Projects » Montezuma (Gold)
Montezuma, near Bulawayo
The Montezuma property is located in the southwest of the Zimbabwe Craton. This is an Archaean basement complex composed of broad areas of gneisses, deformed and underformed granites and greenstone belts. The Montezuma tenement lies within the eastern part of the Bulawayo Greenstone Belt which connects to the Filabusi Greenstone Belt to the east.
A broad deformation zone, the Umzingwane Shear Zone, occurs on the southern margin of the Bulawayo Greenstone Belt and extends eastwards into the Filabusi Greenstone Belt. It is composed of multiple closely spaced subparallel major and second order shears. These structures trend WNW-ESE in the west but they converge to the east within the Montezuma claims area and undergo an E-W strike swing in the SE corner of the Bulawayo Greenstone Belt. Further east the shear zone has an ENE-WSW trend before it intersects the Lancaster-Irisvale Shear Zone.
A zone of anastomosing and bifurcating NNW-SSE trending shears in the eastern part of the Bulawayo Greenstone Belt represents the Crocodile Shear Zone, which is described by Baglow (1998) as a strong but diffuse carbonated shear zone. The southern part of this structure is intersected by the Umzingwane Shear Zone. Some of the strands of the Crocodile Shear Zone swing in to subparallelism with the Umzingwane Shear Zone consistent with dextral shearing.
The convergence zone between the two shear zones would have represented a high strain constructional zone. This appears to have had an important control on shear zone hosted gold mineralization.
The geological model of orogenic mesothermal lode gold deposits in structurally controlled veins and shear zones within Archean greenstone belts is well-known.
The Montezuma Mining Lease in the Bulawayo Greenstone Belt at intersection of two crustal-scale shears. Note how the WNW-striking Umzingwane Shear Zone (blue) curves in the region where it intersects the NNW-striking Crocodile Shear Zone (red). The Bulawayo Greenstone Belt host to a number of major gold mines, past and present.
Fracture frequency greatly increases and spacing between fractures decreases within favourable rock types at the intersection of the major shears.
Property and Infrastructure
Tinker Mining (Pvt) Limited holds a Mining Lease to 1,177 hectares granting the exclusive right to mine for gold. The Montezuma property is located 56km ESE of Bulawayo and 8km northeast of Mbalabala. Access is by the Bulawayo to Beitbridge tarred road and via a secondary road that branches east some 52 km from Bulawayo.
Access to bulk transport, water and power is easily available. The main A6 road from Bulawayo to South Africa lies 8km to the west. The Bulawayo/Gwanda railway line and the Umzingwane River are close to the southern boundary of the project area. Two major reservoirs, Upper Ncema Dam and Inyankuni Dam, are adjacent to the north. Electrical power can be accessed some 3km from the eastern boundary of the property.
History of Exploration and Mining
The Montezuma tenement and hinterland have a long history of gold exploration and production. There are many old mines and artisanal workings throughout a wide area. Official gold production figures published in 1998 show 11 mines within close proximity to the Montezuma property recorded over 9,300 ozs with an average grade of 5.89 g/t.
Seven gold mines of varying size and past production levels are within the property. Production was first recorded in 1925 and was sporadic thereafter up to 1951. Total production was 1,487 ozs Au grading 1.88 g/t. Montezuma was the largest producer with a reported output of 810 ozs Au averaging 1.58 g/t. 7th Trial Mine produced over 17 kg of gold in 1934/1935 grading over 2 g/t. Adder, Jim Crow, Spartan and Zimba were smaller gold producers producing over 60 ozs Au. Zimba recorded small output at a grade of 11.4 g/t. Adder’s grade was 5.18 g/t. The Flag South Mine closed in 1980.
From 1998 to 2007 Tinker Mining and other parties completed soil sampling and drilling. This involved 3,000 metres of trenching and 5,000 metres of cross trenching. Over 1,600 samples were taken from overburden over two areas covering 520,000 sq. metres. Circa 260 assays reported values over 1 g/t. Over 30 exceeded 10 g/t.
Between 2000 and 2007 16 boreholes were drilled in several areas. In the eastern sector a bore hole gave 5 good intersections with grade of 6.92 g/t, 7.12 g/t, 7.6 g/t 10.6 g/t and 13.4 g/t. Nearby drilling recorded good results with a grade range of 3.2 g/t to 16.8 g/t. Drilling focused on closely spaced vein systems.
Exploration work has confirmed the presence of significant gold enrichment. Of the 1,177 ha holding, only 177 ha has been explored to date. The property has not been explored by modern methods.
Structural Interpretation Studies
Landsat ETM+ structural sensing studies were completed by Murphy Geological Services (MGS) in 2007 and 2017 to create a structural interpretation of the Montezuma tenement and its hinterland. Initially, 10 exploration targets were identified.
In 2017 MGS conducted another structural interpretation over Montezuma’s 1,177 ha and hinterland. GeoEye – 1 used high resolution imagery. This allowed the detailed analysis of veins, third order structures, artisanal workings/areas of ground disturbance which were not visible on the Landsat data. Satellite image analysis has revealed for the first time the very high density of veins and the occurrence of favourable structural features in the south-east of the property.
The GeoEye-1 study identified:
- 7 vein systems; high density of closely spaced vein systems.
- Over 215 artisanal workings throughout the eastern and central parts of the tenement.
- 40 exploration targets. 9 are priority 1 targets with 2 targets having open pit potential.
- The presence of extensive artisanal workings along veins and restraining bends along shears that control the veins.
- Target M-23 is the most prospective of the priority 1 targets and is supported by past soil sampling and drilling results.
- Potential for both low cost tonnage pittable gold deposits and high grade narrow vein deposits.
- Targets can be prioritised by the number of features in any one area.
- The targets have been defined on the basis of the results of the GeoEye-1 interpretation and past exploration results.
Although satellite images do not identify gold deposits directly, experts in image analysis and structural geology can locate the positions of a range of structural and environmental features which are effectively proxies for gold.
The criteria used to identify the targets included the presence of major/second order shears, restraining bends along shears, converging shears, splays along shears, presence of old mines and/or artisanal workings, presence of veins, particularly veins that have been worked by artisanal miners, spoil heaps, areas of extensive quartz float/bleached zones and significant gold assays from past exploration.
The most important of the targeting criteria are the presence of extensive artisanal workings along veins and restraining bends along the shears that control the veins.
Montezuma – Development Focus
The GeoEye-1 study identified Target M-23 as the most prospective within the 9 priority 1 targets. A work programme within the 20.7 ha area was recommended for the following reasons:
- High density, closely-spaced vein sets within favourable “felsic” schist.
- A long history of extensive soil sampling and some drilling.
- Channel sampling of old trenches showed some assays of over 8 g/t.
- Best results from a borehole gave had five good intersections with ranging in grade from 6.92 g/t, to 13.4 g/t.
- An overburden programme (800 samples) identified gold concentrations in excess of 10 g/t at 15 sample sites.
- 35 drill targets on quartz veins showing releasing and restraining bends in a dextral shear. Some targets were worked by Tinker Mining previously.
- Satellite imagery show intense artisanal activity within the area with over 110 workings evident.
Consulting Geologists have prepared a report on M-23 covering Ground Truthing; Geophysics/Trenching and Diamond Drilling over a planned 6 month period. The objective is to accelerate from exploration to early stage production. Processing of the overburden where past soil sampling results were good will facilitate this.
There are 39 exploration “hot spots” identified in the GeoEye -1 satellite study with considerable geological merits. Many are close to the M-23 area and have open pit possibilities. Itinerant Resources will consider how best to continue high level exploration aimed at defining a JORC compliant resource.
Itinerant Resources is interested in partnering with a gold exploration/production company to explore initially the M-23 area and if geologically attractive the remaining 1,000 ha.
Further details on the Montezuma Project are set out in the Montezuma Project Information Sheet - July 2018 in the Investors Section under Presentations.