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

