Distribution of the Hoskinnini tongue of the Cutler formation in southwestern Utah and adjoining parts of Arizona and Colorado

Recent field work indicates the Hoskinnini tongue of the Cutler formation is present in much of southeastern Utah and adjoining parts of Colorado. Previously the Hoskinnini had been recognized only in the Monument Valley region of southeastern Utah and northeastern Arizona.

The Hoskinnini tongue is pale reddish brown and is composed mainly of silt and very fine-grained sand and minor quantities of fine, medium, and coarse sand grains. The Hoskinnini is indistinctly bedded in horizontal beds generally ranging from 1 to 2 feet thick, and individual beds are composed of indistinct
discontinuous wavy laminae bounded by grayish-red clay or silt films.

The Hoskinnini is generally 50 to 120 feet thick but ranges up to 126 feet thick' Pinchouts of the Hoskinnini on the west are abrupt, and the Hoskinnini near some of these pinchouts contains unusual features such as intraformational and chert pebble conglomerates, contorted stratification, and petroliferous material.

The combination of coarse grains in the finer-grained matrix and discontinuous wavy laminae serve to differentiate the Hoskinnini tongue from the underlying and overlying formations' The distinctive combination of grain size and wavy laminae also assures correlation of the Hoskinnini with rocks not previously
correlated with the Hoskinnini in southeastern Utah and adjoining parts of Colorado.

Although the Hoskinnini tongue is cUJITently classified as a part of the Permian Cutler formation, stratigraphic relations show the Hoskinnini to be conttasted with typical Cutler rocks and to be closely related to the Lower and Middle (?) Triassic Moenkopi formation.