Field Survey Work Program - 1989 - EP20, Northern Territory, Australia

Abstract

A surface survey of selected geologic, geomorphic and airborne anomaly leads has been conducted for Indigo Oil Pty. Ltd. in EP-20, Northern Territory, Australia. The survey included 1530 measurements at 510 stations along 12 profiles focussed on targets previously identified in Year One reconnaissance surveys. Simultaneous measurements of the following indicators were performed at each station: 1) soil magnetic susceptibility, 2) potassium and uranium by gamma-ray spectrometry and 3) interstitial soil gas hydrocarbons. Additionally, available high-sensitivity aerial magnetic gradiometer data were reinterpreted to outline possible micromagnetic evidence of diagenetic magnetic minerals which have been found in near-surface rocks over petroleum deposits.

Inspection of the anomaly maps shows that by far the strongest anomalous zones are along the Wallara Ranch Road with the largest and strongest anomalies in the immediate vicinity of the Wallara Ranch. These prospective zones show strong evidence of both hydrocarbon microseepages and their effects in producing diagenetic magnetic minerals and diagnostic potassium and uranium radiometric anomalies. The anomalies are quite similar to those found over the recently-discovered Alabama Ferry major oil and gas field.