Ying Chengjuan, Yao Duoxi, Chen Haiming
School of Earth and Environment, Anhui University of Science and Technology, Huainan 232001, China.
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan 232001, China.
ACS Omega. 2024 Jun 18;9(26):27998-28007. doi: 10.1021/acsomega.4c00597. eCollection 2024 Jul 2.
The pelite samples were collected from drillholes from the Chengmen area of the Fuzhou Basin of Fujian, China to reveal the sediments resource and tectonic environment of these pelites via an analysis of its lithology and geochemistry. The rare earth element distribution pattern of the pelites exhibited a high degree of fractionation between light and heavy rare earth elements, moderate negative Eu anomalies, and positive Ce anomalies, which are consistent with the rare earth element distribution pattern of Minjiang sediments and Fujian soils. Moreover, the variations in trace elements are also generally consistent, indicating a common provenance. The extremely high chemical index of alteration (CIA) and index of chemical variability (ICV) values of the pelites suggest that the source area experienced intense weathering, indicating a subtropical hot and humid climate environment in the source area and the Fuzhou Basin at that time. The source rock attribute discrimination diagrams show that the main source of pelites is felsic igneous rocks. The ratios of REDOX parameters show that during the sedimentary period, the water body in the study area was predominantly in an oxidizing environment. Furthermore, the tectonic background diagrams reveal that the source area underwent geological tectonic evolution processes of active and passive continental margins, marking the transition from the continental margin above the subduction of the ancient Pacific plate to the continental margin extension after subduction cessation.
从中国福建福州盆地城门地区的钻孔中采集了泥质岩样品，通过对其岩性和地球化学分析，揭示这些泥质岩的沉积物来源和构造环境。泥质岩的稀土元素分布模式显示出轻重稀土元素之间高度分馏、中等负铕异常和正铈异常，这与闽江沉积物和福建土壤的稀土元素分布模式一致。此外，微量元素的变化也总体一致，表明有共同的物源。泥质岩极高的化学蚀变指数（CIA）和化学变异指数（ICV）值表明源区经历了强烈风化作用，指示当时源区和福州盆地处于亚热带炎热潮湿的气候环境。源岩属性判别图表明泥质岩的主要来源是长英质火成岩。氧化还原参数比值表明，沉积时期研究区水体主要处于氧化环境。此外，构造背景图显示源区经历了主动和被动大陆边缘的地质构造演化过程，标志着从古代太平洋板块俯冲之上的大陆边缘向俯冲停止后的大陆边缘伸展的转变。
