Nature and significance of the late Mesozoic granitoids in the southern Great Xing’an range, eastern Central Asian Orogenic Belt

2018 ◽  
Vol 61 (5) ◽  
pp. 584-606 ◽  
Author(s):  
Le Wan ◽  
Chengdong Lu ◽  
Zuoxun Zeng ◽  
Adil S Mohammed ◽  
Zhenghong Liu ◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Late Mesozoic ◽  
Central Asian ◽  
Mesozoic Granitoids ◽  
Great Xing’An Range

scholarly journals Crustal growth and reworking: A case study from the Erguna Massif, eastern Central Asian Orogenic Belt

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Chenyang Sun ◽  
Wenliang Xu ◽  
Peter A. Cawood ◽  
Jie Tang ◽  
Shuo Zhao ◽  
...  
Keyword(s):  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Crustal Growth ◽  
Central Asian ◽  
Mesozoic Granitoids ◽  
Tectonic Settings ◽  
Crustal Heterogeneity ◽  
Erguna Massif ◽  
T Values

AbstractDespite being the largest accretionary orogen on Earth, the record of crustal growth and reworking of individual microcontinental massifs within the Central Asian Orogenic Belt (CAOB) remain poorly constrained. Here, we focus on zircon records from granitoids in the Erguna Massif to discuss its crustal evolution through time. Proterozoic–Mesozoic granitoids are widespread in the Erguna Massif, and spatiotemporal variations in their zircon εHf(t) values and TDM2(Hf) ages reveal the crustal heterogeneity of the massif. Crustal growth curve demonstrates that the initial crust formed in the Mesoarchean, and shows a step-like pattern with three growth periods: 2.9–2.7, 2.1–1.9, and 1.7–0.5 Ga. This suggests that microcontinental massifs in the eastern CAOB have Precambrian basement, contradicting the hypothesis of significant crustal growth during the Phanerozoic. Phases of growth are constrained by multiple tectonic settings related to supercontinent development. Calculated reworked crustal proportions and the reworking curve indicate four reworking periods at 1.86–1.78 Ga, 860–720 Ma, 500–440 Ma, and 300–120 Ma, which limited the growth rate. These periods of reworking account for the crustal heterogeneity of the Erguna Massif.

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