摘要: |
本文利用扫描电镜对冲绳海槽沉积物中火山型石英颗粒表面的微结构进行了研宄。发现此类石英颗粒具有明显的火山作用痕迹;如有结晶良好的六方双锥状高温β-石英晶体,有被高温熔蚀成卵形的石英颗粒,有的石英颗粒表面粘附着火山玻璃,有的在火山玻璃气泡内壁存在大小不等的熔蚀坑。上述各种火山型石英的出现,再次证明了冲绳海槽存在着火山沉积作用。 |
关键词: 石英颗粒 微结构 火山沉积 |
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SURFACE TEXTURES OF VOLCANIC QUARTZ GRAINS IN THE SEDIMENTS OF OKINAWA TROUGH |
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Abstract: |
Surface textures of volcanic quartz grains in the sediments of Okinawa Trough were studied with the scanning electron microscope. The volcanic trace was found in the surface of quartz grains. Our research shows that some volcanic quartz grains occur as hexagonal bipyramid crystals-β quartz. Its crystal face without solution traces is very smooth. Some quartz grains with resorption border are in "likely fusoid". Its crystal edge and pyramid top are always in the shape of arc. Other quartz grains are frequently covered with volcanic glasses. Near the bleb endotheca of volcanic glasses are found small big resorption pits. The occurrence of the different volcanic quartz grains mentioned above indicates that the volcanic deposits are distributed in the Okinawa Trough. |
Key words: Quartz Microstructure Volcanic Sediments |