DOI: 10.1016/j.palaeo.2017.06.022
论文题名: Late Holocene sea-level changes and paleoclimate recorded in Lake Lungué, southern Mozambique
作者: Sitoe S.R. ; Risberg J. ; Norström E. ; Westerberg L.-O.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
语种: 英语
英文关键词: Diatom
; Human impact
; Lake level changes
; Limpopo River
; Mineral magnetic properties
英文摘要: We report on late Holocene paleoenvironmental and sea-level changes in southern Mozambique, based on analysis of diatom stratigraphy, mineral magnetic susceptibility, Saturation Isothermal Remnant Magnetization (SIRM) and organic carbon content in a sediment core from Lake Lungué, located ca. 30. km north of Xai Xai City in the Limpopo River floodplain. Eleven radiocarbon dates performed on terrestrial shells allowed establishment of an age-depth model. High content of brackish-marine taxa, especially Diploneis suborbicularis and Navicula yarrensis, suggests that the Lake Lungué basin was part of the Indian Ocean coastal zone between ca. 740 and 910. CE, suggesting higher relative sea-level during this phase. A similar diatom distribution in older parts of the sequence, of unknown age, indicates that the site was connected to the Indian Ocean also at some stage prior to 740. CE. Between ca. 910 and 1130. CE the basin was under a combined effect of sporadic marine water influx and Limpopo River actions. A freshwater lake was established sometime between 1130 and 1360. CE, when the basin became less affected by marine influences due to lower sea-levels. Instead, the lake system was more influenced by Limpopo River meandering dynamics and flooding events, and eventually isolated into a more or less independent lake ecosystem where diatom diversity most likely responded to lake levels fluctuations driven by shifts in relative humidity and rainfall amounts within the floodplain and also from upstream sources. During this phase, high abundance of freshwater planktonic species, i.e. Aulacoseira granulata and A. ambigua, indicates high lake levels and wetter conditions dated to ca. 1360-1560. CE. From 1560. CE until present, the lake has been subject to drier conditions and higher evaporation as indicated by lower lake levels, reported by a decline in freshwater planktonic taxa and increase in brackish taxa, e.g. Amphora robusta. © 2017. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68088
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Physical Geography, Stockholm University, S-106 91 Stockholm, Sweden; Department of Geology, University of Eduardo Mondlane, Maputo, Mozambique; Bolin Centre for Climate Research, Stockholm University, S-106 91 Stockholm, Sweden; Department of Geological Sciences, Stockholm University, S-106 91 Stockholm, Sweden
Recommended Citation:
Sitoe S.R.,Risberg J.,Norström E.,et al. Late Holocene sea-level changes and paleoclimate recorded in Lake Lungué, southern Mozambique[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01