Brearley A J
Institute of Meteoritics, Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, USA.
Science. 1997 May 16;276(5315):1103-5. doi: 10.1126/science.276.5315.1103.
Transmission electron microscope observations of the Allende carbonaceous chondrite provided evidence of widespread hydrous phases replacing enstatite in chondrules. Calcic amphibole and talc occur in thin (less than 0.3 micrometer) crosscutting veins and as alteration products of primary chondrule glass in contraction cracks within the enstatite. In addition, talc and disordered biopyriboles were found replacing enstatite grains along cracks and fractures. Although rare hydrous phases have been reported in calcium- and aluminum-rich inclusions in the Allende meteorite, these observations suggest that aqueous fluids played a much more significant role in the mineralogical and geochemical evolution of Allende than has previously been thought.
对阿连德碳质球粒陨石的透射电子显微镜观察提供了证据，表明在球粒中广泛存在着含水相替代顽火辉石的现象。钙角闪石和滑石出现在细小（小于0.3微米）的交叉脉中，并作为原生球粒玻璃在顽火辉石内部收缩裂缝中的蚀变产物。此外，还发现滑石和无序的双锥辉石沿裂缝和断裂处替代顽火辉石颗粒。尽管在阿连德陨石中富含钙和铝的包体中已报道过罕见的含水相，但这些观察结果表明，水流体在阿连德陨石的矿物学和地球化学演化中所起的作用比之前认为的要重要得多。
