Results 51 to 60 of about 5,404 (212)

Experimental early crystallization of K-feldspar in granitic systems. Implications on the origin of magmatic fabrics in granitic rocks

open access: yesGeologica Acta, 2017
One of the most outstanding characteristics of some granodioritic to granitic rocks is the presence of K-feldspar megacrysts. For instance, granodiorites and monzogranites of the Spanish Central System batholith present variable amounts of large (up to ...
J. DÍAZ-ALVARADO
doaj  

How much K is OK? Evaluating different methods for K-concentration determination and the effect of the internal K concentration on feldspar luminescence dating [PDF]

open access: yesGeochronology
For luminescence dating of potassium-rich (K) feldspars, the presence of 40K within the K-feldspar grains contributes significantly to the internal dose rate of the sample.
L. A. E. Maßon   +7 more
doaj   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

open access: yesGeological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid   +9 more
wiley   +1 more source

Geochemical modeling of diagenetic reactions between albitization of K-feldspar and plagioclase feldspar in sandstone reservoirs under the influence of CO2 partial pressure

open access: yesEvolving Earth
Diagenetic albitization has been observed in sedimentary basins around the world. This process significantly changes the original composition of sandstones and the chemistry of the formation waters under the influence of partial pressure of CO2.
Marcos Antonio Klunk   +6 more
doaj   +1 more source

Heterogeneous Exhumation Mechanisms in Neoproterozoic Collisional Metamorphism: P–T Constraints From Pelotas and Punta del Este Terranes, Southern Brazil and Uruguay

open access: yesGeological Journal, EarlyView.
Petrography, thermobarometry, and pseudosection modelling reveal peak metamorphic conditions of 3–7.5 kbar and 520°C–800°C in Tonian‐Cryogenian orthogneisses of the Dom Feliciano Belt. Metamorphic field gradients of 27°C/km–39°C/km and variable exhumation mechanisms support correlation of these units as remnants of a Himalayan‐type Piratini Orogeny ...
Thaiane Niederauer‐Santos   +6 more
wiley   +1 more source

Miocene to Quaternary Tectonostratigraphic Evolution of the Northern Section of the Burdur‐Fethiye Shear Zone, South‐Western Türkiye

open access: yesGeological Journal, EarlyView.
New zircon ages reveal that lacustrine sedimentation initiated in the Late Miocene (Messinian), revising earlier Pliocene age assignments. The study results support the interpretation of the northern BFSZ as a broad left‐lateral transtensional shear zone rather than a discrete sinistral fault or simple extensional graben array.
İrem Elitez   +3 more
wiley   +1 more source

Platinum Group Element Traces of CAMP Volcanism Associated With Low‐Latitude Environmental and Biological Disruptions

open access: yesGeophysical Monograph Series, Page 263-304., 2021

Exploring the links between Large Igneous Provinces and dramatic environmental impact

An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Jessica H. Whiteside   +3 more
wiley  

+2 more sources

Integrating ZooMS and taphonomy further highlights differential processing of animal and Neandertal carcasses in the Quina Mousterian at Les Pradelles (Marillac‐le‐Franc, southwest France)

open access: yesJournal of Quaternary Science, EarlyView.
ABSTRACT The cave of Les Pradelles (Marillac‐le‐Franc, France) was repeatedly visited by Neandertals ~55 000 years ago and is a key site in discussions of Neandertal cannibalism. Excavations between 1967 and 1980 (Vandermeersch) and between 2001 and 2013 (Maureille/Mann) produced a rich faunal assemblage (>20 000 bones), alongside Quina Mousterian ...
Pauline Raymond   +7 more
wiley   +1 more source

A talus rock glacier in Nantlle Valley, North Wales

open access: yesJournal of Quaternary Science, EarlyView.
ABSTRACT Landforms comprising mixtures of fine and coarse sediment and deposited during late glacial times are ubiquitous in the British mountains. In many cases, their interpretation has often proved contentious; as a result, the non‐generic term discrete debris accumulations (DDA) has been used to describe them and, over the last 50 years, some have ...
Stephan Harrison, Ed Anderson
wiley   +1 more source

Petrogenesis and tectonic implications of intrusive rocks in the Jiangjunmu porphyry deposit, East Kunlun orogeny, NW China

open access: yesFrontiers in Earth Science
The newly discovered Jiangjunmu Cu–Au deposits are hosted within granodiorite porphyry and K-feldspar granite of the East Kunlun metallogenic belt. Previous understanding of these deposits has been limited due to a lack of comprehensive isotopic data. To
Yu Junzhen   +12 more
doaj   +1 more source

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