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.

14. Uplift, warping and degradation to Tertiary baselevel; deposition
of Pamunkey and Chesapeake.

15. Depression and deposition of Lafayette.

16. Uplift and erosion to lower Tertiary baselevel.

17. Uplift, warping and erosion to Pleistocene baselevel; deposition
of high-level Columbia.