gS STEPHEN TABER 



Radio Station, some falling from racks to the floor, but no damage 

 resulted. The descriptions of these two earthquakes and the fact 

 that they were not recorded on the seisomographs at Panama, 

 Port-au-Prince, or Vieques indicate that they were local, probably 

 originating close to Swan Island. 



An earthquake at ii>^ oi'" 46^ G.M.T. on January i, 1910, was 

 of sufficient intensity to throw two men out of bed. Instrumental 

 records indicate an origin about 35 miles south of Swan Island 

 but this determination is not regarded as very accurate.^ 



The submerged scarp bounding the Bartlett Trough on the south 

 continues beyond Swan Island in a southwesterly direction and is 

 especially well defined north of the Bay Islands (Utilla, Ruatan, 

 and Bonacca) where it has a height of about 4,000 m. The Bay 

 Islands are probably the eastern continuation of the Sierra de Omoa 

 of Honduras^ and they are also in ahgnment with Swan Island. 

 Basalt-flows on the Island of Utilla and in the Sierra de Omoa at 

 Chameleconcito near Puerto Cortez are beheved by Powers to be 

 Recent, perhaps Pleistocene in age;^ and their presence is indica- 

 tive of profound faulting such as has permitted the effusion of 

 basalts in the fault trough of Southern Haiti. 



Topographic evidence suggests that the separation of Jamaica 

 and Haiti has resulted from faulting along a branch of the Swan 

 Island-Jamaica-South Haiti fault zone, extending from a point 

 near the north coast of Jamaica eastward along the south coast of 

 Haiti until it joins the northern escarpment of the Caribbean 

 Basin. The Tiburon Peninsula of Haiti continues westward 

 beyond Cape Dame Marie as a submarine ridge for 150 km., pass- 

 ing through Navassa Island and Formigas Bank; a parallel ridge 

 extends eastward from Morant Point, Jamaica, through Albatross 

 Bank for a distance of over 100 km.; between the two lies a narrow 

 channel having a nearly uniform depth of 2,000 m. Immediately 

 south of the Tiburon Peninsula there are very steep slopes, espe- 

 cially near Vache Island and near Jacmel where soundings of over 



^ These data were supplied by Professor Harry Fielding Reid. 



^ Karl Sapper, "Uber Gebirgsbau und Boden des siidlichen Mittelamerika, " 

 Petermann's Mitteil., Bd. 32, Heft 151 (1906), p. 17. 



3 Sidney Powers, "Notes on the Geology of Eastern Guatemala and Northwestern 

 Honduras," Jour. GeoL, Vol. XXVI (1918), p. 514. 



