Characteristics of the late Quaternary tephra layers in the East/Japan Sea and their new occurrences in western Ulleung Basin sediments
Characteristics of the late Quaternary tephra layers in the East/Japan Sea and their new occurrences in western Ulleung Basin sediments
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DOI：
10.1016/s0025-3227(03)00287-1
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发表时间：
2003-11
期刊：
影响因子：
2.9
通讯作者：
Myong-ho Park;Ilsoo Kim;Jae-Bong Shin
中科院分区：
文献类型：
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作者：
Myong-ho Park;Ilsoo Kim;Jae-Bong Shin
根据东/日本海郁陵海盆地西部的4个活塞岩心，确定了晚第四纪火山灰层的岩性特征、地层关系和平面分布。结果表明，使用形态学和主要元素组成数据，分散在火山灰层中的火山玻璃碎片与郁陵岛（约）的沉降沉积物相同。9.3 ka），Aira-Tanzawa（ca. 22 ka），and Ulleung-Yamato（ca. 33 ka）。产自郁陵岛的火山碎屑层（郁陵岛-隐岐和郁陵岛-大和）主要由浮石型玻璃碎片组成，并伴有少量的碱长石、黑云母和斜长石。另一方面，来自日本岛屿的火山灰层（包括Aira-Tanzawa火山灰）主要由气泡壁和/或平面型玻璃组成，其含有比火山砾火山灰层更高的SiO2和更低的Al 2 O3。郁良盆地西部火山灰层的出现及其地层对比使浮石型玻璃碎片的分布范围扩大到先前已知的沉降区以西约50-100公里处。
The lithologic characteristics, stratigraphic relationships, and areal distribution of late Quaternary tephra layers have been determined based on four piston cores, recovered from the western Ulleung Basin of East/Japan Sea. The results show that, using morphological and major element compositional data, volcanic glass shards dispersed in tephra layers are identical to those of fallout deposits of the Ulleung–Oki (ca. 9.3 ka), Aira–Tanzawa (ca. 22 ka), and Ulleung–Yamato (ca. 33 ka). The lapilli tephra layers (Ulleung–Oki and Ulleung–Yamato) originating from Ulleung Island consist predominantly of pumice-type glass shards associated with minor amounts of alkali-feldspar, biotite, and plagioclase. On the other hand, the ash layers (including the Aira–Tanzawa ash) derived from the Japanese islands are mainly composed of bubble-wall and/or plane-type glasses that contain higher SiO2and lower Al2O3than the lapilli tephra layers. The occurrence of tephra layers in the western Ulleung Basin and their stratigraphic correlation extend the distribution of pumice-type glass shards about 50–100 km west of the previously known fallout zone.