The Stateline property is located in the Paradise Mountains, Iron County Utah. As is the case for Brik and Easter, Stateline comprises a series of low-sulfidation, epithermal gold targets located in the “Eastern Calderas” setting of southeastern Nevada and southwestern Utah. The property incorporates numerous quartz veins hosted within rhyolite flows, domes and tuffs, with anomalous gold and silver in outcrop.
The district has seen relatively little historic exploration but has long been known as a gold camp with official reported production of 32,900 tons, grading 0.39 opt Au and 5.2 opt Ag. Amax, Hecla, Phelps Dodge, and Newmont all conducted geologic mapping and surface sampling programs in the project area over the period 1980-2008. Newmont is known to have completed 14 RC drill holes which returned narrow intervals of 1-5 g/t Au within broader haloes of .1-.5 g/t.
All drilling and workings to date have targeted veins in outcropping felsic volcanics and the more prospective underlying andesite remains untested.
Location and Land Tenure
The Stateline District is located in southwestern Iron County, Utah, approximately 100 km west of Cedar City. The project is accessed via state highway 25 to Modena Junction, hence by improved gravel road and two track dirt roads to the old town site of Stateline.
The claim block comprises 94 unpatented lode claims under BLM jurisdiction, and three Utah state leases. The claim block abuts against and includes third party patented claim groups which protect small historic mines.
Geology and Alteration
Outcropping mineralization is hosted by a series of rhyolite flows and pyroclastic rocks, and related hypabyssal intrusives. Academic studies indicate this felsic sequence is of the order of 500 meters in thickness and overlies a basal volcanic stratigraphy dominated by andesite flows and pyroclastic rocks.
Alteration in the vicinity of quartz veins consists of the assemblage quartz – adularia – clay.
Gold and silver mineralization at Stateline is associated with quartz-adularia veins and stockworks over an area of several square kilometers. Mineralization is accompanied by minor amounts of pyrite and local fluorite, calcite, and sericite. Silica in veins takes the form of banded chalcedony, dark grey silicified breccia, and more coarsely crystalline quartz.
In detail, veins occur as en-echelon swarms within silicified rhyolite, often with undefined vein margins. The most prominent vein sets trend to the northeast and are cut by a weaker set of east-west veins. Where these veins intersect, host rhyolites exhibit broad zones of silicification and iron staining.
Modern exploration within the district is thought to have begun with Amax in the 1980s, although the focus of the program was molybdenum. There followed exploration programs conducted by Hecla, Phelps Dodge, and Newmont. With the exception of 14 reverse-circulation holes drilled by Newmont in 2008, all the exploration programs were limited to geologic mapping and geochemical surface sampling. Four of the Newmont holes encountered 1.5 meter intercepts with gold concentrations between 1.5 and 4.5 g/t along a 305 meter strike length of a single vein. Newmont also commissioned a broad soil sampling program across an underexplored area in the southwest portion of the claim block.
Stateline is a large property, much of which has seen very little exploration effort. Logan believes that a new phase of target generation work is required prior to any further drilling. At least two target concepts are appropriate:
- Low grade, bulk mineable gold deposits hosted by felsic volcanic rocks (Round Mountain, McDonald Meadows, Rawhide, Castle Mountain).
- Higher grade and more continuous quartz vein mineralization in the lower andesitic volcanic rocks (Sierra Madre, Mexico, Karangahake, New Zealand)
A program of work will be considered for 2017, beginning with prospecting of the poorly-known northwestern, northeastern, and extreme southern portions of the claim block. Further geologic mapping focused on the andesite basement, together with soil sampling, and ground geophysical surveys will also be considered.