BURR AND BURKE : FOSSILS IN ROXBURY CONGLOMERATE. 183 
determine the age of the conglomerate. They might have come 
from the Devonian or the Trias as well as from the Carboniferous. 
But they surely do settle the question as between Cambrian and 
Carboniferous. And this is and has been the point at issue. 
The fossils were found in Forest Hills Cemetery, on the south¬ 
ern edge of the wide belt of conglomerate extending through 
Brookline, Roxbury and Dorchester. The field relations show 
that this conglomerate mass is, structurally, a broad, flat-topped 
anticline. The fossil horizon is, therefore, at the top of the series. 
The slates surround this anticline, and everywhere dip and strike 
conformably with the adjacent beds of the conglomerate series. It 
is a safe assumption that they overlie the conglomerates and are 
conformable with them. The accompanying section shows the 
Conglomerate with Sandstone bands in upper portions. 
FOSSIL 
/horizon. 
Sla^te 
fSSSjPF, 1 ’. -vet o 9 S ( 
& ° o a,-) •? <?. ' o/j % .•/?„ c —v-p <=■ o ° o 
__ ° Q O Vf ° * 
BROOKLINE. 
O o Q ^ ^ 
Slate. 
JAMAICA PLAIN. 
FOREST HILLS. 
GENERALIZED SECTION ACROSS MAIN CONGLOMERATE MASS. 
o 
L 
2 3 4 
i_i_i 
MILES 
structural relation of the fossil horizon to the conglomerates and 
the overlying slates. The evidence from these fossils seems appli¬ 
cable to the whole of this conformable series. 
It has not, as yet, been definitely proved that the other conglom¬ 
erates of the region are of the same age as those of the central belt, 
although such is generally assumed to be the case. They are much 
alike lithologically, show the same degree of secondary alteration, 
and have the same apparent relations with the igneous rocks. The 
outcrops of slate are so scattered that it is not possible to correlate 
them in a satisfactory manner. It seems probable, however, that 
the greater part of the slate is closely associated with the conglom¬ 
erate, and of approximately the same age. 
It is believed, then, that the discovery of these forms serves to 
establish the fact that Carboniferous sediments are present in the 
Boston basin, and to render it probable that the greater part of the 
area is occupied by sediments of this age. 
