- a clayey rock with the texture and composition of shale but little or no lamination.
Origin of mudstone
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a dark grey clay rock similar to shale but with the lamination less well developed
- A fine-grained, dark gray sedimentary rock consisting primarily of compacted and hardened silt and clay, similar to shale but without laminations. The proportions of silt and clay in mudstone are approximately equal.
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