Results 41 to 50 of about 29,640 (237)

SHRIMP Zircon U-Pb Dating of Mid-Pleistocene Dacite and Discussion of Relative Problems

Yankuang ceshi, 2015
K-Ar and U series disequilibria methods have been applied to geochronology research of young volcanic rocks in Tengchong, China. Previous K-Ar dating methods yielded ages of 0.013 to 17.84 Ma and isochron ages of 0.13 to 2.9 Ma in this area. The U series
LI Lin-lin, WANG Shu-bing, SHI Yu-ruo
doaj   +1 more source

U–Pb Geochronology and Stable Isotope Geochemistry of Terrestrial Carbonates, Lower Cretaceous Cedar Mountain Formation, Utah: Implications for Synchronicity of Terrestrial and Marine Carbon Isotope Excursions

Geosciences, 2022
The terrestrial Lower Cretaceous Cedar Mountain Formation, Utah, is a critical archive of paleoclimate, tectonics, and vertebrate ecology and evolution.
Erik L. Gulbranson, E. Troy Rasbury, Greg A. Ludvigson, Andreas Möller, Gregory A. Henkes, Marina B. Suarez, Paul Northrup, Ryan V. Tappero, Julie A. Maxson, Russell S. Shapiro, Kathleen M. Wooton   +10 more
doaj   +1 more source

Rutile Ages and Thermometry Along a Grenville Anorthosite Pathway

Geochemistry, Geophysics, Geosystems, 2023
The Grenville Orogen, in North America, contains a belt of Proterozoic anorthosite massifs with an episodic emplacement history. These distinctive magmas reflect extensive fractional crystallization of plagioclase from a mafic magma and contain layers ...
Janne Liebmann, Milo Barham, Christopher L. Kirkland   +2 more
doaj   +1 more source

Petrographic, chemical and geochronological characteristics of the Onzaga Metarhyolite and its correlation with Ordovician magmatic events in the northern Andes, Colombia

Boletín Geológico, 2022
The macroscopic, microscopic, and chemical characteristics as well as crystallization age of the Onzaga Metarhyolite unit are described. The spatiotemporal relationships among the magmatic events that occurred during the Ordovician in the Santander, La ...
Gabriel Rodríguez García
doaj   +1 more source

Timing of diagenesis and very low-grade metamorphism in the eastern sector of the Sierra de Cameros (Iberian Range, Spain): a U–Pb SHRIMP study on monazite [PDF]

, 2009
The Sierra de Cameros is an intracontinental orogen and represents the north-western part of the Iberian Range in Northern Spain. It comprises a thick sequence of syn-rift continental sediments (mainly sandstones and carbonates) deposited during ...
Aleinikoff, Bollinger, Cabella, Casas-Sainz, Casquet, Cherniak, Del Río, Evans, Evans, Frantz, Förster, Gabudianu Radulescu, Gil-Imaz, Goldberg, Janots, Janots, Kempe, Krenn, Lanzirotti, Lev, Mantilla-Figueroa, Mas, Masuda, Mata, Mata, Mata, Milodowski, Montel, Pan, Pan, Parrish, Rasmussen, Rasmussen, Rasmussen, Rubatto, Sawka, Smith, Spear, Tera, Tischer, Wilby, Williams, Wing   +42 more
core   +2 more sources

Correlated errors in U-Pb geochronology.

GEOCHEMICAL JOURNAL, 1979
Formulae are derived for the correlation of errors in the most used lead-lead and uranium-lead diagrams. It is emphasized that with the usual measurement schemes, error correlation is high in the conventional diagrams. An inverse lead-lead diagram is described in which, by proper choice of the measurement scheme, there is no correlation between errors.
openaire   +2 more sources

Variscan sourcing of Westphalian (Pennsylvanian) sandstones in the Canobie Coalfield, UK [PDF]

, 2010
The zircon age spectrum in a sample from the Canonbie Bridge Sandstone Formation (Asturian) of southern Scotland contains two main peaks. One is Early Carboniferous in age (348– 318 Ma), and corresponds to the age of igneous activity during the ...
ANDREW MORTON, Barrett, Besly, Bishop, Cope, Day, Guerrot, Heckel, Ludwig, Ludwig, Lumsden, MARK FANNING, Morton, Nance, NEIL JONES, Powell, Ramsbottom, Roach, Simpson, Strachan, Trueman, Waters   +21 more
core   +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

Metamorphic and metasomatic evolution of the Western Domain of the Karagwe-Ankole Belt (Central Africa) [PDF]

, 2020
The tectonometamorphic evolution of the Western Domain of the Karagwe-Ankole Belt, containing widespread granite-related W-Nb-Ta-Sn mineralization in pegmatites and hydrothermal quartz veins of Early Neoproterozoic age, is largely unknown.
Dewaele, Stijn, Hulsbosch, Niels, Muchez, Philippe, Van Daele, Johanna   +3 more
core   +1 more source

A Sample Characterization Toolkit for Carbonate U-Pb Geochronology [PDF]

, 2020
Abstract. Laser ablation U-Pb analyses of carbonate (LAcarb) samples has greatly expanded the potential for U-Pb dating to a variety of carbonate producing settings. Carbonates that were previously considered impossible to date using isotope dilution methods may preserve domains that are favorably interrogated when using spatially resolved laser ...
E. Troy Rasbury, Theodore M. Present, Paul Northrup, Ryan V. Tappero, Antonio Lanzirotti, Jennifer M. Cole, Kathleen Wooton, Kevin Hatton   +7 more
openaire   +1 more source