Ngula 1 comprises a wide area of east-west trending artisanal mining activity, including some hard rock mining through deep shafts and adjacent exploitation of colluvial material. A secondary target area some 400m to the north is defined by anomalous gold in soil/RAB samples in historical exploration. The area is characterized by several east-west trending magnetic lineaments along which artisanal activity is focused, interpreted to be focussed on sub-vertical brittle ductile shears hosting quartz veins, sulphide mineralization and associated alteration with gold hosted within the veins and altered meta-basalt host rock.
Diamond and reverse circulation drilling has been aimed at testing the dominant structures being mined and test for similar hidden structures between these. To date thirty-five diamond and forty-one RC holes have been completed for this target, comprising 7952m and 7623m respectively.
Along the principal set of workings, drill holes intersected multiple structures hosting mineralization between and beneath a prominent northern and southern zone of artisanal workings at vertical depths down to 200m. The program tested along a strike of 600m to determine the lateral extent of the mineralization. All these holes are drilled to a final down-hole depth of approximately 300m.
In order to achieve intersections on all structures, due to the the extent of surface workings and the interpreted sub-vertical to steep north dip of these structures, holes were drilled from the north and south on both northern and southern interpreted structural zones along broad 200m wide corridor. Drilling lines were spaced 100m apart, with a limited number of in-fill drillholes at 50m spacing also completed.
A recent preliminary wireframe modeling exercise has defined at least 6 sub-parallel north dipping structures, each of which has returned one or more significant intersections. A number of these results are exceptional and follow-up drilling will endeavour to define the extent of high grade zones along strike and dip with the aim to extend the drilling and define resources.
The drilling to date has returned the following best results (shown below):
- TDD0004: 3.13g/t Au over 25.89m from 41.00m including 4.46g/t Au over 2.60m and 9.38g/t Au over 6.30m;
- TDD0005: 13.50g/t Au over 0.33m from 38.08m and 8.50g/t Au over 5.14m from 152.86m, including 58.49g/t Au over 0.68m;
- TDD0010: 3.72g/t Au over 2.50m from 189.00m including 6.44g/t Au over 1.20m;
- TDD0012: 8.6g/t Au over 0.98m from 171.92m;
- TDD0014: 2.50g/t Au over 1.50m from 87.00m including 3.50g/t Au over 1.00m;
- TDD0041: 22.81g/t Au over 15.00m from 299.00m including 34.58g/t Au over 9.70m, and 2.76g/t Au over 2.00m from 447.40m including 5.07g/t Au;
- TDD0049: 2.99g/t Au over 2.00m from 23.00m;
- TDD0051: 2.89g/t Au over 1.00m from 89.00m and 2.57g/t Au over 1.00m from 94.00m;
- TDD0053: 2.86g/t Au over 2.03m from 266.00m including 5.37g/t Au over 1.47m;
- TDD0054: 8.17g/t Au over 11.05m from 116.95m including 11.85g/t Au over 8.02m, 7.00g/t Au over 1.00m from 132.00m, 3.19g/t Au over 2.00m from 139.00m, and 4.53g/t Au over 2.00m from 149.93m;
- TDD0059: 5.93g/t Au over 0.64m from 142.33m and 3.72g/t Au over 0.61m from 310.99m;
- TDD0106: 5.09g/t Au over 2.77m from 285.42m including 11.70g/t Au over 0.98m;
- TDD0110: 4.22g/t Au over 5.00m from 195.00m including 6.58g/t Au over 3.00m;
- TDD0125: 19.03g/t Au over 0.94m from 35.16m including 26.40g/t Au over 0.66m, and 1.77g/t Au over 5.23m from 206.27m including 5.90g/t Au over 1.14m;
- TDD0126: 1.80g/t Au over 6.46m from 25.00m and 1.89g/t Au over 2.20m from 167.80m;
- TDD0136: 1.61g/t Au over 3.50m from 141.50m including 3.91g/t Au over 1.00m:
- TDD0145: 2.14g/t Au over 3.50m from 267.00m;
- TDD0146: 2.35g/t Au over 1.50m from 167.90m and 4.77g/t Au over 2.50m including 10.70g/t Au over 1.00m;
- TRC0001: 1.76g/t Au over 3.00m from 46.00m and 38.20g/t Au over 1.00m from 85.00m;
- TRC0002: 2.58g/t Au over 2.00m from 8.00m including 4.59g/t Au over 1.00m, and 3.77g/t Au over 1.00m from 54.00m;
- TRC0003: 3.76g/t Au over 2.00m from 21.00m, 28.57g/t Au over 3.00m from 54.00m, and 5.28g/t Au over 4.00m from 72.00m;
- TRC0006: 4.52g/t Au over 1.00m from 5.00m; and 3.16g/t Au over 3.00m from 206.00m including 4.41g/t Au over 2.00m;
- TRC0008: 5.18g/t Au over 1.00m from 9.00m and 3.75g/t Au over 6.00m from 35.00m;
- TRC0013: 17.23g/t Au over 4.00m, including 22.53g/t Au over 3.00m from 19.00m, 1.99g/t Au over 4.00m from 86.00m and 13.00g/t Au over 1.00m from 104m;
- TRC0014: 19.80g/t Au over 1.00m from 114.00m and 10.00g/t over 1.00m from 122.00m.
The geology comprises predominantly mafic meta-volcanic rocks, with thin intercalated meta-sedimentary units within the meta-volcanic pile. There is no surface expression of the geology other than ruddy ferruginous soils, the weathering products of the mafic meta-volcanic rocks and there is no outcrop to reveal host rocks, geological structure or mineralization.
Completed drilling shows that the main east west trends appear to comprise multiple semi-continuous shear zones that are interpreted to pinch and swell along strike and up and down dip and dip steeply (80-90°) to the north. These shear zones are possibly linked by steeply dipping cross-shears trending either northeast-southwest or northwest-southeast at varying dips, and which are considered important controls on pinching and swelling as well as tenor of gold mineralization.
Mineralization consists of sulphides concentrated in shear zones, with accompanying quartz veins and alteration of sheared anf fractured host rocks within and adjacent adjacent to these structures. Small quartz veinlets can also contain appreciable amounts of sulphide away from areas where observable shearing has occurred. The margins of basaltic pillow lavas commonly host abundant pyrrhotite, pyrite and minor chalcopyrite but these do not generally contain gold unless associated within or adjacent to shear zones.
Pyrrhotite is the dominant sulphide with lesser finely disseminated pyrite and chalcopyrite. Sulphide also occurs as coarse blebs, masses and bands associated with more siliceous and chloritised zones within the shears. Pyrrhotite associated with chalcopyrite can also be found concentrated along milky and smoky quartz vein margins, or as fine stringers or replacement blebs.
Diamond and RC drilling has been aimed at testing the dominant structures being mined and test for similar hidden structures between these. To date 35 diamond and 41 RC holes have been completed, comprising 7952m and 7623m respectively.
Future drilling at Ngula 1 will consider the delineation of shallow low grade resources, and deeper diamond drilling to define the extent of previously intersected high grade mineralization and the potential of these shoots to host open pit and underground exploitable resources.