首页 | 本学科首页   官方微博 | 高级检索  
     


Diatom paleoecology of the Mar Chiquita lagoon delta,Argentina
Authors:Marcela A. Espinosa
Affiliation:(1) Centro de Geologia de Costas y del Cuaternario (UNMDP), c.c. 722, 7600 Mar del Plata, Argentina
Abstract:A 68 cm thick outcrop of diatomaceous sediments at the head of Mar Chiquita Lagoon on the Argentine coast near Buenos Aires provides evidence of Holocene paleoenvironmental changes related to sea level changes and freshwater input to the lagoon system. Salinity tolerances of extant diatom taxa were used for the reconstruction and multivariate analytical techniques were applied to reduce subjective interpretations of the diatom percentage data.The basal half of the record was deposited before 3000 years ago and fossil diatoms indicate generally freshwater conditions with one fluctuation in mesohalobous diatoms suggesting brackish water conditions at a depth of about 60 cm. Polyhalobous (marine) diatoms characterize the record after 3000 years ago and large numbers of epiphytic diatoms indicate salt marsh environments with episodic seawater fluctuations to supratidal levels. Freshwater diatoms returned at the top of the outcrop, presumably as a result of the restriction of the historic marine inlet to the lagoon and the effects of freshwater inflow to the basin.This is the second in a series of papers published in this issue on ldquoPaleolimnology in Southern South Americardquo. Dr. C. A. Fernández served as guest editor for these papers.
Keywords:diatoms  paleoecology  multivariate analysis  coastal lagoon  Holocene  environmental changes  South America  Argentina
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号