Comparative study of felsic magmas with explosive or not explosive eruption

爆炸性喷发与非爆炸性喷发的长英质岩浆对比研究

基本信息

批准号：
10440141
负责人：
SAWADA Yoshihiro
金额：
$ 8万
依托单位：
Shimane University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10440141/
关键词：
Quaternary volcanoes lava dome pyroclastic flow felsic magma volatile components organic matter paleomagnetism reverse thermoremanent magnetism 自己反転熱残留磁性鉱物

项目摘要

(1) On the basis of paleomagnetic and petrographical studies, it estimates that the four lava domes of Mt. Sanbe formed at 3.7-3.8 Ka. Hemoilmenite showing self-reversal of thermo-remnant magnetization was found in dacite clasts and lava from Mt. Sanbe and Mt. Daisen.(2) Laboratory experiments aimed at allowing estimation of emplacement temperatures of pyroclastic deposits flows using H/C ratios of entrained carbonized wood were carried by simulating the thermal conditions in pyroclastic flows. H/C ratios show a strong correlation with temperature. H/C thermometry was tested by natural carbonized woods and paleomagnetic blocking temperatures from Holocene pyroclastic flow deposits. Emplacement temperatures of Taiheizan pyroclastic flow deposits about 5.5km from the conduit of the Sanbe volcano were estimated 530-560℃ by these methods.(3) Organic matter was found in igneous rocks related to sediments during the generation and ascent of magmas, such as S-type felsic rocks, high Mg andesite, rocks formed by slab melting and sedimentary origin migmatite.(4) Experiments were carried out to examine transformation of sediment-derived hydrocarbons contained in felsic magma and during its solidification at middle crustal condition. Carbonaceous materials remained in all experimental products, not only as carbonate and graphite but also as solid state hydrocarbon, indicating that polymerization occurred.

（1）基于古磁和岩石学研究，它估计Sanbe山的四个熔岩域名以3.7-3.8 ka形成。在Dacite经典和Daisen山的熔岩和熔岩中发现了表现出自我反转的半油石。（2）实验室实验，旨在允许使用碳化型木材流量的H/C率估算热塑料沉积物的Emplacement温度，该实验通过模拟型碳化木材的h/c估计。 H/C比显示与温度有很强的相关性。通过自然碳化木材和全新世塑形流量沉积物的古磁阻滞温度测试H/C温度测定法。通过这些方法估计，距离桑贝火山渠道约5.5公里的太极拳流动流量的就业温度估计为530-560℃。（3）在与岩浆的一代和岩浆中，诸如S-type Felsic Rocks，高Mgs and Spems，slocks and slongs and slocks and slocks and slocks and slocks and slocks and slocks and rocks rocks andssient slongs and Slocks and Slocks and Slocks and Slocks and Slongs and Slocks and Slocks and Slongs rocks andssient，有机物是有机物。（4）进行了实验，以检查长英质岩浆中包含的沉积物衍生的碳氢化合物的转化，并在中层状态下固化时。碳质材料保留在所有实验产物中，不仅是碳酸盐和石墨，而且作为固态碳氢化合物，表明发生了聚合。