- Photo Gallery
M&I - 7,225,000 tonnes @ 4.1 g/t Au - 951,000 ounces
Inf - 5,072,000 tonnes @ 3.9 g/t Au - 633,000 ounces
James Bay, Québec
Potential Mining Method
Open Pit and Underground
Gravity 93%, Floatation 98%
The Clearwater Project covers approximately 500 square kilometres of Archean geology similar to that which underlies many of the major mining camps within the Canadian Shield. The project is situated approximately 800 kilometres north of Montréal, 80 kilometres north of the airport at Nemiscau and less than 20 kilometres northeast of Hydro Québec's EM-1 complex.
The Eau Claire gold deposit is situated at the western end of the Clearwater property, 2.5 kilometres from Hydro Québec's road network and approximately 15 kilometres from one of the world's largest hydro-electric power installations. Year-round access to the 30-person base camp is facilitated via drill roads five kilometres from the permanent road network.
Goldcorp has forecasted 2016 production of 250,000 to 280,000 ounces of gold at its Éléonore Mine, which is located only 45 kilometres north of Clearwater.
Eastmain’s objective is to establish Eau Claire as a high-grade gold resource that will support a profitable, stand-alone mining operation, based on prevailing metal prices.
Clearwater and Lac Clarkie are located within the Middle Eastmain Volcanic Belt of the Eastmain Sub-Province and overlain by sedimentary rocks of the Opinaca Sub-Province. Over the last few years, Eastmain focused on expanding and defining the high-grade Eau Claire gold deposit, potentially amenable to extraction by open pit and underground mining methods. The structural deformation zone which hosts the Eau Claire deposit continues along the southern portion of the property, and prompted the company to step out and test four additional gold showings within 15 km of the deposit, and two targets outside the zone.
Lac Clarkie Property
The new Lac Clarkie claims are located to the east and contiguous with Clearwater. Preliminary work in the area has identified two key areas for initial exploration focus, the Southern Structural Zone and the Northern Sedimentary Basin.
SOUTHERN STRUCTURAL ZONE: This area is underlain by mafic flows of the 3 km by 15 km Natel Formation, representing a possible extension of the Eau Claire host stratigraphy from Clearwater. The Natel formation ranges along a major east-west trending crustal deformation zone which extends through both the Clearwater and Clarkie Projects and is spatially related to the Eau Claire deposit.
NORTHERN SEDIMENTARY BASIN: This area is underlain by Opinaca-type Clarkie Formation sedimentary rocks comparable to the host rocks of the Eleonore gold mine. These sediments are hosted in southeast trending 26 km long by 15 km wide basin. Several marker horizons, such as polymictic conglomerates, that have been identified on the eastern shore of Lac Clarkie are also found in the sedimentary rocks located east of the Eleonore gold mine. These are comparable to the Timiskaming conglomerates observed within the Kirkland Lake gold camp and are indicative of a regional structural/stratigraphic break.
Eau Claire Gold Deposit
The most prevalent Archean gold deposits are associated with deep-seated regional structural breaks in the vicinity of a geologic contact, near intrusive bodies. Most gold production in these camps comes from structurally controlled, vein-hosted deposits occurring within iron-rich mafic volcanic rocks associated with felsic porphyry intrusions. Eau Claire is situated approximately one kilometre north of a structural break, which extends east-west for more than 100 kilometres. At Clearwater, this break coincides with a major geologic contact between iron-rich mafic volcanic rocks and felsic volcaniclastic units, and the Eau Claire gold deposit occurs near a swarm of felsic porphyritic intrusive rocks.
As at April 27, 2015, the Eau Claire Deposit hosts a measured and indicated (“M&I”) mineral resource of 7.2 million tonnes at an average grade of 4.09 g/t gold containing 951,000 ounces of gold, plus an additional 5.1 million tonnes at an average grade of 3.88 g/t gold, classified as inferred mineral resources, containing 633,000 ounces of gold. Eau Claire hosts the combination of high-grade in-situ open pit gold resources and underground mineralization. Block model in-situ M&I open pit resources at Eau Claire are 885,000 ounces at 4.05 g/t Au, contained within 6.8 million tonnes(2015 Mineral Resource Statement) (1).
Eau Claire is a structurally controlled gold deposit consisting of multiple en-echelon, sheeted quartz-tourmaline veins and altered rock, forming two distinctly oriented vein sets known as the 450 and 850 West Zones. These sectors coincide with major structural shear zones, near a mafic/felsic volcaniclastic rock contact, to form a crescent-shaped body covering a footprint that is over 100 metres wide, extends for about 1.8 kilometres in length, and has, to date, been traced to a vertical depth in excess of 900 metres. Portions of the 450 & 850 West Zones outcrop on topographic highs. The 450 West Zone vein set is oriented at N 85o E, dips 45 to 60o south and plunges steeply to the southeast, sub-parallel to an F2 fold axis. The 850 West Zone vein set is aligned N 60o E, dips sub-vertically and plunges gently southwest.
Polyphase gold mineralization evident throughout the Eau Claire deposit includes: early-stage, gold-rich stratabound schist units, which are generally lower grade, but when crosscut by other gold-bearing structures can often exceed 10 g/t across widths of in excess of 10 metres; high-grade laminated quartz-tourmaline feeder veins, ranging from 10 to more than 100 grams gold per tonne in 0.5- to 10-metre-wide intervals (approximately 2.0 metres on average), which infill deep-seated east-west trending gold-bearing hydrothermal structures; and later cross-cutting and extensional, gold-rich veins and gashes within both laminated east-west veins and schist zones.
Distinct rock alteration associated with gold mineralization, consisting of actinolite-tourmaline-biotite-carbonate can often create wide zones of lower-grade gold mineralization ranging from 0.5 to 10 grams per tonne over thicknesses of 5.0 to 25 metres. Gold-bearing units vary in composition from 100% vein quartz to 100% schist. Many drill intersections and channel samples contain significant amounts of gold within tourmaline and/or actinolite and/or biotite-altered rock with little or no visible vein quartz. Both veins and alteration zones contain finely disseminated particles of free gold, tellurides and bismuth minerals. Gold also occurs as coatings and interstitial filling within tourmaline grains and accessory sulphides. Accessory sulphide minerals range from nil to 1% pyrite, pyrrhotite and chalcopyrite.
(1) Mineral resources are not mineral reserves and as such have not demonstrated economic viability. All figures are rounded to reflect the relative accuracy of the estimate. Composites have been capped where appropriate. Mineral Resources are only a preliminary estimation, through exploration and sampling, of a concentration of material of intrinsic economic interest, which has been identified in such form, grade, quality and quantity that may have reasonable prospects for eventual economic extraction. Mineral Resources are the first step in the process to establishing potential economic viability. Both the quality and quantity of Mineral Resources may subsequently be re-defined and re-estimated, through additional consideration and the application of several de-risking modifying factors during preliminary economic assessment, to potentially minable mineral resources. Please refer to Scientific & Technical disclosure for further detail.