Insight into Metallogenic Mechanism of the Kalatongke Orefield in Northwest China From a High-Resolution Deep Seismic Reflection Image

Session: Seismic Imaging of Fault Zones [Poster]
Type: Poster
Date: 4/29/2020
Time: 08:00 AM
Room: Ballroom
Description: 

The Kalatongke Orefield is a large Cu-Ni deposit in the northern part of the Central Asian Orogenic Belt (CAOB). The shallow distributions of mineral ores are explicitly documented after years of exploration (Qin et al., 2014). However, the metallogenic mechanism remains mysterious due to the lack of deep constraints. The spatial and temporal settings of the super-large Cu-Ni deposits indicate Cu-Ni deposits generally developed near the craton margins and in supercontinent break-up stage (Begget al., 2010; Maier and Groves, 2011). Detailed studies on typical super-large magmatic sulfide deposits, such as the Voisey’s Bay in Canada, Jinchuan in China and Noril’sk in Russia (Naldrett, 1997) indicated an ore-forming model in magma conduit systems. Thus, whether the Kalatongke metallogenic mechanism accords with the magma conduit system and how it extended in the deep crust still remain enigmatic. To address these questions, a deep seismic reflection profile ‘ALT2018’ was collected across the Kalatongke Orefield. The profile can reveal the fine structure of the crust and uppermost mantle. Considering the relatively silence of the ore area in Mesozoic and Cenozoic, the present lithosphere structure preserves information of Paleozoic continental growth. The detailed geometry visible on the profiles then provides constraints for regional metallogenic process and tectonic evolution models.Based on seismic imaging, we find the deep magma intrusion channels, chambers and Moho entrance for magma intrusion beneath the Kalatongke Orefield, which accorded with the magma conduit system. The fine crustal structure beneath the Altai Mountains revealed the obduction of the East Junggar to the Altai Mountains rather than subduction in the later part of collisional orogeny in late Carboniferous to early Permian before Kalatongke formed, resulted in the crust of the Altai Mountains shortening and thickening. This research was supported by the National Key Research and Development Program of China (2017YFC0601206) and the National Natural Science Foundation of China (41974041, 41630210).

Presenting Author: Lei Zhang

Authors