The blueberry (iron nodule) from the Shark Bay area, Western Australia and its implication to the genetic environments of iron nodules on Mars

摘要: Fist-sized iron nodules, extensively found on the ground of Western Australia, were investigated by element analysis (XRF, ICP-MS and ICP-AES), electron microscopes, X-ray diffraction Mossbauser spectroscopy. Loosely-packed pisoidic structures a few to >10 mm in size observed cross-section nodules. Chemically, nodules are majorly made O, Si, Fe Al, share similar REE pattern with loess sourced Greatford concretions from New Zealand. Angular quartz particles, nano-sized goethite hematite be major mineral phases. Other minerals, such as detrital zircon, barite Ce-containing particles can also but very low abundance. No detectable carbonate or amorphous silica implies that these have experienced little underground fluid alteration. The showing particularly three sections fractal size-distributions, together their extensive broken features conchoidal fractures, strongly suggest situ fragmentation host rock minimum later dynamic sorting. These observations indicate genetic environment those is always close surface tectonically stable since formation. Because similarity climatic geological features, genesis preservation Australia may provide clues formation Martian