scholarly journals Geochemical and Stratigraphic Analysis of the Chisana Formation, Wrangellia Terrane, Eastern Alaska: Insights Into Early Cretaceous Magmatism and Tectonics Along the Northern Cordilleran Margin

Tectonics ◽  
2020 ◽  
Vol 39 (8) ◽  
Author(s):  
Patrick Manselle ◽  
Matthew E. Brueseke ◽  
Jeffrey M. Trop ◽  
Jeffrey A. Benowitz ◽  
Darin C. Snyder ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Stratigraphic Analysis ◽  
Wrangellia Terrane ◽  
Cordilleran Margin ◽  
Cretaceous Magmatism

A syn-collisional model for Early Cretaceous magmatism in the northern and central Lhasa subterranes

2017 ◽  
Vol 41 ◽  
pp. 93-109 ◽  
Author(s):  
Sheng-Sheng Chen ◽  
Ren-Deng Shi ◽  
Xiao-Han Gong ◽  
De-Liang Liu ◽  
Qi-Shuai Huang ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Cretaceous Magmatism

Early Cretaceous magmatism and ore mineralization in Northeast China: examples from Taolaituo Mo and Aobaotu Pb–Zn deposits

2015 ◽  
Vol 57 (2) ◽  
pp. 229-256 ◽  
Author(s):  
Zhenhua Zhou ◽  
Jingwen Mao ◽  
Jun Liu ◽  
Hegen Ouyang ◽  
Hewei Che ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Northeast China ◽  
Ore Mineralization ◽  
Cretaceous Magmatism

Late Jurassic to Early Cretaceous magmatism in the Xiong’ershan gold district, central China: implications for gold mineralization and geodynamics

2019 ◽  
Vol 157 (3) ◽  
pp. 435-457
Author(s):  
Zhenshan Pang ◽  
Fuping Gao ◽  
Yangsong Du ◽  
Yilun Du ◽  
Zhaojian Zong ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Inductively Coupled Plasma ◽  
Late Jurassic ◽  
Gold Mineralization ◽  
Central China ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Metamorphic Basement ◽  
Plasma Mass Spectrometry ◽  
Cretaceous Magmatism

AbstractThe Xiong’ershan area is the third largest gold-producing district in China. The Late Jurassic to Early Cretaceous magmatism in the Xiong’ershan area can be divided into two episodes: early (165–150 Ma) and late (138–113 Ma). Laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) zircon U–Pb dating yields ages of 160.7 ± 0.6 Ma and 127.2 ± 1.0 Ma for the Wuzhangshan and Huashan monzogranites in the Xiong’ershan area, respectively, representing the two magmatic episodes. The Wuzhangshan monzogranites exhibit adakite-like geochemical features (e.g. high Sr/Y ratios, low Yb and Y contents). Their Sr–Nd–Hf isotopic compositions are consistent with those of the amphibolites of the Taihua Group, indicating that the Wuzhangshan monzogranites were formed from partial melting of the Taihua Group metamorphic rocks. Compared to the Wuzhangshan rocks, the Huashan monzogranites have higher MgO, Cr, Co and Ni contents, but lower Sr/Y and Fe3+/Fe2+. All the samples from the Huashan monzogranites plot in the area between the Taihua Group amphibolite rocks and the mantle rocks in the (87Sr/86Sr)t vs εNd(t) and age vs εHf(t) diagrams, suggesting that the Huashan monzogranites were probably generated by mixing of mantle-derived magmas and the Taihua Group metamorphic basement melts. The gold mineralization (136–110 Ma) is coeval with the emplacement of the late-episode magmas, implying that crustal–mantle mixed magma might be a better target for gold mineralization compared to the ancient metamorphic basement melt. The data presented in this study further indicate that the transformation of the lithosphere from thickening to thinning in the Xiong’ershan area probably occurred between ~160 Ma and ~127 Ma, and that the gold mineralization in this area was probably related to lithospheric thinning.

The Early Cretaceous tectonic evolution of the southern Great Xing'an Range, NE China: New constraints from A2-type granite and monzodiorite

2021 ◽  
Author(s):  
Chenghan Xu ◽  
Fengyue Sun ◽  
Xingzhu Fan ◽  
Liang Huo ◽  
Depeng Yang ◽  
...  
Keyword(s):  
Partial Melting ◽  
Early Cretaceous ◽  
Tectonic Evolution ◽  
Large Scale ◽  
Crustal Contamination ◽  
Stress Regime ◽  
Slab Breakoff ◽  
Significant Addition ◽  
Cretaceous Magmatism ◽  
Great Xing’An Range

The widespread Early Cretaceous plutons intruding along the southern Great Xing’an Range (SGXR) provide evidence for tectonic evolution of the region. Petrological, geochemical, zircon U–Pb geochronology and zircon Hf isotopic studies are conducted on intrusions from Bianjiadayuan and Hongling areas. These suites classify as A2-type granites and monzodiorites, respectively. The 138–133 Ma A2-type granites originated from partial melting of continental crustal materials at high temperatures and shallow depths with significant addition of juvenile mafic lower crust sourced from a metasomatized mantle. The 136–134 Ma monzodiorites originated from the partial melting of an enriched mantle that was modified by melts of a previously subducted slab coupled with crustal contamination. The Early Cretaceous magmatism in the SGXR occurred in two periods: ∼145–136 Ma (peak at ∼139 Ma; εHf (t) = 5 to 10) and ∼136–130 Ma (peak at ∼131 Ma; εHf (t) = −10 to 15). The Early Cretaceous granite–monzodiorite suite in the SGXR suggests a bimodal magmatism in an extensional setting. The ∼145–130 Ma magmatism may have been triggered by asthenospheric upwelling induced by the Mongol–Okhotsk oceanic slab breakoff and large-scale lithospheric delamination resulting from post-orogenic extension. The variation of subduction direction of the Paleo-Pacific Ocean likely triggered a change in stress regime at ca. 136 Ma and likely promoted the lithospheric delamination beneath the SGXR resulting in intense magmatism originating from various sources. As such, the Paleo-Pacific Oceanic subduction likely played an important role in the Early Cretaceous magmatism in the SGXR.

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