PRESENT CONDITION OF MONT PELE 569 



mass, whether there were a constantly open vent or vents there or not. The activ- 

 ity was not central within the old crater, but was most intense in the northwestern 

 quarter. This eccenta*icity allowed the lava of the southern portion of the conduit 

 to exude rather continuously and solidify as a very steep-sided cone which was 

 disturbed perhaps only during the heavier eruptions. The eccentricity of the 

 maximum activity seems also to account for the northern portion of the dome 

 rising faster than the southern. The relief of pressure at the orifice of the general 

 conduit permitted expansion of the occluded gases and vapor, which increased the 

 cross-section of the dome with reference to the conduit and maintained it in posi- 

 tion, even when there was little pressure from below or rise of material. In the 

 extreme northern part of the crater there is an area of new rock which, like the 

 southern portion, has not risen as rapidly or as much as the subcentral part bear- 

 ing the spine. The spine-bearing portion of the dome seems to have been com- 

 paratively independent of the other two rock portions of the dome and probably 

 was separated from them by actual or potential fracture zones. 



SOUFRIERE OF SAIXT LUCIA * 

 BY EDMUND OTIS HOVEY 



I Abstract] 



The island of Saint Lucia is entirely volcanic in origin. The rocks and tuffs of 

 the island have suffered extreme subaereal alteration ; erosion is in an advanced 

 stage, and volcanic eruptions seem to have ceased on Saint Lucia long before they 

 did on any other of the inner line of the Caribbees. No semblance of a volcanic 

 cone or crater has been reported from any part of the island, but the northern end 

 of the island might repay search for recognizable remains of strato- volcanoes, as 

 indeed has been suggested by Sapper. Warm springs are known to occur in sev- 

 eral places on the island, but the only important locality is one called the Soufriere, 

 which lies about a mile east of the northern of the two remarkable pinnacles of 

 volcanic rock, which rise precipitously from the seaabout 13 miles south of Castries 

 and are known as the Gros and the Petit Piton. This fumarole area covers 2 or 3 

 acres of the Ventine estate near the head of one branch of the valley which dis- 

 charges at the little town of Soufriere on the west coast a mile or more north of 

 the Petit Piton. 



At the time of the author's visit, March 16-18, 1903, there were within the area 

 eight distinct boiling springs, one vigorous blow hole, which was driving out with 

 much force and noise the water flowing into it from a little stream, many less vig- 

 orous vents, and numberless quiet fnmaroles. The water was thoroughly boiling 

 in the large springs and was scalding hot in the smaller ones. During the rainy 

 season there is much more water in the springs than there was at the time of the 

 author's visit, the temperature of the springs is lower, and the activity less violent. 

 The pools vary in size up to 30 feet in diameter. 



The vapor rising from these vents is steam charged with varying quantities of 

 hydrogen sulphide. Crystalline sulphur is forming around most of the fnmaroles 

 and in the cavities of the porous deposits from the springs which are permeated by 

 the volcanic gases. Ferrous sulphide blackens the mud of many of the springs, 

 particularly the quieter ones. Alum forms in places from the discharges and min- 



* Based upon field observations made for the American Museum of Natural History. 



