Results 61 to 70 of about 1,440 (281)

Petrology of Oligocene Ghaleh Yaghmesh granitoids in the west of Yazd province

Journal of Economic Geology, 2017
Introduction The generation and evolution of granitic magmas has been a hot debated subject among petrologists. The diversity of their origin has led different authors to propose that these rocks are not simple in their origin and might be generated in
Bahareh Fazeli, Mahmoud Khalili, Roy Beavers, Mahin Mansouri Esfahani, Zahra Loghmani Dastjerdi   +4 more
doaj   +1 more source

Cryogenian Glacial Erosion and Tectonics as Agents of Crustal Recycling

Terra Nova, EarlyView.
ABSTRACT Zircon preserves evidence of recycling processes that link surface environments to the mantle. Combined δ18O‐εHf in zircon fingerprints magmatic sources and tracks how crustal material is reworked over time. We apply statistical analyses to a global compilation that apparently resolves shifts in zircon U–Pb, δ18O, and Lu‐Hf data spanning the ...
M. Seraine, C. J. Spencer, T. M. Gernon, T. Hincks, C. L. Kirkland, E. Rugen, L. DaSilva, H. Shafaii Moghadam, L. P. Soares, G. Fazio   +9 more
wiley   +1 more source

Essentials of Igneous and Metamorphic Petrology [PDF]

American Mineralogist, 2015
B. Ronald Frost and Carol D. Frost (2013) Cambridge University Press, U.K. ISBN: 9781107696297, 314 pages. Essentials of Igneous and Metamorphic Petrology , which is easy to recommend, is presented in a concise and compelling manner. The book is about 300 pages and is subdivided into eighteen chapters that convey the fundamental principles that govern
openaire   +1 more source

Near‐Synchronous Cambrian Evolution of the Transbrasiliano‐Kandi‐4°50′ Shear Zone in South America and Africa

Terra Nova, EarlyView.
ABSTRACT The Transbrasiliano‐Kandi‐4°50′ (TK4) shear zone in western Gondwana crosscuts South America and NW Africa for at least 6000 km. Despite its impressive size, the timing of the main episode of dextral ductile shearing is uncertain. We present detailed in situ multi‐mineral geochronology of mylonites from both Brazil and Algeria supporting that ...
F. A. Caxito, B. V. Ribeiro, F. Alkmim, A. Deramchi, C. L. Kirkland   +4 more
wiley   +1 more source

Petrology and Geochemistry of the Qozlou Granitoid and Related Fe skarn (west Zanjan)

Journal of Economic Geology, 2020
Introduction Fe skarn deposits are one of the important Fe deposits in the Zanjan province which have been exploited in recent years. The Qozlou Fe deposit is one of these Fe skarn deposits which is located at 65 km west of Zanjan.
Neda Shafaiepour, Mir Ali Asghar Mokhtari, Hossein Kouhestani, Maryam Honarmand   +3 more
doaj   +1 more source

Giant Porphyry Copper Deposits Caused by a Slab Jamming in the Mantle Transition Zone

Terra Nova, EarlyView.
ABSTRACT Two giant porphyry copper deposits in the Southern Central Andes formed during the Miocene–Pliocene transition when a bend in the subducting Juan de Fernández hotspot chain jammed in the mantle transition zone, causing mega‐scale slab‐kinking. This geometry implies mechanical resistance that caused East–West compression and eventually a thrust‐
Nipaporn Nakrong, Marnie Forster, Wim Spakman, Hielke Jelsma, Francois Gaboury, Gordon Lister   +5 more
wiley   +1 more source

Comparison of the Thermometery-Barometery methods by using Thermocalc and Theriak-domino to study Calc- silicate Hornfelses in Cheshin, Hamedan

Journal of Economic Geology, 2019
Introduction The pseudo-section method, first proposed by Hensen (1971), is used today by scientists to determine the thermodynamic conditions of mineral crystallization and modeling in metamorphic lithology (Hoschek, 2004; Omrani et al., 2013).
Haleh Ghorbani, Mohssen Moazzen, Adel Saki   +2 more
doaj   +1 more source

Long‐Term Storage of Meteoric Water in the Variscan Basement: Stable Isotope Constraints (δD–δ18O)

Terra Nova, EarlyView.
ABSTRACT F‐Ba‐Pb‐Zn (±Ag) deposits near the unconformity between the Armorican and Aquitaine basins formed by mixing surface waters and brines with fluid ascending from the basement. To better constrain the source of this fluid and the conditions of mixing, we analyzed the hydrogen (δDwater) and oxygen (δ18Owater) isotopic composition of water trapped ...
Loïc Bouat, Pierre Strzerzynski, Véronique Gardien   +2 more
wiley   +1 more source

Dating C/S Structures in Syntectonic Granites by In Situ Rb‐Sr Analyses on Muscovite

Terra Nova, EarlyView.
ABSTRACT The interplay of crystallisation, deformation and fluid–rock interactions makes deciphering geochronological information complex in syntectonic granites. In this study, we apply in situ Rb‐Sr analyses to selected samples from the Questembert Variscan syntectonic granite in Western France, which was emplaced along the South Armorican Shear Zone
Philippe Boulvais, Romain Tartèse
wiley   +1 more source

3D Quantification of Subsidence During Pyrenean Retro‐Wedge Initiation: Role of Structural and Thermal Inheritance on Hyperextended Margin Inversion (Aquitaine Basin)

Terra Nova, EarlyView.
ABSTRACT We present novel 3D subsidence data enabling vertical movements' quantification during the early formation of the Pyrenean retro‐wedge. From Cenomanian to Turonian times, subsidence is relatively low (~26 ± 10 m/Myr), corresponding to a brief 10 Myr thermal re‐equilibration of the European lithosphere following the hyperextended rift episode ...
Benoit Issautier, Nicolas Saspiturry, Paul Angrand, Eric Lasseur, Simon Andrieu, Cécile Robin   +5 more
wiley   +1 more source