Blockhouse

Blockhouse is a past-producing, high-grade gold mine on Nova Scotia's South Shore. In January 2017, seven NQ diamond drill holes totalling 644 metres were completed from three sites around the historic Prest workings. The standout hole, BH-17-01, intersected 1.06 g/t Au over 10.25 m from 36.0 m in a bedding-parallel fault zone of quartz veining with visible gold, including vein samples of 25.7 g/t and 12.1 g/t Au, and BH-17-07 returned 1.49 g/t Au over 1.8 m. The BH-17-01 zone points to a second style of target at Blockhouse: bedding-parallel faults that offset the Prest Vein. Several similar faults are mapped on historic plans of the property and have not yet been drill-tested. Next-phase work will target a continuous mineralized system potentially extending along strike within the Blockhouse anticline, the key structure controlling mineralization at the property.

Coordinates are UTM NAD83 Zone 20N, located by handheld GPS. Intervals are core lengths. Results are from Actlabs certificates A17-01077 and A17-01783, as reported in MacKay (2017, revised June 9, 2017), the assessment report for exploration licence 50564.

Location

The Blockhouse Property is located in Lunenburg County, Nova Scotia, roughly 4 km west of the town of Mahone Bay and about 70 km west-southwest of Halifax. Access is excellent: the property is reached via Mines Road off Highway 325, and Highway 103 passes near its northwest corner. Secondary roads reach most of the property directly from the highway.

Geology

Blockhouse lies within the Meguma Supergroup, the host of most of Nova Scotia's historic gold production. The property straddles the northeast-trending Blockhouse anticline, where quartzites and greywackes of the Goldenville Group meet the overlying slates of the Halifax Group.

Gold occurs in quartz fissure veins that cut across the south flank of the anticline, most notably the Prest Vein. The richest historic ore came from where the Prest Vein crosses a 25 m thick, sulphide-rich slate unit known as the "favourable horizon", a zone called the Prest Shoot. Recent drilling has shown that bedding-parallel faults offsetting the Prest Vein can also host broad zones of gold-bearing quartz veining, opening a second style of target on the property.

History

Blockhouse is a past-producing gold mine. Underground work on the Prest Vein ran from the late 1800s into the early 1930s, with sporadic activity into the mid-1950s. Total reported historical production is 3,588 oz of gold from 6,210 tons of ore, an average of 0.58 oz/ton.

The Prest Shoot alone produced 3,259 oz of gold from 2,043 tons of mill feed between 1896 and 1935, an average historical grade of 1.59 oz/ton (49.6 g/t). The vein was stoped over about 300 m of strike to a depth of 60 m, with drifting at the 90 m level. Sampling of the 60 m level in the late 1930s traced the Prest Shoot for 138 m, averaging 0.37 oz/ton over 0.35 m.

Key modern work:

• 1982-1983: Ten diamond drill holes tested near-surface potential, alongside magnetometer and VLF surveys.
• 2016: An induced polarization (IP) and resistivity survey over the old workings outlined two well-defined, steeply dipping chargeability trends, each 5-10 m wide and extending past 68 m depth. Neither had previously been drilled, and both were rated high-priority targets. The same year, a selected sample from the historic muck piles at the old mine site returned 494 g/t Au (21Alpha, 2016).
• January 2017: Seven diamond drill holes (644 m) were completed with support from a $60,000 Nova Scotia shared-funding grant. Hole BH-17-01 intersected 1.06 g/t Au over 10.25 m from 36.0 m, in a zone of quartz veining with visible gold. Individual vein samples within the zone returned 12.1 g/t, 7.08 g/t and 22.0 g/t Au (25.7 g/t by metallic screen fire assay). The program geologist described the intercept as a significant discovery, with its full extent still untested (MacKay, 2017).
• 2018: During a humus geochemical sampling program, quartz vein float with visible gold was found about 700 m south of the old workings. A sample of this float assayed 77 g/t Au (AGAT certificate 18T360617), and its source has not yet been followed up. Humus samples in the same area outlined a northeast-trending gold anomaly (21Alpha, 2018).

Exploration Plans

Our geologists are currently finalizing exploration plans that will take place over the course of the fall and winter months using a combination of soil geochemistry and geophysical methods. The open BH-17-01 zone, the untested IP trends, the extension of the Prest Shoot beyond the historic workings, and the source of the 77 g/t Au float 700 m to the south offer multiple compelling targets for follow-up.