Vegetational History of the Area around Kashira Island in the Inland Sea, Okayama Prefecture, Western Japan

Abstract

Kashira Island is situated in the Inland Sea, near Hinase town, Okayama Prefecture. The 44-m core consisted of clay, sandy clay, gravel with sand, humus and tephra (Aira: 2, 540-2, 390cm depth, Akahoya: 1, 900-1, 890cm depth). The humus portion (2, 368-2, 360cm depth) was dated to 21, 100±400yr B. P. by the ¹⁴C-dating method.
Pollen analysis revealed the core to consist of nine pollen and two barren zones. Layers containing Lagerstroemia pollen, the important index taxa for the warm period, were regarded as sediments of the warm period. This core may contain the sediments of four warm (KS-9, 8, 6, 4-1) and three cold periods (KS-7, 5 and BZ-2, 1). KS-4-1 represent the post glacial period.