Holes N039 to N043 totalled 2,668 metres which demonstrated continuity of good grade mineralization, including 135 metres of 0.60 CuEq (copper equivalent).The strike length of the North Zone now spans approximately 1,600 metres.
Richard Lock, CEO, commented: “We are very pleased with the results of the first 43 drill holes of our 2021-2022 North Zone drill program. They have confirmed and expanded the higher-grade, near-surface mineralization amenable to early-year open-pit mining. We are also looking forward to the results of the horizontal drill program currently being conducted in the previously untested southwest area of the North Zone as it has the potential to significantly add to the mineral resource estimate in support of our upcoming Preliminary Economic Assessment.”
Highlights: Drill hole N039, approximately 200 metres downdip from N001 (255 m of 0.39% CuEq) and 200 metres up-dip from N029 (106.1 m of 0.31 CuEq) demonstrates the continuity of good grade mineralization in the North Zone, confirming and expanding the Cu >0.30% Gradeshell model defined in the 2019 Technical Report.
Drill hole N040 returned one of the deepest intersections of copper in the North Zone as it intersected a down-dip extension of the North Zone to 200 metres below sea level, demonstrating that mineralization extends 700 metres down-dip from surface while still being open down-dip and to the west.
Drill holes N041, N042 and N043 continued testing the southern end of the North Zone as the company continued its efforts to confirm shallow-seated higher-grade mineralization at the southern end of the North Zone and to define its southern extent.
Drill hole N041 was drilled downdip of N032 (88.7 m of 0.34% CuEq), confirms the Gradeshell while defining the southern limit of the North Zone.
Drill hole N042, 200 metres north of drill hole N041, returned mineralization both broader and higher grade than predicted by the Gradeshell.
Drill hole N043 intersected only minor mineralization as it intersected a steeply-dipping east-west fault that defines the southern extent of the North Zone.
All drill holes tested the deposit perpendicular to its structural attitude. Core intervals are within approximately 10% of true thickness.
Drill holes N039 and N040 continued the company’s testing of the hanging wall side of the deposit in the north-west side of the central axis of the deposit.
Drill hole N039 returned three mineralized intervals, with a main interval of 265.0 metres of 0.36% CuEq commencing approximately 40 metres above the Gradeshell and extending 50 metres below it.
Drill hole N040 returned four mineralized intervals, with a main interval of 152.1 metres of 0.33% CuEq in a downdip extension approximately 200 metres west of the Gradeshell.
The southern portion of the North Zone is blind to surface and beneath a blanket of post-mineralization volcanic rock. Modelling of the historical results and structural analysis successfully delineated the North Zone 400 metres south from hole N020 to the limit of the zone at drill hole N043.
The North Zone program confirmed good-grade mineralization in a gently north-plunging panel beneath the Santo Tomas ridge, extending 1,600 metres along strike, to 400 metres and 800 metres down-dip below surface.
Drill hole N042 returned 135.0 metres of 0.60% CuEq extending across and below the Gradeshell.
Drill hole N041, collared approximately 200 metres south of N042, continued confirmation of the Gradeshell with two mineralized intervals, with the first interval returning 20 metres of 0.35 CuEq, and the second main interval commencing 5 metres deeper returning 96 metres of 0.52 CuEq.
Drill hole N043, collared approximately 100 metres south of N041, returned three minor intervals of mineralization. N043 intersects the faults that are the south termination of the North Zone.
Oroco has largely completed its North Zone drill program in support of the planned Preliminary Economic Feasibility Study. The balance of the program focusses on horizontal drilling from the base of the Santo Tomas ridge.
Horizontal holes and shallow dipping holes will allow testing of the southern 400 metres of the North Zone, at depths 300 to 500 metres below surface, to the south of hole N038. This area of the North Zone has the potential to add significant tonnage to the resource estimate being prepared in support of the planned Preliminary Economic Assessment.
The South Zone program has now drilled 19 holes (11,069 m) in its program to confirm and test the South Zone deposit, with the assay results of holes S004 through S019 pending. Historical drilling, surface geological mapping, and the Dias Geo 3D Induced Polarization survey have defined near-surface mineralization projected to 400 metres below the surface along 2,500 metres of strike length.
Oroco holds a net 85.5% interest in the collective 1,172.9 ha Core Concessions of the Santo Tomas Project. The company also holds an 80% interest in 8,154.3 ha of mineral concessions surrounding and adjacent to the Core Concessions (for a total project area of 23,048 acres).
The Santo Tomas Project is within 160 km of the Pacific deep-water port at Topolobampo and is serviced via highway and proximal rail (and parallel corridors of trunk grid power lines and natural gas) through the city of Los Mochis to the northern city of Choix. The property is reached by a 32-km access road.