The Campito Formation is mainly composed of very fine to fine-grained
quartzite, with small amounts of
siltstone, getting up to thick. It is overlain by the
Poleta Formation, whilst it is underlain by the
Deep Spring Formation.
Members The formation is split into two distinct members, which are as follows, in ascending
stratigraphic order (lowest to highest): •
Andrews Mountain Member: It is the thickest of the two members, getting up to thick. It is composed of olive-gray or greenish-gray very fine to fine grained silty
quartzitic sandstone or quartzite and interbedded layers of dark-greenish-gray
siltstones, which weather to a greenish-black or just black. The quartzite layers are composed of sub-angular very fine to fine grains of
quartz,
feldspar and other metallic minerals, all set within a
muscovite,
chlorite, and
biotite. •
Montenegro Member: It is the thinnest of the two members, only getting up to thick. It is composed of dark-greenish-gray and greenish-gray siltstone composed of a mixture of quartz, muscovite, and chlorite. The siltstone is evenly laminated to thin-bedded. There are also commonly occurring archeocyathid-bearing limestone beds in the upper sections of the member. == Paleobiota ==