Diagenesis and the following metamorphism can be studied by means of mineralogical equations and resultant marker minerals. As far as the diagenesis is concerned organic matter can be studied using the reflectivity (e.g. vitrinite reflection) and inorganic substances in sediments can be studied by the crystallinity of clay minerals such as the illite crystallinity. These numerical data enable the researcher to provide a secure evaluation of the carbonate rocks´state of diagenesis because there are always organic and in organic impurities to be identified under the microscope.

HGD

Thanks a lot!

Hi Andrey - If you get an answer to your question then please forward the answer to me. my point is that I continously see geologists refer to that carbonate rocks have been diagenetic altered, cemented etc., but I have never found any reference that can explain how much any given carbonate rock has been changed and this puzzle me. It puzzle me because I can see that geolgist refer to that e.g. some North Se chalks from the Cretaceous have been diagenetically changed, but when I look at these chalks then they have the same poroperms as the chalks that have not been diagenetically changed and thus that I cannot see any effect on the grain size distribution, grain morphology etc. So what is it that the diagenesis have changed and how much has the diagenesis changed the parameters.

Hi Finn - Beyond the features of late diagenesis mentioned by Dr Dill, there are a lot of semi-quantitative characters, such as geochemical (e.g. Brand & Veizer, 1980; Swart, 2015) and petrographic (e.g. Flugelhorn, 2010). But all these characters are not purely quantitative, excluding evaluation of the thermal maturity (vitrinite R, CAI, etc.). I'm working on a machine learning approach for solving this problem on the basis of thin-sections... and waiting for answers.