8 
J. G. ANDERSSON, 
(Schwed. Südpolar-Exp. 
marked on the Admiralty Chart another orographic direction WNW. — ESE., in the 
NVV. part of W. Falkland. This direction is indicated in the mountain-range run- 
ning from Mt. Adam across Byron Heights to Gibraltar Reef, the islands on the north 
side of Byron Sound and the Jason Islands possibly forming another parallel range. 
These orographic lines strictly correspond to the direction of the folds in the 
western part of E. Falkland. 
I 
It remains for future explorers to clear up the tectonic lines of W. Falkland. 
In order to afford some contributions to the knowledge of the Falkland Island 
sandstone series I will give a more detailed description of the three localities where 
I have studied this formation. 
Port Louis. The innermost part of Berkeley Sound inside Long Island is 
named Port Louis. (For this description compare plan of upper part of Berkeley 
Sound. Admiralty Charts [1117]). Close to the south of Port Louis there runs 
another submarine W. — E. valley, Duperrey Harbour, that is joined to Port Louis by 
a narrow transverse entrance like that of Stanley Harbour. On the east side of this 
entrance the dip of the strata is 40” S. 10° W. and some short distance NW. of the 
entrance I measured 30°S.5°W. At the westernmost part of Duperrey Harbour the 
dip of the slaty sandstone is identical with that at the E. side of the entrance. 
From the south coast of Port Louis I have two observations: at Aiguade Cove dark 
sandstone dipping i8°S. 5°E. and at Canard Cove fine-grained sandstone dipping 
25 — 35°S. At the head of Port Louis the rock is a lightgrey slate, easily crum- 
bling to an earthy substance. Here was noticed a very marked vertical cleavage 
running VV. 20° S. — E. 20° N. On the north coast at Sir J. Ross’ Tidal Tablets the 
strike of the vertical cleavage is W. 15° S. — E. 15° N. Between the two last-mentioned 
places I noticed an almost horizontal bedding of the slaty rock. 
The common rock round Port Louis is a yellowish grey, rather fine-grained- 
sandstone with the bedding planes almost covered with small mica-scales. This 
rock often exhibits a beautiful current-bedding (Fig. 4). The fossils which are 
found here in several places are bound to some thin seams of sandstone which are 
crowded with them, the intermediate thick beds being quite empty of fossils. This 
alternation of barren beds and seams crowded with fossils appears from the following 
section that I measured in the low coastal cliff some short way SVV. of the tidal tablets: 
1. Type a. Fine-grained sandstone, no or very few fossils i m. -t- 
2. » b. Sandstone- seam, crowded with fossils 0.07 » 
3. » a. O.g » 
4. » b. 0.03 — 0.08 » 
5. » 1.5 » -f 
