Alfred Miles No. 1 channel (Nokai Mesa channel; Channel No. 1), Skeleton Mesa, Nakai Mesa Mining District, Navajo County, Arizona, USAi

Regional Level Types
Alfred Miles No. 1 channel (Nokai Mesa channel; Channel No. 1)	Paleochannel
Skeleton Mesa	Mesa
Nakai Mesa Mining District	Mining District
Navajo County	County
Arizona	State
USA	Country

The Alfred Miles channel No. 1, among the largest noted, can be traced for about 4 miles in Arizona and Utah. The channel is intersected by deep canyons and is broken into segments; channel strata crop out in several localities, and it is on these exposures that claims have been staked by various prospectors. The channel is known by the following names: the Todechenee, Nakai Mesa (C. Clare Gregg, written communication, 1952), Peninsula, and Alfred Miles.

The part of the channel within Arizona is in Navajo County, at lat 36°59'48" N. and long 110°28'6" W. Sources of water and supplies are remote. The channel remnants on both the Arizona and Utah parts of Nakai Mesa are accessible by a graded dirt road. Parts of the channel are on a narrow projection of Hoskinnini Mesa; however, and these can be reached by a pack trail that extends along the projection from the southwest edge of Hoskinnini Mesa. Another route to these channel exposures is along the floor of Copper Canyon. An ungraded dirt road extends westward from the Oljeto trading post, Utah, and ends at the base of the steep slopes that underlie the channel remnants on the projection.

Consolidated sedimentary strata exposed in the Alfred Miles channel No. 1 area range from the Organ Rock tongue of the Cutler formation at the base of the Mesa, to the Shinarump member of the Chinle formation, which forms the canyon rims. About 90 feet of the Shinarump member is exposed, and it commonly stands as a vertical cliff. Where there are channels, the Shinarump member thickens to 120 feet or more. On Nakai Mesa the Shinarump member is covered by dune sand that ranges in thickness from a thin film along mesa edges to 15 feet back from the rim. There is practically no sand cover on the projection of Hoskinnini Mesa. The surface of the Shinarump member is pitted with depressions as much as 20 feet wide and 5 feet deep and marked by irregular hummocks that rise about 20 feet above the general
ground surface.

The Alfred Miles channel No. 1 describes a broad curve. In Arizona its trend is about N. 50° E., but as it is traced northeastward it curves and where it reenters Utah, its trend is to the northwest. The channel is about 2,150 feet wide and has been cut about 70 feet into the Moenkopi formation. Channel strata consist predominantly of massive uniform-textured coarse- grained sandstone that forms cliffs. A few small conglomerate lenses are in the basal strata Claystone boulders, cobbles, and pebbles make up the coarse material. These fragments range in size from small rounded chips about a quarter of an inch in diameter to angular boulders as much as 5 feet in long dimension. In places where the clay fragments have weathered out, the sandstone matrix remains as a fretwork. Much of the clay has been derived from the Moenkopi formation. These fragments can be found in various stages of alteration, from those that are all red and show no alteration, to others that are totally altered and are grayish green. An altered zone, in the uppermost strata of the Moenkopi formation below the channel, ranges in thickness from 2 to 8 inches. This is one of the few channels noted in the Monument Valley area, Arizona, where the altered zone did not thicken under a channel..........

........Discussing the geology of the mineralized deposits found along the base of this channel, C. Clare Gregg (written communication, 1952) states:

Mineralization occurs in the bottom of channels, usually on one side and generally in a roll or gouge where logs and organic trash collect. Generally mineralization is directly above a muddy Moenkopi siltstone, the upper layers of which may be also mineralized. The important associations seem to be carbon in the form of logs of wood trash; and copper, usually as malachite, although many outcrops revealing the characteristic color of copper mineralization contain no uranium.