After optioning the project in 2013, Tower embarked on a multidisciplinary exploration program consisting of prospecting, geological mapping, re-logging of historic drill core, airborne and ground magnetic surveys, and a 3D induced polarity survey. Nine drill-ready targets were recognized: Chrysocolla East and Main, Western Magnetite, Central Monzonite Main and South, Kwil, KV, Buff and Dominic; five of these zones were identified or discovered by Tower. The targets cover an area of approximately 4 kilometers by 4 kilometres.
In late 2013 - following the initial sampling and mapping reconnaissance program - Tower completed two geophysical surveys on the property. The purpose of both surveys was to refine drill targets in areas of known mineralization and to identify new targets in areas with overburden cover. The surveys consisted of a 50 line kilometer Induced Polarization (IP) survey and ground magnetics over the core of the Rabbit North property and a 2,900 line kilometer high resolution helicopter magnetic survey over the recently expanded claim package.
In late 2016 Tower Resources completed the first drill program on the property in 12 years, intersecting the best grades reported from the property to date. RN-008 returned 200 metres of 0.30% copper and 0.15g/t gold, including a 72m interval of 0.47% copper and 0.20g/t gold (see Tower’s news release December 8, 2016).
Drill hole RN-008 was completed in the Western Magnetite Zone, on the western margin of the Durand Stock. The drill hole was collared near P70-01, a historic shallow percussion drill hole which ended in 6.1m of 0.38% copper. Mineralization in RN-008 started at top of bedrock. Chalcopyrite and pyrite occurs in veinlets and as disseminations in mafic sites associated with moderate to strong overprinting sodic, potassic and inner propylitic alteration in Nicola Group volcaniclastics. Drill holes RN-001, -002, -009, -010, and -011 were also drilled in and around the Western Magnetite Zone.
Other zones of mineralization tested by drilling in 2016 include the Central Monzonite South showing (RN-003 and -004), where sampling by Tower recovered up to 0.62% Cu and 0.73 g/t Au in surface samples, Chrysocolla East (RN-005 and -007), a new undrilled showing where surface sampling recovered up to 1.6% Cu and 1.9 g/t Au, and Dominic (RN-006), a deep porphyry target represented by a >1.6 km wide chargeability and magnetic anomaly.
Table 1: 2016 Diamond drilling Assay Composites
|HoleID||From (m)||To (m)||Interval* (m)||Cu (%)||Au (g/t)||CuEq (ppm)**||Cu Eq (%)**|
|*Width refers to drill hole intercept. True widths have not been determined.|
|**Copper Equivalent (Cu Eq) is used to express the combined value of copper and gold as a percentage of copper, for illustrative purposes. No allowances have been made for recovery losses that would occur in a mining scenario. Calculated on the basis of $2.30 per pound of copper and $1240 per troy ounce of gold, using the formula: Cu eq = [(%Cu)(22.0462)($lbCu)+(gptAu)(1/31.1035)($ozAu)]/[(22.0462)($lbCu)]|
Following up on the significant results from the 2016 diamond drilling program, Tower completed 3325.81 meters of diamond drilling in 10 holes at the Western Magnetite and Chrysocolla Zones. The 2017 diamond drill program have returned long intervals of porphyry related copper and gold mineralization in several holes. Drill hole RN17-15 returned the most significant drill intercept to date at Rabbit North (see Tower’s press release July 11, 2017)
Highlights from hole RN17-015, include:
Drill hole RN17-015 was drilled in the Western Magnetite Zone (WMZ), an area of copper and gold porphyry mineralization predominantly hosted in Nicola volcaniclastic rocks on the western edge of the Durand stock. The drill hole was collared 180 metres southeast of 2016 drill hole RN-008, which intersected 200 metres of 0.30% Cu and 0.15g/t Au including a 72m interval of 0.47% Cu and 0.20g/t Au (see Tower’s Press Release dated December 8, 2016). Drill hole RN17-015 is considered a substantial step-out from RN-008 and thereby significantly expands and upgrades the zone of known porphyry related mineralization at the Western Magnetite Zone.
Mineralization in RN17-015 begins at 208 meters downhole, and consists of chalcopyrite and lesser pyrite as fine-grained disseminations associated with intense, overprinting inner propylitic (chlorite, magnetite, epidote, carbonate), potassic (biotite, kspar) and sodic (albite) alteration of host Nicola Group volcaniclastic rocks. Higher-grade zones are defined by breccia-hosted chalcopyrite and pyrite mineralization. Here, hydrothermal-breccia hosted mineralization is seen as coarse chalcopyrite clots in a gangue of chlorite+/-pyrite+/-carbonate +/- epidote. Mineralization styles and alteration assemblages described above are considered characteristic of alkalic porphyry systems in BC.
Further significant intervals were returned from additional holes in the Western Magnetite Zone, including drillhole RN17-018; collared as a 110m step-out to the southeast from RN17-015.
Highlights from hole RN17-018, include:
Drill hole RN17-021 was collared due south of the Chrysocolla Zone as a >1km step-out to the southeast from RN17-015. The Chrysocolla Zone is a historically identified area of copper and gold porphyry predominantly hosted in dioritic intrusive rocks on the southwestern edge of the Durand stock. Significant to this zone is the elevated values of gold seen associated with the copper-porphyry mineralization.
The area of known mineralization at the Chrysocolla Zone is notably expanded by the results of this drill hole into a previously undrilled, till covered area southwest of historic drilling.
Mineralization in RN17-021 starts at the top-of-bedrock and consists of chalcopyrite, bornite and pyrite occurring in veinlets and disseminations in dioritic intrusives and lesser mafic volcanics.
Table 2: 2017 Diamond Drill Results Composite Assays
|HoleId||From (m)||To (m)||Interval (m)*||Cu (ppm)||Cu (%)||Au (g/t)||CuEq (ppm)**||CuEq (%)**|
|*Width refers to drill hole intercept. True widths have not been determined.
**Copper Equivalent (CuEq) is used for illustrative purposes, to express the combined value of copper and gold as a percentage of copper. No allowances have been made for recovery losses that would occur in a mining scenario. CuEq is calculated on the basis of $2.65 per pound of copper and $1250 per troy ounce of gold, using the formula:
CuEq = [(%Cu)(22.0462)($lbCu)+(gptAu)(1/31.1035)($ozAu)]/[(22.0462)($lbCu)
2018 Exploration Plans
Tower plans to continue aggressive exploration on the property. Further drilling is set to commence once comprehensive geochemical and geological modelling on the 2017 drill data and further ground geophysical surveys can be executed and modelled.
Alteration at the Western Magnetite Zone is predominantly magnetite-destructive; thus, the 2017 drill program was designed to test priority targets within a 800 by 1800 metre magnetic-low geophysical anomaly between the WMZ and the Chrysocolla Zone. This area is only partially tested by 2016-2017 drillholes and remains a priority target for further drilling.
Multiple untested targets with analogous geophysical signatures and geological settings also exist under till cover northeast and west of the 2017 drilling in Nicola volcanics proximal to the Durand stock; these areas are slated for target generation and testing in 2018.