Diamond Grove Mines



The Stargrove Project is located in Chabanel Township, Ontario, approximately 15 kilometers by road, north of the town of Wawa. The claims are road accessible and occur in an area of sparse vegetation.

Stargrove Stargrove

Project History

As originally staked in 2000, the Property consisted of four contiguous legacy claims totalling 52 claim units (872.7 ha) located primarily in northeastern Chabanel Township and a small portion in the adjoining southeastern Musquash Township, approximately 15 km northeast of the town of Wawa, Ontario. By virtue of the Mining Lands Administration System (MLAS) which took effect on April 10, 2018 in Ontario, the Property now consists of 37 single cell and 19 boundary cell mining claims totalling approximately 1,208 ha. The claims are currently registered in the name of Diamond Grove.

In 2000, an agreement with the Magpie Syndicate was entered into, which was subsequently amended, to acquire a 100% interest in 357 claims, including the claims comprising what is now known as the Stargrove Property, subject to a 2% Net Smelter Return (NSR) royalty, half of which (1%) can be bought out for $1.0 million. For inter corporate purposes, the legal and beneficial title to the Property was transferred to Diamond Grove Mines Ltd.

A limited amount of sampling of a heterolithic breccia unit on the southern portion of the Property in 2005 yielded microdiamonds and shortly thereafter, Metalex Ventures Ltd. (Metalex) acquired an option to earn a 60% interest in the Property. Metalex then entered into an agreement with Diamond Grove Mines (formily Mori Diamonds) and with Dianor Resources Ltd. (Dianor) whereby Dianor could earn a 50% interest in Metalex’ interest in the Property. From 2005 to 2009, Metalex/Dianor completed overburden sampling, a detailed helicopter borne magnetic survey, a limited ground follow up magnetic surveying and two drilling programs totalling 23 holes for 5,506.8 m. Results from the two drillings can be reviewed on MetalNews.com.

The Rio Tinto Mining Company optioned the Property from 2016 to 2018 and completed geological mapping, surface sampling and conducted an airborne gravity survey.

Project History

Regional Geology

The Project is underlain by rocks of the Archean Michipicoten Greenstone Belt (MGB), part of the Wawa subprovince, Superior Province.

The Wawa subprovince is composed of two linear concentrations, or zones of greenstone belts: (1) one along its northern border with the Quetico subprovince, comprising the Shebandowan, Schreiber-Hemlo, Manitouwadge-Hornepayne, White River, Dayohessarah, and Kabinakagarni greenstone belts, and (2) a second in the south-central portion of the Wawa subprovince, including the Mishibishu, Michipicoten, and Garnitagama greenstone belts. These supracrustal zones are composed dominantly of mafic volcanic rocks, with subordinate ultramafic, intermediate, and felsic flows. Sedimentary rocks are predominantly siliciclastic turbiditic wackes and shales, with minor conglomerates, iron formations, cherts, and carbonates. The two linear concentrations of greenstone belts are separated by domains of tonalite-trondhjemite-granodioritic (TTG) plutonic rocks.

The Project area has been extensively glaciated and extensive deposits of glacial material exists throughout the map area.

Property Geology

Work conducted on the Stargrove Project confirmed that metasedimentary rocks consisting of interbedded, thin bedded siltstones and sandstones to thick bedded, cross bedded sandstones overlie a conglomeratic unit. The fine clastic facies are interpreted as being distal turbidites that overlie conglomeratic debris flows. The debris flows or conglomerates consist of polymictic pebble, cobble, and boulder beds with rounded to subangular clasts of rhyolite, chert, sandstone, and rare gabbroic clasts. The coarse conglomerate units appear to be up to 80 m in thickness and dip steeply to the north-northwest. The conglomeratic beds grade out laterally into pebbly sandstones that in turn grade into and/or are overlain by thin bedded, interbedded siltstone-sandstone sequence. Top determinations suggest that the sequence is overturned. The clastic sequence is in contact to the north with pillow lavas (basalts).

On the west side of the Project, at Blueberry Lake, the conglomerate unit terminates abruptly against the Mildred Lake fault. Left lateral motion of three kilometres on the Mildred Lake fault is interpreted as having been responsible for offsetting the conglomerate unit on the Project from that at Leadbetter. The conglomerate unit continues to the east of Project onto ground held by others.

Geology Map


Diamond mineralization is confined predominately to polymictic conglomerate units interpreted as paleo placer debris flows. Locally, the debris flow units dip steeply to the north-northwest and range from five metres to greater than 200 m in true thickness along a 3.5 km strike length. Diamonds have been recovered from both surface grab samples and drill core intersections. Drill core samples subjected to caustic dissolution have yielded diamond counts in the range of < 0.5 stones per tonne (spt) to two spt from the main polymictic conglomerate. Minor counts of microdiamonds have been recovered from finer grained units and mixed conglomerate-volcanics.

Although the quantities of diamonds present in the Stargrove Project conglomerates are comparable to those from the Leadbetter Conglomerate, the Leadbetter Conglomerate does not contain the abundant coloured diamonds that have been reported at the Stargrove Project (Metalex News Release June 25, 2008).

Exploration of the Project will primarily involve defining the lateral and down dip extent of the diamondiferous conglomerate and creating a geological model and characterizing the size, frequency, distribution, and quantity of diamonds contained herein. Geophysical work using magnetic, electromagnetic, or other properties of the host rock should be used to further target areas for follow up sampling and/or drill testing, particularly in areas of the Property that remain under cover.

Sampling and Prospecting

Sampling and prospecting were also carried out on the Property from 2005 to 2007.

Surface rock samples of exposed conglomerate weighing 25 kg or more were collected at 41 sites. The samples were sent either to SRC or SGS Lakefield for microdiamond analysis. Some samples were sent to CF Mineral Research Ltd. (CFM) for attrition milling and recovery of indicator minerals.

Stream sediment samples were taken from 16 streams and at each sample site 15 kg to 20 kg was collected from the active portion of stream channels. The samples were shipped to CFM for concentration and recovery of indicator minerals. The largest diamond recovered from these reconnaissance samples was a 0.09 carat brown crystal aggregate measuring 2.869 mm by 2.508 mm by 1.850 mm in size.

During this period, a helicopter supported reconnaissance till sampling and prospecting program was conducted. A total of 52 samples were taken on the Stargrove property. Ten kilogram samples were manually taken from pre-selected sites and sieved in the field. Whenever possible the sample material was collected from pits, dug by shovel to a depth of 0.3 m to one metre to enable sampling of the till bedrock interface and the basal till. The sieved samples were shipped to CFM for processing and indicator mineral analysis (Ulansky, 2005).


In 2017, the Rio Tinto Mining Company conducted a surface sampling program and submitted 61 samples to SRC for microdiamond analysis and description. A composite sample from drill core was submitted to SGS Lakefield for heavy mineral concentration and indicator mineral selection.



Two core drilling programs were completed on the Stargrove Property. An initial 13 hole NQ diameter drilling program totalling 2,807.8 m was completed from January to April 2007. The objective of the drilling program was to test the subsurface extent of the outcropping diamond bearing conglomerates. The drill program recovered 5,234 diamonds >75 µm from 180 samples from conglomerate drill core with a total weight of 8,078 kg. The 10 largest diamonds recovered were greater than 0.850 mm in size, weighing from 1.0583 mg to 2.6327 mg. Of note is the observation that over half of the diamonds in the core were coloured.

During the fourth quarter of 2009 Diamond Grove completed ten drill holes from four set-ups to test the geometry of the conglomerate and lateral continuity of the diamond bearing unit. A total of 213 drill core samples were sent to CFM for DIMs and microdiamond analysis.

Microdiamond analysis was completed by CFM on all the samples collected from the 2007 drill campaign and only selected samples from the 2009 drill campaign. One drill hole (of three) from each of the three hole drill fences was selected for analysis for gold in 2009 and one drill hole (of three) from each of the three hole drill fences was selected for diamond analysis by the Rio Tinto Mining Company in 2017. Samples selected by from three drill holes were analyzed for diamonds at SRC, and samples from three hole were analyzed for gold at Swastika Laboratories Ltd. (Swastika) in Swastika, ON.

Drilling Map Drilling Map Drilling Map


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