Final Report Daly Waters Project ELs 7951, 7952, 7953.

Abstract

This report outlines work completed by Fodina Minerals Pty Ltd; as manager of a Joint Venture Agreement with Omega Oil NL, within EL7953 during the period July to December 1993. The prospect lies about 180Km southeast of Katherine in the Northern Territory, and is situated in the Garrie Sub Basin within the Roper Basin.

Clastic sediments dominate the stratigraphy of the Roper Basin which is traversed by a major north-south trending structural high called the Daly Waters Arch. The area of exploration interest, detailed in this report, lies on the western flank of this structure where a 2.5 mgal gravity anomaly was identified.

The cause of the gravity anomaly was unclear, however, Omega Oil NL proposed two models to explain the anomaly; a) the large gravity anomaly was the expression of a narrow infilled rift within the Gorrie Sub Basin, or b) the gravity anomaly was caused by a large accumulation of relatively dense sulphide-bearing carbonaceous shales.

The seismic and gravity data were used to underpin a stratiform sediment-hosted zinc/lead deposit model. Pacific Oil and Gas Co. had previously drilled a hole in the Roper Basin (Sever #1) and intersected black shales, showing base metals results, in the Middle Velkerri Formation. Subsequently a gravity survey was carried out by Doug Barrett and Associates on behalf of MPI. Modelling of this data offered several different explanations. One of the favoured interpretations was that the anomaly is best explained by a major density contrast in the host lithologies, possibly due to dolomitisation of an existing reefal limestone'. This interpretation, if correct, suggested a Mississippi Valley type target.

It was proposed to drill two diamond holes each of 450m to test the gravity models interpreted by Doug Barrett and Associates. Only one hole was completed (DWD-l) which was drilled to a total depth of 595.8m. Unfortunately no carbonate build ups were discovered and very little carbonaceous shale was found. Neither was an adequate explanation for the gravity anomaly found in the sequence drilled.

The main sequence drilled is thought to be the Chambers River Formation; consisting mainly of siltstones and silty mudstones. The hole is thought to have been terminated in the Bukalorkmi Sandstone, with the Velkerrie Formation (intersected in Sever #1 by Pacific Oil and Gas) still some depth below. This clearly eliminates the black shales of the Velkerri as targets for base metal exploration. Any sulphide accumulations at this depth would be uneconomic to exploit.