5. Surface eruption of diabase.
6. Erosion.
7. Submergence, deposition of Cambrian formations; slight oscillations during their deposition; reduction of land to baselevel.
8. Eastward tilting and deposition of Martinsburg shale; oscillations during later Paleozoic time.
9. Uplift, post-Carboniferous deformation and erosion.
10. Depression and Newark deposition; diabase intrusion.
11. Uplift, Newark deformation; and erosion to Catoctin baselevel.
12. Depression and deposition of Potomac, Magothy, and Severn.
13. Uplift southwestward and erosion to baselevel.