Abstract
THE United States Geological Survey, under the directorship of G. Otis Smith, continues to discuss theoretical and practical problems from the most liberal point of view. T. Nelson Dale's account (Bulletin 589) of “Marble and Dolomite of Eastern Vermont” directs attention to a rose-coloured man-ganiferous calcite marble, “alternating in very small beds with equally small beds of fine-textured white dolomite.” The author refers to his previous discussion of dolomite (Bull. 521), and suggests that the dolomite layers were precipitated inorganically, while the pink calcite layers received their manganese from organisms. Both the hard and soft parts of molluscs may contain appreciable percentages of manganese; but why should rose-coloured marbles be comparatively rare? The examples from Vermont lose their colour if used for external decoration.
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C., G. Geological Work in the United States . Nature 98, 117–119 (1916). https://doi.org/10.1038/098117a0
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DOI: https://doi.org/10.1038/098117a0