干旱区生态环境知识资源中心

[ 1] We present a high-resolution record of calcareous nannofossils from the northern Red Sea for the last 22 kyr. Extreme conditions with enhanced salinities during the Last Glacial Maximum are characterized by high values of Gephyrocapsa ericsonii. The dominance of Emiliania huxleyi in Heinrich event 1 indicates a climatic cooling favoring the bloom of opportunistic species. The calcareous nannofossils record a two-step onset of the postglacial humid climate, punctuated by the Younger Dryas. Both steps show an early oligotrophic phase dominated by Florisphaera profunda and Gladiolithus flabellatus and a subsequent fertile phase characterized by E. huxleyi. The Younger Dryas is described by high values of Gephyrocapsa oceanica, indicating an increased mixing of the water column. In the late Holocene, repetitive increases in abundance of F. profunda and G. flabellatus reflect restricted oligotrophic conditions, caused by the high aridity following the Holocene humid period.