NI43-101Pre-Feasibility Study Report - page 131

Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
, 2014
10135-200-46 – Rev. 0
8 Deposit Types
8.1 Introduction
This section discusses the characterization of the rare earth deposit types within the
Bear Lodge REE district, based on the most current geological and mineralogical
data accumulated through 2013.
8.2 Carbonatite-Hosted Rare Earths
The USGS stated that the Bear Lodge Mountains contain one of the largest deposits
of disseminated rare earth elements (REE) in North America (Staatz, 1983). REE-
mineralized carbonatites were discovered and defined during exploration of the Bear
Lodge Project area over the past forty years. The carbonatites occur within an
alkaline intrusive complex and share similarities with the Mountain Pass (California)
carbonatite-hosted rare earth deposit and with the Mount Weld Carbonatite-hosted
REE deposit in Western Australia. The geological and mineralogical characteristics of
these two REE deposits can serve as exploration models for the current project.
Based on knowledge of carbonatite-hosted REE deposits, including the two
aforementioned, Rare Element Resources conducted detailed exploration of the Bear
Lodge property between 2004 and 2013, using a variety of geological, geochemical,
and geophysical methods, as well as historic exploration data from other companies
that had worked previously on the property, to identify a series of exploration targets.
Exploration methods included detailed geological mapping, structural studies, soil and
rock chip geochemical surveys, and airborne and ground geophysical surveys. The
latter included magnetics, radiometrics, gravity, and CSAMT. The database
developed from this work was utilized to develop sophisticated targeting methods.
Drilling based on this work defined the Bull Hill and Whitetail deposits under current
development, and confirmed the potential of adjacent target areas at Bull Hill
Northwest, Carbon, and Taylor.
The Bear Lodge REE deposit comprises three main resource areas: Bull Hill (includes
Bull Hill West); Bull Hill Northwest, and Whitetail Ridge, plus several exploration
targets that may contain resources but need further work (Figure 8.1). These three
deposits contain carbonatite-related dikes and veins that range in size from hairline
fracture veinlets to dikes that may exceed 80 feet (24.4m) in width. The higher-grade
REE-bearing dikes and veins are commonly surrounded by lower-grade stockworks
of veinlets. Oxidized mineralization (FMR and OxCa) extends to depths of 500 to 600
feet (152 to 183 meters) beneath the surface and contains the mineral resource
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