21. Aldeburgh Brick Pit is a site showing a clear stratigraphy of Corralline Crag. 22. Biostratigraphy or paleontologic stratigraphy is based on fossil evidence in the rock layers. 23. Stratigraphy starts with the Upper Devonian Famennian argillaceous sediments.24. The post-Acadian movements are highlighted in the stratigraphy of the region. 25. In British stratigraphy , the Serpukhovian ( lower Namurian ) contains three substages. 26. These bodies are often discordant to stratigraphy and are quite podiform in nature. 27. It was marked by an intense focus on stratigraphy . 28. Stratigraphy provides a relative ordering ( ordinal ranking ) of the CRBG layers.29. The stratigraphy of the formation was most recently revised in a 1971 study. 30. The Cenozoic has seen more recent revisions by the International Commission on Stratigraphy .
