Wackestone petrography and bipolar orientation of cephalopods as indicators of littoral sedimentation in the Ludlovian of Gotland
作者:
Björn Sundquist,
期刊:
Geologiska Föreningen i Stockholm Förhandlingar
(Taylor Available online 1982)
卷期:
Volume 104,
issue 1
页码: 81-90
ISSN:0016-786X
年代: 1982
DOI:10.1080/11035898209454544
出版商: Taylor & Francis Group
关键词: Limestone petrography;early lithification;orientation of cephalopods;bipolar orientation;littoral sedimentation;ephemeral sedimentation;bathymetry;Hemse Beds;Ludlovian;Silurian;Gotland;Sweden;N5726 N5727 E1854 E1853
数据来源: Taylor
摘要:
The orientations of the apical end of orthoconic nautiloids that occur in abundance on the bedding planes of a sequence of wackestones in the Hemse Beds show two subequal opposing maxima, giving a bipolar orientation pattern. The petrography of the wackestones indicates an early lithification. It is concluded that the rocks represent littoral deposition in a lagoonal environment, and that the nautiloid shell accumulations were caused by stranding in connection with ephemeral incidents. The inferred bathymetry contradicts earlier opinions based exclusively on palaeontological criteria.
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