巴西东南海域被动陆缘盆地岩浆活动特征及期次——以桑托斯盆地B区块火成岩为例
Characteristics and Stages of Magma Events in Passive Continental Margin Basins in South-East Offshore of Brazil—Taking Igneous Rocks in Block B, Santos Basin as an Example
摘要: 巴西东南海域被动陆缘盆地内部岩浆活动频繁，导致火成岩分布广泛。本文以桑托斯盆地B区块火成岩为研究对象，通过对其岩石学、矿物学、年代学和岩石地球化学等研究，明确了区内火成岩岩石类型及分布，重点分析了岩浆活动特征及期次，尝试总结不同期次火成岩的油气地质意义。B区块至少经历了阿普特期(113.3 ± 1.2 Ma~122.5 ± 0.6 Ma)和圣通–坎潘期(77.4 ± 0.4 Ma~86.5 ± 5.9 Ma)两期岩浆活动。其中，Aptian期岩浆属钙–碱性，以喷发岩为主，集中分布在Itapema组及以下，属盆地裂陷初期的岩浆活动，经历了多次喷发过程，通过改变湖盆底部地形地貌，影响并控制同时期Itapema组介壳灰岩沉积；圣通–坎潘期岩浆以碱性辉绿岩为主，属于侵入岩，不仅在盐下分布，也可以穿透盐层进入盐上或滞留盐内，并对围岩进行烘烤，产生接触热变质，降低储层孔渗性，增加储层复杂程度。
Abstract: Multiple magma events induced widespread distribution of igneous rocks in the passive conti-nental margin basins in the South-East offshore of Brazil. This paper takes igneous rock associa-tions in Block B in Santos Basin as a study case. Through the study of petrology, mineralogy, chronology and petrochemistry, the types and distribution of igneous rocks are clarified firstly, then the characteristics and stages are analyzed, and finally their petroleum significance is attempted to be summarized respectively. In Block B, at least two stages of magma events were developed, the Aptian period (113.3 ± 1.2 Ma~122.5 ± 0.6Ma) and Santonian-Campanian period (77.4 ± 0.4 Ma~86.5 ± 5.9 Ma) respectively. The Aptian magma is calcium-alkaline and occurs in the facies of eruption. They are mainly distributed in Itapema Formation and its lower sections. It belongs to the earlier magma in the rift stage of the basin and has experienced multiple eruptions, which influenced and controlled the deposition of the Itapema Formation by changing the topography and geomorphology of the lake bottom. The Santonian-Campanian magma is mainly alkaline diabase, which belongs to intrusive rock, not only distributed within the pre-salt, but also penetrated the salt layer and post-salt layers, baking surrounding rock, producing contact thermal metamorphism, reducing reservoir permeability and increasing reservoir complexity.
文章引用：黄雪飞. 巴西东南海域被动陆缘盆地岩浆活动特征及期次——以桑托斯盆地B区块火成岩为例[J]. 地球科学前沿, 2022, 12(10): 1309-1316. https://doi.org/10.12677/AG.2022.1210126

参考文献

[1] 温志新, 吴亚东, 边海光, 等. 南大西洋两岸被动陆缘盆地结构差异与大油气田分布[J]. 地学前缘, 2018, 25(4): 132-141.
[2] Ren, K., Zhao, J., Liu, Q. and Zhao, J. (2020) Hydrocarbons in Igneous Rock of Brazil: A Review. Petroleum Research, 5, 265-275. [Google Scholar] [CrossRef] 
[3] Moreira, J.L.P., Madeira, C.V., Gil, J.A., et al. (2007) Bacia de Santos. Boletim de Geociencias da Petrobras, 15, 531-549.
[4] Geraldes, M.C., Motoki, A., Costa, A., Mota, C.E. and Mohriak, W.U. (2013) Geochronology (Ar/Ar and K-Ar) of the South Atlantic Post-Breakup Magmatism. In: Mohriak, W.U., Danforth, A., Post, P.J., Brown, D.E., Tari, G.C., Nemčok, M. and Sinha, S.T., Eds., Conjugate Divergent Margins, Geological Society, London, 41-74. [Google Scholar] [CrossRef] 
[5] 赵健, 赵俊峰, 任康绪, 等. 巴西桑托斯盆地CO2区域分布及主控因素[J]. 地球科学, 2021, 46(9): 3217-3229.
[6] 程涛, 康洪全, 梁建设, 等. 巴西桑托斯盆地岩浆岩成因类型划分与活动期次分析[J]. 中国海上油气, 2019, 31(4): 55-66.
[7] Norvick, M.S. and Schaller, H. (1998) A Three-Phase Early Cretaceous Rift History of the South Atlantic Salt Basins and Its Influence on Lacustrine Source Facies Distribution. ABGP/AAPG International Conference and Exhibition, Rio de Janeiro.
[8] Karner, G.D. (2000) Rifts of the Campos and Santos Basins, Southeastern Brazil: Distribution and Timing. In: Mello, M.R. and Katz, B.J., Eds., Petroleum Systems of South Atlantic Margins, Vol. 73, American Association of Petroleum Geologists, Tulsa, 301-315.
[9] Meisling, K.E., Cobbold, P.R. and Mount, V.S. (2001) Segmentation of an Obliquely Rifted Margin, Campos and Santos Basins, Southeastern Brazil. AAPG Bulletin, 85, 1903-1924. [Google Scholar] [CrossRef] 
[10] Dickson, W., Schiefeelbein, S., Zumberge, J., et al. (2005) Basin Analysis in Brazilian and West African Conjugates: Combining Disciplines to Deconstruct Petroleum Systems. GCSSEPM Foundation 25th Annual Bob F. Perkins Research Conference, Houston. [Google Scholar] [CrossRef] 
[11] Aslanian, D., et al. (2008) Brazilian and African Passive Margins of the Central Segment of the South Atlantic Ocean: Kinematic Constraints. Tectonophysics, 468, 98-112. [Google Scholar] [CrossRef] 
[12] Stanton, N., Ponte-Neto, C.F., Bijani, R., et al. (2013) The Rifting Evolution of the Santos Basin: A Geophysical View. 13th International Congress of the Brazilian Geophysical Society, Rio de Janeiro, 26-29 August 2013, 1-4. [Google Scholar] [CrossRef] 
[13] 陶崇智, 殷进垠, 陆红梅, 等. 南大西洋被动陆缘盆地盐岩对油气成藏的影响[J]. 石油实验地质, 2015, 37(5): 614-618, 626.
[14] Winchester, J.A. and Floyd, P.A. (1977) Geochemical Discrimination of Different Magma Series and Their Differentiation Products Using Immobile Elements. Chemical Geology, 20, 325-343. [Google Scholar] [CrossRef] 
[15] Anna, C.L.S., Sandra, N.T. and Egberto, P. (2020) Silicification and Dissolution Features in the Brazilian Pre-Salt Barra Velha Formation: Impacts in the Reservoir Quality and Insights for 3D Geological Modeling. Rio Oil & Gas Expo and Conference, Rio de Janeiro. [Google Scholar] [CrossRef] 
[16] Ren, K.X., Zhao, J.F., Zhao, J., et al. (2021) Using Logging and Seismic Data to Identify Boundaries Between Different OWC Units in a Deepwater Carbonate Reservoirs. The International Petroleum Technology Conference, Virtual, March 2021, IPTC-21438-MS. [Google Scholar] [CrossRef] 
[17] Ren, K.X., Oliveira, M.J.R., et al. (2019) Metamorphism of Pre-Salt Limestones Produced by Santonian-Campanian Alkaline Sills in the Libra Block, Santos Basin. LASI VI Conference, Vol. 1, 131-132. http://lasi6.org/wp-content/uploads/2019/11/LASI6-abstract-book-1.pdf