Original paper
Manganese carbonates in the Groote Eylandt sedimentary manganese deposit
Ostwald, J.
Neues Jahrbuch für Mineralogie - Abhandlungen Band 157 Heft 3 (1987), p. 285 - 301
42 references
published: Oct 15, 1987
DOI: 10.1127/njma/157/1987/285
ArtNo. ESP154015703004, Price: 29.00 €
Abstract
Cenomanian age manganese sedimentation on Groote Eylandt, Australia, consists of shallow marine pisolitic manganese oxides (manganese oxide ore) in claystones and sandstones, and unexposed deeper water Ca-Mn carbonates in glauconitic sandy clay (marl). Microanalysis of the carbonate indicates a wide solid-solution range from (Mn0.06Ca0.94)CO3 to (Mn0.98Ca0.02)CO3. Textural studies indicate that the carbonate occurs in at least two generations, an earlier crystallisation with composition in the range (Mn0.36Ca0.60Mg0.04)CO3 to (Mn0.58Ca0.38Mg0.04)CO3 and a more restricted occurrence of (Mn0.7Ca0.3)CO3 to MnCO3 which is concentrated in a particular zone in the sediment, and is interpreted as a later transformation, possibly the result of water shallowing during a marine regression.
Keywords
Manganese deposits • Groote Eylandt (Australia) • diagnesis • Mn-carbonates