Exhumation and Preservation of the Yangchuling Porphyry W-Mo Deposit in the Jiangnan Tungsten Ore Belt, South China: Insights from (U-Th)/He and Fission Track Dating

Abstract

The Yangchuling porphyry W-Mo deposit (YPWD), located in the Jiangnan porphyry-skarn tungsten ore belt, is one of the most important and large-scale porphyry W-Mo deposits in South China. While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling W-Mo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at ∼150–144 Ma, their post emplacement history remains poorly understood, making their preservation status at depth uncertain. In this paper, new zircon and apatite (U-Th)/He and apatite fission track (ZHe, AHe and AFT, respectively) data of one hornfels and five intrusive rocks from a 1 000-meter borehole are presented. These, together with new inverse thermal history models and previous geochronological data, help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit. In general, ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation, ranging from 133 to 73 Ma and 67 to 25 Ma, respectively. All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2 ± 0.7 to 12.6 ± 0.5 µm. Thermal history modelling indicates that the Yangchuling ore district experienced slow, monotonic cooling since the Cretaceous. Age-depth relationships are interpreted as recording ∼3.7 ± 0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate. Comparison of estimated net exhumation and previous metallogenic depth of ∼4–5 km suggests that W-Mo ore bodies could still exist at depths of up to ∼1.3 ± 0.8 km relative to Earth surface in the YPWD region. Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.

References

[] Beucher R, Brown R W, Roper S . Natural Age Dispersion Arising from the Analysis of Broken Crystals: Part II. Practical Application to Apatite (U-Th)/He Thermochronometry. Geochimica et Cosmochimica Acta, 2013, 120 395-416.

[] Cao X Z, Zahirovic S, Li S Z . A Deforming Plate Tectonic Model of the South China Block since the Jurassic. Gondwana Research, 2022, 102 3-16.

[] Carlson W D, Donelick R A, Ketcham R A. Variability of Apatite Fission-Track Annealing Kinetics; I, Experimental Results. American Mineralogist, 1999, 84(9): 1213-1223.

[] Chen Y L, Li H, Zheng C Y . Exhumation History and Exploration Potential of Gold Deposits in the NE Jiaodong Peninsula, North China: Evidence from Apatite and Zircon Fission Track Thermochronology. Journal of Earth Science, 2023, 34(3): 776-789.

[] Chew D M, Spikings R A. Geochronology and Thermochronology Using Apatite: Time and Temperature, Lower Crust to Surface. Elements, 2015, 11(3): 189-194.

[] Ehlers T A, Farley K A. Apatite (U-Th)/He Thermochronometry: Methods and Applications to Problems in Tectonic and Surface Processes. Earth and Planetary Science Letters, 2003, 206(1/2): 1-14.

[] Fan C, Ni P, Wang G . Accessory Minerals U-Pb Geochronology of Monzogranitic Porphyry in Yangchuling Porphyry W-Mo Deposit in Northern of Jiangxi Province, South China. Mineral Deposits, 2022, 41(1): 35-52 (in Chinese with English Abstract)

[] Farley K A, Wolf R A, Silver L T. The Effects of Long Alpha-Stopping Distances on (U - Th)/He Ages. Geochimica et Cosmochimica Acta, 1996, 60(21): 4223-4229.

[] Gallagher K. Transdimensional Inverse Thermal History Modeling for Quantitative Thermochronology. Journal of Geophysical Research (Solid Earth), 2012, 117(B2): B02408

[] Gautheron C, Tassan-Got L, Barbarand J . Effect of Alpha-Damage Annealing on Apatite (U-Th)/He Thermochronology. Chemical Geology, 2009, 266(3/4): 157-170.

[] Ge X, Shen C B, Yang Z . Low-Temperature Thermochronology Constraints on the Mesozoic – Cenozoic Exhumation of the Huangling Massif in the Middle Yangtze Block, Central China. Journal of Earth Science, 2013, 24(4): 541-552.

[] Gleadow A J W, Duddy I R. A Natural Long-Term Track Annealing Experiment for Apatite. Nuclear Tracks, 1981, 5(1/2): 169-174.

[] Gong L, Kohn B P, Zhang Z Y . Exhumation and Preservation of Paleozoic Porphyry Cu Deposits: Insights from the Yandong Deposit, Southern Central Asian Orogenic Belt. Economic Geology, 2021, 116(3): 607-628.

[] Guenthner W R, Reiners P W, Ketcham R A . Helium Diffusion in Natural Zircon: Radiation Damage, Anisotropy, and the Interpretation of Zircon (U-Th)/He Thermochronology. American Journal of Science, 2013, 313(3): 145-198.

[] Guenthner W R, Reiners P W, Tian Y T. Interpreting Date-EU Correlations in Zircon (U-Th)/He Datasets: a Case Study from the Longmen Shan, China. Earth and Planetary Science Letters, 2014, 403 328-339.

[] Hasebe N, Barbarand J, Jarvis K . Apatite Fission-Track Chronometry Using Laser Ablation ICP-MS. Chemical Geology, 2004, 207(3/4): 135-145.

[] Hu R Z, Zhou M F. Multiple Mesozoic Mineralization Events in South China—An Introduction to the Thematic Issue. Mineralium Deposita, 2012, 47(6): 579-588.

[] Kesler S E, Wilkinson B H. The Role of Exhumation in the Temporal Distribution of Ore Deposits. Economic Geology, 2006, 101(5): 919-922.

[] Ketcham R A, Carter A, Donelick R A . Improved Modeling of Fission-Track Annealing in Apatite. American Mineralogist, 2007, 92(5/6): 799-810.

[] Li B L, Xie Y H, Zhao R . Magmatic Process and Geochemistry of Yangchuling Calc-Alkaline Complex, Jiangxi Province. Chinese Journal of Geochemistry, 1986, 5(1): 15-33.

[] Li C L, Wang Z X, Lü Q T . Mesozoic Tectonic Evolution of the Eastern South China Block: A Review on the Synthesis of the Regional Deformation and Magmatism. Ore Geology Reviews, 2021, 131 104028.

[] Li J Y, Wang X L, Zhang F F . A Rhythmic Source Change of the Neoproterozoic Basement Meta-Sedimentary Sequences in the Jiangnan Orogen: Implications for Tectonic Evolution on the Southeastern Margin of the Yangtze Block. Precambrian Research, 2016, 280 46-60.

[] Li L, Lin S, Xing G . Ca. 830 Ma Back-Arc Type Volcanic Rocks in the Eastern Part of the Jiangnan Orogen: Implications for the Neoproterozoic Tectonic Evolution of South China Block. Precambrian Research, 2016, 275 209-224.

[] Li S Z, Suo Y H, Li X Y . Mesozoic Tectono-Magmatic Response in the East Asian Ocean-Continent Connection Zone to Subduction of the Paleo-Pacific Plate. Earth-Science Reviews, 2019, 192 91-137.

[] Li X H, Li W X, Li Z X . Amalgamation between the Yangtze and Cathaysia Blocks in South China: Constraints from SHRIMP U-Pb Zircon Ages, Geochemistry and Nd-Hf Isotopes of the Shuangxiwu Volcanic Rocks. Precambrian Research, 2009, 174(1/2): 117-128.

[] Li Y J, Zheng D W, Wu Y . A Potential (U-Th)/He Zircon Reference Material from Penglai Zircon Megacrysts. Geostandards and Geoanalytical Research, 2017, 41(3): 359-365.

[] Malusá M G, Fitzgerald P G. Fission-Track Thermochronology and Its Application to Geology. Springer Textbooks in Earth Sciences, Geography and Environment, 2019

[] Man F, Wang X. Study on the Isotopic Geochronology of Yangchuling Porphyry Type of Tungsten and Molybdenum Deposit. Mineral Resources and Geology, 1988, 2(1): 61-66 (in Chinese with English Abstract)

[] Mao J W, Xiong B K, Liu J . Molybdenite Re/Os Dating, Zircon U-Pb Age and Geochemistry of Granitoids in the Yangchuling Porphyry W-Mo Deposit (Jiangnan Tungsten Ore Belt), China: Implications for Petrogenesis, Mineralization and Geodynamic Setting. Lithos, 2017, 286 35-52.

[] McInnes B I A, Evans N J, Fu F Q . Application of Thermochronology to Hydrothermal Ore Deposits. Reviews in Mineralogy and Geochemistry, 2005, 58(1): 467-498.

[] Min K, Gao J F. Application of Low-Temperature Thermochronology on Ore Deposits Preservation Framework in South China: a Review. Acta Geochimica, 2022, 41(2): 165-184.

[] Mo M. A preliminary Study on Alteration Zoning of the Yangchuling Porphyry W-Mo Deposit and Its Relationship to Mineralization. Mineral Deposits, 1988, 7(3): 50-59 (in Chinese with English Abstract)

[] Pang J Z, Zheng D W, Ma Y . Combined Apatite Fission-Track Dating, Chlorine and REE Content Analysis by LA-ICPMS. Science Bulletin, 2017, 62(22): 1497-1500.

[] Qin K, Zhao J, Fan H . On the Ore-Forming Depth and Possible Maximum Vertical Extension of the Major Type Ore Deposits. Earth Science Frontiers, 2021, 28(3): 271-294 (in Chinese with English Abstract)

[] Reiners P W, Brandon M T. Using Thermochronology to Understand Orogenic Erosion. Annual Review of Earth and Planetary Sciences, 2006, 34 419-466.

[] Seedorff, E., Dilles, J. H., Proffett, J. M., Jr, et al., 2005. Porphyry Deposits: Characteristics and Origin of Hypogene Features. Society of Economic Geologists, (One Hundredth Anniversary Volume): 251–298. https://doi.org/10.5382/av100.10

[] Shu L S, Wang J Q, Yao J L. Tectonic Evolution of the Eastern Jiangnan Region, South China: New Findings and Implications on the Assembly of the Rodinia Supercontinent. Precambrian Research, 2019, 322 42-65.

[] Shu L S, Zhou X M, Deng P . Mesozoic Tectonic Evolution of the SouthEast China Block: New Insights from Basin Analysis. Journal of Asian Earth Sciences, 2009, 34(3): 376-391.

[] Sun J J, Shu L S, Santosh M . Neoproterozoic Tectonic Evolution of the Jiuling Terrane in the Central Jiangnan Orogenic Belt (South China): Constraints from Magmatic Suites. Precambrian Research, 2017, 302 279-297.

[] Sun W D, Yang X Y, Fan W M . Mesozoic Large Scale Magmatism and Mineralization in South China: Preface. Lithos, 2012, 150 1-5.

[] Sun Y, Kohn B P, Boone S C . Burial and Exhumation History of the Lujing Uranium Ore Field, Zhuguangshan Complex, South China: Evidence from Low-Temperature Thermochronology. Minerals, 2021, 11(2): 116.

[] Sun Y, Chen Z L, Boone S C . Exhumation History and Preservation of the Changjiang Uranium Ore Field, South China, Revealed by (U-Th)/He and Fission Track Thermochronology. Ore Geology Reviews, 2021, 133 104101.

[] Tian Y T, Kohn B P, Gleadow A J W . Constructing the Longmen Shan Eastern Tibetan Plateau Margin: Insights from Low-Temperature Thermochronology. Tectonics, 2013, 32(3): 576-592.

[] Vermeesch P. RadialPlotter: A Java Application for Fission Track, Luminescence and Other Radial Plots. Radiation Measurements, 2009, 44(4): 409-410.

[] Wang H Y, Liu S W, Lei X. Present Geothermal Regime of the Lower Yangtze Area, South China. Journal of China Coal Society, 2013, 38(5): 896-900 (in Chinese with English Abstract)

[] Wang X L, Zhao G C, Zhou J C . Geochronology and Hf Isotopes of Zircon from Volcanic Rocks of the Shuangqiaoshan Group, South China: Implications for the Neoproterozoic Tectonic Evolution of the Eastern Jiangnan Orogen. Gondwana Research, 2008, 14(3): 355-367.

[] Wang X L, Zhou J C, Chen X . Formation and Evolution of the Jiangnan Orogen. Bulletin of Mineralogy, Petrology and Geochemistry, 2017, 36(5): 714-735 696 (in Chinese with English Abstract)

[] Wang X L, Zhou J C, Griffin W L . Detrital Zircon Geochronology of Precambrian Basement Sequences in the Jiangnan Orogen: Dating the Assembly of the Yangtze and Cathaysia Blocks. Precambrian Research, 2007, 159(1/2): 117-131.

[] Wang X S, Man F S, Chen D G. A Study of Ore Forming Conditions and Sulfur Origin of Yang Chuling W(Mo) Deposit. Journal of University of Science and Technology of China, 1985, 15(3): 339-351 (in Chinese with English Abstract)

[] Wang Y J, Fan W M, Zhang G W . Phanerozoic Tectonics of the South China Block: Key Observations and Controversies. Gondwana Research, 2013, 23(4): 1273-1305.

[] Wang Y, Wang Y J, Li S B . Exhumation and Landscape Evolution in Eastern South China since the Cretaceous: New Insights from Fission-Track Thermochronology. Journal of Asian Earth Sciences, 2020, 191 104239.

[] Wang Y, Zheng DW, Wu Y . Measurement Procedure of Single-Grain Apatite (U-Th)/He Dating and Its Validation by Durango Apatite Standard. Seismology and Geology, 2017, 39(6): 1143-1157 (in Chinese with English Abstract)

[] Wilkinson B H, Kesler S E. Tectonism and Exhumation in Convergent Margin Orogens: Insights from Ore Deposits. The Journal of Geology, 2007, 115(6): 611-627.

[] Wolf R A, Farley K A, Kass D M. Modeling of the Temperature Sensitivity of the Apatite (U-Th)/He Thermochronometer. Chemical Geology, 1998, 148(1/2): 105-114.

[] Wolfe M R, Stockli D F. Zircon (U-Th)/He Thermochronometry in the KTB Drill Hole, Germany, and Its Implications for Bulk He Diffusion Kinetics in Zircon. Earth and Planetary Science Letters, 2010, 295(1/2): 69-82.

[] Xue H M. Geochronology Geochemistry and Stratospheric Interactions of Late Mesozoic Granitoids near the Boundary between Anhui and Zhejiang Provinces in the Eastern Segment of the Jiangnan Orogenic Belt. Acta Petrologica Sinica, 2021, 37(2): 433-461. in Chinese with English Abstract)

[] Yuan W M. Thermochronological Method of Revealing Conservation and Changes of Mineral Deposits. Acta Petrologica Sinica, 2016, 32(8): 2571-2578 (in Chinese with English Abstract)

[] Zeng Q Q, Hu Z H, Wang X G . Geochronology of the Yangchuling Tungsten-Molybdenum Depoist in Duchang County, Jiangxi Province. Geology in China, 2019, 46(4): 841-849 (in Chinese with English Abstract)

[] Zhang G W, Guo A L, Wang Y J . Tectonics of South China Continent and Its Implications. Science China Earth Sciences, 2013, 56(11): 1804-1828.

[] Zhang Y Q, Dong S W, Li J H . The New Progress in the Study of Mesozoic Tectonics of South China. Acta Geoscientica Sinica, 2012, 33(3): 257-279 (in Chinese with English Abstract)

[] Zhang Y X. Geochemical Characteristics and Origin of Yangchuling Porphyry W-Mo Deposit. Geochemistry, 1983, 2(2): 99-112.

[] Zhao G C. Jiangnan Orogen in South China: Developing from Divergent Double Subduction. Gondwana Research, 2015, 27(3): 1173-1180.

[] Zhao Z, Fu T Y, Gan J W . A Synthesis of Mineralization Style and Regional Distribution and a Proposed New Metallogenic Model of Mesozoic W-Dominated Polymentallic Deposits in South China. Ore Geology Reviews, 2021, 133 104008.

[] Zheng Y L, Zhao Z, Zhang C Q . Genetic Relationship between the Two-Period Magmatism and Tungsten Mineralization in the Yangchuling Deposit, Jiangxi Province: Evidence from Biotite Geochemistry. Acta Petrologica Sinica, 2022, 38(2): 495-512. in Chinese with English Abstract)

[] Zhou A, Dai J G, Li Y L . Differential Exhumation Histories between Qulong and Xiongcun Porphyry Copper Deposits in the Gangdese Copper Metallogenic Belt: Insights from Low Temperature Thermochronology. Ore Geology Reviews, 2019, 107 801-819.