Lemitar Mountains
The Lemitar Mountains are composed predominantly of Precambrian granites, diorite-gabbro, and arkoses and quartzites of the Corkscrew Canyon sequence.
The Lemitar Mountains are composed predominantly of Precambrian granites, diorite-gabbro, and arkoses and quartzites of the Corkscrew Canyon sequence.
Anomalously radioactive potassic dykes occur in quartz monzonites of the southern Caballo Mountains. More than 45 of these bodies have been mapped within an area of 5x2 km (Staatz et al., 1965, Fig. 1). They consist chiefly of brick-red microcline.
Apart from Pajarito Mountain (No.
The greater part of this syenite-nepheline syenite complex lies in Canada - see 031-00-037.
The North Moccasin Mountains were formed by doming concentric to a single large laccolithic intrusion, while the South Moccasin Mountains were uplifted by a cluster of stocks, laccoliths and sills.
The Judith Mountains are formed of a series of coalescing dome-shaped uplifts caused by the intrusion of a series of laccoliths and sills into a conformable sequence of marine sedimentary rocks of Cambrian to Cretaceous age.
What is probably a small pipe, or possibly a dyke, together with a thin sill of alnoite occur 17 km due west of Winnett amongst necks, dykes and sills of other rock types.
The Smoky Butte outcrops extend north-south for some 3.4 km and are mainly small plugs and thin dykes cutting Palaeocene sediments. Three varieties of lamproite are described by Velde (1975), all of which come from a quarry in a plug on the south side of Smoky Butte.
Among the granites, diorites, porphyries and rhyolites of the Castle Mountains trachytic intrusions with sodic pyroxene are reported.
The Crazy Mountains rise to over 3500 m above sea-level and some 2000 m above the surrounding plains. They consist of sandstones and shales of Cretaceous-Eocene age which have been injected by numerous laccoliths, stocks, sills and dykes.