Trinity Group

Trinity Group
State Arkansas
Name Trinity Group
Geologic age Early Cretaceous
Lithologic constituents
Sedimentary > Carbonate > Marlstone (Bed)
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Carbonate > Limestone (Lens)
Sedimentary > Chemical > Novaculite (Bed)
Sedimentary > Chemical > Evaporite > Gypsum (Lens)
Comments Alternating fine qtz. sand and gypsiferous marls with lenticular fossiliferous limestone, gypsum and minor novaculite gravel. Approximatly 2500 ft. thick. Novaculite-similar to chert but characterized by dominance of microcrystalline quartz over chalcedony.
Stratigraphic units De Queen limestone member, Dierks limestone member.

Dane, C.H.,1929, Upper Cretaceous formations of southwestern Arkansas: Arkansas Geol. Survey Bull.1, 215 pp.

NGMDB product
Counties Howard - Pike - Sevier