Collaborative Research: U-Series Constraints on Rhyolite Genesis at Medicine Lake Volcano

由于流纹岩的高粘度和浓缩水的能力，它具有高度爆炸性喷发的能力，有可能造成大范围的破坏。美国大陆最近的流纹岩喷发之一发生在大约850年前加利福尼亚北部的梅迪辛湖火山。这次喷发从火山顶部附近的一系列喷口喷出了流纹岩和英安岩，这些流纹岩和英安岩以熔岩流和火山灰的形式存在。喀斯喀特火山可能喷发出更大的流纹岩（例如7700年前火山口湖火山口的流纹岩的高潮喷发）。最近我们从火山口湖收集的气候喷射物的u系列数据表明，这些流纹岩是在105年的时间尺度上产生的。我们当前项目的目标是确定产生从梅迪辛湖火山喷发的小体积流纹岩所需的时间尺度。我们打算确定这些流纹岩是在形成后直接迁移到地表，还是有可能在地壳中聚集。

0001003/0000886Reagan/SimsBecause of its high viscosity and ability to concentrate water, rhyolite is capable of highly explosive eruptions that have the potential to cause widespread destruction. One of the most recent rhyolitic eruptions in the continental U.S. took place at the Medicine Lake volcano in northern California about 850 years ago. This eruption ejected about 1 km3 of rhyolite and dacite in lava flows and tephras from a chain of vents near the summit of the volcano. Much larger eruptions of rhyolite are possible from Cascades volcanoes (e.g. the climactic eruption of rhyolite from Crater Lake caldera 7700 years ago). Recent U-series data we collected on climactic ejecta from Crater Lake suggest that these rhyolites were generated over 105 year time-scales. The goal of our current project is to determine the time-scales of required to generate the smaller volumes of rhyolite erupted from the Medicine Lake volcano. We intend to determine whether these rhyolites migrate directly to the surface after being generated, or whether there is a potential that they are accumulating in the crust.