34 NATURAL HISTORY OF KEEGUELEN ISLAND. 



9391. Basalt with amygdules of calcite and crystals of chdbazite 



and augite. 



9392. Calcite, radio-columnar. 



9393. Dolerite. A volcanic rock related to basalt, containing oU 



vine and lahradorite. 



9394. Aragonite. Large radio- columnar colorless crystals found 



in deep pockets in basalt. 



Summary. — " The volcanic rocks of the region examined contain a lim- 

 ited number of zeolitic species, and some carbonates, as epigene products. 

 The main rocks are basalt and dolerite, of uniform physical character 

 and constancy of inclosed minerals." 



The foregoing list represents fairly the constitution of the surface- 

 rock in the southern part of Kerguelen Island. The streams had cut 

 their way deeply in places, exposing extensive surfaces of rock ; but 

 diligent search along these water-courses failed to disclose any strati- 

 fied or fossiliferous beds. At the northern eud of the island, however, 

 in the neighborhood of Christmas Harbor, stratified rocks are abundant, 

 with extensive deposits of coal (of poor quality), and contain many 

 trunks of petrified trees. For a specimen of these last I am indebted to 

 Mr. E. P. Maynard, bearer of dispatches on board the United States 

 steamer Monongahela ; my own observations having been confined to 

 the neighborhood of the head of Royal Sound, at the southern end of 

 the island. 



Sealers and whalers say that there is a great glacier in the middle of 

 the island, extending in a general easterly and westerly direction, and 

 reaching quite to the sea on the western coast. It is related by them that 

 a party of fourteen French sailors, from a wrecked sealing-schooner, 

 tried several years ago to reach the southern part of the island on foot, 

 and that all but six perished in crossing this glacier from exposure and 

 starvation. 



The island is hilly everywhere and in parts mountainous — Mount Eoss 

 reaching an altitude of over 5,000 feet, and Mount Crozier, near the 

 American station, about 3,000. The higher peaks are remarkably sharp 

 and irregular in outline, quite bare of vegetation, and mostly covered 

 with snow. Table-topped hills are frequent, as also are level plateaux 

 or terraces of basalt, projecting from the sloping sides of the less sharply 

 defined hills. These terraces no doubt indicate former flows of the vol- 

 canic material, but our limited field of observation did not permit suffi- 

 ciently extensive investigation to determine the points of outflow. 



