Structural Geology Overview
Matador’s Central Zone Project has a JORC resource of 810,000oz Au at 2.6g/t Au (see Footnote 1, page 1) and is hosted in second order structures and splays off the main Cape Ray Shear. The Cape Ray Shear is a major structural boundary and is defined as the contact between the Dunnage and Gander tectonostratigraphic zones. The shear hosts a large number of the gold occurrences in Newfoundland, including the Valentine Lake deposit (4.22Moz Au at 1.8 g/t Au), which is hosted in rocks analogous to Matador’s Window Glass Hill deposit.
In addition to the above-mentioned deposits, numerous high-grade gold intercepts have been encountered by exploration companies along the shear, including the Wildling Lake Project (5.35m grading 10g/t Au) and the Moosehead Project (11.9m at 44.96g/t Au). These high-grade gold occurrences and the Cape Ray shear are highlighted in Image 4 below.
Image 1: Major gold occurrences along the Cape Ray Shear
Structural geological analysis and mapping program
During the past field season, Matador engaged highly regarded structural geology consultants Terrane Geoscience, based in Halifax, Nova Scotia and led by Dr Stefan Kruse (Ph.D., P.Geo), to undertake a structural analysis and structural mapping of zones of interest along the Cape Ray Shear. The structural analysis comprised two phases of work:
- Phase 1 – Lineament interpretation of historical aeromagnetic geophysical data
- Phase 2 – Structural field mapping and rock chip sampling
The Phase 1 lineament interpretation was based on historical aeromagnetic data, with offsets of magnetic anomalies used to define cross structures and kinematics along the structures. Two sets of cross structures (NE-SW and E-W) were identified and are found adjacent to the all of the deposits which currently comprise Matador’s gold resource of 1.02Moz Au (See Footnote 1, page 1).
Further structural targets were identified along the Cape Ray Shear where the cross structures intersect with the main shear. These intersections provide the potential pathways and traps for the mineralized fluids during deposition events.
The Phase 2 fieldwork component comprised structural mapping of the targets identified from alteration mapping and historical sampling. Fieldwork was conducted during October 2018. A total of 165 rock chip samples were collected during the mapping exercise to support the interpretation of the structural environment.
The fieldwork identified a number of potential targets as highlighted in Image 5 below. Four of these targets are located on major second order structures (similar to Central Zone) and the other two targets on cross structures similar to Window Glass Hill as well as the 4.2Moz Au Valentine deposit.
Image 2: Structural Lineament Analysis and Structural Targets
Geochemistry sampling and analysis
Geochemical analysis has identified several trends of gold in soil anomalies as highlighted in Image 6 below. Soil sampling grids were completed across the project area between June 2018 and October 2018 as an extension to historical soil sampling grids. A total of 1,453 extensional soil samples were collected on a 200m x 50m sample spacing, and a total of 159 infill soil samples were collected on a 25m x 50m spacing.
In addition, a large historical geochemical dataset of over 1,000 rock chip samples and 3,500 soil samples has been compiled to highlight additional anomalies that are yet to be tested by drilling. Image 6 below highlights the major soil anomalies identified to date.
Image 3: Soil Geochemistry Anomalies
Infill soil sampling at Target 2 located 100m to the north of the Central Zone extension (previously referred to as Anomaly A in the company’s Drilling and Regional Exploration Update Announcement, 9th Nov 2018) was followed-up with infill sample lines that have confirmed the anomaly as representative of in-situ mineralisation as opposed to transported cover. Additionally, a brief ground-truthing exercise identified gossanous quartz veining containing up to 100ppm Zn.
Multiple anomalies of >100ppb Au in historical soil sampling were also identified in areas with no previous drilling and the nature of material also indicated it is representative of in-situ mineralisation.
A number of historical rock chips around Window Glass Hill have returned gold assays >500ppb in areas untested by drilling and represents growth opportunities for the Window Glass Hill resource.
For more information download the ASX announcement from March 2019.