中文摘要：

对鄂霍次克海东南部科学院隆起区OS03—1岩心碎屑重矿物及火山灰层进行了详细分析。岩心重矿物以紫苏辉石、绿帘石和普通角闪石为主，特征矿物为钛磁铁矿和普通辉石，矿物特征表明本岩心的物质主要来源于冰筏搬运（陆源）和火山喷发。陆源物质大部分来源于鄂霍次克海西部和北部地区，少量来自堪察加半岛冰川携带沉积物；火山物质则来源于堪察加半岛和千岛群岛的火山喷发产物。在岩心中识别出3个火山灰层，各种证据表明火山灰层1与已知的K2火山灰层相同，形成年代为26kaBP；火山灰层3具有明显火山物质与陆源物质混合特征，而火山灰层2则只能通过碎屑矿物的含量特征来判定，外在颜色不明显，已经明显的被陆源物质所稀释。研究表明，碎屑矿物组分参数可以有效地指示物质来源，也是识别火山灰层存在（特别是被陆源物质稀释）的可靠指标。

英文摘要：

Composition and assemblage characteristics of heavy minerals were analyzed in core OS03- 1 sediment collected from the Academy of Sciences Rise of southeastern Okhotsk Sea. The results show that the dominant minerals are hyperthene, epidote and common hornblende, and characteristic minerals are titanomagnetite and augite; the sediments are mostly ice-rafted debris （IRD） and volcanogenic matter. IRD were mainly derived from the western and northern Okhotsk Sea,and a little from Kamchatka peninsula. Volcanogenic matter was mainly from Kamchatka Peninsula and Kurile Islands. Three tephra layers were identified. The first layer is characterized by special color,grain size and mineral composition, which was same to the well studied K2 tephra layer and deposited at 26.0 ka BP. The third layer could be recognized by color,but was clearly diluted by terrigenous sediment. The second tephra layer couldn＇t be distinguished by color and grain size because of mixing with terrigenous sediment. The study also shows that composition and assemblage of heavy minerals are both effective indicators of sediment sources,and credible indentifying index of tephra,especially those diluted by terrigenous matter.