“North Balusty” and “Kerbay”Geologists undertaking exploration for gold deposits have long understood their heterogeneous distribution, - to such an extent that experts have made it an art to refine their classification into very specific types based upon their distribution in space and time.
These mineral deposits exhibit extremely heterogeneous distributions with each major deposit type showing a distinctive (typically unique) temporal pattern; and these individual temporal patterns reflect a complex interplay between fundamental forces of formation and forces of preservation that (in turn) have largely been shaped by changing tectonic processes and environmental conditions.
In essence: the temporal distribution of gold deposits will reflect the forces that originally produced the deposits (global heat flows in a cooling Earth), the depositional environments in which they formed (changes in tectonic regime), and then the preservation potential of the deposit-hosting environments (where these deposits currently reside).
Within the metallogenic province of northern Kazakhstan, major gold deposits are located along the trend of deep seated lineaments (orientated within synclinal zones), being composed mainly of Ordovician sediments. Both Alhambra’s North Balusty Project Area ("North Balusty") and its Kerbay Project Area (“Kerbay”) are located along the same structure of volcano-sediment hosted Orogenic style mineralization as is the world-class Aksu/Quartzite Hills gold deposit. This same distinctive temporal pattern also hosts Alhambra’s promising Shirotnaia and Dombraly targets, - and it seems more than likely that similar volcano-sediment hosted Orogenic style mineralization will be evident at both the North Balusty and Kerbay project areas.
At all these sites gold deposits are found in effusive-sedimentary Ordovician masses; with gold deposits genetically and spatially related to granite-like rocks where the larger gold deposits are related to intrusions characterized by multi-stage complex activity; with intrusion formation made up of various structures and ages (with small intrusions and dykes lying inside them). On this prolific trend, Kerbay is positioned between Dombraly (30 kilometers to the North) and Shirotnaia (15 kilometers to the SouthWest); while Dombraly is located just 7 kilometers south of North Balusty.
North Balusty is a particularly promising early-stage exploration project
where a Middle Ordovician volcano-sediment sequence (forming a very large generally N-S trending regional syncline structure) underlies the prospect.
As a result of exploration already conducted, a 12.8 kilometer long and up to 2.5 kilometer wide zone of gold anomalism in alluvium and saprolitic rocks was established, consisting of numerous wide individual anomalies ranging from several meters to tens of meters where the gold grades exceed 0.1 grams per tonne gold ("g/t Au"); and in three potential target areas the concentration of anomalies is higher and the gold grades reach 0.5 g/t in RAB samples. Trenching in the same areas have returned the best intercepts of 30 meters @ 0.4 g/t Au, 9 meters @ 0.76 g/t Au and 6 meters @ 0.36 g/t Au. Going into the 2010 exploration season, it was still unclear whether it is a very large zone of low grade mineralization, broad low grade aureole of a significant deposit, or just a set of transported anomalies in reworked saprolite and alluvium.
The objective of the 2010 exploration program at North Balusty was to check the origin of the gold anomalies (established by trenching in 2005 and 2007) and to estimate the width of the mineralized zone. During 2010, Alhambra’s exploration activity consisted of a test line where 51 KGK holes were completed; with a total of 2,018 meters drilled at depths ranging from seven to 79 meters with an average depth of 40 meters, and, in all, a total of 988 samples were taken, split and prepared for shipment to the lab. We eagerly await the results. Contingent upon a favorable outcome of these drill results, approximately 900 meters of deep reverse circulation ("RC") holes are planned for 2011 with the objective to check possible mineralized zones established by KGK drilling.
Meanwhile, at the Kerbay project area, where a Middle Ordovician volcano-sediment sequence is covered by an Upper Ordovician terrigenous sediment formation (and truncated by Late Ordovician intrusions), during 2010, two diamond holes were completed with a total of 305 meters drilled; and both holes intercepted interesting intervals of hydrothermal alterations in andesite and siltstone (that could indicate the presence of gold mineralization). Kerbay is intruded by granodiorite and diorite stocks belonging to the Late Ordovician Krykkuduk intrusive sequence and it is believed that the multi-million ounce orogenic gold deposits known in the district (such as Vasilkovskoe, Aksu and Stepnyak) are related to the intrusions of the same complex. Actually, Aksu’s 15.0 million ounce gold deposits are situated just 18 kilometers to the south.
By way of perspective: mineralization in the Kerbay area was discovered in 1951-1952 during regional geological mapping; and in the 1970's, the National Geological Survey carried out soil sampling of the area, – establishing a +100 parts per billion gold ("ppb Au") anomaly about 3.5 kilometers long and 500-1,000 meters wide. This was followed by 3 trenches, several lines of hydro-core lift ("KGK") drilling and 2 diamond drill-holes. The Northern core hole returned an intercept of 36.0 meters @ 1.47 grams per tonne ("g/t") Au starting from 94 meters, with gold values ranging from 0.4 g/t to 2.3 g/t Au. Meanwhile, the Southern hole returned several intercepts; the best being 17.1 meters @ 0.71 g/t Au starting from 6.6 meters, with gold values ranging from 0.25 g/t to 1.4 g/t Au.
Modern exploration by Alhambra started in 2003 when 387 rotary air-blast ("RAB") holes on four lines were completed and 2,230 samples taken. Exploration continued in 2005 when 12 trenches were completed, with 1,316 channel samples (each being 1 meter long). A second stage of trenching was conducted in 2006 with 19 more trenches dug and 2,868 channel samples taken. Both trenching and RAB drilling outlined an anomalous gold zone with open flanks measuring about 1,200 meters long and 300-500 meters wide where the gold grade in saprolitic rocks usually exceeds 0.1 g/t Au. The gold grades tend higher in the Northeast ("NE") and Southwest ("SW") where values of 3.98 and 4.05 g/t Au, respectively, in 1 meter long trench samples were measured. The best trench intercepts are 12 meters at 1.27 g/t Au and 16 meters at 0.71 g/t Au. The highest gold grade returned by RAB drilling is 32.5 g/t Au in a 2 meter long individual chip sample. Overall, the gold grades tend to increase in depth; a trend confirmed by the old core hole data.
The objective of the 2010 exploration program at Kerbay was to determine the dip direction and continuity to depth of the gold mineralization established by trenching; with the exploration program concentrating on those areas where the mineralization exhibits significant width and higher gold grades. As already noted, during 2010, both holes intercepted interesting intervals; and, during the 2011 drilling season, - follow-up drilling programs will continue to determine the size, quality and continuity of mineralization.
Keep an eye on these two early-stage projects (particularly North Balusty), - they could someday become significant.