The strata through which the pipe has been pierced usually dip in towards the latter, and at their junction with the coarse agglomerate often shew marks of the action of heat, coal-seams having sometimes been 'burned' useless for a number of yards away from the 'neck.
"Geology"
James Geikie
21.-Neck filled with Volcanic agglomerate.
"Geology"
James Geikie
What is a neck of volcanic agglomerate?
"Geology"
James Geikie