NT122 Annual report for Djuburala West year ending 24-5-75.

Abstract

During the year Central Pacific Minerals NL has continued exploration on EL 402 by means of airborne survey, track etch survey method of radon measurement, regional geological mapping and percussion and diamond drilling. Follow up work on the airborne survey showed 15 anomalies. Of these, two were caused by previously known mineralization and the remainder was attributed to sand/shale radioactivity contrast within the Mt. Eclipse Sandstone. The track etch survey located 3 major radon anomalies and one minor. The previously known mineralization at Dingo?s Rest North was located by this survey. The cause of these anomalies is not known at the present time. Regional geological mapping (1:25,000) defined 5 mappable units within the Mt. Eclipse Sandstone. A 279m combined percussion and diamond drill hole was drilled 300m west of NGDD 2 at Dingo?s Rest South. Minor uranium mineralization was intersected between 232 to 252 m. From 237.70m to 2337.80m an assay value of 1,770 ppm U3O8 was reported. During the year effort on EL 402 involved interpretation and follow up work on the 1974 airborne survey, regional geological mapping at 1:25,000, track etch survey (a technique for measuring radon concentrations by means of radon sensitive film placed in the ground) and the drilling of a 286m percussion and diamond drill hole at The Dingo?s Rest South Prospect. The airborne survey carried out in April 1974 was assessed during the year. The airborne survey covered all outcrops of Mt Eclipse Sandstone within the exploration license and 15 anomalies were located. Of these 2 were associated with the known mineralization at Dingo?s Rest South and the remainder are attributable to shale sandstone lithological contrast within the Mt Eclipse Sandstone. During the year, EL 402 was included in the 1:25,000 mapping of the northern part of the Ngalia Basin. Air photo interpretation followed by ground traverses in selected critical areas has permitted subdivision of the Mt. Eclipse Sandstone into five units. Anomaly B to the north west comprises 3 separate high areas. A plot of these on to 1:25,000 geological maps shows that these anomalies are orientated around the Vaughan Springs Syncline. The orientation of the values suggests an anomalous stratigraphic level in the Mt. Eclipse Sandstone following the structure of the Vaughan Springs Syncline. Anomaly C in the southern central part of the area is composed of 2 high values with a maximum of 114 T/mm2. The anomaly strikes south easterly and is open to the south. This anomaly could be related to a fault line in the vicinity of these cups (see Mt Doreen 1:250,000 geological sheet). A smaller anomaly immediately north of C (maximum value 67.9 T/mm2) is thought to be associated with present day drainage patterns. In the eastern part of the exploration license, a cup was placed approximately 100m down dip of surface carnotite2 at the Dingo?s Rest North prospect. A value of 40 T/mm2 was recorded for this cup which is anomalous. Hence the survey successfully detected this known mineralization. The ground scintillometer reading taken at each track etch cup locality gave results varying from 25 to 55 cps. It is considered that these results are background values. Further work will be carried out to determine the significance of these anomalies. A 279m percussion and diamond drill hole was drilled 300m west of NGDD 2 at Dingo?s Rest South. The hole intersected Mt Eclipse Sandstone from surface to 269m from 269m to 279m red shale and fine grained quartzite?s of the Djagamara Formation were intersected. From 232 - 252m carbonaceous grey sandstones with minor mineralization were intersected. Within this section, from 237.70m to 237.8m an assay value of 1,770 ppm U3O8 was returned from a small calcite filled fault zone within carbonaceous, pyritic sandstone with calcite stringers.