HILL: GEOLOGY OF JAMAICA. 97 
Another type of old reef rock is seen near Barbican, some three miles 
fast of the foregoing locality, in an excellent exposure. This is similarly 
Situated relativo to tho road and sea as the Hopewell Reef, and likewise 
Occurs unconformably upon the black Richmond shales, here having a 
dip of 45 degrees. This old reef, which we term the Barbican forma- 
SEA LeveL , 
Fieurn 34. Elevated Reef and Profile near Barbican. 
Caribbean Sea. 
Low coast plain five feet above sea, and 200 yards wide. 
The Barbican Reef. 
A bench 70 feet above sea, occupying the level of the Hopewell Reef. 
Back coast country, largely composed of the vertically tilted Richmond Beds 
of the Blue Mountain Series. 
SAS 
tion, is only three feet in thickness, and is largely composed of a species 
se coral having an elongated cylindrical or club-like form, and a concen- 
trio Arrangement of its layers. Figures 34, 35, and 36 show the occur- 
"ence of the Barbican reef and its relations to the adjacent topography. 
Tho Juxtaposition of the Hopewell and Barbican reefs and the lowest 
Coast terrace relative to each other are well shown in the topography 
Uj) 
OH, 
727 
Fıgurn 35, Relation of Barbican and Older Reef near Mosquito Cove. 
SEA 
adjacent, to Mile Post 19, displaying three distinct benches or terraces 
Against the mountainous back coast country. 
Immediately at Barbican the Barbican terrace, or twenty-five foot 
9vel, Approaches close to the sea and overlies a fossiliferous sinter 
r marl which is exposed at the foot of the escarpment, and which is 
f : 
ll of molluscan fossils resembling those of the Falmouth formation. 
VOL, Xxx1V, 7 
