Exposures of enclave-bearing granitoids can provide rare opportunities to directly evaluate the connection between compositional variability and the depth of origin of arc magmatic rocks. The ∼1000 km long Gangdese batholith is a composite batholith with composition from mafic to felsic; SiO2 ranges from 51 wt% to 70 wt%. New zircon U−Pb dating of the Nyemo plutons, Renbu plutons, and Xigaze plutons in the Gangdese batholith is consistent with their emplacement and crystallization in the Late Cretaceous (ca. 90−85 Ma). Mafic magmatic enclaves (MMEs) in the plutons are characterized by low SiO2 (50.9−56.0 wt%) and Nb/U, Ce/Pb, and Nb/La ratios coupled with enrichment in light rare earth elements and large ion lithophile elements and depletion in high field strength elements. These geochemical features, combined with depleted whole-rock εNd(t) (+4.2 to +4.7) and zircon εHf(t) (+9.0 to +13.8), suggest that they were derived by partial melting of a depleted mantle source associated with subduction-related fluids. The granitoids with high SiO2 (55.6−66.9 wt%) display adakitic geochemical characteristics, such as low Y and Yb contents, and high Sr/Y and La/Yb ratios. Their positive whole-rock εNd(t) (+4.0 to +5.5) and zircon εHf(t) (+6.9 to +14.3) values, as well as enrichment of incompatible elements, indicate that the granitoids were derived from partial melting of the juvenile lower crust. Geochemical modeling suggests that the compositional diversities of MMEs and adakitic granitoids were inherited from heterogeneous sources. This genetic relationship indicates that the underplated basaltic magmas could have supplied sufficient heat to trigger the melting of the thickened crust and thus formation of the enclave-bearing granitoid. In this regard, the origin of arc rocks can mirror the evolution of crustal thickness. Our results reveal that the crust was thickened to ∼50 km during the Late Cretaceous (90−85 Ma) and provide a magmatic record of crustal thickening prior to the Cenozoic Indo-Asia collision.
Skip Nav Destination
Article navigation
Article Contents
Research Article|
January 10, 2023
Origin of Late Cretaceous, enclave-bearing granitoids in southern Tibet: Implications for magma recharge and crustal thickening
Ding-Jun Wen;
Ding-Jun Wen
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Search for other works by this author on:
Xiumian Hu;
Xiumian Hu
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Search for other works by this author on:
Jin-Hai Yu;
Jin-Hai Yu
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Search for other works by this author on:
Xiao-Lei Wang;
Xiao-Lei Wang
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Search for other works by this author on:
Timothy Chapman;
Timothy Chapman
2
Earth Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
Search for other works by this author on:
Rui-Qiang Wang
Rui-Qiang Wang
3
School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China
Search for other works by this author on:
Ding-Jun Wen
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Xiumian Hu
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Jin-Hai Yu
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Xiao-Lei Wang
1
State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China
Timothy Chapman
2
Earth Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
Rui-Qiang Wang
3
School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China
Publisher: Geological Society of America
Received:
28 Mar 2022
Revision Received:
14 Sep 2022
Accepted:
17 Oct 2022
First Online:
11 Jan 2023
Online ISSN: 1943-2674
Print ISSN: 0016-7606
© 2023 Geological Society of America
GSA Bulletin (2023)
Article history
Received:
28 Mar 2022
Revision Received:
14 Sep 2022
Accepted:
17 Oct 2022
First Online:
11 Jan 2023
Citation
Ding-Jun Wen, Xiumian Hu, Jin-Hai Yu, Xiao-Lei Wang, Timothy Chapman, Rui-Qiang Wang; Origin of Late Cretaceous, enclave-bearing granitoids in southern Tibet: Implications for magma recharge and crustal thickening. GSA Bulletin 2023; doi: https://doi.org/10.1130/B36530.1
Download citation file:
You could not be signed in. Please check your email address / username and password and try again.
Index Terms/Descriptors
- alkaline earth metals
- Asia
- basalts
- cathodoluminescence
- Cretaceous
- crustal thickening
- hafnium
- Hf-177/Hf-176
- ICP mass spectra
- igneous rocks
- intrusions
- isotope ratios
- isotopes
- laser ablation
- laser methods
- magmas
- mass spectra
- Mesozoic
- metals
- Nd-144/Nd-143
- neodymium
- nesosilicates
- orthosilicates
- plutons
- rare earths
- silicates
- spectra
- Sr-87/Sr-86
- stable isotopes
- strontium
- Tibetan Plateau
- U/Pb
- Upper Cretaceous
- volcanic rocks
- zircon
- zircon group
- Gangdese Batholith
- magmatic arcs
Latitude & Longitude
Citing articles via
Related Articles
Related Book Content
Day 6: Overview of arc processes and tempos
Formation of the Sierra Nevada Batholith
Origin of the Ordovician Mansehra granite in the NW Himalaya, Pakistan: constraints from Sr–Nd isotopic data, zircon U–Pb age and Hf isotopes
Crustal Architecture and Evolution of the Himalaya–Karakoram–Tibet Orogen
Ages and some cryptic sources of Mesozoic plutonic rocks in the Klamath Mountains, California and Oregon
Geological Studies in the Klamath Mountains Province, California and Oregon: A volume in honor of William P. Irwin
Composite Sunrise Butte pluton: Insights into Jurassic–Cretaceous collisional tectonics and magmatism in the Blue Mountains Province, northeastern Oregon
Late Jurassic Margin of Laurasia–A Record of Faulting Accommodating Plate Rotation