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Geology topics

C. C. Hawley

Publications and source records attributed to C. C. Hawley.

At least 19 recordsLinked to original sources
USGS1969

Results of geological and geochemical investigations in an area northwest of the Chulitna River, central Alaska Range

Sedimentary and volcanic rock units of Paleozoic and Mesozoic age, faults, and elongate bodies of intrusive rock, particularly serpentinites, have a dominant northeasterly trend in an area northwest of the Chulitna River between Eldridge Glacier and Bull River. The serpentinites locally contain abnormal (as much as 0.5 percent) concentrations of nickel, have one newly identified occurrence of chromite, and are hosts to small epigenetic lodes containing copper, gold, and silver. Other epigenetic concentrations of copper or other metals occur in interlayered basalt and limestone at Partin and Canyon Creeks in the southwestern part of the area and in porphyry near Costello Creek in the northern part of the area. Tin occurs in greisen on upper Ohio Creek, and abnormal concentrations of tin also characterize mineralized rocks along Canyon Creek and at a prospect near Long Creek. Mineralized rocks characterized by silver, lead, and zinc crop out near Lookout Mountain. Anomalous concentrations of gold and other metals occur in stream sediments at isolated sites in upper Long Creek and at Coal Creek, as well as in several areas near known lode mineral occurrences. Shotgun and McCallie Creeks both contain stream sediments with anomalous concentrations of metals and both head into the basalt-limestone unit which is the host rock at Partin and Canyon Creeks; these facts suggest that other concentrations may be found.

Circular↗
USGS1969

Geochemical maps of an area northwest of the Chulitna River, central Alaska Range

An area northwest of the Chulitna River in west-central Alaska Range locally shows local anomalous concentrations of gold, silver, arsenic, copper, zinc, and lead in stream-sediment samples. Most stream sediments showing anomalous concentrations of metals can be correlated with either known or newly discovered deposits or occurrences described in Circular 617.

Alaska↗
USGS1968

Distribution of beryllium, tin, and tungsten in the Lake George area, Colorado

Complex ore deposits are spatially associated with granitic bodies of Precambrian age in the Lake George area, Colorado. They include greisens that contain high concentrations of beryllium and subordinate amounts of tin, tungsten, and other metals associated with the Redskin Granite. Scheelite deposits in calc-silicate rocks and greisen deposits near Tappan Mountain that contain tin and tungsten minerals are associated with the Silver Plume (?) Granite. Samples of stream sediments and soils locally show anomalous concentrations of beryllium, tin, copper, lead, and molybdenum. Some of the areas of anomalous concentrations correlate with known deposits; others do not, and this fact suggests that further prospecting is warranted.

Colorado↗
USGS1968

Geology of the Golden Zone mine area, Alaska

The Golden Zone mine area, in the upper Chulitna district, is underlain mainly by siltstone and tuff, volcanic conglomerate and breccia, and limestone. These rocks were invaded, probably in the Tertiary, by dikes and a small stock of porphyry. The ore deposits of the area are the Golden Zone breccia pipe, a nearly vertical body about in the center of the porphyry stock, and steeply dipping veins. Most veins strike north to northeast and are commonly only 1-5 feet thick, but locally are as much as 15 feet thick. Both pipe and vein deposits are gold deposits of low to moderate grade that are characterized by abundant arsenopyrite; some contain possibly economic amounts of copper, lead and zinc minerals. Of the deposits of the mine area, only the Golden Zone has been explored to any extent, and both it and some of. the veins deserve further exploration to determine their potential.

Alaska↗
USGS1968

Reconnaissance geology, mineral occurrences, and geochemical anomalies of the Yentna district, Alaska

The Yentna district, in south-central Alaska, is underlain by slightly metamorphosed Mesozoic sedimentary rocks, and by sandstones, conglomerates and coaly minerals of the Tertiary Kenai Formation. The bedrock is locally covered by extensive surficial deposits of Quaternary and Recent (Holocene) age. The Mesozoic strata are cut by a quartz monzonite batholith in the Tokositna Mountains and by alaskitic dikes and plugs in the Peters and Dutch Hills. A silica-carbonate dike, which formed by alteration of a mafic or ultramafic dike, was noted in the Peters Hills. The major ore deposits are gold placer deposits of several types, including stream and bench deposits of Recent (Holocene) age, glacial-fluviatile deposits of Quaternary age, and conglomerates of Tertiary age. Quartz-rich conglomerates and breccias have also been productive and are interesting and controversial genetically. The present study indicates that they are closely related to shear zones containing quartz veins and highly altered rocks; previously the origin of the associated altered rocks had been ascribed to deep weathering. The report also contains descriptions of a few gold lode prospects and of geochemically anomalous areas such as those at Bunco Creek and near Mount Goldie.

Open-File Report↗