Photomicrographs of representative mineralogy are here presented for each unit defined in our study. Unit A is dominated by quartz and feldspar whereas clay minerals, clinopyroxene and micas are in minor proportions (S4.1 and S4.2). Quartz, especially polycrystalline quartz, is dominant within the Unit B whereas micas and clinopyroxene are low in abundance (S4.3 and S4.4). Unit C is characterized by a high content in clay minerals as well as feldspar and monocrystalline quartz (S4.5). Unit D is characterized by a high content of polycrystalline quartz (chert) and feldspar (S4.6 and S4.7).