66 NEW YORK STATE MUSEUM 
The present surface distribution of the Upper Cretacie beds is 
much like that of the Lower Cretacic, and they also dip under the 
still later formatioms of the Coastal plain (see figure 22). The 
thickness of the Upper Cretacic 1s never more than a few hundred 
feet, 
Fic. 22 Diagrammatic section through the Atlantic slope, at about the 
latitude of northern New Jersey, showing the structures and relations of the 
various physiographic provinces as they now exist. 
A to B = Folded Paleozoic strata of the Appalachian mountains, with hard 
strata standing out to form the ridges. 
B to C = Piedmont plateau consisting of highly folded and metamorphosed 
rocks of Precambrian and early Paleozoic ages. 
C to E=Triassic strata showing tilting and faulting of the beds and 
mode of occurrence of an igmeous rock sheet (D) which outcrops to form a 
low ridge. 
E to H — Coastal plain, consisting of comparatively thin sheets of uncon- 
solidated sediments. 
E to F = Cretacic beds (upper and lower). 
F to G= Tertiary beds. 
G to H = Quaternary beds 
H — Present coast line. 
The dotted line represents the peneplain character of the surface (except 
for the tilting) at the close of the Cretacic period. 
To summarize: The Cretacic period opened with slight subsi- 
dence of the Coastal plain region, including southeastern New York, 
to produce low-lying flats upon which the nonmarine Potomac sedi- 
ments were deposited. Then came a slight reelevation (accom- 
panied by erosion) followed by subsidence of the Coastal plain 
region enough to allow encroachment of the shallow sea in which 
the Upper Cretaceous sediments were accumulated. 
LIFE OF THE MESOZOIC 
The life of the Mesozoic is but scantily represented within New 
York State because rocks of that age are so poorly exposed. The 
Mesozoic era is commonly referred to as the “ Age of Reptiles” 
because animals of that class then reached their culmination of 
