CONCLUSIONS. 367 
New Jersey, or the uppermost Potomac of Alabama as to furnish strong 
reason for the belief that the middle of Heer’s groups is the Greenland 
contemporary of the Amboy clays. The Patoot series, which appears 
lithologically and stratigraphically to be inseparable from the Atane 
series, contains at the same time many plants common in the upper 
part cf the Amboy clays, with others allied more closely to the higher 
Cretaceous floras, such as that of the Laramie. The Patoot series may 
perhaps be safely interpreted as constituting a paleontological as well as 
sedimentary transition from the Atane series to the Tertiary. The thick- 
ness of the Atane and Patoot series (Senonian) is not less than 1,300 feet 
and may considerably exceed this. 
The Tertiary clastics at Atanikerdluk attain a thickness of not less 
than 1,500 feet, not including the intruded basalts at least 200 feet thick. 
The horizon of most of the plants described by Heer as Miocene is as- 
sumed to be near the base of that series, the demarkation of which appears 
to be purely arbitrary.* It is more probable that the age of the plants 
now generally conceded by paleobotanists to be Oligocene may even be 
Kocene instead of Miocene. No remains of marine animals have as yet 
been discovered with these plants. 
The Tertiary clastic zone appears to be thinner west of Atanikerdluk, 
and at Patoot and Atane it is presumably represented by the upper sand- 
stone horizon 200 to 300 feet in thickness. At the western end of the 
peninsula its presence is established in the occurrence of “Atanikerdluk ” 
plants. On the north coast east of Niakornat there may be a slight devel- 
opment of this zone, and it evidently is represented in the interior east 
of Kook. 
The systematic differentiation of the described plant material from the 
Greenland Cretaceous, by means of which so important a distinction be- 
tween the floras of the three series, as well as such voluminous local 
floras, was attained, appears to have necessitated a refinement in species 
separation that seems in many cases to be impracticable if not impossible 
of satisfactory recognition. 
(6) An apparent angle between the horizontally bedded Tertiary basalt 
and the supposed Upper Cretaceous sediments west of Niakornat may 
warrant the hypothesis of Tertiary erosion in that vicinity. On thesouth 
coast, at Atane and Patoot, the Tertiary sediments are thought to be 
thinner than at Atanikerdluk, which lends further support to this sup- 
position. 
* The conglomeratic sandstone at 1,000 feet above tide at Atanikerdluk, assumed by the writers 
to be the base of the Tertiary at that point, is the only hypothetical lithological bench mark ob- 
served in any section. 
LIV—Butt. Geox. Soc. Am., Vou. 9, 1897 
