|Quadrangle map, 1:250,000-scale||AR|
|Quadrangle map, 1:63,360-scale||B-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||Located north of VABM Ruby on ridge between Ambler and Shungnak Rivers in Sec. 17, T. 22 N., R. 10 E., of the Kateel River Meridian. Shown as locality 39 in Mayfield and Grybeck (1978) and accurate to within 1000 ft. (600m).|
Geologic descriptionPyrite, chalcopyrite, bornite, galena and sphalerite form lenses, stringers, disseminations, and locally massive pods in metamorphosed Devonian-Mississippian volcanic, volcaniclastic, and sedimentary rocks. Sulfide lenses are complexly folded and faulted. Country rocks are interbedded porphyroblastic quartz-muscovite-calcite schist, graphitic schist, greenstone, (some have pillow structure, and some occur as plugs and sills throughout the section), and weakly metamorphosed semischistose graywacke (Nana Development Corp., written communication, 1997). Deposit is reported similar to Arctic deposit (AR025). Horse Creek it is a highly complex deformed sequence of predominantly country rock schists and greenstones. Exposures are found along a prominent north-south trending cliff. Two inter-layered sequences of 'package' rocks have been identified; and contain the Cliff North/Horse Creek mineral showings. The Horse Creek occurrence is on the north limb of an overturned syncline and the Cliff North (described in more detail separately) occurrence is on the south limb (Ellis, 1980).
|Geologic map unit||(-156.702764454066, 67.3094678971509)|
|Mineral deposit model||Kuroko massive sulfide (Cox and Singer, 1986; model 28a).|
|Mineral deposit model number||28a|
|Age of mineralization||Devonian, based on age of host rock (Ellis, 1980).|
|Alteration of deposit||Quartz, chlorite, calcite, and sericite alteration is associated with mineralization; there is also sericite-altered quartz -muscovite-schist (Ellis, 1980).|
|Workings or exploration||Initial exploration efforts started in the early 1970s. Exploration efforts include geochemical surveys such as rock, soil, and stream sediment sampling, hand trenching, geologic mapping, geophysical surveys that included induced polarity (IP) and electromagnetic (EM) surveys, and diamond core drilling of eight drill holes. The majority of this work was completed between 1976 and 1980 (Ellis, 1980).|
|Indication of production||None|
This massive sulfide prospect is in the Ambler schist belt. Nana Development Corporation information based on a 1984 unpublished Bear Creek Exploration report.Cliff North and Cliff South are referred to in this record generally as 'Cliff'. In 2014, Cliff North and Cliff South were created as a separate records from Horse Creek since both are on separate parts of a large overturned syncline and the prospects are separated by about a mile from Horse Creek (W.T. Ellis, Vice President, Alaska Earth Sciences, Inc., oral commun., 2014).
Cox, D.P., and Singer, D.A., eds., 1986, Mineral deposit models: U.S. Geological Survey Bulletin 1693, 379 p.
Ellis, W.T., 1980, Ambler River Project, Alaska, Project Memorandum No. 7, Summary Report of Past Field Investigations and 1980 Field Investigations, Sunshine Mining Company, 114 p. (Report held at Alaska Earth Sciences, Inc., Anchorage, AK).
|Reporters||K.R. Leonard (USGS), R.L. Elliott (USGS), J.M. Schmidt (USGS), S.W. Nelson (USGS retired); V.C. Zinno (Alaska Earth Sciences, Inc.)|
|Last report date||3/11/2014|