Diagenetic microlamination in chalk

The Maastrichtian chalk of Denmark contains units that exhibit a very fine lamination of presumed diagenetic origin. The chalk laminae, only a few tens or hundreds of microns thick, are bounded by irregularly wrinkled, parallel, pressure-solution planes. These appear to be microstylolitic seams that contain no detectable films of clay or other insoluble material. They possibly represent a stratigraphic condensation of up to 15%. Despite the release of considerable amounts of calcium carbonate in solution, the chalk has remained poorly cemented.