Geothermometry of Kilauea Iki lava lake, Hawaii
Geothermometry of Kilauea Iki lava lake, Hawaii
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DOI：
10.1007/bf01080357
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发表时间：
1987-10
影响因子：
3.5
通讯作者：
R. T. Helz;C. Thornber
中科院分区：
文献类型：
--
作者：
R. T. Helz;C. Thornber
温度随时间和空间变化的数据对于全面了解基拉韦厄伊基熔岩湖玄武岩浆的结晶历史至关重要。用于确定湖中温度的方法包括直接井下热电偶测量和铁钛氧化物地质测温法。此外，MgO和CaO含量的玻璃，在适当的基拉韦厄样品的熔化实验中确定的温度变化，已被校准作为纯粹的经验地质温度计使用，并直接适用于填隙玻璃在含橄榄石的核心从基拉韦厄伊基。推断出的淬火温度的不确定度为±8−10° C。三种方法的比较表明：（1）氧化物和玻璃地质测温法给出的结果彼此一致，并与岩石学和样品的相对位置一致;（2）井下热电偶测量值在所有井中都很低，但最早、最浅的井除外，因为较深的井永远不会完全恢复到钻前温度，（3）玻璃地质测温法提供了关于部分熔融区中的温度分布的最详细的信息，其中大部分是以其他方式无法获得的，以及（4）所有三种方法对于构建任何给定钻孔的完整温度分布都是必要的。对1975-1981年回收的部分熔融岩心应用玻璃基地质测温法，详细揭示了基拉韦厄伊基熔岩湖部分熔融带内温度在时间和空间上的变化。这里开发的地质温度计也可能适用于其他基拉韦厄熔岩湖的玻璃样品和快速淬火的熔岩样品从喷发的基拉韦厄和莫纳罗亚山。
Data on the variation of temperature with time and in space are essential to a complete understanding of the crystallization history of basaltic magma in Kilauea Iki lava lake. Methods used to determine temperatures in the lake have included direct, downhole thermocouple measurements and Fe-Ti oxide geothermometry. In addition, the temperature variations of MgO and CaO contents of glasses, as determined in melting experiments on appropriate Kilauean samples, have been calibrated for use as purely empirical geothermometers and are directly applicable to interstitial glasses in olivine-bearing core from Kilauea Iki. The uncertainty in inferred quenching temperatures is ±8−10° C. Comparison of the three methods shows that (1) oxide and glass geothermometry give results that are consistent with each other and consistent with the petrography and relative position of samples, (2) downhole thermo-couple measurements are low in all but the earliest, shallowest holes because the deeper holes never completely recover to predrilling temperatures, (3) glass geothermometry provides the greatest detail on temperature profiles in the partially molten zone, much of which is otherwise inaccessible, and (4) all three methods are necessary to construct a complete temperature profile for any given drill hole. Application of glass-based geothermometry to partially molten drill core recovered in 1975–1981 reveals in great detail the variation of temperature, in both time and space, within the partially molten zone of Kilauea Iki lava lake. The geothermometers developed here are also potentially applicable to glassy samples from other Kilauea lava lakes and to rapidly quenched lava samples from eruptions of Kilauea and Mauna Loa.