Petrology of iron- and phosphorus-rich nodules from the E Australian continental shelf

Phosphatic-glauconitic-goethitic nodules occur on the continental shelf of eastern Australia in water depths of c. 200–300 m, and resemble relict phosphatic nodules from other continental margins. However, there is a striking morphological resemblance of late-stage carbonate-fluorapatite crystallites in the E Australian material to those off Chile and Peru, which are known to be Pleistocene–Holocene in age. There have probably been several phases of transportation, erosion, precipitation and cementation, and consequently the inter-relationships between the co-existing collophane, glauconite and goethite are complex.