PDF
Full
Outline
The submarine topographic features and distribution types of the Xuande atoll in the Xisha Islands have important indications for the influence of regional geological structure, sea level rise and fall, and ocean hydrodynamics. In order to study the submarine topography and geomorphology of the Xuande atoll, we detailed survey in the Xuande atoll of the Xisha Islands, including side scan sonar, single-beam sounding, and surface sediment sampling. The results show that: (1) Xuande atoll is a type of incomplete atoll, with lagoon deposits in the middle, and four water channels with a water depth of about 60 m had been divided, namely, the gate of the Xishazhou at the northwest of the atoll, the “Red Grass Gate” of the Nanshazhou-Yongxing, the gap on the west side of the atoll, and the gap on the south side of the atoll; (2) according to the geomorphic features, the underwater geomorphic types of the Xuande atoll are divided into 3 grades and 11 types of grades classification systems. The dynamic geomorphology units such as sand waves and grooves in the study area show that the submarine features in the shallow water area of Xuande atoll are controlled by prevailing monsoons and wave sites. The tidal channel water body formed by the deep water entrance is the main factor shaping the dynamic geomorphology of the Xuande atoll lagoon area. There are six levels of underwater terraces on the seaward slope in the southeastern part of the study area. By comparing the characteristics of the coral reef terraces in the South China Sea, the genesis of the seaward slope terraces on the Xuande atoll is likely to be a combination of global sea level changes and crustal subsidence.
PDF
145
55
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
