Late Early-Cretaceous Magma Mixing in the Langqi Island, Fujian Province, China: Evidences from Petrology, Geochemistry and Zircon Geochronology

Abstract

The mafic enclaves from Mesozoic intermediate-acid magmatic rocks, widely developed along Fujian coast, are considered to be the results of large-scale crust-mantle interaction and magma mixing. In this paper, petrography, mineralogy, and geochemistry of granites and mafic microgranular enclaves (MMEs) in Langqi Island are studied to provide new information for tracing crust-mantle interaction. The zircon U-Pb dating results show that the Langqi rocks were formed at ∼101 Ma, which are metaluminous, enriched in silica and high-K calc-alkaline I-type granites. The enclaves have a typical magmatic structure, which is characterized by magma mixing between high-temperature basic magma and low-temperature acidic magma through injecting. The enclaves and host granites show a tendency to mixed major and trace elements, displaying a clear-cut contact relationship, which is indicative of coeval magmatism. The genesis of Langqi rocks is related to the extensional setting caused by the subduction of Paleo-Pacific Plate, and they are the results of mixing of subduction-related metasomatized mantle-derived mafic and induced crustal-melted granitic magma originating from partial melting of the crustal material.

Keywords

magma mixing / granite / mafic microgranular enclaves / Langqi / Fujian

References

[1] Barbarin B. Mafic Magmatic Enclaves and Mafic Rocks Associated with some Granitoids of the Central Sierra Nevada Batholith, California: Nature, Origin, and Relations with the Hosts. Lithos, 2005, 80(1/2/3/4): 155-177.

[2] Bora S, Kumar S, Yi K, . Geochemistry and U-Pb SHRIMP Zircon Chronology of Granitoids and Microgranular Enclaves from Jhirgadandi Pluton of Mahakoshal Belt, Central India Tectonic Zone, India. Journal of Asian Earth Sciences, 2013, 70/1: 99-114.

[3] Castro A. Tonalite-Granodiorite Suites as Cotectic Systems: A Review of Experimental Studies with Applications to Granitoid Petrogenesis. Earth-Science Reviews, 2013, 1: 68-95.

[4] Chappell B W, White A J R, Wyborn D. The Importance of Residual Source Material (Restite) in Granite Petrogenesis. Journal of Petrology, 1987, 28(6): 1111-1138.

[5] Cui J J, Zhang Y Q, Dong S W, . Zircon U-Pb Geochronology of the Mesozoic Metamorphic Rocks and Granitoids in the Coastal Tectonic Zone of SE China: Constraints on the Timing of Late Mesozoic Orogeny. Journal of Asian Earth Sciences, 2013, 1: 237-252.

[6] Ding C, Zhao Z D, Yang J B, . Geochronology, Geochemistry of the Cretaceous Granitoids and Mafic to Intermediate Dykes in Shishi Area, Coastal Fujian Province. Acta Petrologica Sinica, 2015, 31(5): 1433-1447. (in Chinese with English Abstract)

[7] Dodge F C W, Kistler R W. Some Additional Observations on Inclusions in the Granitic Rocks of the Sierra Nevada. Journal of Geophysical Research, 1990, 95(B11): 17841-17848.

[8] Dong S W, Zhang Y Q, Zhang F Q, . Late Jurassic-Early Cretaceous Continental Convergence and Intracontinental Orogenesis in East Asia: A Synthesis of the Yanshan Revolution. Journal of Asian Earth Sciences, 2015, 1: 750-770.

[9] Dorais M J, Spencer C J. Revisiting the Importance of Residual Source Material (Restite) in Granite Petrogenesis: The Cardigan Pluton, New Hampshire. Lithos, 2014, 202/1: 237-249.

[10] Guo F, Fan W M, Li C W, . Multi-Stage Crust-Mantle Interaction in SE China: Temporal, Thermal and Compositional Constraints from the Mesozoic Felsic Volcanic Rocks in Eastern Guangdong-Fujian Provinces. Lithos, 2012, 1: 62-84.

[11] Hu R Z, Bi X W, Peng J T, . Some Problems Concerning Relationship between Mesozoic/Cenozoic Lithospheric Extension and Uranium Matallogenesis in South China. Mineral Deposits, 2007, 26(2): 139-152. (in Chinese with English Abstract)

[12] Jochum K P, McDonough W F, Palme H, . Compositional Constraints on the Continental Lithospheric Mantle from Trace Elements in Spinel Peridotite Xenoliths. Nature, 1989, 340(6234): 548-550.

[13] Li J H, Zhang Y Q, Dong S W, . The Hengshan Low-Angle Normal Fault Zone: Structural and Geochronological Constraints on the Late Mesozoic Crustal Extension in South China. Tectonophysics, 2013, 1: 97-115.

[14] Li S Z, Suo Y H, Li X Y, . Mesozoic Plate Subduction in West Pacific and Tectono-Magmatic Response in the East Asian Ocean-Continent Connection Zone. Chinese Science Bulletin, 2018, 63(16): 1550-1593.

[15] Li X H, Hu R Z, Rao B. Geochronology and Geochemistry of Cretaceous Mafic Dikes from Northern Guangdong, SE China. Geochimica, 1997, 26(2): 14-31. (in Chinese with English Abstract)

[16] Li X H. Cretaceous Magmatism and Lithospheric Extension in Southeast China. Journal of Asian Earth Sciences, 2000, 18(3): 293-305.

[17] Li Z, Qiu J S, Yang X M. A Review of the Geochronology and Geochemistry of Late Yanshanian (Cretaceous) Plutons along the Fujian Coastal Area of Southeastern China: Implications for Magma Evolution Related to Slab Break-off and Rollback in the Cretaceous. Earth-Science Reviews, 2014, 1: 232-248.

[18] Liu L, Qiu J S, Zhao J L, . Geochronological, Geochemical, and Sr-Nd-Hf Isotopic Characteristics of Cretaceous Monzonitic Plutons in Western Zhejiang Province, Southeast China: New Insights into the Petrogenesis of Intermediate Rocks. Lithos, 2014, 196/1: 242-260.

[19] Liu X, Zhao D P, Li S Z, . Age of the Subducting Pacific Slab beneath East Asia and Its Geodynamic Implications. Earth and Planetary Science Letters, 2017, 1: 166-174.

[20] Liu Y S, Hu Z C, Gao S, . In situ Analysis of Major and Trace Elements of Anhydrous Minerals by LA-ICP-MS without Applying an Internal Standard. Chemical Geology, 2008, 257(1/2): 34-43.

[21] Maas R, Nicholls I A, Legg C. Igneous and Metamorphic Enclaves in the S-Type Deddick Granodiorite, Lachlan Fold Belt, SE Australia: Petrographic, Geochemical and Nd-Sr Isotopic Evidence for Crustal Melting and Magma Mixing. Journal of Petrology, 1997, 38(7): 815-841.

[22] Mao J R, Li Z L, Ye H M. Mesozoic Tectono-Magmatic Activities in South China: Retrospect and Prospect. Science China Earth Sciences, 2014, 57(12): 2853-2877.

[23] Mao J R, Ye H M, Liu K, . The Indosinian Collision-Extension Event between the South China Block and the Palaeo-Pacific Plate: Evidence from Indosinian Alkaline Granitic Rocks in Dashuang, Eastern Zhejiang, South China. Lithos, 2013, 172/1: 81-97.

[24] Niu M L, Zhao Q Q, Wu Q, . Magma Mixing Identified in the Guokeshan Pluton, Northern Margin of the Qaidam Basin: Evidences from Petrography, Mineral Chemistry, and Whole-Rock Geochemistry. Acta Petrologica Sinica, 2018, 34(7): 1991-2016. (in Chinese with English Abstract)

[25] Niu Y L. Experimental Demonstrations on the Sources and Conditions of Mantle Melting. Science Bulletin, 2015, 60(22): 1871-1872.

[26] Qiu J S, Li Z, Liu L, . Petrogeniesis of the Zhangpu Composite Granite Pluton in Fujian Province: Constraints from Zircon U-Pb Ages, Elemental Geochemistry and Nd-Hf Isotopes. Acta Geologica Sinica, 2012, 86(4): 561-576. (in Chinese with English Abstract)

[27] Shellnutt J G, Jahn B M, Dostal J. Elemental and Sr-Nd Isotope Geochemistry of Microgranular Enclaves from Peralkaline A-Type Granitic Plutons of the Emeishan Large Igneous Province, SW China. Lithos, 2010, 119(1/2): 34-46.

[28] Sisson T W, Ratajeski K, Hankins W B, . Voluminous Granitic Magmas from Common Basaltic Sources. Contributions to Mineralogy and Petrology, 2005, 148(6): 635-661.

[29] Tao K Y, Mao J R, Xing G F, . Strong Yanshanian Volcanic-Magmatic Explosion in East China (in Chinese). Mineral Deposits, 2007, 1: 316-322. (in Chinese with English Abstract)

[30] Tsuchiya N, Suzuki S, Kimura J I, . Evidence for Slab Melt/Mantle Reaction: Petrogenesis of Early Cretaceous and Eocene High-Mg Andesites from the Kitakami Mountains, Japan. Lithos, 2005, 79(1/2): 179-206.

[31] 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.

[32] Xu H J, Ma C Q, Zhao J H, . Magma Mixing Generated Triassic I-Type Granites in South China. The Journal of Geology, 2014, 122(3): 329-351.

[33] Yang J B, Sheng D, Zhao Z D, . Petrogenesis and Implications of Granites and Associated Dioritic Enclaves in Jiaomei Area, Zhangzhou, Fujian Province. Acta Petrologica Sinica, 2013, 29(11): 4004-4010. (in Chinese with English Abstract)

[34] Yang J H, Sun J F, Zhang J H, . Petrogenesis of Late Triassic Intrusive Rocks in the Northern Liaodong Peninsula Related to Decratonization of the North China Craton: Zircon U-Pb Age and Hf-O Isotope Evidence. Lithos, 2012, 1: 108-128.

[35] Yang J H, Wu F Y, Wilde S A, . Tracing Magma Mixing in Granite Genesis: In situ U-Pb Dating and Hf-Isotope Analysis of Zircons. Contributions to Mineralogy and Petrology, 2007, 153(2): 177-190.

[36] Zhang Q, Wang Y, Pan G Q, . Source of Granites: Some Crucial Questions on Granite Study. Acta Petrologica Sinica, 2008, 24(6): 1193-1204. (in Chinese with English Abstract)

[37] Zheng Y F, Xiao W J, Zhao G C. Introduction to Tectonics of China. Gondwana Research, 2013, 23(4): 1189-1206.

[38] Zorpi M J, Coulon C, Orsini J B, . Magma Mingling, Zoning and Emplacement in Calc-Alkaline Granitoid Plutons. Tectonophysics, 1989, 157(4): 315-329.