Abstract

In the Ritchie’s Archipelago of the Andaman group of islands (Northern Indian Ocean), Havelock Island is the largest one. The present study on diatoms has been carried out on three outcrops of Havelock Island situated in Kalapathar, South Point and Laccam Point localities. Samples collected from the three Neogene outcrops yielded poor to moderately preserved diatom valves. Two lithological units are exposed in this island, i.e., Inglis and Long formations. The diatoms have been recovered from the Inglis Formation and the diatom assemblages are represented by the marker diatom species, viz., Actinocyclus ingens, Annellus californicus, Araniscus lewisianus, Cestodiscus peplum, Craspedodiscus coscinodiscus, Denticulopsis simonsenii, and Rossiella paleacea that indicate the age as Burdigalian to early Serravallian.

中文翻译：

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北印度洋哈夫洛克岛的布尔迪加利至早期塞拉瓦利亚硅藻生物地层

摘要

在安达曼群岛（北印度洋）的里奇群岛中，哈夫洛克岛是最大的岛屿。目前对硅藻的研究是在位于卡拉帕塔尔，南点和拉克坎点地区的哈夫洛克岛的三个露头上进行的。从三个Neogene露头收集的样品产生的硅藻瓣差到中等程度保留。该岛上有两个岩性单元，即英格里斯（Inglis）和朗格（Long）地层。硅藻已从英格里斯组中回收，硅藻组合以标记硅藻种为代表，即标记猕猴桃，Actinocyclus ingens，Annellus californicus，Leaniscus lewisianus，Cestodiscus peplum，Craspedodiscus coscinodiscus，Denticulopsis simonsenii和Rossiella paleacea表示年龄为Burdigalian到Serravallian早期。