Extremely High Primary Productivity and Organic Matter Enrichment in Lacustrine Sediments: Late Triassic Chang 7³ Sub-Member, Western Ordos Basin

Figure 4

The photomicrographs of Chang 8 and 7³ intervals in well DP1. (a) Fine-grained sandstone in the 6^th roundtrip. (b) Organic matter occurred along bedding in the 5^th roundtrip. (c–e) Biodetritus including phosphorus and spherical fragments in the 1^st to 5^th roundtrips. (f) Horizontal bedding in the 1^st roundtrip. (g) Framboidal pyrite with a size less than 7 μm in the Chang 7³ interval. (h) Tiny cracks in the Chang 7³ black shale. Note that (g–h) are obtained under scanning electron microscope.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)