大洋洲查亚峰的形成与演化

MOUNTAIN BUILDING AND EVOLUTION OF PEAK JAYA, OCEANIA

位于大洋洲新几内亚岛的查亚峰的形成与中新世以来澳大利亚大陆北部被动边缘俯冲碰撞到Melanesian岛弧之下有关 .2 .8Ma以来 ,查亚峰岩石隆升幅度为 70 0 0m ,隆升速率为 2 .5mm/a ,其剥蚀速率为 0 .7mm/a .据查亚峰南坡石炭—二叠系测年得出 ,自 2 .3Ma以来 ,岩石隆升幅度为 6 5 0 0m ,隆升速度为 2 .88mm/a ,剥蚀速率为 1.7mm/a ;更南可能为前寒武纪的绿片岩分布区 ,剥蚀速率更快 ,已剥蚀深度达 9km ,是全岛剥露最深的地区 .正是这种强烈的切割和剥蚀 ,在均衡抬升作用强烈影响下使查亚峰成为大洋洲最高峰 .

The Peak Jaya and its neighboring areas within the New Guinea island in Oceania are located at the junction of several lithospheric plates: Pacific plate, Australian plate and Southeast Asian plate. In the Peak Jaya are present a concentration of tectonic stress, an intensification of tectonic disturbance and a complicate tectonic evolution history. The mountain building of Peak Jaya is a product of subduction of north Australian passive continental margin into the area below the Melanesian island arc since the Miocene. Since 2.8?Ma, the rock uplift amplitude of the Peak Jaya has reached about 7?000?m with the uplift rate 2.5?mm/a and the exhumation rate 0.7?mm/a.Based on the dating of the Carboniferous_Permian obtained in the southern slope of Peak Jaya, the rock uplift amplitude has reached, since 2.3?Ma, 6?500?m with the uplift rate 2.8?mm/a and exhumation rate 1.7?mm/a. Further to the south, there exists a greenschist domain of probably Precambrian. The exhumation rate there has reached a faster rate, since the exhumed depth has already reached 9?km, the deepest part of the whole island. It is this violent down_cutting and exhumation that has made Peak Jaya the highest peak in Oceania by means of equilibrium elevation.