Seismic reflection characteristics and evolution of intrusions in the Qiongdongnan Basin: Implications for the rifting of the South China Sea

Abstract

The Qiongdongnan Basin (QDNB) is situated in the extensional zone at the vertex of the V-shaped northwest sub-basin, non-volcanic northern margin of the South China Sea (SCS). From north to south, the thickness of the continental lithosphere decreases from 22 km on the northern continental shelf to 17 km at the deepest area of the central depression. A sharp change on the crustal structure is of importance to hydrocarbon exploration yet the dynamic causes remain unknown. A comprehensive study including (1) interpretation of seismic profiles, (2) P-wave velocity data modeling, and (3) magnetic anomalies analysis reveals that there are some high-density intrusions along the lithospheric thinning belt. Chaotic reflections can be found in the southwest of the QDNB, with a low velocity (<3.4 km/s), while in the center and the east, the intensively deformed strata passing towards the diapir flanks and their high velocities (>6 km/s) suggest the existence of igneous diapirs. Diapirism differentiation are primarily achieved through analysis of the contact relationship and the thickness variations in the surrounding strata. The first phase of diapirism along the Songnan low uplift occurred in the Late Mesozoic, and the second phase of diapirism in a form of subsequent gas movement remained active until the Late Quaternary. The distribution and the evolution of the diapirs would have major implications for post-rift emplacement.

Keywords

Qiongdongnan Basin / intrusion / seismic reflection anomaly / diapirism / rifting of the South China Sea

References

Jackson C., Kane K. E. Busby C. J., Azor A. 3D Seismic Interpretation Techniques: Applications to Basin Analysis. Tectonics of Sedimentary Basins: Recent Advances, 2011, 95-110.

Bacon M., Simm R., Redshaw T. 3-D Seismic Interpretation, 2007.

Briais A., Patriat P., Tapponnier P. Updated Interpretation of Magnetic Anomalies and Seafloor Spreading Stages in the South China Sea: Implications for the Tertiary Tectonics of Southeast Asia. Journal of Geophysical Research, 1993, 98 B4 6299

Cohen H. A., McClay K. Sedimentation and Shale Tectonics of the Northwestern Niger Delta Front. Marine and Petroleum Geology, 1996, 13(3): 313-328.

Damuth J. Neogene Evolution of the Niger Delta. Marine Petroleum Geology, 1994, 11: 320-345.

Dix C. H. Seismic Velocities from Surface Measurements. Geophysics, 1955, 20(1): 68-86.

Galland O., Planke S., Neumann E. R., . Experimental Modelling of Shallow Magma Emplacement: Application to Saucer-Shaped Intrusions. Earth and Planetary Science Letters, 2009, 277(3/4): 373-383.

Hansen D. M., Redfern J., Federici F., . Miocene Igneous Activity in the Northern Subbasin, Offshore Senegal, NW Africa. Marine and Petroleum Geology, 2008, 25(1): 1-15.

Hao F., Li S. T., Gong Z., . Thermal Regime, Interreservoir Compositional Heterogeneities, and Reservoir-Filling History of the Dongfang Gas Field, Yinggehai Basin, South China Sea: Evidence for Episodic Fluid Injections in Overpressured Basins?. AAPG Bulletin, 2000, 84(5): 607-626.

He J. X., Zhu Y. H., Weng J. N. Characters of North-West Mud Diapirs Volcanoes in South China Sea and Relationship between Them and Accumulation and Migration of Oil and Gas. Earth Science-Journal of China University of Geosciences, 2010, 35(1): 75-86.

Huang C., Chen K., Li S. Periodicities of Diapiric Rise in the Yinggehai Basin. Petroleum Exploration and Development, 2002, 29(4): 44-46.

Ivanov M. K., Limonov A. F., van Weering T. C. E. V. Comparative Characteristics of the Black Sea and Mediterranean Ridge Mud Volcanoes. Marine Geology, 1996, 132(1–4): 253-271.

Jackson M. P. A., Vendeville B. C. Regional Extension as a Geologic Trigger for Diapirism. Geological Society of America Bulletin, 1994, 106(1): 57-73.

Jahn B. M., Chen P. Y., Yen T. P. Rb-Sr Ages of Granitic Rocks in Southeastern China and Their Tectonic Significance. Geological Society of America Bulletin, 1976, 87(5): 763-776.

Koyi H. Experimental Modeling of Role of Gravity and Lateral Shortening in Zagros Mountain Belt. AAPG Bulletin, 1988, 72(11): 1381-1394.

Lei C., Ren J. Y., Clift P. D., . The Structure and Formation of Diapirs in the Yinggehai-Song Hong Basin, South China Sea. Marine and Petroleum Geology, 2011, 28(5): 980-991.

Lester R. v., Avendonk H. J. A. V., McIntosh K., . Rifting and Magmatism in the Northeastern South China Sea from Wide-Angle Tomography and Seismic Reflection Imaging. Journal of Geophysical Research: Solid Earth, 2014, 119(3): 2305-2323.

Li P. L., Rao C. T. Tectonic Characteristics and Evolution History of the Pearl River Mouth Basin. Tectonophysics, 1994, 235(1/2): 13-25.

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

Li X., Ou B., Li Q., . 3D Geopressure Field and Hydrocarbon Migration in Yinggehai and Qiongdongnan Basins. Geological Science and Technology Information, 2005, 24(3): 70-74.

Magee C., Hunt-Stewart E., Jackson C. A. L. Volcano Growth Mechanisms and the Role of Sub-Volcanic Intrusions: Insights from 2D Seismic Reflection Data. Earth and Planetary Science Letters, 2013, 373: 41-53.

Morley C. Mobile Shale Related Deformation in Large Deltas Developed on Passive and Active Margins. Subsurface Sediment Mobilization. Geological Society, London, Special Publications, 2003, 216: 335-357.

Pang X., Chen C., Shao L., . Baiyun Movement, a Great Tectonic Event on the Oligocene–Miocene Boundary in the Northern South China Sea and Its Implications. Geological Review, 2007, 53(2): 145-151.

Pei J., Yu J., Wang L. Key Challenges and Strategies for the Success of Natural Gas Exploration in Mid-Deep Strata of the Yinggehai Basin. Acta Petrolei Sinica, 2011, 32(4): 573-579.

Polteau S., Mazzini A., Galland O., . Saucer-Shaped Intrusions: Occurrences, Emplacement and Implications. Earth and Planetary Science Letters, 2008, 266(1/2): 195-204.

Qiu X. L., Ye S. Y., Wu S. M., . Crustal Structure Across the Xisha Trough, Northwestern South China Sea. Tectonophysics, 2001, 341(1–4): 179-193.

Ren J., Pang X., Lei C., . Ocean and Continent Transition in Passive Continental Margins and Analysis of Lithospheric Extension and Breakup Process: Implication for Research of the Deepwater Basins in the Continental Margins of South China Sea. Earth Science Frontiers, 2015, 22(1): 102-114.

Ren J. Y., Tamaki K., Li S. T., . Late Mesozoic and Cenozoic Rifting and Its Dynamic Setting in Eastern China and Adjacent Areas. Tectonophysics, 2002, 344(3–4): 175-205.

Ren J. Y., Tong D. J., Li T., . Tectonic Structure and Evolution of the Deepwater Area in Qiongdongnan Basin. National Science and Technology Major Project Report, 2014.

Ren J. Y., Zhang D. J., Tong D. J., . Characterising the Nature, Evolution and Origin of Detachment Fault in Central Depression Belt, Qiongdongnan Basin of South China Sea: Evidence from Seismic Reflection Data. Acta Oceanologica Sinica, 2014, 33(12): 118-126.

Rohrman M. Prospectivity of Volcanic Basins: Trap Delineation and Acreage De-Risking. AAPG Bulletin, 2007, 91(6): 915-939.

Russell S. M., Whitmarsh R. B. Magmatism at the West Iberia Non-Volcanic Rifted Continental Margin: Evidence from Analyses of Magnetic Anomalies. Geophysical Journal International, 2003, 154(3): 706-730.

Savva D., Pubellier M., Franke D., . Different Expressions of Rifting on the South China Sea Margins. Marine and Petroleum Geology, 2014, 58: 579-598.

Sheriff R. E., Geldart L. P. Exploration Seismology 2nd Edition, 1995, Cambridge: Cambridge University Press

Shi W., Song Z., Wang X., . Diapir Structure and Its Origin in the Baiyun Depression. Pearl River Mouth Basin China. Journal of Earth Science, 2009, 34(5): 778-784.

Song Y., Ren J. Y., Stepashko A. A., . Post-Rift Geodynamics of the Songliao Basin, NE China: Origin and Significance of T11 (Coniacian) Unconformity. Tectonophysics, 2014, 634: 1-18.

Song Y., Stepashko A. A., Ren J. Y. The Cretaceous Climax of Compression in Eastern Asia: Age 87–89 Ma (Late Turonian/Coniacian), Pacific Cause, Continental Consequences. Cretaceous Research, 2015, 55: 262-284.

Sun Q., Wu S., Chen D., . Focused Fluid Flow Systems and Their Implications for Hydrocarbon and Gas Hydrate Accumulations in the Deep-Water Basins of the Northern South China Sea. Chinese J. Geophysics, 2014, 57(12): 4052-4062.

Taylor B., Hayes D. E. The Tectonic Evolution of the South China Basin. The Tectonic and Geologic Evolution of Southeast Asian Seas and Islands. American Geophysical Union Geophysical Monograph, 1980, 23: 89-104.

Tong D., Ren J., Lei C., . Lithosphere Stretching Model of Deep Water in Qiongdongnan Basin, Northern Continental Margin of South China Sea, and Controlling of the Post-Rift Subsidence. Journal of Earth Science, 2009, 34(6): 963-974.

Vendeville B. C., Jackson M. P. A. The Rise of Diapirs during Thin-Skinned Extension. Marine and Petroleum Geology, 1992, 9(4): 331-354.

Wang J., Pang X., Wang C., . Discovery and Recognition of the Central Diapiric Zone in Baiyun Depression, Pearl River Mouth Basin. Journal of Earth Science, 2006, 31(2): 209-213.

White R., McKenzie D. Magmatism at Rift Zones: The Generation of Volcanic Continental Margins and Flood Basalts. Journal of Geophysical Research, 1989, 94(B6): 7685-7729.

Whitmarsh R., Manatschal G., Minshull T. Evolution of Magma-Poor Continental Margins from Rifting to Seafloor Spreading. Nature, 2001, 413(6852): 150-154.

Wu S., Qin Y. The Research of Deepwater Depositional System in the Northern South China Sea. Sedimentology, 2009, 27(5): 922-930.

Xie W., Wang T., Zhang Y., Jiang J. Characteristics and Dynamic Analysis of Cenozoic Rifting and Magmatism in Southwest Qiongdongnan Basin. Geotectonica et Metallogenia, 2009, 33: 199-205.

Xie X. N., Chen Z. H., Sun Z. P., . Depositional Architecture Characteristics of Deepwater Depositional Systems on the Continental Margins of Northwestern South China Sea. Earth Science-Journal of China University of Geosciences, 2012, 37(4): 627-634.

Xie X. N., Jiang T., Wang H., . Expulsion of Overpressured Fluid Revealed by Geochemistry of Formation Water in the Diapiric Structures of Yinggehai Basin. Acta Petrologica Sinica, 2006, 22(8): 2243-2248.

Xie X. N., Ren J. Y., Wang Z. F., . Difference of Tectonic Evolution of Continental Marginal Basins of South China Sea and Relationship with SCS Spreading. Earth Science Frontiers., 2015, 22(1): 77-87.

Xie Y. H., Li X. S., Tong C. X. High Temperature and High Pressure Gas Enrichment Condition, Distribution Law and Accumulation Model in Central Diapir Zone of Yinggehai Basin. China Offshore Oil and Gas, 2015, 27(4): 1-12.

Yan P., Deng H., Liu H. L., . The Temporal and Spatial Distribution of Volcanism in the South China Sea Region. Journal of Asian Earth Sciences, 2006, 27(5): 647-659.

Yan P., Zhou D., Liu Z. S. A Crustal Structure Profile Across the Northern Continental Margin of the South China Sea. Tectonophysics, 2001, 338(1): 1-21.

Yilmaz. Seismic Data Analysis: Processing, Inversion, and Interpretation of Seismic Data, 2001

Yuan S. Q., Wu S. G., Thomas L., . Fine-Grained Pleistocene Deepwater Turbidite Channel System on the Slope of Qiongdongnan Basin, Northern South China Sea. Marine and Petroleum Geology, 2009, 26(8): 1441-1451.

Zhao F., Wu S. G., Sun Q. L., . Submarine Volcanic Mounds in the Pearl River Mouth Basin, Northern South China Sea. Marine Geology, 2014, 355: 162-172.

Zhou X. M., Li W. X. Origin of Late Mesozoic Igneous Rocks in Southeastern China: Implications for Lithosphere Subduction and Underplating of Mafic Magmas. Tectonophysics, 2000, 326(3/4): 269-287.

Zhu W. L., Huang B. J., Mi L. J., . Geochemistry, Origin, and Deep-Water Exploration Potential of Natural Gases in the Pearl River Mouth and Qiongdongnan Basins, South China Sea. AAPG Bulletin, 2009, 93(6): 741-761.

Zou H., Li P., Rao C. Geochemistry of Cenozoic Volcanic Rocks in Zhujiangkou Basin and Its Geodynamic Significance. Geochemica, 1995, 24: 33-45.