The Calico Peak property is located approximately 52 km (32 Miles) north-northwest of Durango, Colorado at Calico Peak along the west portion of the Rico Mountain Range in the Rico Mining District. It is centered on a large potassic (alunitic) alteration zone with polymetallic veins related to a Tertiary intrusive porphyry suite.
There are 65 lode mining claims (approximately 1300 acres) within which are 8 older patented claims held by others. 44 claims were acquired by staking and 21 additional claims were later purchased by Napier. In addition, Napier has an option on 4 of the patented claims surrounded by the lode mining claims.
The Calico Peak property was first explored by old time prospectors in the late 1800s. The Rico Mining District was originally discovered in 1869 but the rich silver ores were not mined in large quantities until 1879. The district produced lead, zinc, gold, and a little copper in addition to silver. The ore occurs in veins related to faults, as well as in replacement deposits in limestone. A large amount of mineralization was also found where gypsum layers within the Hermosa Formation had been dissolved, leaving open space for ore-bearing solutions. Early Tertiary intrusives (Laramide) are common in the district, and are probably closely genetically related to the mineralization.
In more recent times during the 1970s and 1980s Anaconda Mining Company explored the Calico Peak property where it identified the potential porphyry molybdenum target. Anaconda Mining Company completed surface work including geological mapping, surface sampling and drilling of three shallow drill holes to depths of 500 feet to identify a molybdenum porphyry target. The results indicated porphyry mineralization existed, but the project was abandoned in the early 1980s when the molybdenum market was depressed.
Napier has completed a brief program which consisted of limited mapping and sampling, soil sampling, geochemical analysis of rock and soil sampling and an orientation Induced Polarization (IP) geophysical survey.
Similar porphyry molybdenum targets have been explored east of Rico, where a small but high grade molybdenum resource was also drilled by Anaconda. This is the type of target sought by Napier. Two very large deep porphyry molybdenum deposits are being mined in Colorado, providing an exploration model.
There is a large alteration of alunite (potassium aluminum sulphate) sericite and silica that has been studied by Mario Serna lsaza, in a Master's Degree thesis study completed in 1971. Alunite is a result of oxidation of host rocks through the acid leaching of former sulphides and is sometimes an indicator of gold deposits or of buried porphyry copper/molybdenum systems. While the alunite is of interest as an alteration feature, it is low grade in terms of potassium or aluminum, and the main target is a buried, moderate to large size molybdenum porphyry deposit similar to that at Silver Creek. A secondary target would be gold-silver mineralization in veins peripheral to the suspected porphyry. There is also potential for geothermal resources in the Rico area.
A work program for the upcoming exploration season will consist of:
- Data compilation
- Prospecting, mapping and sampling
- A deep IP survey
- This would be followed by drilling at least 2 deep holes, 1000-2000 feet each centered on Calico Peak below the alteration zone to search for molybdenum mineralization at depth.