Late 2013 following up on the companies sampling and mapping reconnaissance program Tower completed two geophysical surveys.
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 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.
Induced Polarization Geophysical Survey
The IP survey covered a grid centered on the Durand Stock with a footprint of approximately 2.8 by 3.6 kilometers with lines oriented northerly spaced 200 metres apart. A pole-dipole array was used with readings taken every 100 meters measuring 1 to 10 separations. This setup allowed for a maximum depth of investigation of approximately 400 metres below surface. The goal of the survey was to establish a geophysical baseline for chargeability and resistivity response associated with known porphyry related copper and gold mineralization and alteration. Furthermore, the survey was also designed to investigate areas peripheral to and deeper than the known areas of mineralization. The survey was carried out by Scott Geophysics Ltd. of Vancouver from October 16th to November 10th, 2013.
The IP survey identified numerous significant high chargeability anomalies (indicative of increased sulphide concentrations) which are also in-part coincident with strong magnetic anomalies outlined by an earlier ground magnetic survey and expanded by the helicopter-borne magnetic survey (see below). For example, the inverted chargeability 200 meter depth plan outlines a +12.5 mV/V (millivolt per volt) anomaly with a strike length of at least 1.9 kilometers and a width of at least 1.4 kilometers. This anomaly is open to the east and to the south where chargeability readings in the core of the anomaly reach +60 mV/V. Previously within this large anomaly, a small area of approximately 190 by 175 meters (the Chrysacolla Zone) was tested with diamond drill holes (see Tower's October 22nd, 2013 Press Release). The Chrysocolla Zone is associated with the western extent of the anomaly. Also on the inverted chargeability 200 meter depth plan, the northern extent of the Western Magnetite Zone is associated with a +12.5 mV/V anomaly which appears to extend 2.4 kilometers to the northeast producing an arcuate shaped high chargeability anomaly. Bedrock associated with this anomaly has been poorly tested.
Helicopter Magnetic Survey
The helicopter magnetic survey was flown on easterly oriented lines at 100 meter separation covering a survey block with dimensions of approximately 29 by 11 kilometers. In total, 2,900 line kilometers of data was collected between December 4th and December 9th, 2013 by Precision GeoSurveys Inc of Vancouver. The purpose of the survey was to provide high resolution magnetic data to assist in the interpretation of the property geology and to help define drill targets in areas proximal to the Durand Stock. The Durand Stock comprises an oval shaped magnetic high rim measuring 2.7 by 2.2 kilometers, with a magnetic low core. Magnetic highs proximal to the stock are also observed where magnetite alteration is documented in Nicola Group volcanic rocks. Magnetic highs of similar magnitude have been identified in areas with limited historic exploration proximal to the Durand Stock. These anomalies are considered significant targets for follow-up. Furthermore, the survey effectively identified new magnetic highs, lineaments and breaks which may represent possible intrusions and structures in unexplored areas where publically available, low resolution magnetic data exhibits coarse featureless anomalies.
2013 saw Tower conduct a detailed sampling and reconnaissance program at its recently acquired Rabbit North Copper and Gold Property located in the active Kamloops mining division in south-central British Columbia.
The focus of the program was to evaluate the style and grade of copper (Cu), gold (Au) and silver (Ag) mineralization described in historic reports. Representative grab and chip samples were collected from outcrops and historic trenches and historic drill core from 1997 and 2004 was re-examined. In total 47 samples were collected for geochemical analysis. Rock exposure is sparse owing to a widespread and thick cover of glacial overburden, therefore, Tower completed a detailed ground magnetic geophysical survey covering an area of 3.7 by up to 2.4 kilometers on 100 meter spaced lines. This survey delineated multiple new areas of interest mostly buried beneath overburden. Tower's technical team concludes that three main drill-ready targets exist on the property and include; Chrysocolla Zone, Western Magnetite Zone, and Central Monzonite Zone. The Western Magnetite and the Central Monzonite zones are 1.2 kilometers northwest and 1.8 kilometers northeast of the Chrysocolla Zone respectively.
Alkalic porphyry related mineralization and alteration at the Rabbit North property is documented in two host rock types; the 3 by 2 kilometer Late Triassic to Early Jurassic zoned alkaline intrusion termed the Durand stock, and the intrusion's volcanic country rocks assigned to the Upper Triassic Nicola Group. The age of the Durand stock is approximately the same age as the Guichon and Iron Mask batholiths which host the Highland Valley and New Afton mines respectively. Copper mineralization within the porphyritic monzonite core of the Durand stock is characterized by disseminated and blebby chalcopyrite (i.e., Central Monzonite zone) whereas mineralization hosted in the Nicola volcanics is dominantly characterized by disseminated and blebby chalcopyrite and pyrite (+/- bornite) associated with varying degrees of albite, biotite, epidote and magnetite alteration (i.e., Chrysocolla and Western Magnetite zones).
Table of 2013 Grab Sample Highlights from Rabbit North Property:
|Area||Sample||Type||Cu (%)||Au (g/t)||Ag (g/t)||Pd (g/t)|
|Chrysocolla||1709459||3 meter chip||0.84||1.48||2.20||0.03|
Tower cautions readers that grab samples are selective in nature and that the resulting assays from the samples may not be representative of all mineralization on the property.
The Chrysocolla target covers an area of at least 300 by 300 metres and was the focus of exploration during the 1997 and 2004 drill campaigns where 14 drill holes were completed. These drill holes were targeting porphyry related copper and gold mineralization and overprinting quartz + sulphide vein hosted gold mineralization. Drilling in this area in 1997 returned numerous gold and copper intersections such as 33 metres of 0.76 g/t Au with 0.27% Cu in drill hole DDH-97-17. Furthermore, historic drilling 150 metres north of the main trench retuned an impressive gold intersection highlighted by 10 metres of 12.35 g/t Au in DDH-97-07 reportedly characterized by fracture controlled pyrite and chalcopyrite mineralization.
Western Magnetite Zone
The poorly exposed Western Magnetite Zone is underlain by Nicola volcanic rocks coincident with a ground magnetic anomaly covering an area of 600 by 400 metres. The centre of the magnetic anomaly has been tested by multiple shallow percussion holes in the early 1970s and by two diamond drill holes in 1975. The diamond drill holes were shallow but reportedly intersected intervals characterized by magnetite breccias with copper sulphide mineralization. Three follow-up diamond drill holes were completed in 1997 collared 350 to 400 metres east of the magnetic anomaly and intersected copper and gold mineralization hosted in strong albite + magnetite + biotite altered volcanic rocks. Here, disseminated and vein controlled sulphides are pyrite, chalcopyrite and lesser bornite. One such hole returned an interval of 31.5 metres of 0.16 g/t Au with 0.37% Cu (DDH-97-09). Due to limited drill testing, this zone is open in all directions and at depth.
Central Monzonite Zone
The Central Monzonite Zone spans the core of the Durand Stock with copper mineralization covering a strike length of greater than 1.5 kilometers. Ubiquitous copper mineralization characterized by disseminated and clotted chalcopyrite is associated with varying degrees of carbonate + epidote alteration. One diamond drill hole in 1997 tested the Central Monzonite zone on the western side following up on a geochemical anomaly (located 900 metres west of the historic trench where Tower's grab sample 1709453 yielded 1.32% Cu with 0.27 g/t Au and 3.9 g/t Ag). This hole (DDH-97-08) intersected copper mineralization in the bottom of the hole comprising clotted chalcopyrite. An interval of 20 metres of 0.14 g/t Au with 0.35% Cu was returned. This area is open in all directions and at depth and warrants deep diamond drilling.