230 CARNEGIE INSTITUTION OF WASHINGTON. 



larney near Carmichael, and between lakes Killarney and Cunningham, New 

 Providence Island. In some places the marine oolite is evidently older than 

 the dunes; for instance, a conch shell is reported by Judge Ray from a depth of 

 10 feet in Nassau at the corner of Frederick and Bay Streets. In other in- 

 stances certain oolitic deposits are clearly younger than some of the dunes; 

 while in still other instances the age relations are not yet clear and more 

 detailed work than was practicable on the expedition is necessary. It is 

 evident that not all the Bahaman oolites nor all the dune ridges are con- 

 temporaneous, and that the formation of both oolite and dunes has been in 

 process for some time. Slightly elevated coraliferous limestone was observed 

 at a number of places along the east front of Andros Island and along the 

 north front of New Providence Island. 



Physiographic evidence was procured clearly showing that the last change of 

 sea-level was by a minor uplift of the land. A definite wave-cut scarp, its 

 base standing about 10 feet above water-level, was seen on the south side of 

 the west end of Lake Cunningham. Indefinite suggestions of elevated scarps 

 were seen around the east end of South Bight and in places on New Providence 

 Island. A definite, slightly elevated scarp, with one well-developed sea cave, 

 extends interruptedly from Morgan's Bluff to Mastic Point, Andros Island. 

 Usually the base of the scarp is only 3 or 4 feet above sea-level, but the cave 

 at Nicollstown light indicates an elevation of about 18 feet at that point. 

 The elevation has been accompanied by minor warping. Cracks and joints, 

 probably associated ^vith earthquakes, are visible in the vicinity of Nicollstown. 

 From the additional observations it is evident that in large areas of the Baha- 

 mas, specifically Andros and New Providence Islands, the last change of sea- 

 level was through uplift accompanied by warping, to amounts ranging from 1 

 or 2 to 18 feet. The uplift, however, is subordinate in amount to the ante- 

 cedent submergence. 



Attempts were made to procure additional information on "blue" or 

 "ocean" holes. Under the guidance of Mr. Lenox Forsyth and his son, Mr. 

 E. W. Forsyth, one hole on Gibson (locally known as Hog) Cay in Middle 

 Bight w^as sounded and found to be 7| fathoms deep. After our departure 

 from Andros soundings in two other holes were made by the latter and the 

 results have been reported to me. One hole in the open water of North 

 Bight, three-fourths of a mile northwest of Booth Cay, has depths of 31, 32, 

 and 33 fathoms according to four soundings. A second hole is in an area 

 of North Bight, locally known as Fat Turtle Sound. It is almost separated 

 from the open water by a rocky ridge partly submerged at spring tides. Of 

 four soundings, two gave a depth of 9| fathoms, 30 feet from shore; and two 

 a depth of 11^ fathoms near the center. 



Mr. Paul 0. Meeres, of Nassau, supplied the following information on one 

 of these holes near Black Point, on the shore of Little Abaco. It is almost 

 circular, with sheer walls to a depth of 10 fathoms. The total depth is not 

 knowTi, but it exceeds 18 fathoms. Gray snappers, tarpon, and other species 

 of fish live in it. 



On the assumption that these holes were subaerially formed, parts of Andros 

 must have once stood 192 feet higher than now. 



In the report for 1912 I pointed out that the present barrier reef is growing 

 on the edge of a platform which is submerged to a depth of about 2 fathoms, 

 and that some of the "blue" holes occur on this platform between the barrier 

 reef and the shore. The sudden, scarp-like drop to depths "between 4 antl 

 10 fathoms," on the leeward side of the reef, was also pointed out. The 

 accordance in depth of several pot-holes, 36 to 45 feet below sea-level, sug- 

 gested the presence of a submerged terrace seaward of the barrier reef at a 



