CLASTIC EOCKS. 
Classification of the clastic rocks. 
119 
Rock. 
Principal components. 
Typical exposures. 
Volcanic tuffs 
Ash and lapilli (glassy) . . 
Fragments of igneous 
Castle Hill tuff. 
Volcanic sandstones 
Conglomerate on Welts 
and conglomerates. 
rock. 
Brook. 
1 . Few fragments of igne- 
Sheridan sandstone. 1 
eous rock, quartz, 
feldspar. 
2. Quartz, feldspar, and 
Chapman sandstone. 
fragments of sedi- 
Sandstone and con- 
glomerates. 
mentary rock. 
3. Quartz and fragments 
of sedimentary rock. 
Mars Hill conglomerate. 
4. Quartz, fragments of 
On Sheridan road. 
sedimentary rock, 
and calcite. 
- 
5. Quartz and (little) 
In railroad cuts south 
calcite. 
of Masardis. 
Calciferous sandstones . 
Calcite and quartz 
New Sweden Township. 
Arenaceous limestone. . 
Calcite and (little) quartz. 
Gritty beds in Aroos- 
took limestone. 
Slated limestone 
White limestone 
Calcite 
Aroostook limestone. 
Fossiliferous limestone 
Calcite 
at Ashland. 
Slates and schists 
Ashland Branch. 
Wade Township. 
Manganif erous i r o 1 1 
slates. 
!The general names applied to the sedimentary rocks in this paper were suggested by Professor 
Williams, and are further elaborated as to age and condition of formation in Part I of this bulletin. 
VOLCANIC TUFFS. 
Under this general heading will be included all the pyroclastic rocks 
of northeast Maine which contain lapilli and other original volcanic 
materials, and are thereby distinguished from volcanic conglomerates, 
which are composed principally of angular fragments of volcanic rocks. 
FIELD DESCRIPTION. 
The true volcanic tuffs are found on the southern half of the Castle 
Hill ridge, as outcrops in the road near the northeast corner of Ashland 
Township, and in several places on the Ashland-Sheridan road near 
the line separating these two townships. 
