Annual Report on Nicholson River 1986-1987 NT.

Abstract

A series of targets, isolated from fixed wing magnetic surveys flown over selected areas of the 1icences during the 1986 field season, was subjected to a helicopter borne magnetic survey for greater definition. A total of 948 line km of survey was flown over 16 targets with a surveyed area equal to 64 sq km during May 1987. During June, 1987 each of the 16 targets was then subjected to ground follow-up in the form of a magnetic survey in conjunction with loam/stream/rock sanpling as necessary. During this period, a total of 105 stream and loam sedimant sanples and 6 rock samples was collected. A summary of the interpretation of the recovered ground magnetic data is as follows: Of the 16 targets examined, the source of the magnetic anomaly is thought to be surficial (and therefore non-kimberlitic) in 3 cases, possibly of kimberlitic origin but shallow enough to be easily detectable by ground sanpl ing in 5 cases and possibly of kimberlitic origin but at depths at which improved arnomaly definition by SIROTEM is required in 8 cases.