shale
/ʃeɪl
/noun [mass noun]
Soft finely stratified sedimentary rock that formed from consolidated mud or clay and can be split easily into fragile plates.The soils are developed on weathered materials derived from sandstone, shale, and limestone....
- Glaciers have deposited shale, slate, schist, and limestone throughout the region.
- Towering over the town was Turtle Mountain, a massive hulk of limestone and shale layered with veins of coal in its core.
Derivatives
shaly
/ (also shaley) adjective (shalier, shaliest) ...- The Liassic in Mochras consists predominantly of alternating shaly limestones, marly siltstones, and micaceous mudstones.
- The Green Point Formation is the more distal and is dominated by shale and shaley lime mudstones.
- An organic-rich shaly horizon of this age can be traced into continental Europe and possibly into North and South America; the stratigraphy suggests regional transgression and deepening.
Origin
Mid 18th century: probably from German Schale; related to English dialect shale 'dish' (see scale2).