Lac de Gras / ATW

Northwest Territories, Canada


100% Almadex owned

Overview of the Project

The Lac de Gras area diamond project is situated at Mackay Lake in the Northwest Territories, immediately south of the Diavik property and west of the DHK property. 150,000 acres was staked by ATW Resources Ltd. in 1992, which is operated by a joint venture agreement between Almadex Minerals, Williams Creek, and Harry Winston.

In 2003 and 2008, sonic drilling was conducted to collect samples of till sediments in the base of Mackay Lake. The drilling was undertaken in a series of north-south fences in the vicinity of previously recovered kimberlitic indicator minerals. The samples from 2003 and 2008 were processed by Vancouver Indicator Processing and the resulting concentrates sorted by KIM Dynamics of North Vancouver, B.C. A total of 7122 potentially kimberlitic indicator minerals were recovered from these samples including numerous garnets and olivines and minor chromite, ilmenite and Cr-Diopside. The mineral recoveries define a mineral dispersion train of approximately 3 km (E-W) by 1.3 km (N-S). The Mackay Lake indicator mineral plume (MKIP) is constrained to the east and south but is open to the north, and possibly also to the west.

News & Updates

Please note: Prior to June 2015, work on Lac de Gras was conducted by Almadex's predecessor, Almaden Minerals. News releases below link to archived releases. To read all news releases of Almaden's prior work on the project, please visit Almaden Minerals' newsroom.

February 14th, 2011
The winter 2011 joint venture exploration program is now underway. The winter 2011 program will comprise the completion of approximately 134 sonic overburden drill holes. The holes will be drilled within a 3 kilometre by 4 kilometre area of interest that lies at the at the “up ice” terminus of a 20 kilometre long kimberlite indicator mineral (KIM) dispersion train. The dispersion train has been traced “up ice” and easterly under MacKay Lake. The purpose of the 2011 drill program is to define the “up ice” and lateral extent of the head of the KIM dispersion train under Mackay Lake. Previous sonic drilling campaigns completed during 2003 and 2008 have defined the southern and “up ice” (eastern) cut-off of the dispersion train, resulting in the definition of the present high priority area if interest. Based on the results of winter 2011 exploration, targets will be chosen for diamond drill testing during winter 2012. Read more +

April 9th, 2009
During winter 2009 exploration at the ATW Diamond Property nine diamond drill holes totaling 694 metres were completed. The drill holes were designed to test a series of priority magnetic and weak electromagnetic (conductive) geophysical anomalies located at the up-ice terminus of a 20 kilometres long kimberlite indicator mineral (KIM) dispersion train.

Drill testing of six isolated magnetic high anomalies resulted in the intersection of weakly magnetic pyrrhotite beaTring metamorphosed sedimentary rocks. The magnetic susceptibility of these rocks was sufficient to explain the observed geophysical signatures. A single linear magnetic anomaly was also drill tested. The anomaly was found to correspond with a region of locally thick overburden cover interpreted to contain an increased proportion of magnetic minerals. The remaining two drill holes tested subtle conductive anomalies and did not intersect kimberlite.

2009 drill testing of geophysical anomalies at the ATW Diamond Property did not locate the kimberlite source(s) of a compelling KIM dispersion train. The dispersion train has been traced “up ice” and easterly under MacKay Lake over several campaigns by Almaden and partners. Future exploration will include an examination of KIM grain morphology and the completion of additional sonic overburden drilling, gravity geophysical and bathymetric surveys if warranted, in an effort to further refine the “up ice” terminus of the KIM dispersion train and locate the KIM source or sources.  Read more +

March 2nd, 2009
A quick progress report from the field. The APEX crew arrived at the camp on Saturday afternoon, and everything is in order. Our ground geophysical survey crew is currently on the lake covering the ATW004 and dyke targets today. Surveys should be complete over the first 5 proposed drill targets prior to arrival of the drill crews. The collar location for the 1st drill hole (anomaly ATW004) will be finalized in early next week, with finalization of a further 4 collars in the following few days. Drilling should commence by March 6th.

February 4th, 2009
Almaden has received the results of a comprehensive reinterpretation of past magnetic, electromagnetic/resistivity and gravity survey data. The reinterpretation was undertaken by Petra Geophysical Consulting Inc. (Petra) on geophysical surveys previously completed. Petra’s analysis in conjunction with the Spring 2008 sonic drilling results forms part of a recent reinterpretation of extensive geophysical and geochemical data that has identified numerous high-quality targets. Drill testing is planned for at least seven of these targets during the coming months. Read more +

October 22nd, 2008
Almaden has received results from a Mineral Composition and Surface Texture Study conducted by Mineral Services Canada Inc. (MSC) on mineral grains recovered in 2003 and 2008 on the ATW diamond property. MSC’s analysis suggests that there could be as many as five distinct kimberlite sources contributing minerals to the Mackay Lake indicator mineral train. The mineral abundance and composition and surface texture data further suggest that these sources may lie within the currently defined mineral train, which extends over an area of approximately 3.5 kilometres by 1.5 kilometres. Three of these sources show the potential to contain diamonds of peridotitic or eclogitic origin. The identification of rare eclogitic garnets with diamond association compositions in this work is encouraging as diamondiferous eclogite can be a significant contributor to the economic potential of kimberlites. Read more +

Winter 2003- 2004
A magnetic and electromagnetic geophysics program was completed in December 2003 and several subtle anomalies were identified. No drilling is contemplated this winter.

April 2003
A till sampling program has been completed. Seventy-seven holes were drilled to recover samples of basal till in order to determine the source of a 20 kilometre long kimberlitic indicator mineral train in glacial till. This train had previously been traced easterly and up ice to within five kilometres from a fence of holes which did not encounter indicator minerals, outlining a source area for the kimberlitic body.

March 1999
7 additional claims were staked totalling 15,495 acres to further cover the area in the direction up-ice from the indicator mineral train.