Triassic siltsone. The specimen is very thinly to thinly bedded, very pale grey (Munsell value 10YR 8/1) sedimentary rock. The layering is defined by contrasting porous, quartz-rich sandy bands weakly stained with secondary iron oxyhydroxides (“limonite”) and low-porosity, quartz-poor muddy bands.
Images are examples of specimens only.
Size and shape may vary.
Specimens are usually no smaller than 75mm in one dimension.