CAJ | 학술논문

　　对珠江三角洲PRD16孔的微体动物群进行了分析，共发现底栖有孔虫12属24种，介形类9属13种，它们可分别划分为3种生态类型。根据有孔虫和介形类微体动物群的分布特征、并结合岩性和沉积粒度特征，推断PRD16孔研究区晚更新世以来沉积环境演化经历了5个阶段：①34600 cal a BP以前为河流相环境，形成了研究区最早的第四纪河床相砂砾沉积；②34600～23900 cal a BP推测为河口湾环境；③23900～7960 cal a BP受末次盛冰期影响，研究区暴露地表遭受风化剥蚀，形成花斑黏土；④7960～2810 cal a BP为全新世大海侵时期，研究区为河口海湾环境，发育以广盐性有孔虫和中盐-多盐性介形类为主的微体动物群，其间发生了2次小规模海平面波动，受地块区域沉降作用影响，研究区在3873 cal a BP左右水深达到最大，主要有孔虫和介形类属种的丰度达到全新世最高值；⑤2810 cal a BP以来海平面持续下降，研究区由潮坪环境变为河口砂坝，随后河流作用增强，又逐渐变为河流冲积-潮上带环境。
　　대주강삼각주PRD16공적미체동물군진행료분석，공발현저서유공충12속24충，개형류9속13충，타문가분별화분위3충생태류형。근거유공충화개형류미체동물군적분포특정、병결합암성화침적립도특정，추단PRD16공연구구만경신세이래침적배경연화경력료5개계단：①34600 cal a BP이전위하류상배경，형성료연구구최조적제사기하상상사력침적；②34600～23900 cal a BP추측위하구만배경；③23900～7960 cal a BP수말차성빙기영향，연구구폭로지표조수풍화박식，형성화반점토；④7960～2810 cal a BP위전신세대해침시기，연구구위하구해만배경，발육이엄염성유공충화중염-다염성개형류위주적미체동물군，기간발생료2차소규모해평면파동，수지괴구역침강작용영향，연구구재3873 cal a BP좌우수심체도최대，주요유공충화개형류속충적봉도체도전신세최고치；⑤2810 cal a BP이래해평면지속하강，연구구유조평배경변위하구사패，수후하류작용증강，우축점변위하류충적-조상대배경。
Microfaunas of borehole PRD16 in the Pearl River Delta have been quantitatively analyzed in this paper.A total of 24 benthic foraminifera species referred to 12 genera and 13 ostracod species re-ferred to 9 genera were found in the borehole.They can be divided into 3 ecological groups.The micro-faunal analytical results, combined with lithological and sedimentary grain characteristics , suggest that the study area experienced environmental changes since the Late Pleistocene .A riverine environment be-gan to develop before 34 600 cal a BP.Between 34 600 and 23 900 cal a BP, the environment generally changed to an estuarine condition .Between 23 900 and 7 960 cal a BP, the sediments experienced weathering and erosion, characterized by a layer of mottled clay .At around 7 960 cal a BP, sea level rose rapidly and an estuary environment with euryhaline foraminifera and brackish ostracod faunas existed until 2 810 cal a BP.Two second-order sea level fluctuations can be recognized based on the composition and abundance of microfaunas .The maximum water depth occurred at approximately 3 873 cal a BP, demonstrated by the highest abundance of foraminifera and ostracods in the borehole .Since 2 810 cal a BP, the environment gradually changed into a fluvial supratidal zone with increased influence of river processes.