The Genesis and Geological Implications for Oceanic Redbeds of the South China Sea in U1434 of IODP Expedition 349——the Constraint from Diffuse Reflectance and X-Ray Fluorescence Spectroscopy
JIANG Lian-ting1, SUN Jie1*, HU Li-tian2, 3*, ZHAN Wen-huan1, TANG Qin-qin1, LI Jian1
1. Key Laboratory of Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
2. School of Earth Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275, China
3. Guangdong Provincal Key Lab of Geodynamics and Geohazards, School of Earth Sciences and Engineering, Sun Yat-sen University, Guangzhou 510275, China
Abstract：We presented a new finding that the occurrences of oceanic redbeds in the South China Sea (SCS) first discovered from Expedition 349 are similar to those in Sulu Sea and Celebes Sea from Expedition 124, as well as to the continental redbeds in Sanshui Basin of China, all directly covering massive magmatic rocks with significance for revealing the connections between oceanic redbeds and magma thermal events. We measured the samples collectted from marine sedimentary with colors ranging from celadon to rufous in U1434 of IODP Expedition 349, and analyzed the influence of oxygen fugacity and geothermal temperature on the formation of pigment in redbeds. By comparing red-nonred sediments and experimental samples, we discussed the redbed genesis and its geological implications. We obtained the red values, the content of goethite, hematite and quantivalent Fe in marine sediments and experiment samples through the analysis of diffuse reflectance and fluorescent spectroscopy and Fe2+ in titration test. The results showed that, (1) Red and non-red marine sediments are formed at high oxygen fugacity environment in U1434 of IODP Expedition 349, and difference in oxidation-deoxidation environment was not the controlling factor on red and non-red sediments; (2) The oceanic redbeds directly covering basalts in U1434 of IODP Expedition 349 originated from high geothermal temperature during sedimentary- diagenesis process; (3) And we found that continental redbeds and Cretaceous oceanic redbeds formed in different geological periods are closely associated with tectonic- magmatic active belts, showing that redbeds have significance in indicating geological thermal events.
Key words：Oceanic redbeds; Theraml origin; Oxygen fugacity; South China Sea
姜莲婷，孙 杰，胡立天，詹文欢，唐琴琴，李 健. 南海IODP 349航次U1434站位海相红层成因——来自漫反射光谱与X荧光光谱的制约[J]. 光谱学与光谱分析, 2019, 39(04): 1294-1300.
JIANG Lian-ting, SUN Jie, HU Li-tian, ZHAN Wen-huan, TANG Qin-qin, LI Jian. The Genesis and Geological Implications for Oceanic Redbeds of the South China Sea in U1434 of IODP Expedition 349——the Constraint from Diffuse Reflectance and X-Ray Fluorescence Spectroscopy. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(04): 1294-1300.
[1] Li J, Hu X, Zhao K, et al. Cretaceous Research, 2016, 66: 115.
[2] Xu X M, Wang C S, Scott R W, et al. SEPM Society for Sedimentary Geology Special Publication, 2009.
[3] Li C F, Lin J, Kulhanek D K, et al. Proceedings of the International Ocean Discovery Program, 349: South China Sea Tectonics: College Station, TX (International Ocean Discovery Program), 2014.
[4] SONG Xiao-xiao, LI Chun-feng(宋晓晓，李春峰). Journal of Tropical Oceanography（热带海洋学报）, 2016, 35(1): 17.
[5] Eker C S, Korkmaz S. Journal of Mineralogy and Geochemistry, 2011, 188: 235.
[6] Jiang L T, Chen G N, Grapes R, et al. Journal of Asian Earth Sciences, 2015, 101: 14.
[7] Balsam W, Deaton B C. Reviews in Aquatic Sciences, 1991, 4: 411.
[8] JIANG Lian-ting, CHEN Guo-neng, PENG Zhuo-lun(姜莲婷，陈国能，彭卓伦). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2013, 33(10): 2727.
[9] HU Xiu-mian, WANG Cheng-shan, LI Xiang-hui, et al(胡修棉，王成善，李祥辉，等). Science in China Series D Earth Sciences(中国科学D辑地球科学), 2006, 36(9): 811.
[10] Li X, Cai Y. Cretaceous Research, 2013, 46: 257.
[11] Chen X, Wang C S, Hu X M, et al. Acta Geologica Sinica, 2007, 81: 1070.
[12] Gialanella S, Girardi F, Ischia G, et al. Journal of Thermal Analysis Calorimetry, 2010, 102: 867.
[13] Chen G N, Grapes R H. Granite Genesis: in-situ Melting and Crustal Evolution. Dordrecht, The Netherlands: Springer, 2007.
[14] LIU Yu-shan, ZHANG Gui-lan(刘玉山，张桂兰). Geochimica(地球化学), 1996，(1)：53.
[15] Chan L H, Alt J C, Teagle D A H. Earth & Planetary Science Letters, 2002, 201: 187.
