from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A fine-grained rock of consolidated silt.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A sedimentary rock whose composition is intermediate in grain size between the coarser sandstone and the finer mudstone.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a fine-grained sandstone of consolidated silt
Sorry, no etymologies found.
Ancient mud deposits harden over geological time to form sedimentary rock such as siltstone or solid, mudrock lutites.
Anyway, the ground was a very light grey, almost purple in places, a weathered clay or mudstone or siltstone of some sort.
We climbed over the craggy outcrops of Cambro-Ordovician age Fort Burnside Formation and Jamestown Formation, crazily tilted beds of phyllite and slate and siltstone and stark white veins of calcite.
“You're damn sexy is what you are,” says Jillie, straddling the narrow part of the creek as she hands me another piece of siltstone.
Here, rocks of the Cambro-Ordovician Conanicut Group, specifically interstratified beds of the Fort Burnside Formation and the older Jamestown Formation form great flat tables of phyllite and siltstone, metamorphosed to varying degrees.
Mississippian to Ordovician-age limestone, chert, sandstone, siltstone and shale compose the landforms of open hills, irregular plains, and tablelands.
More forest covered than most adjacent ecoregions, the North Central Appalachians ecoregion is part of a vast, elevated plateau composed of horizontally bedded sandstone, shale, siltstone, conglomerate, and coal.
It is a semiarid rolling plain of shale, siltstone, and sandstone punctuated by occasional buttes and badlands.
The mountainous Mid-Coastal Sedimentary ecoregion lies outside of the coastal fog zone and is typically underlain by massive beds of sandstone and siltstone in contrast to the volcanics of Ecoregion 1d.
Ecoregion 84d is lithologically distinct from the reddish shale, sandstone, argillite, and siltstone of the neighboring Triassic Lowlands (64a).