Numerical Modeling of Deformation at the Baiyun Gold Deposit, Northeastern China: Insights into the Structural Controls on Mineralization

Abstract

The Qingchengzi ore field is an important gold-polymetallic center of the North China Craton. It has been recognized that the gold deposits in Qingchengzi were controlled by structures like lithological interfaces and fractures along mechanically weak bedding and foliation planes, but it still remains poorly understood how the structures affected the localization of the gold deposits. Finite element based numerical modeling was used to reproduce the deformation process of the Baiyun gold deposit during the mineralization period. Paleoproterozoic schist and marble are widely exposed in Qingchengzi, and a large part of the Baiyun gold ores occurs along the interfaces between the schist and the marble. The modeling results suggest that the mechanical contrast between the schist and the marble may be a major reason why the stress was localized along their lithological interfaces under a compressional stress regime. Two parts of their lithological interfaces were identified to be easily stress-localized and first fractured: the interface between the schist and its underlying marble at shallower levels and the one between the schist and its overlying marble at deeper levels. Stress concentration in these two parts is independent on the dipping angle and direction of the interfaces. Therefore, mineralizing fluids may have been concentrated into these two parts. The first one is consistent with the present ore bodies of the Baiyun gold deposit, and the second one could be considered for deep prospecting. These findings also provide implications for the structural controls of lithological interfaces on the mineralization in other gold deposits of this region.

Keywords

Baiyun gold deposit / Qingchengzi / numerical modeling / lithological interfaces / mechanical contrast

References

[1] Bedeaux P, Rafini S, Pilote P, . Modelling Seismically Induced Mesothermal Goldfields along the Deep-Rooted Cadillac-Larder Lake Fault, Abitibi, Canada. Geofuids, 2018, 2018(2366): 1-21

[2] Chen B L. Development Process of Fault Structure and Formation and Evolution of Ore-Controlling Structure: A Case Study of the Zoujiashan Uranium Deposit. Journal of Geomechanics, 2020, 26(3): 285-298

[3] Cox S F, . Hedenquist J W, Thompson J F H, Goldfarb R J, . Coupling between Deformation, Fluid Pressures, and Fluid Flow in Ore-Producing Hydrothermal Systems at Depth in the Crust. Economic Geology One Hundredth Anniversary Volume, 2005, Litteton, Colorado: Society of Economic Geologists, 39-76

[4] Cui T, Yang J, Samson I M. Tectonic Deformation and Fluid Flow: Implications for the Formation of Unconformity-Related Uranium Deposits. Economic Geology, 2012, 107(1): 147-163.

[5] Duan K, Kwok C Y, Pierce M. Discrete Element Method Modeling of Inherently Anisotropic Rocks under Uniaxial Compression Loading. International Journal for Numerical and Analytical Methods in Geomechanics, 2016, 40(8): 1150-1183.

[6] Duan X X, Zeng Q D, Wang Y B, . Genesis of the Pb-Zn Deposits of the Qingchengzi Ore Field, Eastern Liaoning, China: Constraints from Carbonate LA-ICPMS Trace Element Analysis and C-O-S-Pb Isotopes. Ore Geology Reviews, 2017, 89: 752-771.

[7] Duan X X, Zeng Q D, Yang J H, . Geochronology, Geochemistry and Hf Isotope of Late Triassic Magmatic Rocks of Qingchengzi District in Liaodong Peninsula, Northeast China. Journal of Asian Earth Sciences, 2014, 91: 107-124.

[8] Eckert A, Connolly P, Liu X L. Large-Scale Mechanical Buckle Fold Development and the Initiation of Tensile Fractures. Geochemistry, Geophysics, Geosystems, 2014, 15(11): 4570-4587.

[9] Gercek H. Poisson’s Ratio Values for Rocks. International Journal of Rock Mechanics and Mining Sciences, 2007, 44(1): 1-13.

[10] Hao L B, Zhao X, Zhao Y Y. Stable Isotope Characteristics and Ore Genesis of the Baiyun Gold Deposit, Liaoning Province. Journal of Jilin University (Earth Science Edtion), 2017, 47(2): 442-451

[11] Hronsky J M A. Deposit-Scale Structural Controls on Orogenic Gold Deposits: An Integrated, Physical Process-Based Hypothesis and Practical Targeting Implications. Mineralium Deposita, 2020, 55(2): 197-216.

[12] Leader L D, Robinson J A, Wilson C J L. Numerical Modelling of Fluid Infiltration Constrained by Fault and Bedding Relationships in the Fosterville Goldfield, Victoria, Australia. Ore Geology Reviews, 2012, 48: 384-402.

[13] Li C P, Shen J F, Li S R, . In-situ LA-ICP-MS Trace Elements Analysis of Pyrite and the Physicochemical Conditions of Telluride Formation at the Baiyun Gold Deposit, North East China: Implications for Gold Distribution and Deposition. Minerals, 2019, 9(2): 129

[14] Li J, Cai W Y, Li B, . Paleoproterozoic SEDEX-Type Stratiform Mineralization Overprinted by Mesozoic Vein-Type Mineralization in the Qingchengzi Pb-Zn Deposit, Northeastern China. Journal of Asian Earth Sciences, 2019, 184: 104009

[15] Li J, Cai W Y, Wang K Y, . Initial Decratonization of the Eastern North China Craton: New Constraints from Geochronology, Geochemistry, and Hf Isotopic Compositions of Mesozoic Igneous Rocks in the Qingchengzi District. Geological Journal, 2019, 55 5 3796-3820.

[16] Li J, Wang K Y, Cai W Y, . Triassic Gold-Silver Metallogenesis in Qingchengzi Orefield, North China Craton: Perspective from Fluid Inclusions, REE and H-O-S-Pb Isotope Systematics. Ore Geology Reviews, 2020, 121 103567

[17] Li Q S, Xing H L. Numerical Analysis of the Material Parameter Effects on the Initiation of Hydraulic Fracture in a near Wellbore Region. Journal of Natural Gas Science and Engineering, 2015, 27 1597-1608.

[18] Li X H, Yuan F, Zhang M M, . 3D Computational Simulation-Based Mineral Prospectivity Modeling for Exploration for Concealed Fe-Cu Skarn-Type Mineralization within the Yueshan Orefield, Anqing District, Anhui Province, China. Ore Geology Reviews, 2019, 105: 1-17.

[19] Li Z H, Chi G X, Bethune K M, . Structural Controls on Fluid Flow during Compressional Reactivation of Basement Faults: Insights from Numerical Modeling for the Formation of Unconformity-Related Uranium Deposits in the Athabasca Basin, Canada. Economic Geology, 2017, 112(2): 451-466.

[20] Li Z H, Chi G X, Bethune K M, . Numerical Simulation of Strain Localization and Its Relationship to Formation of the Sue Unconformity-Related Uranium Deposits, Eastern Athabasca Basin, Canada. Ore Geology Reviews, 2018, 101: 17-31.

[21] Li, Z. H., Chi, G. X., Bethune, K. M., et al., 2020. Interplay between Thermal Convection and Compressional Fault Reactivation in the Formation of Unconformity-Related Uranium Deposits. Mineralium Deposita, 44(5530): online. https://doi.org/10.1007/s00126-020-01011-6

[22] Liu G P, Ai Y F. A Discussion on Some Major Problems of the Baiyun Gold Deposit, Eastern Liaoning. Mineral Deposits, 1999, 18(3): 219-226

[23] Liu J, Liu F X, Li S H, . Formation of the Baiyun Gold Deposit, Liaodong Gold Province, NE China: Constraints from Zircon U-Pb Age, Fluid Inclusion, and C-H-O-Pb-He Isotopes. Ore Geology Reviews, 2019, 104: 686-706.

[24] Liu L M, Zhao Y L, Sun T. 3D Computational Shape and Cooling Process-Modeling of Magmatic Intrusion and Its Implication for Genesis and Exploration of Intrusion-Related Ore Deposits: An Example from the Yueshan Intrusion in Anqing, China. Tectonophysics, 2012, 526–529: 110-123.

[25] Liu X C, Ma Y, Xing H L, . Chemical Responses to Hydraulic Fracturing and Wolframite Precipitation in the Vein-Type Tungsten Deposits of Southern China. Ore Geology Reviews, 2018, 102: 44-58.

[26] Liu X C, Xing H L, Zhang D H. Hydraulic Fracturing Leads to Wolframite Deposition at Magmatic-Hydrothermal Transition. Acta Geologica Sinica: English Edition, 2018, 92(2): 862-863.

[27] Nasseri M H B, Rao K S, Ramamurthy T. Anisotropic Strength and Deformational Behavior of Himalayan Schists. International Journal of Rock Mechanics and Mining Sciences, 2003, 40(1): 3-23.

[28] Oliver N H S, Pearson P J, Holcombe R J, . Mary Kathleen Metamorphic-Hydrothermal Uranium—Rare-Earth Element Deposit: Ore Genesis and Numerical Model of Coupled Deformation and Fluid Flow. Australian Journal of Earth Sciences, 1999, 46(3): 467-484.

[29] Ord A, Oliver N H S. Mechanical Controls on Fluid Flow during Regional Metamorphism: Some Numerical Models. Journal of Metamorphic Geology, 1997, 15(3): 345-359.

[30] Pariseau W G. Design Analysis in Rock Mechanics, 2006, London: Taylor & Francis, 560

[31] Schön J H. Physical Properties of Rocks: Fundamentals and Principles of Petrophysics, 2015, Amsterdam: Elsevier, 497

[32] Sheldon H A, Micklethwaite S. Damage and Permeability around Faults: Implications for Mineralization. Geology, 2007, 35(10): 903-906.

[33] Sibson R H. Controls on Maximum Fluid Overpressure Defining Conditions for Mesozonal Mineralisation. Journal of Structural Geology, 2004, 26(6/7): 1127-1136.

[34] Sun G T, Zeng Q D, Wang Y B, . Geochronology and Geochemistry of Mesozoic Dykes in the Qingchengzi Ore Field, Liaoning Province, China: Magmatic Evolution and Implications for Ore Genesis. Geological Journal, 2019, 55(8): 5745-5763.

[35] Sun G T, Zeng Q D, Li T Y, . Ore Genesis of the Baiyun Gold Deposit in Liaoning Province, NE China: Constraints from Fluid Inclusions and Zircon U-Pb Ages. Arabian Journal of Geosciences, 2019, 12(9): 299

[36] Sun G T, Zeng Q D, Zhou L L, . Trace Element Contents and in situ Sulfur Isotope Analyses of Pyrite in the Baiyun Gold Deposit, NE China: Implication for the Genesis of Intrusion-Related Gold Deposits. Ore Geology Reviews, 2020, 118: 103330

[37] Sun L M, Sun W T, Zhao G F. Geological Characteristics of Xiaotongjiapuzi Gold-Silver Deposit of Qing-Cheng-Zi Ore Field and Its Source of Mineralized Matter. Gold, 1997, 18 12 13-18

[38] Upton P, Begbie M, Craw D. Numerical Modelling of Mechanical Controls on Coeval Steep and Shallow Dipping Auriferous Quartz Vein Formation in a Thrust Zone, Macraes Mine, New Zealand. Mineralium Deposita, 2008, 43(1): 23-35.

[39] Vearncombe J, Zelic M. Structural Paradigms for Gold: Do They Help Us Find and Mine?. Applied Earth Science, 2015, 124(1): 2-19.

[40] Wang Y, Wang F, Shi W, . Timing and Processes of Ore Formation in the Qingchengzi Polymetallic Orefield, Northeast China: Evidence from ⁴⁰Ar/³⁹Ar Geochronology. Acta Geologica Sinica: English Edition, 2020, 94(3): 789-800.

[41] Wang Y Z, Wang F, Wu L, . (U-Th)/He Thermochronology of Metallic Ore Deposits in the Liaodong Peninsula: Implications for Orefield Evolution in Northeast China. Ore Geology Reviews, 2018, 92 348-365.

[42] Wang Y W, Xie H J, Li D D, . Prospecting Prediction of Ore Concentration Area Exemplified by Qingchengzi Pb-Zn-Au-Ag Ore Concentration Area, Eastern Liaoning Province. Mineral Deposits, 2017, 36(1): 1-24

[43] Xing H L, Makinouchi A. FE Modeling of Thermo-Elasto-Plastic Finite Deformation and Its Application in Sheet Warm Forming. Engineering Computations, 2002, 19(4): 392-410.

[44] Xue C J, Chen Y C, Lu Y F, . Metallogenic Epochs of Au and Ag Deposits in Qingchengzi Ore-Clustered Area, Eastern Liaoning Province. Mineral Deposits, 2003, 22(2): 177-184

[45] Yu G, Chen J F, Xue C J, . Geochronological Framework and Pb, Sr Isotope Geochemistry of the Qingchengzi Pb-Zn-Ag-Au Orefield, Northeastern China. Ore Geology Reviews, 2009, 35(3/4): 367-382.

[46] Zeng Q D, Wang Y B, Yang J H, . Spatial-Temporal Distribution and Tectonic Setting of Gold Deposits in the Northern Margin Gold Belt of the North China Craton. International Geology Review, 2020, 25(5): 1-32

[47] Zhang P, Kou L L, Zhao Y, . Fluid Inclusions, H-O, S, Pb, and Noble Gas Isotope Studies of the Baiyun Gold Deposit in the Qingchengzi Orefield, NE China. Journal of Geochemical Exploration, 2019, 200: 37-53.

[48] Zhang P, Li B, Li J, . Re-Os Isotopic Dating and its Geological Implication of Gold Bearing Pyrite from the Baiyun Gold Deposit in Liaodong Rift. Geotectonica et Metallogenia, 2016, 40(4): 731-738

[49] Zhang P, Yang H Z, Li B, . Ore source, Ore-Forming Age and Geodynamic Setting of Yaojiagou Molybdenum Deposit in Qingchengzi Ore-Clustered Area, Eastern Liaoning Province. Journal of Jilin University (Earth Science Edtion), 2016, 46(6): 1684-1696

[50] Zhang S H, Hu G H, Li J F, . Ore-Controlling Structures and Metallogenic Prediction in Baiyun-Xiaotongjiabuzi Ore Concentration Area, Eastern Liaoning Province. Earth Science, 2020, 45(11): 1-11

[51] Zhang Y H, Roberts P A, Murphy B. Understanding Regional Structural Controls on Mineralization at the Century Deposit: A Numerical Modelling Approach. Journal of Geochemical Exploration, 2010, 106(1/2/3): 244-250.

[52] Zhang Y, Schaubs P M, Sheldon H A, . Modelling Fault Reactivation and Fluid Flow around a Fault Restraining Step-Over Structure in the Laverton Gold Region, Yilgarn Craton, Western Australia. Geofluids, 2013, 13(2): 127-139.

[53] Zhang Y, Schaubs P M, Zhao C, . Fault-Related Dilation, Permeability Enhancement, Fluid Flow and Mineral Precipitation Patterns: Numerical Models. Geological Society, London, Special Publications, 2008, 299(1): 239-255.

[54] Zheng Y F, Xu Z, Zhao Z F, . Mesozoic Mafic Magmatism in North China: Implications for Thinning and Destruction of Cratonic Lithosphere. Science China Earth Sciences, 2018, 61(4): 353-385.

[55] Zhu J, Li Z, Lin G, . Numerical Simulation of Mylonitization and Structural Controls on Fluid Flow and Mineralization of the Hetai Gold Deposit, West Guangdong, China. Geofluids, 2014, 14(2): 221-233.

[56] Zhu R X, Fan H R, Li J W, . Decratonic Gold Deposits. Science China Earth Sciences, 2015, 58(9): 1523-1537.