Special Depositional Environments and Sediments

Sediments greenish in color are fairly common in the present-day oceans at various water depths. They are also frequently observed in ancient sediments, but in these cases the minerals causing the green color may differ from those found in young sediments due to diagenesis. The correct identification, crystallographic and geochemical characterization of fine-grained green minerals is difficult and can be done only in the laboratory using special methods in clay mineralogy. For simple rock descriptions in the field, barely more than the greenish color can be noted, which in turn may be modified by other sediment components such as organic matter and finegrained particles of different composition.