Basic Rocks of Northeastern Maryland. — Leonard. 147 
NORYTE. 
The norytes are closely associated with the hypersthene- 
g-abbros and together they form a long and narrow belt border- 
ing the diorytes on the north. The area occupied by these pyr- 
oxene rocks extends from the vicinty of Reckord, on the Little 
Gunpowder, across Harford and northeast Cecil counties to the 
Pennsylvanian line. It here changes its course and runs parallel 
to the boundary, gradually narrowing to the east. While these 
two types are associated thus closely and merge into each other 
so that no sharp line can be drawn between them, it will be ad- 
vantageous to consider each one by itself. 
The norytes are not confined to any particular portion of the 
district, but have a wide distribution throughout the area of 
basic rocks. Good outcrops are found along the Susquehanna, 
"both above and below the mouth of Conowingo creek, and also 
on either side of Octoraro creek above the paper mill. Bould- 
ers of noryte are common at many points between Stone run 
and the state line, near Oakwood, along the serpentine border 
south of Rock Springs, and at numerous other localities. In 
Harford county they are abundant at Dublin, Castleton, and at 
Husbands Forge on Deer creek. The rock of which these out- 
crops and boulders are composed varies widely in color and 
texture. Some are dark, others are light colored, while many 
have a purplish tinge. As a rule, they are medium coarse- 
grained, but not as coarse as the diorytes. They are some- 
times firm and compact, but more commonly have a rather 
loose texture and a more or less crumbly appearance. But as a 
matter of fact the grains are held firmly together and the rock 
does not readily break in pieces. Quite a common type is one 
composed of rounded grains of reddish-brown hypersthene 
and colorless feldspar, the latter mineral forming but a small 
part of the mass and serving as a cement for the rest. This 
variety approaches pyroxenyte in composition and graduates 
into the latter type l)y intermediate stages. A porphyritic 
noryte was found near the Mount Hope church. This con- 
tained good sized phenocrysts of diallage, some measuring one- 
half an inch (13 millimeters) in length, imbedded in a fine- 
grained groundmass of plagioclase and hypersthene. The dial- 
lage contained inclusions of the latter mineral. In another var- 
iety which was seen just north of Conowingo the minerals 
