasticity in the dentition of the lungfish Gnathorhiza from the Permian of Brazil: A population‐level geometric morphometric analysis

The Anatomical Record, EarlyView.
Abstract Dental plates are pivotal in the lungfish paleontological record, constituting highly mineralized structures resilient to diagenetic processes. This study provides a detailed description and quantitative shape analysis of 95 newly discovered Gnathorhiza sp. dental plates from the Middle–Late Permian Corumbataí Formation, Brazil.
Mauro B. S. Lacerda, Gustavo H. N. Petreca, Gabriel E. B. de Barros, Ana Emilia Quezado, Marcelo A. Fernandes   +4 more
wiley   +1 more source

SHRIMP ion probe zircon geochronology and Sr and Nd isotope geochemistry for southern Longwood Range and Bluff Peninsula intrusive rocks of Southland, New Zealand [PDF]

, 2006
Permian–Jurassic ultramafic to felsic intrusive complexes at Bluff Peninsula and in the southern Longwood Range along the Southland coast represent a series of intraoceanic magmatic arcs with ages spanning a time interval of 110 m.y.
Ireland, Trevor R., Arculus, Richard J., Richard J. Arculus, Trevor R. Ireland, Richard C. Price, Price, Richard C., Maas, Roland, Roland Maas   +7 more
core   +1 more source

Thermochronologic Constraints on the Extensional History of the Ibex Hills, Southeastern Black Mountains, Death Valley, California

Geological Journal, EarlyView.
A. Modeled T‐t paths for samples in the northern Ibex Hills, showing steady cooling throughout much of the Cenozoic, until rapid Miocene cooling. B. Weighted mean paths for each sample in this study. Note that all show a rapid cooling event at or just after 10 Ma, which is interpreted to represent exhumation as a result of regional extenstion ...
Zachariah D. Fleming
wiley   +1 more source

Cenozoic geochronology

, 1985
We present a revised Cenozoic geochronology based upon a best-fit to selected high-temperature radiometric dates on a number of identified magnetic polarity chrons (within the Late Cretaceous, Paleogene, and Neogene) which minimizes apparent ...
Flynn, John J., Berggren, William A., Kent, Dennis V., Van Couvering, John A.   +3 more
core   +1 more source

Geochemistry and Geochronology of Magmatic Rocks in Southwestern and Northeastern Cambodia: Implications for the Tectonic Evolution and Metallogenesis of the Loei Fold Belt

Geological Journal, EarlyView.
The composition of intrusive rocks suggests that the magma was likely generated in a subduction‐related setting. The arc crustal thickness in the Phnom Sro Ngam and Halo Prospects was probably < 40 km during emplacement. Zircon U–Pb age range indicates a correlation with Loei Fold Belt magmatic activity.
Sirisokha Seang, Khin Zaw, Kakda Kret, Ivan Belousov, Kotaro Yonezu, Koichiro Watanabe, Charles Makoundi   +6 more
wiley   +1 more source

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

Geological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta, Saumitra Misra, Thembiso O. Basupi   +2 more
wiley   +1 more source

MAIN STAGES OF CONTINENTAL CRUST FORMATION IN THE WESTERN ALDAN SHIELD: CONSTRAINTS FROM SM-ND ISOTOPE SYSTEMATICS OF CENOZOIC SANDS IN THE CHARA AND TOKKA BASINS

Геодинамика и тектонофизика, 2017
Previous geochronological and Sm-Nd isotopegeochemical studies have identified the main stages of the Precambrian continental crust formation in the central and eastern parts of the Aldan Shield [Kotov et al., 2006], while its western part (Chara-Olekma ...
A. B. Коtоv, T. M. Skovitina, V. P. Kovach, S. D. Velikoslavinsky, D. V. Lopatin, E. V. Sklyarov, E. V. Tolmacheva, O. V. Bobrovskaya   +7 more
doaj   +1 more source