Öksüt is Stratex’s latest high-sulphidation (HS) gold discovery in Central Anatolia, located 25 km south of Develi and 70 km south of Kayseri. It is a new 109.4  km2 licence area with the key licence acquired in October 2007. This key licence, Ortaçam Tepe, was targeted on the basis of significant gold grades (including 0.93 g/t Au over 25 m) yielded from rock samples obtained during 2007.

Prospect Geology

The Öksüt property comprises Miocene andesitic lava flow domes overlain by alternating pyroclastics (andesitic volcanic breccias/agglomerates and andesitic lithic tuff) and lava flows. These units show strong lithological controlled alteration, predominantly silicification and advanced argillic alteration. The altered units are overlain by Pliocene lava flows.

The main silica types are:

• brecciated silica;
• massive silica;
• vuggy/granular silica
• quartz-alunite/kaolinite;
• opal/chalcedonic silica .

Exploration

Mapping and sampling commenced in April 2008 with a view to fast-track a reconnaissance drilling programme. Significant gold grades obtained from rock chip sampling identified the Ortaçam zone as an early priority. They include:

• 21 metres grading 2.91 g/t Au;
• 111 metres grading 0.90 g.t Au;
• 21 metres grading 2.67 g/t Au;
• 24 metres grading 1.72 g/t Au;
• 18 metres grading 2.61 g/t Au (57 metres grading 0.29 g/t Au)

At Ortaçam, the zone of massive and vuggy silica is exposed over an area of 200 m by 300 m, with an estimated thickness of approximately 100m (Figs.1 and 2). The shallow dip of the beds (6-20 degrees towards the NNE) demonstrates that the silica zones are lithologically controlled, related to the lateral replacement of near-horizontal volcanic beds. This lateral bed-controlled mineralization has the potential of generating a large near-surface tonnage of mineralized material and is characteristic of very large high-sulphidation mines e.g. Yanacocha (35 Moz) and Pierina (9 Moz) in Peru. The silicified zones show both vertical and lateral zonation, although the former is more dominant. Vertically the zonation is observed as opal/chalcedony ± kaolinite at high elevations, overlying quartz-kaolinite and quartz-alunite horizons, subsequently overlying massive and vuggy silica.

Fig.1  Ortaçam;  massive and locally vuggy silica zones looking from north-west.

Fig.2 Results from rock chip sampling of m assive and locally vuggy silica zones at Ortaçam, looking from west.

The project has advanced rapidly in recent months with 18 km of access road being constructed/upgraded to facilitate initial drilling of the Ortaçam Zone, as shown in the following site plan (Fig.3):

Fig.3 Ortaçam site plan showing the newly constructed roads, drill hole locations and identified zones of silica alteration.

 

Drilling commenced in mid-August (Fig. 4) and initial results are shown below (Table 1). ODD-8 yielded 270.20 metres averaging 1.22 g/t Au using a 0.2 g/t Au cut-off. To date this is the longest interval of continuous gold mineralization drilled by Stratex on any of its projects.

Hole	Dip	Intersection
		From (m)	To      (m)	Length (m)	Au (g/t) (cut-off grade 0.2 g/t)
ODD-1	-075°	No significant intersection
ODD-1	-075°	0.80	20.10	19.30	2.96
ODD-3	-075°	14.75	77.20	62.45	2.16
ODD-4	-075°	71.80	145.10	73.30	1.36
ODD-5	-075°	No significant intersection
ODD-6	-045°	0.00	171.70	171.70	0.51
ODD-7	-045°	7.30	113.00	105.70	0.59
ODD-8	-045°	0.00	270.20	270.20	1.22
including		0.00	45.50	45.50	1.58
including		77.00	117.70	40.70	2.77
including		224.60	262.80	38.20	2.94
including		226.40	234.50	8.10	10.23

Table 1.  Initial drilling results from the Ortaçam Zone. All intersections are within the oxide zone.

 

Fig.4 Initial drilling of the Ortaçam Zone, looking towards the south-west.

Results show that partial to complete oxidation persists down to a vertical interval of more than 100 metres, dependent on the degree of pervasive fracturing present within the silica zones. This is reflected in the distribution of oxide gold values observed in the following cross-section (Fig. 5):

Fig.5 Cross section of the Ortaçam Zone, looking towards the north-west.

In addition, a second zone, Büyükmese Tepe, is located a few hundred metres west of Ortaçam with similar dimensions and geometry for which outcrop sampling results are awaited (Fig.6). Soil sampling of the entire property is currently underway to provide further insight into the project's wider exploration potential.

Fig.6 Ortaçam and Büyükmese Zones, looking from the south.