Research output: Contribution to journal › Article › peer-review
1U-Pb SIMS and Ar-Ar geochronology, petrography, mineralogy and gold mineralization of the late Mesozoic Amga alkaline rocks (Aldan shield, Russia). / Prokopyev, I. R.; Doroshkevich, A. G.; Ponomarchuk, A. V. et al.
In: Ore Geology Reviews, Vol. 109, 01.06.2019, p. 520-534.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - 1U-Pb SIMS and Ar-Ar geochronology, petrography, mineralogy and gold mineralization of the late Mesozoic Amga alkaline rocks (Aldan shield, Russia)
AU - Prokopyev, I. R.
AU - Doroshkevich, A. G.
AU - Ponomarchuk, A. V.
AU - Redina, A. A.
AU - Yegitova, I. V.
AU - Ponomarev, J. D.
AU - Sergeev, S. A.
AU - Kravchenko, A. A.
AU - Ivanov, A. I.
AU - Sokolov, E. P.
AU - Kardash, E. A.
AU - Minakov, A. V.
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Late Mesozoic Upper Amga alkaline rocks are located in the Amga tectonic mélange zone within the Aldan-Stanovoy shield, Russia. The main phases of the Upper Amga complex consist of alkaline syenite intrusions as well as the lamprophyre dikes and sills. The mineralogical features indicate that the lamprophyre may belong to minette. Recent geological works revealed the linear and area-specific geochemical gold anomalies in association with late Mesozoic alkaline magmatism in the Upper Amga gold district. The age of the syenite intrusions is 131.4 ± 1.5 (2.9)Ma, and the lamprophyre sills and dikes were formed at 134.9 ± 1.6, 132.3 ± 1.5 and 117.7 ± 3.4 Ma. The mineralization is represented by the REE-Ti-Th, polymetallic (sulfide)and telluride-gold types in the quartz-calcite-chlorite alteration of the main magmatic phases of the alkaline rocks. The fluid inclusions study shows that the sulfides were formed from hydrothermal fluids of CO 2 -N 2 -NaCl-H 2 O composition at temperatures ranging from 390 to 340 °C, with 44–22.7 wt% NaCl-eq, whereas the epithermal telluride-gold mineralization originated from low-temperature CO 2 ± N 2 -NaCl-H 2 O fluids, with the homogenization temperature of 230–210 °C and a of 9.2–3.3 wt% NaCl-eq.
AB - Late Mesozoic Upper Amga alkaline rocks are located in the Amga tectonic mélange zone within the Aldan-Stanovoy shield, Russia. The main phases of the Upper Amga complex consist of alkaline syenite intrusions as well as the lamprophyre dikes and sills. The mineralogical features indicate that the lamprophyre may belong to minette. Recent geological works revealed the linear and area-specific geochemical gold anomalies in association with late Mesozoic alkaline magmatism in the Upper Amga gold district. The age of the syenite intrusions is 131.4 ± 1.5 (2.9)Ma, and the lamprophyre sills and dikes were formed at 134.9 ± 1.6, 132.3 ± 1.5 and 117.7 ± 3.4 Ma. The mineralization is represented by the REE-Ti-Th, polymetallic (sulfide)and telluride-gold types in the quartz-calcite-chlorite alteration of the main magmatic phases of the alkaline rocks. The fluid inclusions study shows that the sulfides were formed from hydrothermal fluids of CO 2 -N 2 -NaCl-H 2 O composition at temperatures ranging from 390 to 340 °C, with 44–22.7 wt% NaCl-eq, whereas the epithermal telluride-gold mineralization originated from low-temperature CO 2 ± N 2 -NaCl-H 2 O fluids, with the homogenization temperature of 230–210 °C and a of 9.2–3.3 wt% NaCl-eq.
KW - Aldan-Stanovoy shield
KW - Alkaline magmatism
KW - Alkaline syenite
KW - Fluid inclusion study
KW - Gold
KW - Lamprophyre
KW - Late Mesozoic
KW - OLEKMA GRANITE-GREENSTONE
KW - MAGMATISM
KW - U-PB
KW - REGION
KW - MASSIF
KW - DEPOSITS
KW - JUNCTION ZONE
KW - SYSTEMS
KW - SIBERIAN CRATON
KW - AGE
UR - http://www.scopus.com/inward/record.url?scp=85065539370&partnerID=8YFLogxK
U2 - 10.1016/j.oregeorev.2019.05.011
DO - 10.1016/j.oregeorev.2019.05.011
M3 - Article
AN - SCOPUS:85065539370
VL - 109
SP - 520
EP - 534
JO - Ore Geology Reviews
JF - Ore Geology Reviews
SN - 0169-1368
ER -
ID: 20163211