GRAIN SIZE DISTRIBUTION OF SURFACE SEDIMENTS IN THE SOUTHWESTERN SOUTH CHINA SEA AND TRANSPORT TREND ANALYSIS
-
摘要: 对南海西南部海域(3°56'~11°53'N、108°30'~113°47'E)95个表层沉积物样品进行粒度分析的结果表明,研究区主要分布黏土质粉砂和粉砂质黏土,仅在西南部浅水区分布少量砂和粉砂质砂。沉积物粒度参数的总体特征呈现出从浅水向深水粒径越细、分选越好、偏态值更负偏的趋势。用克里格方法对粒度参数进行插值,然后运用GAST程序对沉积物进行粒径趋势分析,结果表明地形对于研究区沉积物的输运起到控制作用。以广雅海台、南薇滩和永署北海台等海底高地形单元为界,以北,来自南海西部陆架的物质通过陆坡被输送进入南海西南海盆;以南,来自巽他陆架和加里曼丹岛的南部陆源物质,通过陆架坡折带被输送进入南薇西和北康陆坡盆地。阵发性的浊流等异常沉积事件会对沉积物粒径输运趋势分析结果产生显著影响,并且沉积物中μm的细颗粒物质间的黏滞性对于沉积物粒径趋势分析结果也有影响,影响程度有待于今后进一步的研究。Abstract: Grain-size analysis is carried out for the 95 surface sediment samples from the southwestern part of the South China Sea(3°56'~11°53'N,108°30'~113°47'E), where clayey silt and silty clay dominate, with sand and silty sand only occurred in the most southwestern shallow part. There shows a trend of decreasing grain-size, increasing sorting and decreasing skewness from the shallow water to deeper water. The Kriging method was employed to insert data of the grain-size parameters (mean grain-size, sorting coefficient and skewness), and then the trend analysis was carried out for the interpolated data using the GSTA program. It is revealed that the seabed topography plays a key role in the sediment transport. There is a topographic high in the area including the Guang-ya submarine plateau, the Nan-wei-tan plateau, and the Yong-shu-bei submarine plateau. To the north of the high, sediments from the western South China Sea continental shelf are transported into the Southwest Basin of South China Sea; to the south of the boundary, however, materials from the Sunda shelf and the Kalimantan Island are transported into the Nan-wei-xi and Bei-kang slope basin passing by the shelf break. The episodic sedimentary events, such as the turbidity current, also have significant impacts on the grain-size distribution pattern. The aggregation of the components μm should not be ignored. Further researches are required for details.
-
-
[1] 金庆焕. 南海地质与油气资源[M]. 北京:地质出版社, 1989.[JIN Qinghuan. Geology, Oil and Gas Resources in the South China Sea[M]. Beijing:Geological Publishing House,1989.]
[2] 刘昭蜀,赵焕庭,范时清,等.南海地质[M]. 北京:科学出版社, 2002.[LIU Zhaoshu, ZHAO Huanting, FAN Shiqing, et al. Geology of the South China Sea[M]. Beijing:Science Press,2002.]
[3] WANG Pianxian, LI Qianyu. The South China Sea Paleoceanography and Sedimentology[M]. Springer, 2009.
[4] 张富元,章伟艳,杨群慧.南海东部海域沉积物粒度分布特征[J].沉积学报,2003, 21(3):452-460.
[ZHANG Fuyuan, ZHANG Weiyan, YANG Qunhui. Characteristics of grain size distributions of surface sediments in the eastern South China Sea[J]. Acta Sedimentologica Sinica, 2003, 21(3):452-460.]
[5] 吴时国,罗又郎. 南海南部大陆架的残留沉积[J]. 热带海洋,1994,13(3):47-52.
[WU Shiguo, LUO Youlang. The relic sediments in the south shelf of South China Sea[J]. Tropic Oceanology, 1994,13(3):47-52.]
[6] 李粹中. 南海中部沉积物类型和沉积作用特征[J]. 东海海洋,1987, 5(1-2):10
-18.[LI Cuizhong. Sediment types and sedimentation of central South China Sea[J]. Donghai Marine Science, 1987, 5(1-2):10-18.]
[7] 罗又郎,劳焕年,王泳漪.南海东北部表层沉积物类型与粒度特征的初步研究[J]. 热带海洋,1985,4(1):33-41.
[LUO Youlang, LAO Huannian, WANG Yongyi. A preliminary study on the surface sediment types and their grain size characteristics of the northeastern part of the South China Sea[J]. Tropic Oceanology, 1985,4(1):33-41.]
[8] 邱燕,钟和贤,刘坚.南海中南部表层沉积物类型、分布与水动力条件[J].南海地质研究, 2009:1-12.[QIU Yan, ZHONG Hexian, LIU Jian. Type, distribution and hydrodynamic condition of seafloor sediments in the middle and southern part of South China Sea[J]. Geological South China Sea, 2009:1
-12.]
[9] Boulay S, Colin C, Trentesaux A, et al. Sedimentary responses to the Pleistocene climatic variations recorded in the South China Sea[J]. Quaternary Research, 2007, 68:162-172.
[10] Wan Shiming, Li Anchun, Stuut Jan-Berend W, et al. Grain-size records at ODP Site 1146 from the northern South China Sea:Implications on the East Asian monsoon evolution since 20 Ma[J]. Science in China(Series D:Earth), 2007, 50(10):1536-1547.
[11] Chen Muhong, Zheng Fan, Lu Jun, et al. Original component of grain size index in core sediment from southwestern slope of the South China Sea and its paleoenvironmental implication[J].Chinese Science Bulletin,2005, 50(9):896-902.
[12] Jie Huang, Anchun Li, Shiming Wan. Sensitive grain-size records of Holocene East Asian summer monsoon in sediments of northern South China Sea slope[J]. Quaternary Research, 2011, 75:734-744.
[13] Chen Guocheng, Zheng Hongbo, Li Jianru, et al. Dynamic control on grain-size distribution of terrigenous sediments in the western South China Sea:Implication for East Asian monsoon evolution[J].Chinese Science Bulletin, 2008, 53(10):1533-1543.
[14] 高抒. 沉积物粒径趋势分析:原理与应用条件[J]. 沉积学报,2009,27(5):826-836.
[GAO Shu. Grain size trend analysis:Principle and applicability[J]. Acta Sedimentologica Sinica,2009,27(5):826-836.]
[15] Poizot E, Mear Y, Thomas M, et al. The application of geostatistics in defining the characteristic distance for grain size trend analysis[J]. Computers & Geosciences, 2006, 32:360-370.
[16] 谢昕,郑洪波,陈国成,等.古环境研究中深海沉积物粒度测试的预处理方法[J].沉积学报, 2007, 25(5):684-692.
[XIE Xi,ZHENG Hongbo,CHEN Guocheng,et al.Pretreatment method of grain size measurement of marine sediments in paleoenvironment research[J]. Acta Sedimentologica Sinica,2007, 25(5):684-692.]
[17] Folk R L, Ward W C. Brazos River bar:a study in the significance of grain size parameters[J]. Journal of Sedimentary Petrology, 1957, 27:3-26.
[18] Shepard F P. Nomenclature based on sand-silt-clay ratios[J].Journal of sedimentary Petrology, 1954, 24(3):151-158.
[19] Gao S, Collins M. A critique of the McLaren method for defining sediment transport paths:discussion[J]. Journal of Sedimentary Petrology, 1991, 61(1), 143-146.
[20] Gao S, Collins M. Sand sediment transport patterns inferred from grain-size trends based upon definition of "transport vectors"[J]. Sedimentary Geology, 1992, 80, 47-60.
[21] Gao S, Collins M. Analysis of grain size trends, for defining sediment transport pathways in marine environments[J]. Journal of Coastal Research, 1994, 10(1):70-78.
[22] Gao S. A Fortran program for grain-size trend analysis to define sand sediment transport pathways[J]. Computers & Geosciences, 1996, 22(4), 449-452.
[23] 贾建军, 程鹏, 高抒.利用插值试验分析采样网格对粒度趋势分析的影响[J]. 海洋地质与第四纪地质,2004,24(3):135-141.
[JIA Jianjun,CHENG Peng,GAO Shu.Comparison between grain size trends derived from irregular and regular sampling grids with the help of GIS interpolation tools[J]. Marine Geology and Quaternary Geology,2004,24(3):135-141.]
[24] Sahu K B. Depositional mechanisms from the size analysis of clastic sediments[J]. Journal of Sedimentary Petrology, 1964, 34(1):73-8.
[25] 陈弘,邱燕,钟和贤,等.南海西南海盆晚更新世以来沉积物粒度特征与成因分析[J]. 南海地质研究,2004:66-74.[CHEN Hong, QIU Yan, ZHONG Hexian, et al. Characteristics of grain size of core sediments in the southwest basin of South China Sea[J]. Geological South China Sea, 2004:66
-74.]
[26] McCave I N,Manighetti B,Robinson S G. Sortable silt and fine sediment size/composition slicing:Parameters for palaeocurrent speed and palaeoceanography[J]. Paleoceanography, 1995, 10(3):593-610.
[27] Chang T S, Joerdel O, Flemming B W, et al. The role of particle aggregation/disaggregation in muddy sediment dynamics and seasonal sediment turnover in a back-barrier tidal basin, East Frisian Wadden Sea, southern North Sea[J]. Marine Geology, 2006, 235:49-61.
[28] Stevens R L, Bengtsson H, Lepland A. Textural provinces and transport interpretations with fine-grained sediments in the Skagerrak[J]. Journal of Sea Research, 1996, 35(1-3):99-110.
-
计量
- 文章访问数: 1123
- PDF下载数: 4
- 施引文献: 0
下载: