Abstract
Dark clasts (DCs) are common constituents in CV and CO chondrites. They are considered to be either primary aggregates of condensates from the solar nebula or a part of asteroidal body that have undergone aqueous alteration and subsequent dehydration. And the origin of dark inclusions remains contentious. In order to solve this problem, we investigated two DCs in Allende by a SEM-EDS, an EPMA-WDS, and a (S)TEM-EDS.