BURR: MELAPHYR OF BROOKLINE, BRIGHTON, AND NEWTON. 57 
irregular, dike-like intrusions of the melaphyr. The two rocks look 
much alike upon the weathered surface, so that it is difficult to differ- 
entiate them in the outcrop. The main body of melaphyr does not 
appear in contact with the sandstone, but is to be seen in an outcrop 
fifty yards eastward. A half-mile farther east, on the corner of Prince 
Street (Plate 2, Loc. 13), the melaphyr is in contact with similar sand- 
stone. The contact is unmistakably igneous. The sandstone dips north 
at an angle of 15°. The plane of contact also dips north, but ata much 
higher angle, approximating 50°. The effect of the igneous rocks upon 
the sandstone is plainly visible. Structures are obliterated and a distinct 
contact zone is developed, while the irregularity of the contact is such as 
could hardly be produced except by igneous action. Under the micro- 
scope the feldspars are seen to be aligned along the contact. 
The melaphyr is not again seen in contact with sediments for three 
miles toward the east. On Cambridge Street, Brighton, a short distance 
west of Foster Street, a cliff of sandstone and conglomerate is capped by 
melaphyr. The contact shows abundant signs of igneous action. This 
would, however, be true if the melaphyr were a flow. In the Allston 
area, bounded approximately by Cambridge and Warren Streets and Com- 
monwealth and Harvard Avenues, contact exposures are fairly numerous 
and frequently satisfactory. The relations .of the rocks in this area 
have been discussed by several writers, notably W. O. Crosby, E. R. 
Benton, and H. G. Woodward. Benton concludes that the melaphyr is 
intrusive into the sediments. Crosby and Woodward do not accept this 
conclusion, their idea being that the melaphyr masses are made up of 
successive flows. Woodward has mapped the area with great care, and 
has differentiated six flows. His work has not been published, and 
is, therefore, not subject to criticism. His map, however, was printed 
and distributed by Professor Crosby in connection with a course of lec- 
tures given at the Boston Society of Natural History in 1889-90. As 
this map shows very clearly the location of the six supposed flows, it 
seems fair to discuss them, not forgetting that Woodward may have been 
in possession of evidence which has escaped the writer. 
The most southerly of these supposed flows is not well indicated in 
the field. It is not seen in contact with the sedimentary rocks. The 
second “flow” is indicated by three outcrops. One of these, lying north 
of the elbow in Commonwealth Avenue, shows amygdaloidal melaphyr 
overlain by patches of sandstone and slate. The contact is not striking, 
as the melaphyr and the sandstone are of the same dull green color, and 
not unlike in texture. It becomes clear, however, on examination, that 
