Aspects of the Biogeochemistry of Magnesium 2. Calcareous Sediments and Rocks

X-ray and chemical studies of the distribution of magnesium in modern calcareous sediments, fossils, and sedimentary rocks were made. The importance of biologically precipitated magnesium in these three materials is discussed. It is suggested that magnesium originally deposited in the skeletons of calcareous marine organisms can be recognized in ancient limestones.