40 THE STRATIFIED ROCKS OF ESSEX COUNTY. 
On Kent's Island in Newbury, at the junction of Little 
and Parker rivers, there is a bed of argillite interstratified 
with sandstone which extends about one thousand yards on 
the bank of the Parker river to a point near the Eastern 
Railroad and on Little river one hundred yards west. 
Some of the beds are of a dull red color resembling the 
North Attleboro and North Weymouth slates while others 
are of a greenish color. They are cut in several directions 
and are distorted by felsites and amygdaloidal melaphyrs, 
shearino: and faulting to such an extent that the true bed- 
ding is quite difficult to determine. By uncovering the 
glaciated surface, however, and washing away the clay and 
drift the bedding is plainly revealed. The strike is 50° 
north of east, dip 55° southwest. The microscopic struct- 
ure of a very opaque section of the red slate, cut across 
the bedding is : clastic quartz grains and fragments show- 
hm secondary enlaro:ement and crushing and containing nu- 
merous fluid inclusions, surrounded by a ground-mass of 
earthy kaolin, much muscovite and ferruginous magnetite 
and limonite. The sections of tlie green slate from Little 
river are composed of angular and rounded quartz grains, 
a finely fibrous kaolinized ground-mass, some epidote, mus- 
covite, a few grains of zoisite and much chlorite. The al- 
ternating sandstone is composed of quartz and feldspar 
grains, some biotite and scales of muscovite and much fer- 
retic oxide. 
O In Andover, near Butterfield's saw mill, is an outcrop of 
metamorphic micaceous sandstone lying parallel to the horn- 
blende schist on the east ; this formation is again found at 
John Jenkins' farm near the cross road to Ballard Vale. 
The microscopic structure of sections from these outcrops 
is : quartz grains of original sand cemented by a film of fer- 
reous oxide and some secondary quartz, scales of muscovite 
and biotite and masses of fi brio lite. One of the sections 
