全新世以来珠江三角洲快速沉积体的初步研究
A preliminary study on rapid deposition bodies in the Zhujiang Delta since Holocene
-
摘要: 根据珠江三角洲代表性钻孔资料以及PRD-LTMM长周期"动力-沉积-形态"模型分析了珠江三角洲形成发育过程中的快速沉积现象,提出了珠江三角洲快速沉积体的概念,并且对典型快速沉积体的成因进行了初步分析。快速沉积体有明确的沉积环境和特定的沉积动力成因,沉积速率为每年厘米级,研究它可以深入地揭示珠江三角洲基本沉积单元的形成过程,为探索珠江三角洲的形成、发育机制打下基础。初步发现的快速沉积体有古汇潮点快速沉积体、古涨潮射流快速沉积体和台地周边快速沉积体。研究结果表明,快速沉积体的形成多与特定的地形边界条件下形成的中、小尺度动力结构有关,具有高度的时空变化。掌握珠江三角洲地形边界的特点、变化过程及其作用下的中、小尺度动力结构是研究珠江三角洲快速沉积体的关键。Abstract: Based on the typical bore holes of the Zhujiang Delta and the long-term morphodynamic model PRD-LTMM, rapid deposition body (RDB) is examined. The RDB is defined, and the formations of typical RDBs in the Zhujiang Delta are analyzed initially. The RDBs hold the specific sedimentary environment and particular sedimentary dynamics with the annual deposition rate of centimeters; so, the research on the RDBs can help disclose the mechanism of the basic sedimentary units in the Zhujiang Delta, providing a basis for the study of mechanism of the Zhujiang Delta evolution. The initially discovered RDBs include depositions at the paleo-tide convergent flow and the paleo-flood tidal jet, fringing deposition around the palco-terrance. A study result shows that the formation of RDBs, with being highly variable in time and space, is related to the small- to medium-scale dynamic structures under particular morphologic boundaries. Understanding the morphologic boundary,its evolution process and medium- to small-scale dynamic structures under corresponding morphologic boundaries in the Zhujiang Delta is key to the research of the RDBs.
-
Key words:
- Zhujiang Delta /
- morphologic boundary /
- rapid deposition body /
- mechanism
-
李从先.三角洲沉积率及其地质意义[J].海洋科学,1981(3):30—33. STEFANI Marco, VINCENZI Stefano. The interplay of eustasy, climate and human activity in the late Quaternary depositional evolution and sedimentary architecture of the Po Delta system[J]. Marine Geology,2005(222—223):19—48. STEVEN A, KUEHL A, BETH M, et al. Subaqueous delta of the Ganges-Brahmaputra river system[J]. Marine Geology,1997(144):81—96. 黄镇国,等. 珠江三角洲形成发育演变[M]. 广州:科学普及出版社广州分社,1982:1—271. GILBERT G K. Lake Bonneville[J]. U.S.Geological Survey Monograph[J].1890,1(1): 438. FISK H N. Sand facies of recent Mississippi Delta deposit // Fourth World Petroleum Congr. Rome: Proc Sec 1/C,1955:377—398. COLMAN J M, GAGLIANO S M. Cyclic sedimentation in the Mississippi River Deltaic Plain[J]. Trans Gulf Coast Assoc Geol Soc,1964,14:67-80. FRAZIER D E. Recent deltaic deposits of the Mississippi River: their development and chronology[J].Trans Gulf Coast Assoc Geol Soc,1967,17:287—315. 陈吉余,恽才兴,徐海根,等.两千年来长江河口发育的模式[J].海洋学报,1979,1(1):103—111. 周志德.黄河河口三角洲海岸的发育及其对上游河道的影响[J].海洋与湖沼,1980,11(3):211—219. 同济大学海洋地质系三角洲研究组.全新世三角洲的形成发育[J].科学通报,1982(5):310—313. 吴超羽,何志刚,任杰,等.珠江三角洲中部子平原形成演变机理研究——以大鳌平原为例[J].第四纪研究,2007,27(5):814—827. 李平日,乔彭年,郑洪汉,等.珠江三角洲一万年来环境演变[M].北京:海洋出版社, 1991:154. 何志刚.珠江三角洲大鳌平原形成与古磨刀门动力演变的互动机制研究 .广州:中山大学,2006. 汪桂荣.珠江三角洲全新世硅藻[J].古生物学报,1998,37(3):305—324. 吴超羽,包芸,任杰,等.珠江三角洲及网河形成演变的数值模拟和地貌动力学分析:距今6 000~2 500 a[J].海洋学报,2006,28(4):64—80. -
计量
- 文章访问数: 1986
- HTML全文浏览量: 23
- PDF下载量: 1467
- 被引次数: 0
下载:
