Timing and Source of the Hermyingyi W-Sn Deposit in Southern Myanmar, SE Asia: Evidence from Molybdenite Re-Os Age and Sulfur Isotopic Composition
Hai Jiang , Shao-Yong Jiang , Wenqian Li , Kuidong Zhao
Journal of Earth Science ›› 2019, Vol. 30 ›› Issue (1) : 70 -79.
Timing and Source of the Hermyingyi W-Sn Deposit in Southern Myanmar, SE Asia: Evidence from Molybdenite Re-Os Age and Sulfur Isotopic Composition
The Hermyingyi W-Sn deposit, situated in southern Myanmar, SE Asia, is a typical quartz-vein type W-Sn deposit. The ore-bearing quartz veins are mainly hosted by the Hermyingyi monzogranite which intruded into the Carboniferous metasedimentary rocks of Mergui Series. According to mineral assemblages and crosscutting relationships, four ore-forming stages are recognized: (1) silicate-oxide stage; (2) quartz-sulfide stage; (3) barren quartz vein stage; (4) supergene stage. Five molybdenite samples from the deposit yield Re-Os model ages ranging from 67.8±1.6 to 69.2±1.6 Ma (weighted mean age of 68.7±1.2 Ma), and a well-defined isochron age of 68.4±2.5 Ma (MSWD=0.18, 2σ). This Re-Os age is consistent with the previously published zircon U-Pb age of the Hermyingyi monzogranite (70.0±0.4 Ma) (MSWD=0.9, 2σ) within errors, which indicates a genetic link between the monzogranitic magmatism and W-Sn mineralization. The new high-precision geochronological data reveal that the granitic magmatism and associated W-Sn mineralization in southern Myanmar took place during the Late Cretaceous (70-68 Ma). The extremely low Re contents (22.9 ppb to 299 ppb) in molybdenite, coupled with sulfide δ34S values in the range of +1.9‰ to +5.6‰ suggest that ore-forming metals were predominately sourced from the crustal-derived granitic magma.
Hermyingyi W-Sn deposit / molybdenite Re-Os dating / sulfur isotopes / Myanmar / SE Asia
| [1] |
|
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
|
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
| [39] |
|
| [40] |
|
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
|
| [46] |
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
| [51] |
|
| [52] |
|
| [53] |
|
| [54] |
|
| [55] |
|
| [56] |
|
| [57] |
|
| [58] |
|
/
| 〈 |
|
〉 |