. Geology of St. Croix. . 71 
been speaking” in St. Croix and St. Thomas. Indeed, at this 
place, the consolidated rocks were nearly covered by thick strata 
of clay mingled with sand, some of which were partially har- 
dened into stone and dipped with the others at an angle of about 
ten degrees under the calcareous and tertiary formations, which 
constitute so striking and interesting a feature of that island. The 
greater portion of this district, consisting of strata highly inclined, _ 
is, I was informed, exceedingly wild, broken, and mountainous, 
Upon the whole, the entire class of rocks which I have been de- 
scribing, though they may not be of precisely the same age, ap- 
pear to me to have been formed in similar circumstances, and to 
owe their varieties principally to the different degrees of heat to 
which they have been subjected. 
The general aspect of the. calcareous part of the island, as I 
have before said, is undulating. . With the exception of some 
estates on the south and southwest coasts, where the limestone 
risaaaea the surface of the ground, the soil is easily tilled and very 
ferti] 
‘The : strata incline at different angles and in different directions. 
Their prevailing position at the east. end of the island, is a dip 
towards the west at an angle of about 10°.. They crop out to- 
wards the east at Constitution Hill, and at King’s Hill; but at an 
eminence near La Reine, towards the west, I saw them inclining 
in other directions, and, also, nearly horizontal, as at a quarry 
south of Mount Pleasant. 
This formation presents considerable diversity also in compo- 
sition. Perhaps it can best be described under three general di- 
Visions—the section which is now forming on the northwest 
coast—the marl and the calcareous sandstone, which occupy the 
conte pein ee the limestone and coral crag, the former in 
on and together A acai 
side of the island. 
The first of these divisions § is of limited extent. It isa narrow 
belt, from two to six rods wide, extending along the west, with 
few interruptions, from the bluff to Fredoricksted: It consists 
of corals, shells, and comminuted detritus, thrown up by the 
Waves upon the coast and agglutinated by a calcareous cement. 
Most of the shells are broken; the stronger ones, however, such 
as Strombus gigas, Turbo pica, Tellina remies, Arca Noe, are 
found entire, and even retain their natural colors. I observed a 
