[mass noun] Fine-grained sedimentary rock consisting of consolidated silt.
- ‘Thick Permian to Cretaceous continental rise deposits merge southward into a continuous Ordovician to Eocene shelf sedimentary succession of marine carbonate, sandstone, siltstone and shale.’
- ‘The upper Gotham Member also comprises thinly interbedded mudstone, siltstone, and fine-grained calcareous sandstone.’
- ‘Permian shale, sandstone, siltstone, limestone, sands, marls, and dolostones were deposited by sea-level fluctuations.’
- ‘The canyon fill passes conformably upward into limestone and calcareous siltstone and sandstone of the Wonoka Formation.’
- ‘Reddish-brown siltstone and fine-grained sandstone of the Organ Rock Tongue form the lower slopes of the hill and part of the nearly vertical wall above the lower slopes.’