1915- ^"^- 4- REPORT ON ROCK-SPECIMENS. 3 



The rock-specimens collected from Mt. Betty and Scott's Nunataks are 

 igneous (abyssal I rocks with cr\'stalline schists of great geological age, and 

 contain no sedimentaries. 



The exact position of Mt. Betty is lat. 85° 8' S and long. i64°27'\V Gr., 

 on Roald Amundsen's route to the South Pole, not far from the "chief- 

 depot" on Axel Heiberg Glacier. (See the sketch-map Fig. i.|. The distance 

 from Shackleton's and Scott's route at the base of the Beardmore Glacier 

 — the nearest known point in South \'ictoria Land — is about 17 1.5 naut. 

 miles (=318 km.) to X\V. 



Scotts Aitnatdks lie about lat. 77° 13' S and long. 153° 20' \V Gr. a 

 short distance from the NW coast of A7;/^ Edward VII Land and rise to 

 a height of 1260 feet above the sea level. The distance from Mt. Betty 

 is about 480 naut. miles (= 890 km.|. 



In the first part of this paper a description is given of the collected 

 rocks followed b\" a short discussion of the probable connection of the 

 rock-complex of Mt. Bett}- with that^ of Scott's Nunataks. In the second 

 part a short suramarj- will be given of the geological results of the earlier 

 expeditions to other parts of South Victoria Land, and I shall endeavour 

 to point out the connection which the rock-complex from Mt. Bett\- shows 

 with the "basal rock-complex" of the previously known part of South 

 Victoria Land. 



I. Description of the Rock Specimens. 



A. Rocks from Mt. Betty. South Victoria Land. 



The number of rock-specimens collected by Roald Amlndsen from 

 Mt. Betty is about twenty. They belong to two different, well defined 

 groups : 



1. Granites, medium to fine-grained, and light gray to white in colour. 



2. G;z^;5sr5, fine-grained, of dark gray colour and with abundant mica. 



The parallel arrangement of the constituents is prominent. The greater 

 number of these specimens are orthogneisses, derived from plutonic 

 rocks. Onh' one specimen — a true mica-schist — is derived from a 

 sedimentary rock. 



In addition there are some specimens of white, fine-grained quartz, 

 probably from a quartz-vein. 



