KFNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 50- N:0 3. 79 



Physiogiiomy of tlie vegetation. 



1. Geographical caiul geologicaP remarks. See the map. 



The Falkland Island group is situated in the southern part of the Atlantic 

 ocean and extends between 51° and 53° s. Lat. and 57° 40' and 61° 30' w. Long. It 

 consists of two large, West and East Falklands, and a great number of smaller islands. 

 The area of the whole group is set down as about 16,380 square km. The coastline 

 is remarkably broken. Many of the big bays, snch as Berkeley Sound, Port William 

 with Stanley Harbour, Port Howard, Port Edgar etc. are defined as to their general 

 shape by the stratigraphic and tectonic conditions (Pl. IV: 1). An innumerable number 

 of narrow creeks (Pl. V: 2) run down to the bays. Of special interest are the richly 

 branched creek-systems treated by J. G. Andersson, such as Port Salvador, which is the 

 most magnificent of them all. Their segments are continued above sea-level in winding 

 valleys, and it was easy for Andersson to prove that they are drowned river-valleys, 

 formed during a time when the islands lay considerably higher than to-day and now 

 submerged. A very striking example is Double Creek in Port Richards; we do not 

 need much imagination to make it a true river with its tributaries. 



Our knowledge of the geological structure is mainly due to T. Halle. The 

 archsean basement, discovered by Andersson, has hitherto only been found in one 

 place. Cape Meredith, the soutli cape of West Falklands. The rest of this island is 

 built up of Devonian sandstones and quartzites, the latter overlayering the former, 

 rising to more or less pronounced mountain chains. Along the nortli coast of West 

 Falkland, the headland of which is continued in a series of islands ending in 

 Jason Is., the tectonic lines strike ESE — WNW. South of Byron Sound we can 

 trace an irregular mountain-belt extending from West Point towards Port Howard. 

 In this broken liighland the highest mountains of West Falkland are situated, Mt. 

 Adam (700 m., Pl. XI: 1), at the same time the highest peak in the whole group, 

 and Mt. Maria (665 m.), which marks the eastern extremity of the mountain-belt in 

 question. Along the east coast is another conspicuous mountain range, extending from 

 Mt. Maria to Mt. Moody, the Hornby Mountains, striking NNE— SSW in conformity 

 with the fault-lines marking the west coast of Falkland Sound. The northern half 



^ See Andersson (21) and Halle (23). 



