The volcano-sedimentary sequence is characterized by lava flows alternating with grey shales and occasional red chert bands.
Crystals of brown sphalerite are found in fractures and on the surfaces of some chert nodules.
The sedimentary lenses are composed of limestone, sandstone, siltstone, mudstone, shale, chert and well-bedded calci-turbidite.
In fact, seventeen of the fifty-seven sites are specifically listed for agate, chalcedony, chert , jasper, or petrified wood.
It comprises turbiditic elastic rocks with cherts , pillow lavas and greenstones.
These fracture zones occur as parallel layers alternating with cherty lithons, typically 5 mm wide, giving the rock a banded appearance.
The deposits immediately above the maximum flooding surface are thinly interbedded ammonoid-bearing cherts and lime mudstones.
The material was obtained from a cherty layer of sedimentary interbeds and is included in the Kirkpatrick Formation.
The underlying soils are acidic, cherty , infertile, and permeable to water.
The cherty carbonate rocks are resistant to weathering, and regions underlain by them may stand above the surrounding terrain.