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Les Diatomées Holocènes du Bassin Inferieur de l'Aouache (Dépression des Danakil, Ethiopie). Leur Signification Paléoécologique
Author(s) -
Gasse Françoise
Publication year - 1974
Publication title -
internationale revue der gesamten hydrobiologie und hydrographie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 0020-9309
DOI - 10.1002/iroh.19740590113
Subject(s) - holocene , period (music) , geology , diatom , ostracod , brackish water , salinity , structural basin , ecology , physical geography , oceanography , geography , paleontology , biology , physics , acoustics
Holocene Diatoms of Lower Awash Basin (Danakil Depression, Ethiopia). Their Paleoecological Meaning Some residual lakes can be observed in the lower Awash Basin (Danakil Depression, Ethiopia). During the Lower Holocene period, a big lacustrine episode, already known in the South‐Saharian area, has been evidenced here. The deposits are rich in diatoms. Their systematic and quantitative study give valuable information on the ecological and climatic conditions of their sedimentation. During the optimal lacustrine period, the diatoms were the most abundant and the most varied. This period was preceded by several short oscillations of the water level. The shores of the paleolake were marshy, but its central area was deep enough for planktonic flora to prevail. Lacustrine, alkaline waters, rich in nutritive elements of organic origin, were not very saline. However, the salinity reached high enough values to allow the growth of brackish species. The quantitative importance of tropical diatoms shows that a hot climate occured in the Danakil Depression at the beginning of the lacustrine episode. During the lacustrine optimum the temperature was probably lower.