Figure 3
Alterations types occurring in the groundmass of paleosols and in rock fragments under plane polarized light (PPL). (a) P1-Bwb2, 23–34 cm: brown infillings (blue arrows); clay filling vesicles in glass shards (red arrows); brownish clays of former olivines (green arrows); yellow arrows: alterations of plagioclase (b) P1-Bwb2, 23–34 cm: similar alterations occurring inside a rock fragment, the red line defines the limit between rock (below the line) and paleosol (above the line). (c) P2-Bwb1, 20–30 cm: grey infillings are almost transparent under PPL (blue arrows); clay (red arrow) filling vesicles in glass shards; brownish clays in former olivine (green arrows). (d) P2-Bwb1, 20–30 cm: same alterations occurring in a rock fragment; note the brown infilling (blue arrow) surrounded by a white rim due to Fe depletion (black arrows); alteration of plagioclase (yellow arrow).
