The Tinton West Project is situated in the northern Black Hills straddling the boundary between Lawrence County, South Dakota, and Crook County, Wyoming. The Project area is located 18 km southwest of the town of Spearfish and 72 km northwest of Rapid City. Of the 69 unpatented lode mining claims at the Tinton West Project, 20 are located in South Dakota (referred to as the TSD Claim Group) and 49 are located in Wyoming (TW Claim Group). All claims are wholly owned by Patriot Lithium.
The significant historical Rough and Ready, Giant Volney and Spearfish pegmatite mines that occur to the east of the Tinton West Project area produced tin (from cassiterite) as well as tantalum (from columbo-tantalite) and lithium (from spodumene and amblygonite). The pegmatites at the Rough and Ready mine comprise a series of seven discrete dykes, <23 m wide, in the north that converge to the south to form a single pegmatite, the Giant Volney, with a total strike extent of >500 m. The thickness of the Rough and Ready pegmatites varies along strike and down dip, ranging from a few metres to c. 45 m whilst to the north the pegmatites thin and pinch out; some also split or pinch out at depth. Spodumene-rich zones have been identified in historical maps and plans of the pegmatite. The pegmatites associated with the Jersey No. 1 tin mine workings and Lafayette tin prospect both occur within Patriot Lithium’s Tinton West Project.
The claims that comprise the Tinton West Project are underlain by an inlier of Palaeoproterozoic basement rocks similar to those in the Keystone district and exposed on a small domal uplift, a so-called tectonic window. The Tinton West Project covers the southern portion of this dome. The basement rocks here comprise quartz-mica, graphitic and hornblende schists intruded by foliation parallel to slightly transgressive pegmatites.
The Keystone Project encircles the town of Keystone, a small settlement in the central-eastern Black Hills, approximately 26 km southwest of Rapid City, the 2nd largest city in the state of South Dakota.
The Keystone Project comprises 255 unpatented lode mining claims in four separate blocks that are held 100% by Patriot Lithium. The claims, referred to as the Key Claim Group, are located on public lands in the Black Hills National Forest of Pennington and Custer counties, South Dakota.
The Keystone district was the most important of the historic lithium-caesium-tantalum (LCT) pegmatite mining districts in the Black Hills in that it contains the majority and largest of the historic lithium mines. The Etta Mine at Keystone was an important global lithium source in the first half of the 20th century and operated for over 60 years (1898 to 1960). At times it was the main source of spodumene in the world and is famous for its very large (up to >14 m-long) spodumene crystals, the largest known on Earth. The Keystone Project is near and along strike from some of the historical mines and contains several historic mines and prospects as well as numerous outcropping, or underexplored pegmatites.
The Keystone Project lies to the northeast of the main mass of the Harney Peak Granite, the apparent source of the LCT pegmatite melts, and is underlain by Palaeoproterozoic age metasedimentary rocks comprising mostly metagreywacke, metaconglomerate, quartzite, phyllite, biotite schist and iron formation. Similarly aged mafic rocks include volcanics and gabbros that are intrusive into these metasedimentary rocks. The metamorphism and folding of these metasediments occurred the period c. 1,760 to 1,720 Ma, prior to the intrusion of the younger Harney Peak Granite and associated pegmatites. Most of the pegmatites within the Keystone Project strike northwest-southeast to west-northwest to east-southeast, parallel to the regional fabric.