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Jul 27, 1998
Tiris Project, Sumatra, Indonesia
- PHASE 1 WORK COMPLETED ON TIRIS PROJECT
- HARIMAU GOLD PROSPECT EXTENDED
- THREE NEW GOLD ANOMALIES DEFINED
PHASE 1 PROGRAM RESULTS
Tony Climie, P.Geol., President of Mindoro Resources Ltd. ("Mindoro") announces that the Phase 1 Program on the Tiris Project, consisting of stream sediment geochemistry, reconnaissance geological mapping and prospecting has been completed. New results have extended and defined the previously reported Harimau Prospect in the west part of the project. Three new gold anomalies were also located in the east part of the project: Kelawar, Tiku Hilir and Semambu.
The work was supervised by A. Buskas, P.Geo. (B.C.), and performed by exploration crews of PT Handal Srirajasa of Jakarta, Indonesia, Mindoro`s local geological consultant. A total of 1,648 stream sediment samples have been collected, for a sample density of some 16.5 samples per square kilometre (km). Initially weighing approximately 500 grams each, samples were sieved on site and the fine (-80 mesh) fractions shipped to Intertek Testing Services (Bondar Clegg) in Jakarta, Indonesia, for analysis of gold, silver, copper, lead and zinc. The gold analyses were performed by standard fire assay using a 50 gram charge, with a lower detection limit of 2 parts per billion (ppb). A total of 53 standard samples were inserted into the analytical batches. Gold analyses varied within normal limits for these standards. Duplicate samples were collected at every twentieth site and submitted to Intertek under different sample numbers. Results for the 80 duplicates also varied within normal limits. The gold values for the entire data set of 1,648 samples ranged from 0.5 to 18,450 ppb and averaged 226 ppb.
A total of 501 rock samples (mostly float boulders from streams) were collected from throughout the project and analyzed by Intertek using the standard fire assay technique on 50 gram charges, with atomic absorption (AAS) finish. Lower detection limit is 0.005 parts per million (ppm, or grams per tonne (g/t)). The rocks were collected to establish gold background and grades within various alteration and lithologic types. Because of an absence of outcrop between streams due to hydrothermal alteration and tropical weathering, the rock samples cannot be considered as representative of the area as a whole. Rock values ranged from less than 0.005 to 11.7 ppm (11.7 g/t) and averaged 0.14 ppm gold. The accompanying map shows the locations of the stream sediment anomalies and prospects.
The Harimau Prospect was the subject of March 2 and May 6, 1998 news releases. The Prospect is now defined by a total of 249 stream sediments greater than 100 ppb gold, ranging from 102 to 18,450 ppb (18.4 g/t), and averaging 1,338 ppb. The greater than 100 ppb gold contour defines an area of about 6.5 by 6 km, covering 10 major unrelated drainages. The greater than 1,000 ppb (1 g/t) gold contour defines an area of about 4.5 by 3.5 km, and covers five unrelated drainage systems. The 1,000 ppb contour has also been closed off by the additional sampling and appears to fall entirely within the Tiris CoW.
There is a strong correlating silver anomaly and supporting copper, lead, and zinc anomalies. The March 2 release describes extensive (multi-km scale) strong to intense hydrothermal alteration identified as a low-sulphidation (quartz-adularia) system affecting a sequence of dacitic pyroclastics, epiclastics (reworked pyroclastics) and hydrothermal breccias intruded by basaltic andesite stocks or dykes.
A total of 216 rock samples (mostly float boulders) have been assayed from the Harimau Prospect. Results range from less than 0.005 ppm to 9.02 ppm (g/t) gold (average 0.214 ppm). The maximum gold sample also contains 520 ppm silver. Thirteen of these rock samples, from six unrelated drainages, returned values in excess of 1 ppm (g/t) gold (average 2.4 ppm). This is from an area of about 2.5 by 2.5 km that is also coincident with the 1,000 ppb stream sediment area. These also include mineralization located in outcrops 1.3 km apart, with two samples (a grab and a composite grab) assaying 1.78 and 1.73 g/t gold respectively.
These rock results are considered particularly encouraging as they suggest that the areally extensive stream sediment anomaly, which is associated with equally extensive hydrothermal alteration, reflects mineralization in bedrock. Grades which are considered to be of economic interest have been obtained from float in unrelated drainage systems over an extensive area. However, it is emphasised that due to absence of outcrop, there is still no information from the great majority of the prospect, i.e., the large areas (interfluves) between the stream channels which are up to one km apart. It is considered that soil geochemistry will be an effective method of locating blind mineralization within these interfluves. A great deal of systematic work will be required to locate, define and evaluate the sources of mineralized rocks, and other potential areas of mineralization within the large target area.
The greater than 100 ppb gold stream sediment contour defines an area of about 1.3 by 0.5 km covering three separate drainages. Values range from 158 to 5,360 ppb gold (12 samples) and average 1,340 ppb. Geology consists of dacitic pyroclastics, epiclastics and andesitic intrusions. Hydrothermal alteration is strong and consists of chloritization, pyritization, silicification, adularization and argillization. Seven rock samples collected during prospecting in the region ranged from less than 2 ppb to 0.179 ppm gold (average 0.039 ppm ). However, exposure is very poor in this area and it is likely that the source of the anomaly remains unsampled.
TIKU HILIR ANOMALY
The greater than 25 ppb gold stream sediment contour defines an area of about 2.4 by 0.8 km covering 13 tributaries of the Tiku River. Values range from 26 to 2,940 ppb gold and average 490 ppb. Geology consists of dacitic pyroclastics, epiclastics and andesite. Hydrothermal alteration noted includes chloritization, silicification, pyritization and argillization. Rock sampling was not possible due to high wet-season water levels. The anomaly falls on a northwesterly trend along which also occurs the Rawas gold mine of Barisan Tropical Mining (BTM), 4 km to the south-east, Mindoro's Kelawar Anomaly, 1.5 km to the north-west, and BTM's Telun Merangin Prospect, 4 km to the north-west.
The Semambu Prospect is reflected by two subtle stream sediment anomalies of greater than 10 ppb gold. The northernmost anomaly covers an area of about 1.3 by 0.9 km in four drainage systems with 22 samples ranging from 10 to 69 ppb gold, (average 10 ppb). The second anomaly is immediately to the south and is 1.6 by 0.8 km in size. Eight sediment samples ranged from 11 to 461 ppb gold (average 145 ppb). Moderately strong copper and zinc anomalies extend from Semambu to the southeast corner of the project. Geology at Semambu consists of dacitic pyroclastics and epiclastics intruded by andesitic stocks. Strong hydrothermal alteration occurs over an area at least 0.9 by 0.5 km, and consists of chloritization, pyritization, silicification and argillization. Abundant quartz float occurs in streams, with 56 rock samples collected from the area ranging from below detection limit to 1.94 ppm (g/t) gold and averaging 0.106 ppm.
The significance of these three new targets will only be established with additional work, but these initial results indicate that follow-up is warranted.
PHASE 2 PROGRAM
A phase 2, detailed exploration program will commence by the end of July. This will consist of an airborne magnetic survey, detailed soil geochemistry and geological surveys, prospecting, trenching and systematic rock sampling. Initial work will focus on the very high priority Harimau Prospect. Objective is to define drill targets by year end. Mindoro's management is extremely encouraged by the results to date and the potential it sees at Tiris.
Mindoro is a well-financed, Canadian mineral exploration company focussing on gold and gold-copper exploration in the Asia Pacific region and operates projects in the Philippines, Myanmar and Indonesia. Mindoro has 13,515,000 shares issued and outstanding and working capital of approximately $1,900,000.
The Alberta Stock Exchange has neither approved nor disapproved the information contained herein.
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