The reef are currently buried beneath many thousands of feet of Cretaceous, Tertiary, and Quaternary sediments. The ridges of resistant volcanic rock of the Palisades and the Watchung Mountains display steep escarpments on their eastern flanks and gentle slopes on their western flanks. This is an indication of the gentle dipping character of the strata towards the deeper western side of the basin. When the sediments were originally deposited there were probably very nearly flat-lying. The structural dip of the rock probably developed through time as the basin continued to grow with the passage of time, even long after the youngest sediments of the basin were deposited.
Mesozoic basins exist all along the eastern margin of North America.
They may have been continuous or intermittently connected through time, similar to the basins in the Great Basin region of the western United States, however, late Mesozoic and younger structural changes and erosion has stripped away much of these deposits. The Newark and Connecticut River basins were probably part of the same large structural and sedimentary basin. Newark and Connecticut Basin Rocks.