Tubular Form of Interstratified Mineral Consisting of a Serpentine-like Layer Plus Two Brucite-like Sheets Newly Found in the Murchison (C2) Meteorite

摘要

Phyllosilicates in the matrix of the Murchison meteorite can be morphologically classified into three types based on the observation by high resolution electron microscopy; phyllosilicate with extremely low crystallinity, platy phyllosilicate, and tubular phyllosilicate. A new type of phyllosilicate having both platy and tubular forms was found. It consists of an alternation of serpentine-like 1 : 1 layer and a couple of brucite-like sheets, and has 17 Å periodicity. One-dimensional electron microscopic images of this new type phyllosilicate are calculated and compared with the electron micrographs actually taken. The genesis of phyllosilicates and the process of formation of the tubular phyllosilicate in the Murchison meteorite are discussed.