HOLMES RESERVES LTD
1997
Diatomite occurrences in the Perth basin adjacent to the Darling escarpment, form a chain of numerous small freshwater bog deposits between Perth and Geraldton. The Diatomites occupy stabilised Sand dune depressions, occur within 65km of the Australian Western Coast and represent Pleistocene and/or recent deposition.
Generally, the deposits are thin saucer shaped in cross-section. The overlying soil layer consists of low-density, peaty, or organic rich layers, containing abundant roots and vegetive matter. A heavy vegetation cover of brush and trees, blanket some deposits.
Diatomite as a commodity
Diatomite is a light-coloured, lightweight, friable, sedimentary rock: composed of the siliceous remains of microscopic one-celled aquatic plants called diatoms. Physically it looks identical to chalk, which is made of the tiny calcareous shells of microscopic animals. Diatomite may also be called diatomaceous earth or kieselguhr. Commercially, the designation ‘diatomite’ is reserved for those accumulations of diatomaceous silica that are of sufficient quality, size and mine ability to be considered of potential commercial interest. The tiny diatom encloses itself in a shell of frustule of silica, which it derives from the surrounding water. Most of this silica is opal and amorphous, but X-ray studies have identified carrying amount of cristobalite structure. There are many species of diatoms which thrive in fresh, brackish, or marine waters, but few in all three. Most commercial diatomite deposits are of tertiary geologic age.
Diatom frustules have wide diversity in the size, shape, and structural ornamentation. This diversity in the thousands of species of diatoms gives diatomite three of it most important economic characteristics: 1) very large surface area, that gives the diatomite product desirable absorptive effects, 2) numerous small openings in the frustules that allow a selective flow of fluids, and 3) loose packing that result in high porosity. The physical characteristics of diatomite crude greatly influence the physical characteristics and value of diatomite products. The chemical characteristics of diatomite crude strongly affect its purity, and excess amounts of some elements (such as iron, aluminium and arsenic) are regarded as undesirable contaminations.
Badgingarra Deposit
The Badgingarra Deposit, also known as Hill River deposit is generally regarded as having the greatest potential of HRL’s combined diatomite properties in Western Australia. Across two decades numerous exploration and testing by leading mining companies and laboratories have occurred well documenting its diatomite geology and quality.