Results 51 to 60 of about 34,047 (207)

⁸⁷Sr/⁸⁶Sr chemostratigraphy of Neoproterozoic Dalradian limestones of Scotland and Ireland: constraints on depositional ages and time scales [PDF]

, 2004
New calcite ⁸⁷Sr/⁸⁶Sr data for 47 limestones from the metamorphosed and deformed Neoproterozoic-Cambrian Dalradian Supergroup of Scotland and Ireland are used to identify secular trends in seawater <sup>
Fallick, A.E., Robert M. Ellam, Anthony E. Fallick, Graham, C.M., Ellam, R.M., Christopher W. Thomas, Thomas, C.W., Colin M. Graham   +7 more
core   +1 more source

Relationship between deformation structure and partial melting in pelitic migmatites of Hamaden region, Sanandaj-Sirjan Zone [PDF]

پترولوژی
The present paper describes some field characteristics of deformation in a high-strain and high temperature zone in migmatitic rocks, with several kilometers wide occurring in Hamedan and Toyserkan regions, NW of the Sanandaj- Sirjan Zone.
Seyedeh Razieh Jafari, Leyli Izadi Kian
doaj   +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

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

Geological 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, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

Reply to Comment by D. Jiang on “Pressure‐to‐Depth Conversion Models for Metamorphic Rocks: Derivation and Applications”

Geochemistry, Geophysics, Geosystems, 2021
In our study (Bauville & Yamato, 2021, https://doi.org/10.1029/2020gc009280), we derived simple formulas for pressure‐to‐depth conversion that allow (or not) to take into account deviatoric stresses.
A. Bauville, P. Yamato
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

Geological 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, Carla Cristine Porcher, Daniel Triboli Vieira, Edinei Koester, Diego Jaldín, Karina Luengo, Luisa Caon   +6 more
wiley   +1 more source

An appraisal of peak temperatures and thermal histories in ultrahigh-temperature (UHT) crustal metamorphism: the significance of aluminous orthopyroxene [PDF]

, 1998
P(論文)Ultrahigh-temperature (UHT) crustal metamorphism occurs where peak metamorphic temperatures of 900-1100℃ have been attained at pressures in the range 7-13 kbar.
Harley, Simon L.
core  

Plate Tectonics and Metamorphism: Teaching Complex Systems Using Videos and Animations

Geosciences
Metamorphism is a complex geologic process that is often poorly covered in introductory geology courses. This study explores the effectiveness of a video-based instructional intervention in improving student understanding of metamorphism and its ...
Siloa Willis, Robert J. Stern
doaj   +1 more source

Evolution of migmatitic granulite complexes: Implications from Lapland Granulite Belt, Part I: Metamorphic geology [PDF]

Bulletin of the Geological Society of Finland, 2006
The Palaeoproterozoic Lapland granulite belt was juxtaposed between Archaean and Proterozoic terrains in the NE part of the Fennoscandian Shield concurrently with the accretion of Svecofennian arc complexes at ~1.9 Ga.
P. Tuisku, P. Mikkola, H. Huhma
doaj   +1 more source

Mercury cycling during the last glacial period in Arctic Lake El'gygytgyn, NE Russia

Journal of Quaternary Science, EarlyView.
ABSTRACT Tectonic processes play a key role in the global mercury (Hg) cycle on geological timescales, by mobilising Hg from deep Earth reservoirs to the surface. These natural fluxes also introduce a dynamic component to the terrestrial Hg cycle that can interact with other environmental signals and influence Hg delivery to sedimentary records.
Alice R. Paine, Joost Frieling, Bernd Wagner, Martin Melles, Volker Wennrich, Tamsin A. Mather, Stuart A. Robinson, David M. Pyle   +7 more
wiley   +1 more source