Diagenesis in carbonate sediments: A review

Abstract

Reading the old textbooks of more than twenty-five years ago reveals the enormous progress made in our understanding since those days. Advances have been made along several related paths, particularly through the study of texture and structure with the microscope, the examination of Recent marine sediments and the application of the principles of solution chemistry. As a result we can now relate many diagenetic products with distinctive textures or structures to one of, say, four main types of aqueous solution. Sea water yields characteristic growths of aragonite and Mg-calcite whose fossilized calcitic remains we can yet recognise in the ancient. Fresh water gives rise to other individual calcite textures whose imprint also we can distinguish in the old rocks. Solution extruded at depth from compacting clays produce even other calcite textures which we are now beginning to understand. Certain mixtures of sea water with fresh water provide not only beach rocks with aragonite and Mg-calcite cements but dolomites through the Dorag process. Clearly influential in the control of marine precipitation we find organic compounds such as the humic acids.