The Solomon Islands and Their Natives

The Solomon Islands and Their Natives

The Solomon Islands cover an area 600 miles in length. They include seven or eight large mountainous islands attaining an extreme height, as in the case of Guadalcanar and Bougainville, of from 8,000 to 10,000 feet, and possessing a length varying from 70 to 100 miles, and a breadth varying between 20 and 30 miles. In addition, there are a great number of smaller islands which range in size from those 15 to 20 miles in length to the tiny coral island only half a mile across. The islands fall naturally into two divisions, those mainly or entirely of volcanic formations and those mainly or entirely of recent calcareous formations. In the first division, St. Christoval may be taken as a type of the large mountainous islands possessing massive profiles, such as Guadalcanar, Malaita, Isabel, etc. St. Christoval, which rises to a height of 4,100 feet above the sea, is composed in the mass of much altered and sometimes highly crystalline volcanic rocks (such as, in their order of frequency, dolerites, diabases, diorites, gabbros, serpentines, and saussuritic felspar-rock) which, as I learn from Mr. T. Davies, have been both formed and altered at considerable depths and indicate great geological age and extensive denudation. Recent calcareous rocks, such as will be subsequently referred to in the description of the second division of islands, flank the lower slopes at the sea-border up to an elevation of 500 feet. Fragments of similar diorites, dolerites, and other dense basic rocks, all much altered and often schistose, have been transported by trees to the coral islets off the coasts of Guadalcanar and afford evidence of the geological structure of that island. Serpentines were obtained by Dr. Hombron in 1838[1] from St. Georges Island, which is ipso facto a portion of Isabel. Bougainville and New Georgia are largely of more recent origin, as is indicated by their numerous symmetrical volcanic[vii] cones. However, the geological evidence at present at our disposal points generally to the great antiquity of the larger islands. The significance of this fact will be subsequently referred to. There can be little doubt that some of the mountainous islands will be found to yield in quantity the ores of tin and copper. A resident trader, Captain John Macdonald, has discovered arsenical pyrites and stream tin at the head of the Keibeck River in the interior of St. Christoval. A sample of stream tin from the south-east part of Bougainville was given to me by the Shortland chief. Copper will not improbably be found in association with the serpentine rocks of these islands. The smaller islands of volcanic formation group themselves into two classes: ......Buy Now (To Read More)

Product details

Ebook Number: 42388
Author: Guppy, H. B. (Henry Brougham)
Release Date: Mar 22, 2013
Format: eBook
Language: English