南极乔治王岛阿德默勒尔蒂湾火山活动时空演化

在乔治王岛中部的阿德默勒尔蒂湾 ,凯勒半岛、于尔曼山嘴和埃内坎角是第三纪火山岩集中分布区。野外地质调查和同位素年代学研究表明 ,凯勒半岛发生了三期火山喷发 (三个火山喷发旋回 ) ,同时伴随着火山活动中心的不断北移 ;在第二期火山喷发之后 ,火口塌陷 ,形成破火山 ,之后在半岛北部又发生火山喷发 ,并向东迁移到于尔曼山嘴。因此凯勒半岛是一复活破火山 ,火山活动具有随时间迁移的特性。埃内坎角火山活动虽与上述两地区大致同时 ,但化学成分上不存在明显演化关系 ,应属另一相对独立的火山活动中心

TEMPORAL AND SPATIAL EVOLUTION OF VOLCANISM AT THE ADMIRALTY BAY,KING GEORGE ISLAND, ANTARCTICA

At the Admiralty Bay of King George Island, Keller Peninsula, Ullman Spur and Point Hennequin are the main areas of Tertiary volcanic rocks distributed. Field investigation and K-Ar age datings indicate that, in Keller Peninsula, occurred three volcanic eruptions, which accompanies with N-towards continuous migration of volcanic center. After the second eruption, the crater collapsed, and a caldera was formed. Afterwards, the eruptions limited at the northern end of the peninsula, and then migrated to Ullman Spur. Therefore Keller Peninsula is a revived caldera, and its volcanic activities are characteristic of migration of volcanic center with time. Point Hennequin volcanism happened largely simultaneous with the above two areas, but it has not direct evolution relation to the other areas. Thus Point Hennequin has another independent volcanic center.