Depositional processes and geological significance of biogenic magnetite and iron-sulfide by iron bacteria at Anthony's Nose, Westchester County, New York: A proposed method of remediation of biogenic iron from water systems using applied magnetic fields.

摘要

In the Earth's biosphere, more than 80 different kinds of inorganic minerals are known to be produced by bacteria or human beings (Lowenstam, 1981). The study of biomineralization is a multi-disciplinary project that involves biotechnologists, geologists, microbiologists, and physicists. Biogenic minerals are important clues for paleoenvironment and rock paleomagnetism. They can be deposited in sediments and import a natural remanent magnetization preserving a record of the ancient geomagnetic field (Hawthorne and McKenzie, 1993).; Magnetotactic bacteria (MTB) orient and migrate along the geomagnetic field towards favorable habitats, a behavior known as magnetotaxis (Blakemore et al., 1980). They are a morphologically diverse and cosmopolitan group of aquatic microorganisms inhabiting freshwater and marine environments ranging from aerobic to anoxic (Blakemore, 1975).; This research provided new insight into the stratigraphic and mineralogical setting of Anthony's Nose located at Westchester County New York. It gives full consideration to novel interpretations of the evolution of the biogenic iron. The ultimate goal is to present arguments on the developments of biomineralization and to use geochemical and stratigraphic methodology that lead to the discovery of a “biogenic signature” at the research site.; MTB produced perfect little bar magnets (magnetosomes), which differ strikingly from those of inorganic origin. All magnetite (Fe₃O ₄) crystals are octahedral; that is, they have the shape of two 4-sided pyramids put together at their bases. Magnetites from magnetotactic bacteria are elongated by the addition of six faces which enforce their magnetic pull that helps them locate sources of food and energy in the milieu. The study of their processes of deposition can provide significant informations about a region paleoenvironmental setting.; The final aspect of this research addressed the environmental effects of the magnetosomes when they contaminated our water systems or oil pipes. The author constructed a design used for space flight experiments by NASA scientists to establish functional weightlessness and pseudogravity that can reorient the microorganisms trajectory (Doyle et al., 1999). The main idea is to isolate the microorganisms and to precipitate their biologically produced magnetite before sedimentation with the induction of a greater magnetic field in their environment.