Archives for October 15, 2006

Louis Hissink is drilling at Thundelarra Exploration’s Lamboo project located about 40 KM WSW of Halls Creek in the Kimberley Region of Western Australia. His focus is exploration for platinum and nickel.

Louis sent the following note:

“The wet season is on us and the usual climatic signs have appeared – with rain already falling in some of the more remote areas. Another two months of the ‘build-up’ and if Halls Creek gets a good solid drenching from a cyclonic depression over the wet season, then it might replenish the underground water acquifer we the town relies on for its water supply.

Seems the greenies and other do-gooders have put paid to any notion of building a small dam nearby for water catchment solutions. [Indeed, existing dams are being busted in parts of rural and regional Western Australia, click here for previous blog post on the issue.].

Oh there is a drought alright, but it’s in the state parliaments where a serious drought of commonsense is evident. I can’t write what the Western Australian Water Authority thinks of the Environment Protection Agency and its fellow travellers.

Lots of feral horses in the area, and dying from a lack of feed and water – sad to see, but that is reality up here.

Louis is the one on the right.

The drilling rig is a small Reverse Circulation (RC) machine which can bore holes to about 150 metres depth.

Principal drilling method uses a down-hole hammer that pulverises the rock into smaller bits, including dust, using high power air compressors. The sample from the hammer is pushed up the inside of the rod string (hence the term
reverse-circulation) through the inner pipes then via a sample hose into a sampling cyclone where equal volume samples (nominally 1 metre length times the hole area) are collected. These 1 metre samples are then split into 2 fractions,via a Jones splitter in which an aliquot of the 1 metre sample is collected for initial chemical analysis in a laboratory. The remainder of the sample is left in a green plastic mining bag next to the drilled hole for further work. Field assistants later take rock chip samples from each metre sample by seiving through a standard household kitchen sieve and stored in purpose built chip trays – durable plastic things with 20 small compartments.

These chips are studied by the geologist to record the rocks identified down the drilled hole and displayed as a geological log.

Constant volume samples are collected to eliminate the “sample-volume-variance” phenomena when dealing with geological samples, since the variation of any measurement of sample chemical composition depends on the volume of material collected. Unlike social science statistics in which the sample support is an individual human, or in the general physical sciences where objects such as billiard balls, coins, or other discrete objects, is the sample support and from which we note that N, the number of samples, is always an integer value, such objects do not exist in geology or the earth sciences and hence special emphasis is directed to ensuring that the sample-support is maintained, here by ensuring constant volume samples.

Mineral exploration generally involves developing hypotheses about where mineral deposits might be located in the accessible parts of the earth’s crust, and initially tested by collected many inexpensive geochemical soil samples, and again special emphasis is directed to ensuring that sample-support is maintained, again by collecting equal volume samples of soil.

Chemical analysis of these samples are done and the data analysed geomathematically. Usually the samples are reported as metal assays as parts per million or billion, depending on the element, and are “intensive” variables. Because the sample support of data set is uniform, sample-volume-variance issues, as well as the pitfalls of applying statistical analyses to intensive variables are avoided, and that is another issue which won’t be described here.”

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Thanks for sending in the photograph and note.