was taking place during that time. All the evidence goes to
show that these are wave-cut terraces. It may be added here that all of
the elevated Pleistocene coral reefs recorded are plastered on the
surface of the upper Oligocene formations, or in some instances older
geologic rocks. This applies to every later coral terrace that has been
described, beginning with Cabanas and extending entirely around the
island to the City of Santiago.

The existence of marine Pliocene in Cuba has not been proved. There may
be pliocene rocks in the vicinity of Havana some 60 feet above the sea
level. If these are true Pliocene, it would indicate a subsidence during
that time of from ISO to 180 feet. The character of the fauna found in
the quarry on Calle Infanta does not indicate a greater depth than from
SO to 70 feet for the water in which the limestone was deposited.

Subsequent to this deposition, there was an elevation which caused the
land to stand some forty or fifty feet higher than it does to-day. This
probably took place in early Pleistocene times, at which time the Isle
of Pines and Cuba were connected. One reason for the belief in this
elevation is the existence of an old, deep and comparatively narrow cut
in the bed of the present channel leading out of Havana harbor. There is
further evidence of a general elevation found in borings for water,
three miles southeast of the city of Santiago.

At a depth of some 70 feet below the sea level, in the Rio San Juan
Valley, stream-carried pebbles were found. This would indicate that the
bottom of this valley once stood at least 70 feet or more above sea
level. Subsequent to this elevation, there was a subsidence varying from
40 to 70 feet. There were doubtless other slight oscillations during
the Pleistocene period, and these may be going on at the present time,
although we have no evidence from records of actually measured monuments
established since the Spanish occupation of the island.

Paleontologic, biologic and physiographic research seems to indicate
that there has been no land connection between Cuba and North America at
any time since the beginning of the Tertiary, unless perhaps during the
Oligocene period, and it seems probable there was no connection whatever
during cretaceous times.

Cuba furnishes a very interesting field, not only for geologic research,
but for a far more extended study and survey of its many important
mineral zones both for scientific and for e