Results 81 to 90 of about 6,885 (228)

Holocene Normal Faulting in the Southern Rocky Mountain Trench; Orogenic Collapse Modulated by Glacial Unloading?

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 4, April 2026.
Abstract The Southern Rocky Mountain Trench (SRMT) is a conspicuous valley in the eastern Canadian Cordillera. It lies above a sharp change in lithospheric strength and thickness and is occupied by a normal fault thought to have last been active in the Eocene.
T. Finley   +5 more
wiley   +1 more source

Carbonate alteration of ophiolitic rocks in the Arabian–Nubian Shield of Egypt: sources and compositions of the carbonating fluid and implications for the formation of Au deposits [PDF]

open access: yes, 2016
Ultramafic portions of ophiolitic fragments in the Arabian–Nubian Shield (ANS) show pervasive carbonate alteration forming various degrees of carbonated serpentinites and listvenitic rocks.
Azer, Mokhles K.   +9 more
core   +2 more sources

Testing Models for Upper Mantle Earthquakes in the Tanganyika‐Rukwa Rift, Africa

open access: yesJournal of Geophysical Research: Solid Earth, Volume 131, Issue 4, April 2026.
Abstract Rifts that initiate in mechanically strong, stable continental lithosphere are characterized by M > 5 earthquakes at depths >35 km near or below the crust mantle interface. Current models for deep rift zone earthquakes invoke elevated pore pressures associated with magmatism, and rapid stressing from magma intrusions.
Eduardo Arzabala   +4 more
wiley   +1 more source

Genesis of the Xiaotazigou gold deposit in the northern margin of the north China craton: constraints from sulfur isotopes, rare earth elements, and trace elements

open access: yesFrontiers in Earth Science
The Xiaotazigou gold deposit is located in the eastern section of the Chifeng–Chaoyang gold metallogenic belt on the northern margin of the North China Craton. In this study, rare earth and trace element compositions of ores and host rocks, together with
He Yuan   +9 more
doaj   +1 more source

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

open access: yesTerra Nova, Volume 38, Issue 2, Page 106-115, April 2026.
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   +5 more
wiley   +1 more source

U-Pb SHRIMP and 40Ar/39Ar constraints on the timing of mineralization in the Paleoproterozoic Caxias orogenic gold deposit, São Luís cratonic fragment, Brazil

open access: yesBrazilian Journal of Geology
Caxias is an orogenic gold deposit in the São Luís cratonic fragment, which is correlated with the Rhyacian terranes of the West-African Craton. The deposit postdates peak metamorphism (estimated at 2100 ± 15 Ma) and is hosted in a shear zone that cuts ...
Evandro Luiz Klein   +2 more
doaj   +1 more source

Neoarchean Arc Magmatism and Crust Recycling in the Northern Marginal Zone of the Limpopo Complex, Zimbabwe: New Insights From Zircon U‐Pb‐Hf Isotopes of a Charnockite Suite

open access: yesGeological Journal, Volume 61, Issue 3, Page 566-592, March 2026.
Charnockites with 2691–2607 Ma magmatic ages from the NMZ show arc‐magmatic geochemical signatures. They correspond to the lower‐crustal equivalent of the Chilimanzi Suite Granite in the Zimbabwe Craton. Lu‐Hf isotopic data of magmatic zircons show negative εHf(t) values (−11.18 to −2.20) with TDMC ages of 3699–3158 Ma, suggesting their protolith ...
Toshiaki Tsunogae   +6 more
wiley   +1 more source

Gold Fineness in the Jiangnan Orogenic Belt of South China: Correlations with Geological Characteristics and Fluid Conditions [PDF]

open access: yesLithosphere
A large number of Au deposits in the Jiangnan Orogenic Belt (JOB) are characterized by producing the bonanza-style gold with extremely high gold fineness (GF) in orogenic Au deposits and intrusion-related Au deposits.
Yi Liang   +5 more
doaj   +1 more source

Aeolian and Biogeochemical Transformations of Detrital Gold Morphology in the Pool Burn Basin, Central Otago, New Zealand

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 69, Issue 1, March 2026.
The Pool Burn basin is a tectonic depression that became almost isolated from the regional drainage system by river reorientation during Pleistocene uplift of surrounding ridges. Consequently, detrital gold in the basin was largely locally derived, from supergene zones on orogenic deposits and recycled from paleoplacers in erosional remnants of Miocene
Marshall Palmer, Dave Craw
wiley   +1 more source

Alteration Alteration, Mineralization and Geochemistry of Metamorphic Rocks Hosted Hydrothermal Gold Deposit at Rumbia Mountains, Bombana Regency, Southeast Sulawesi, Indonesia

open access: yesJGEET: Journal of Geoscience, Engineering, Environment and Technology, 2019
In Indonesia, gold is commonly mined from porphyry, epithermal and skarn type deposits that are commonly found in volcanic/magmatic belts. However, were recently numerous gold prospects discovered in association with metamorphic rocks.
Hasria Hasria   +2 more
doaj   +1 more source

Home - About - Disclaimer - Privacy