The Ataspaca prospect is in the Cordillera Occidental, 45 km northwest of Tacna, Peru. Epizonal intrusions satellitic to the Caplina- Ataspaca pluton were emplaced 41 m.y. ago into limestones of the Lower Jurassic Pelado Formation along the northeast-trending Chucchuco fault system. Depths of emplacement ranged from 4.5 to 6.0 km....
The Bethlehem Copper Mine, a porphyry copper deposit, is
situated near the geographical center of the Guichon Creek batholith.
The Guichon Creek batholith is located on the east flank of the
Canadian Coast Range in south central British Columbia approximately
250 miles northeast of Vancouver, B. C. The batholith
trends...
The thesis area includes 54 square miles of the southeastern
Cuddy Mountains in west-central Idaho. The oldest rocks within the
area are plutonic phases of the Jurassic Cuddy Mountain complex.
These and Cretaceous (?) intrusive and associated (?) extrusive rocks
and nearby Triassic to Early Jurassic metasedimentary and metavolcanic
rocks...
The oldest rocks of the Sturgill Peak area are herein named the
grassy slope phyllites, and are of Permian (?) age. They are
divided into a phyllitic member, consisting of complexly folded and
highly sheared phyllites and phyllitic cherts, and a limestone member,
containing sheared limestone, silicified limestone, and chert....
The Lateral Lake Area is located 30 km northeast of Dryden in
Echo and Webb Townships in the District of Kenora in northwestern
Ontario. The area has been the focus of molybdenum exploration
since 1906. Most exploration and development has been centered
on the Pidgeon Prospect in Echo Township. Although,...
The Schwartzwalder uranium deposit, in the Front Range west of Denver, Colorado, is the largest vein-type uranium deposit in the United States. The deposit is situated in a steeply dipping fault system that cuts Proterozoic metamorphic rocks. The host rocks represent a submarine volcanic system with associated chert and iron-...
The Seaman Gulch area is located approximately 20
miles east of Redding, California and is part of the
eastern Klamath lithotectonic belt.
Rock units of the area are chiefly mafic and silicic
volcanics of island arc affinity and shale that are Permian
to Triassic in age. Volcanic rocks of Tertiary...
Andesitic and rhyolitic magmatism was active during the mid-
Tertiary (Early Miocene) of the Ash Peak area, southeastern Arizona.
Andesitic magmas of similar composition both preceded and followed the
low- and high-silica rhyolitic magmas. The changes from andesitic to
rhyolitic and back to andesitic volcanism is postulated to be the...
The Coyote Hills are located about 46 kilometers north-northwest
of Lakeview, Oregon, within the Basin and Range physiographic province.
These hills represent a complex volcanic center of bimodal
calc-alkaline igneous activity.
The oldest rocks recorded in the Tertiary succession are horn-blende-
bearing andesite and aphanitic basalt flows, laharic breccias,
conglomerates,...
The Mount Fubilan Intrusion is part of a geologically young hypabyssal stock in the Star Mountains of Papua New Guinea. This stock was mapped as the Ok Tedi Intrusive Complex and divided into four separate bodies: the Mount Fubilan, Sydney Intrusion, Kalgoorlie, and Ningi Intrusions. Hydrothermal fluids caused alteration of...
The San Vicente zinc lead deposit is located in the Eastern Andes of
Central Peru. The deposit is an epigenetic Mississippi Valley-type deposit
based on stratigraphic, geologic, petrographic, and geochemical evidence.
The dolomite host rocks of the Pucara Group are of Triassic-Jurassic
age. The source of metals are red sandstones...
The central part of the Bayhorse Mining District is located in the Salmon River Mountains in north-central Idaho between the towns of Challis and Clayton. The area is underlain by metasedimentary rocks of Early to Middle Paleozoic age that were profoundly affected by the emplacement of a plutonic complex in...
The central Bond Creek area is on the north slope of the Wrangell Mountains approximately 15 miles east of Nabesna, Alaska. The entire area is underlain by plutonic rocks of the Monte Cristo batholith of probable Jurassic age. Early members of this complex are hornblende diorite, quartz diorite, and granodiorite...
The Washougal Mining District is located on the western flanks of the southern Cascade Range of Washington, approximately 50 km (30 miles) northeast of Vancouver, Washington. The district has produced only $573 since 1903, derived from copper and silver. The presence of hydrothermal mineralization and breccia pipes similar to those...
The Washougal Mining District is approximately 50 km (30
miles) northeast of Vancouver, Washington, along the western
slopes of the Cascade Range. Although the district has produced
the unostentatious amount of $572 in metals since 1903, the presence
of porphyritic intrusions, hydrothermal alteration, breccia pipes,
and base-metal mineralization typical of...
Several uranium anomalies, with concentrations of U₃0₈ that
average below 0.003 percent and reach maximums of 0.069 percent,
are associated with black, fossiliferous, pyritic parts of the Ordovician
Ledbetter Slate in northern Stevens County, Washington. The most
uraniferous parts of the slate occur in small (average of 5 by 30...