Laminations are very clear when the thin-section is held up to the light. They are mainly planar, but some wrap around lighter regions in the rock.

Under the microscope, the rock is brown, with fine dark brown streaks, laminated.
Mainly carbonate, some white mica, rare quartz.
Bioclasts, mainly along bedding surfaces, probably gastropods and bivalves. Some of the shells have been dissolved. The spaces left have been filled by secondary calcite.
Sparry carbonate cement.

Fine-grained, so formed in a very low energy environment. 
Shells are too large to have been swept in by such low energy currents, so the shells are in life position. 
If the shells are indeed gastropods and bivalves the rock could be marine or non-marine. The presence of brachiopods would indicate a marine environment.

calcareous mudstone

Reddish brown rock. Medium sand grade.
Round to sub-round grains of quartz, often with a thin rim of red hematite. Mainly reddish and pink-brown grains, fewer white grains and very few black grains. Well sorted and well cemented.
No fizzing with acid, so does not contain significant carbonate. 

Laminations can be observed in sample L326b. There is an inter-layering of coarser and finer laminae.

Fine laminations can be seen when the thin-section is held up to the light. 
Moderately well rounded quartz grains with thin rims of hematite, and overgrowths of quartz in optical continuity with the original grain. 
Occasional grains of very fine quartzite, microcline, plagioclase, mica and decomposed fine-grained igneous rocks. 
Siliceous cement and the secondary quartz overgrowths hold this rock together.

The grains are finer as a whole in L326b, and less well rounded.

Probably deposited in an aeolian environment, since it almost entirely comprises well sorted and well rounded quartz grains.

ferruginous sandstone
ferruginous arenite