对鄂霍次克海东南部OS03-1岩芯180 ka BP以来底栖有孔虫内生种Uvigerina spp.进行了稳定氧碳同位素分析，发现了112-109 ka BP（Ⅵ），102-90 ka BP（Ⅴ），85-76 ka BP（Ⅳ），57-54 ka BP（Ⅲ），44-40 ka BP（Ⅱ）和17-10 ka BP（Ⅰ）的6次δ13C轻值事件，其中发生于102-90 ka BP的轻值事件Ⅴ中的δ^13C降幅最大，达到了2.5‰，其他事件中均达到1‰以上. 研究认为，这些δ13C轻值事件可能由表层生产力增高、鄂霍次克海中层水形成减弱、最低含氧带加强等因素共同引起. 古菌生物标志物结果表明，这些δ^13C轻值事件没有受到天然气水合物分解和甲烷气体释放的影响.
A total of six d13C minimum events,i.e.,VI,V,IV,III,II,and I,were observed via a stable carbon and oxygen isotope analysis of infaunal benthic foraminifera Uvigerina spp.in gravity core OS03-1 in the southeastern Okhotsk Sea over the last 180 ka.These events occurred at112–109,102–90,85–76,57–54,44–40,and 17–10 ka BP.The largest negative excursions reached 2.5%in event V and were greater than 1%in the other events.We proposed that all d13C minimum events were caused by the increase in sea surface water productivity,the weakened formation of Okhotsk Sea intermediate water,and the enhancement of the oxygen minimum zone.The negative excursions were unaffected by methane hydrate destabilization and subsequent methane release based on the results obtained by using archaeal lipid markers.
Yonghua WuXuefa ShiJianjun ZouZhenbo ChengKunshan WangShulan GeFengdeng Shi
