glauconite

The clay fraction of the Tegulines Clay was composed of a quite homogeneous fine-grained matrix of illite-micas (12 [+ or -] 5 wt.%), glauconite (8 [+ or -] 6 wt.%), illite-smectite mixed layers minerals (16 [+ or -] 4wt.%), and kaolinite (16 [+ or -] 5wt.%), with minor chlorite (<2 wt.%) (Figure 3(a)).

Micro-chemical analyses of the studied growths made it possible to characterise the composition of glauconitic micas (glauconite and celadonite).

Glauconite grains are common in the sands of the Caratas Formation.

GA was mixed up with other overlying deposits, such as carbonate rocks, sandstone, glauconite sandstone, and Quaternary sediments, and piled in waste heaps.

The smaller, rounded, darker pellets of composite glauconite within these sandstone beds could have been transported from shallower shelf environment, with the surrounding lighter colored authigenic glauconite forming in-situ.

Glauconite, muscovite and biotite are also present.

K/Ar dating of glauconite found within the blue earth has yielded an estimated age of 44.1 [+ or -] 1.1 Ma (Lutetian, lower middle Eocene) for the sediments (Ritzkowski, 1997).

The nuclei of these phosphatic grains may include shell fragments, detrital quartz, and glauconite grains.

Sadler (1988) characterized this shell bed (its Telm 4) by its thickness (as thick as 3 m), coarseness, and relatively high content of phosphatic teeth and bones, Sadler (1988) interpreted it as a transgressive lag characterized by abundant phosphate pebbles and glauconite. The age of this horizon of ca.

Evidence of changes in the seawater chemistry is captured in the rock record by high rates of carbonate mineral formation early in the Cambrian, as well as the occurrence of extensive beds of glauconite, a potassium-, silica-, and iron-rich mineral that is much rarer today.

The presence of thin horizons containing glauconite grains, marine-affinity bivalves, and crinoids suggests a distal marine influence at various times (Ryan 1998).

Potash West NL (ASX:PWN) has commenced an extensive potassium extraction programme to test samples taken from its world class glauconite deposits in the Dandaragan Trough, Western Australia.