华南海岸沙丘岩的特征及其与海滩岩的区别
- 中山大学地质系, 广州 510275
基金项目:
国家自然科学基金
作者简介:
王建华 男 38岁 副教授 沉积学
- 收稿日期:
1995-11-19
- 刊出日期:
1997-03-10
摘要: 沙丘岩是热带亚热带的一种特殊的岩石类型，尽管外貌相似，但它们成因和特征上有别于海滩岩。作者通过对西沙石岛、海南岛文昌和临高、广东阳江青洲岛、汕头广澳等处具一定代表性的沙丘岩的研究，总结了沙丘岩的沉积学、岩石学特征及其与海滩岩的区别。华南沙丘岩由岛屿上的灰砂和含生物碎屑的海岸风成沙丘物质胶结而成。分布高程可达＋６０ｍ以上，岩石中发育板状交错层理、大型槽状交错层理、上凸层理、似水平层理以及根管构造；其物质来源与海滩砂具继承关系，兼具风成砂的特点，部分沙丘岩还混有坡积物及陆生生物壳体。沙丘岩的颗粒多为中砂粒径，普遍分选好，（ＳＫ１）偏度变化比较大，ＫＧ峰度较小，Ｙ１值为负值，与海滩砂、海滩岩差别较大。沙丘岩中发育各种淡水渗流环境中特有的胶结物和胶结组构。虽然沙丘岩与现代海滩岩相比，其Ｃａ、Ｍｇ、Ｓｒ元素的含量及比例不同，但可以完全与上升海滩岩相似。本文作者认为：辨别沙丘岩主要从产状、沉积构造、粒度分析、胶结物及组构诸方面进行研究。
Characteristics of Dune Rocks in the South China Coast and Their Differences from Beach Rocks
- Department of Geology Zhongshan University Guangzhou 510275
- Received Date:
1995-11-19
- Publish Date:
1997-03-10
Abstract: Dune rock is a special type of rocks in tropic and subtropic areas. Although dune rock is similar tobeach rock in the external figure, their origins and features are quite different. By the study on some rep-resentative outcrops of dune rocks in Shidao (Xisha Islands)，Wenchang and Linggao(Hainan Island)，Qingzhou Island(Yangjian, Guangdong) and Guang- Ao(Shantou, Guangdong)，the author makes asummary to the sedimentological, petrological characteristics of dune rocks and their differences frombeach rocks. Dune rocks in South China are formed by the cementation of island limesands and coastal bioclasticdensands. which can be dstributed in the zone(with an altitude over bom).Th ere are high angle plate cros s一bedding, megatrough cro ss一bedding, conv ex cross- bedding, pares- parallel bedding, megatrough croc s一bedding, conv ex cross- bedding, Parallel bedding, and cacting tubes(mould) of tree roots in therocks. The elastic materials of dune rock inherit the characters of the beach sands, but also carry on thefeatures of eolian sands.Some of them contain the collision sediments or bodies of terrestrial organisms. The grains of dune rocks which are, in general, middle- fine sands arewell sorted with variableand negative Ywhich are quite different from those of beach sands. The cement miner一als and fabrics, Peculiar in the fresh water vadose environment, are welldevoloped in dune rocks. Al-though the Ca Mg} and Sr contents and proportions in dune rocks are different from those of beachrocks, they can be very similar to those of uplift beach rocks. So，the author considers that the main way to recognize dune rocks is to study their outcropo ccur-rence, sedimentary structure, granulometry，cement and〔ement fabric，etc·
王建华. 华南海岸沙丘岩的特征及其与海滩岩的区别[J]. 沉积学报, 1997, 15(1): 104-111.
| 引用本文: |
王建华. 华南海岸沙丘岩的特征及其与海滩岩的区别[J]. 沉积学报, 1997, 15(1): 104-111.
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Wang Jianhua. Characteristics of Dune Rocks in the South China Coast and Their Differences from Beach Rocks[J]. Acta Sedimentologica Sinica, 1997, 15(1): 104-111.
| Citation: |
Wang Jianhua. Characteristics of Dune Rocks in the South China Coast and Their Differences from Beach Rocks[J]. Acta Sedimentologica Sinica, 1997, 15(1): 104-111.
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