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Growth rates and Holocene development of stromatolites from Shark Bay, Western Australia

 

作者: A. R. Chivas,   T. Torgersen,   H. A. Polach,  

 

期刊: Australian Journal of Earth Sciences  (Taylor Available online 1990)
卷期: Volume 37, issue 2  

页码: 113-121

 

ISSN:0812-0099

 

年代: 1990

 

DOI:10.1080/08120099008727913

 

出版商: Taylor & Francis Group

 

关键词: radiocarbon dating;Shark Bay;stromatolites

 

数据来源: Taylor

 

摘要:

The growth rates and patterns of stromatolites are of interest in that fine‐scale laminations in some Precambrian examples have been interpreted as daily growth layers whose orientations reflect the annual transit of the sun. By contrast, the modern and Holocene stromatolites at Shark Bay occur in a high‐energy environment where accumulation and growth only marginally exceed erosion. Long‐term vertical growth rates of ≤0.4 mm/year were determined by radiocarbon dating and supported by uranium‐series methods. These rates are up to 250 times slower than those growth rates estimated from the laminae patterns of some Precambrian stromatolites. Thus, daily bands are not recognized and individual subtidal stromatolite columns from Shark Bay take up to 1000 years to reach their present heights of ∼ 350 mm. The earliest exposed stromatolites at Shark Bay grew during the interval 1250–1000 years ago and are now dead and stranded (in response to falling relative sea level) in terraces some 0.3 m above present high tide.

 

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