thanks once again for your help.
41.1 I keep on the watchlist for now.
42.1 ok
48.1 with your help I found Kankar (Kunkur) in Ball's »A Manual if the Geology of India«, its a sediment of sorts
50m.1 your idea seems resonable.
For the last few days, I did not find much time to work on the manuscript. Also my internet connection may fail further out.
J.