Chronology (SHRIMP II) of magmatism in the Kalguty rare-metal-tungsten-molybdenum ore-magmatic system,Gorny Altai,Russia |
| |
| Authors: | N I Gusev |
| |
| Institution: | 1.Karpinsky Russian Geological Research Institute,St. Petersburg,Russia |
| |
| Abstract: | The Kalguty ore-magmatic system (OMS) contains economic greisen and vein rare-metal-tungsten-molybdenum mineralization. The
data on U-Pb zircon (SHRIMP II) age of nine samples of igneous rocks from the Kalguty OMS are accompanied by chemical, ICP-MS,
and ICP-AES analyses of the main rock varieties. Porphyritic biotite granite of the main phase of the Kalguty pluton is characterized
by the concordant age of 207.5 ± 1.7 Ma (MSWD = 0.034). The concordant age of the leucogranitic dikes pertaining to the East
Kalguty Complex is 204 ± 2 Ma (MSWD = 0.65) for elvan and 200.8 ± 1.1 Ma (MSWD = 0.72) for ultrapotassic rhyolite porphyry.
The two-mica and muscovite leucogranite of the Eastern stock is significantly younger: 195 ± 2.7 Ma (MSWD = 0.076) and 193.1
± 2.1 Ma (MSWD = 0.0009). Thus, the Chingadatui Complex (the main phase of the Kalguty pluton) and dikes of the East Kalguty
Complex are Late Triassic in age. The two-mica leucogranites of the Eastern, Zhumaly, and other stocks are most likely correlated
to the Early Jurassic Alacha Complex of rare-metal granites. The superposition of greisen mineralization on elvan and ongonite
dikes may be related to the emplacement of younger, Early Jurassic ore-forming two-mica and muscovite granites. Judging from
zircon xenocrysts in granites, the Mesoproterozoic igneous rocks dated at 1.5 Ga and products of erosion of the rocks dated
at 1.7 and 2.5 Ga occur in the basement of the Kalguty volcanic-tectonic structure. This is sound evidence for the occurrence
of ancient continental crustal blocks in the southwestern part of the Altai-Sayan region. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
