Viscosity of evolving magmas: a case study of the Glass House Mountains, Australia
Viscosity of evolving magmas: a case study of the Glass House Mountains, Australia
复制标题
DOI：
10.1007/s00445-021-01495-8
复制
发表时间：
2021-10
影响因子：
3.5
通讯作者：
S. Webb
中科院分区：
文献类型：
--
作者：
S. Webb
澳大利亚昆士兰州东南部的玻璃之家山脉的重熔岩石成分的粘度是通过在高粘度区域(108-1013Pa.S)中的微渗透法测定的。还测定了这些熔体从室温到玻璃化转变以上的热容。这两个数据集的组合允许使用组态热容Cpconf(Tg12)和组态熵Sconf(Tg12)通过Adam-Gibbs方程对粘度数据进行拟合。由此得到的拟合参数允许将粘度数据可靠地外推到10-4PA的较高温度和粘度(S)。这些数据现在可以用于讨论形成玻璃屋山脉杂岩的岩塞、熔岩、岩床和岩墙的岩浆侵位以及导致火山堵塞的板块运动和羽流。演化中的岩浆粘度的大幅增加和由此导致的火山喷口排放速度的下降表明，很少有岩浆以喷出熔岩或火山碎屑物质的形式出现，玻璃屋山脉主要是受侵蚀暴露的侵入体的残留物。
The viscosity of the remelted rock compositions of the Glass House Mountains, SE Queensland, Australia, has been determined via micro-penetration in the high-viscosity regime (108–1013Pa s). The heat capacity of these melts has also been determined from room temperature to above the glass transition. The combination of these two data sets allows the fitting of the viscosity data by the Adam-Gibbs equation using the configurational heat capacity Cpconf(Tg12) and configurational entropy Sconf(Tg12). The resulting fit parameters allow the robust extrapolation of the viscosity data to higher temperature and viscosities of 10–4Pa s. This data can now be used in the discussion of the emplacement of the magmas of the plugs, laccoliths, sills and dykes that form the Glass House Mountains complex and the plate motion and the plume responsible for the volcano plugs. The large increase in viscosity of the evolving magma and the resulting decrease in discharge rate of the volcanic vents suggest that very little magma appeared as extrusive lavas or pyroclastic material and that the Glass House Mountains are mainly remnants of intrusive bodies exposed by erosion.