对珠江三角洲第四纪断裂运动的再认识  

Late Quaternary Tectonic Movements in the Pearl River Delta, China, Revealed from Stratigraphic Profiles

作　　者：余章馨 张珂[1] 梁浩[1] 李忠云[1] 

机构地区：[1]中山大学地球科学与地质工程学院,广州510275

出　　处：《热带地理》2016年第3期334-342,共9页Tropical Geography

基　　金：广东省自然科学基金资助(S2011010001511)

摘　　要：编制了珠江三角洲番禺台地东缘第四纪堆积阶地、陆域钻孔及海域地震探测等一系列联合剖面,分析了抬升区、下沉区和海陆之间的沉积差异和控制因素,剖析了地动型和水动型海平面变化对三角洲形成演化的影响,厘清了各组断裂的活动及其对三角洲沉积发育的影响,结果发现北东东向和北北西向2组断裂为珠江三角洲地区的主要活动断裂,它们共轭联动,控制着珠江三角洲沉积的格局和水道的变迁,尤其是北东东向断裂,可能是南海北部大陆架滨海断裂系的组成部分。相比而言,陆域断裂活动性较弱,以缓慢蠕动和断块的差异升降和掀斜为主,海域断裂活动性较强,滨海断裂带是危险性很高的活动大断裂。三角洲其他方向的断裂更新世以来无明显活动。The Pearl River Delta is located at north margin of the South China Sea. Neotectonic movements play important role on the evolution of the delta featured as fault-blocks differential uplift and subsidence. Some critical topics, e.g. the active variation of different fault groups, the pattern of fault-blocks movements, are still debatable. Recently some Quaternary depositional terraces were discovered on Panyu Platform in the north Pearl River Delta. Those terraces can be identified into several stratigraphic layers： A. migmatite or granite bedrocks which have been deeply weathered into vermicular red soil, B. greyish white and yellow medium/coarse sand, cross-bedding structure, with weathering surfaces, C. dark grey to black silt with a few fine sand lense, wood fragments layer in the bottom, and D. dark grey silt, rhythmically intercalated by greyish white sand layers. Study on sedimentary facies of those layers shows that this sequence belongs to the Pearl River Delta lower marine transgressive cycle, which means the delta deposits was tilted after the 1st transgressive deposition, due to the NNW trending Hualong-Huangge fault zone. Other W-E and N-S trending terrace-borehole stratigraphic profiles in the Pearl River Delta area reveal the active variation of different fault groups. The W-E and NE-SW trending faults control the edge of the Pearl River Delta, while little influence on the pattern of delta deposition process and river channel distribution. The NNW-SSE and NEE-SWW trending faults are still active since the 1st marine transgression, making the delta deposits weekly tilt. The comparison of sedimentary sequence in the Pearl River Delta with continental shelf of the Northern South China Sea illustrates that besides the 2 cycles in the Pearl River Delta, there are much older cycles on the continental shelf due to intensive activities of the Littoral Fault Zone.

关 键 词：新构造运动 堆积阶地 活动断层 珠江三角洲 

分 类 号：P54[天文地球—构造地质学]