Gregory.] MAPLETON SANDSTONE. 137 
The strata dip NW. < 15° db and have an average strike N. 45° E. The 
section is shown in fig. 8. 
Petrography.- -The conglomerate varies from fine consolidated gravel, 
partly water sorted and marked by cross bedding, to a confused mass 
of pebbles 2 to 3 inches in diameter. The pebbles contained are 
quartz, reddish and greenish jasperlike fragments, blue limestone, 
white limestone, calcareous slates, quartz-porphyries, and occasionally 
fragments of other igneous rocks. Thin sections examined under the 
microscope show that the fine sandstones are practically identical with 
the conglomerates in composition, and that the cement of all the varie- 
ties is largely calcareous, with a mixture of iron. 
In the red sandstones near the hilltop are abundant remains of a 
branching Psilophyton and other Devonian plants, but diligent search 
has failed to reveal other fossils (see PI. XII, ^4). 
Field relations. — At no place was an actual contact between the 
Mapleton sandstones and the common slated limestones of this region 
observed, but outcrops of the two formations were found near each 
other in several places, and wherever seen the limestones are much 
folded and slated and dip at high angles, while the sandstones dip 
Fig. 8.— Section through VViuslows Hill. 
slightly and show little disturbance since deposition. On such evidence 
it is believed that the Mapleton sandstones lie unconformably upon the 
slated Aroostook limestones. 
These sandstones were examined by Hitchcock, 1 who called them 
Devonian. The field measurements which he made could not be veri- 
fied. Bailey 2 considers them to be of Lower Carboniferous age, and in 
describing this region appears to extend the sandstone area, and men- 
tions vesicular gray sandstone 4 miles from Presque Isle, presumably 
on the Haystack road. In this vicinity, however, no rocks were seen 
except many outcrops of decayed porphyritic andesite. 
SANDSTONES OF OTHEK LOCALITIES. 
Outcrops of a fine-grained sandstone with a decided quartzite appear- 
ance and fracture are exposed on Johnsons Brook, New Sweden; on 
the North Branch of the Caribou in Woodland; on the Aroostook 
1 Agriculture and Geology of Maine, 1861, p. rj">. 
2 Ann. Rept. Geol. Nat. Hist. Survey Canada, 1887-88, Pt. M . p. 17. 
