珠江三角洲潮坪沙蚕遗迹的组成和分布特征及其对沉积环境的指示作用
- 收稿日期:
2024-02-20
- 网络出版日期:
2024-05-23
摘要: 【目的】珠江三角洲潮坪沉积环境复杂，沙蚕遗迹丰富，现代沙蚕遗迹的特点、分布及其与沉积环境、沉积物性质的关系，对遗迹化石及古环境研究具有重要的实证价值，但现代沙蚕遗迹研究起步较晚，国内研究成果较少。【方法】选取珠江三角洲潮坪为研究区，运用现代沉积学及遗迹学方法，通过分析粒度、盐度、浑浊度及 X 射线计算机断层扫描和计算机重构方法对取芯的样品进行处理，对研究区内现代沙蚕遗迹的组成与分布特征进行了精细研究，并分析了遗迹分布与沉积环境和物化条件的关系。【结果】1）双齿围沙蚕主要生活在珠江三角洲的水下汊道和分流间海湾的潮坪区域。2）双齿围沙蚕的遗迹主要有觅食迹和居住迹，但层面上的觅食迹不易观察到，层内居住迹形态主要有简单的Y形、I形和U形以及复杂网状结构，连接处有鼓包。3）双齿围沙蚕适合生活在水动力条件较为低能、盐度较低、浑浊度较低、总有机碳含量丰富的分流间湾潮坪或水下汊道中。【结论】沙蚕遗迹在空间分布上具有不均衡性，多种环境条件共同控制沙蚕遗迹的丰度，沙蚕居住迹与遗迹化石Polykladichnus相似，该遗迹化石可属于Mermia遗迹相和Glossifunites遗迹相，该遗迹化石组合主要出现在潮间带和潮道区域，该研究补充了现代沙蚕遗迹的生物学资料。
The Composition and Distribution Characteristics of Perinereis Trace Fossils in Tidal Flat of Pearl River Delta and Their Indicative Role in the Sedimentary Environment
- Received Date:
2024-02-20
- Available Online:
2024-05-23
Abstract: [Objective] The sedimentary environment of the Pearl River Delta is complex. with abundant Perinereis trace fossils. The characteristics，distribution and assemblage of Perinereis and their relationships with sedimentary environment and sediment properties are significant for the study of trace fossils and palaeoenvironment. [Methods] Based on sedimentary and ichnological methods, grain size analysis, salinity, turbidity, total organic carbon (TOC), X-ray scans, and three-dimensional (3D) reconstruction were applied to the modern biogenic sedimentary structures in different microenvironments of the Pearl River Delta tidal flat, discussed the composition，assemblage and distribution characteristics of Perinereis in tidal flat of Pearl River Delta, and analyzed the relationship between the biological assemblage and the sedimentary environments. [Results] 1) The Perinereis mainly lives in the tidal flat area of the tidal channel and the interdistributary bay in the Pearl River Delta. 2) The remains of the Perinereis mainly have grazing trails and dwelling trails, but the grazing trails on the layer are hard to observe, and the dwelling trails in the layer mainly have simple Y-shaped, I-shaped and U-shaped and complex network structures, and there are bulges at the joints. 3) The Perinereis is suitable for living in the tidal flat or tidal channel of the interdistributary bay with low hydrodynamic conditions, low salinity, low turbidity and rich total organic carbon content. [Conclusions] The spatial distribution of Perinereis’ neoichnology is imbalanced, and multiple environmental conditions jointly control the abundance of Perinereis’ neoichnology. The habitat of Perinereis is similar to the trace fossil Polykladichnus, which can belong to both the Mermia and Glossifunites ichnofacies, the trace fossil assemblage of this relic mainly appears in the channel and tidal flat area, and this study supplements the biological data of modern neoichnology of Perinereis.
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