492 



NA TURE 



[April 22, 1875 



among the many questions on which light may be thrown 

 by the photographs which have been secured in Slam, 

 and which it was hoped would have been duplicated in 

 the Bay of Bengal. As the prismatic camera was the 

 instrument requiring least time for adjustment, so it was 

 the one which could be employed for the longest period 

 during the eclipse. Before and after totality it may have 

 done good service by recording the consiitution of the 

 lower part of the sun's atmosphere in a manner which it 

 will not be very difficult to interpret, though certainly the 

 characters will be of the strangest," 



ARCTIC GEOLOGY* 

 III. 



Coast of Arctic Anicrka. — Melville Peninsula. — 

 Amongst the rock specimens brought home by Dr. Rae, 

 Prof. Tennant recognised gneiss, hornblende slate, and 

 similar metamorphic rocks, a portion probably of the 

 granitic and crystalline rocks described by Sir John 

 Richardson as occupying the central and eastern coun- 

 tries of the Hudson's Bay territory, believed by Sir R. 

 Murchison to belong to the Laurentian system. The 

 latter points out that from the prevalence of a profusion of 

 Upper Silurian corals characteristic of the Niagara and 

 Onondaga limestones (Wenlock or Dudley), the trilobite 

 EnLi-iniirus punctatiis, and the shell Peiitamcnis ob- 

 loiigiis, in the rocks lying on the Laurentian, in the 

 north of (he Hudson's Bay territory, and the absence 

 of any traces of Lower Silurian rocks or fossils in 

 the whole of the known polar region, that it is in the 

 highest degree probable that the whole of the country 

 north of the Laurentian Mountains was dry land during 

 the deposition of the Lower Silurian. In the area to 

 the south, and in Europe, and even in the Upper Silurian 

 times, the sea, as evidenced by the presence of Pcnta- 

 merus, was not a deep one, which is borne out by Sir W. 

 Logan's discovery that the Silurian limestones at the head 

 of Lake Temiscamang include enormous blocks of the 

 sandstone on which they rest.f 



i?(W/'/i'7.— Chalky limestones occur, but do not contain 

 fossils, as at Prince of Wales Island, where the Esquimaux 

 obtain large quantities of native copper on the shore. 



Sir James Ross X describes the River Saumarez, lat. 70, 

 long. 92 W., as never frozen, and gives a sketch showing 

 the gorge So feet in depth, excavated in hard trap, in 

 which it runs. In the month of July he found several 

 butterflies living near the coast, including an Hippar- 

 c/iia, two species of Colias, one being near C. ednsa, and 

 a Polyommatus. In Agnew River he found copper ore. 



West Coast of Baffin Sea. — Crystalline rocks extend 

 from Lancaster Sound to Cape Walter Bathurst and Cum- 

 berland Sound, with the exception of Cape Durban, where 

 coal has been found by the whalers, a continuation pro- 

 bably of that of Disco ; it also occurs at Kingaili, two 

 degrees south of Durban, as well as pure graphite.§ 



Arctic Archipelago. — Dr. Haughton, from an examina- 

 tion of the rocks and fossils collected by Sir Leopold M'Clin- 

 tock from 1849 to i859,now deposited in the museum of the 

 Royal Dublin Society, was enabled to draw up a geologi- 

 cal map of the Arctic Archipelago,|l in which Silurian 

 limestone is shown to occupy nearly all the islands south 

 of Lancaster and Melville Sounds, including the south 

 side of Banks Land, Prince Albert Land, Prince of 

 Wales Land, King William's Island, and Boothia Fehx, 

 the central and western area of North Devon, and the 

 whole of Cornwallis Island, &c. ; granitoid rocks occurred 

 on either side of Peel Sound, and at Ponds Bay, and 



* Continued from p. 469. 



t Narrative of Expedition to Shores of Arctic Se.i. By John Rae. 

 London, 1852. " Siluria," 5th edit. London, 1872. 



t Narrative of Second Voyage in search of a N.W. Passage, by Sir James 

 Ross. 1835. 



§ Quar. Jour. Geol. Soc, vol. ix. 



11 " Voyage of the Ao.r." Appendix IV. (London, 1850.) 



near the mouth of the Fish River ; also the eastern coast 

 of North Devon and the opposite side of Baffin Bay, to 

 77° north latitude. 



The lower carboniferous close-grained white sandstone 

 (" Ursa stage" of Heer), with beds of coal, strikes S.W. 

 and N.E. from Baring or Banks Land, where it rests on 

 the Silurian, through Melville Island to Bathurst Island, 

 where it disappears under the carboniferous limestone 

 between Penny Strait and Queen's Channel. 



The carboniferous limestone appears to strike nearly 

 east and west; the whole of Prince Patrick Island is com- 

 posed of it, and the northward portion of Parry Islands 

 and the whole of Grinnell Land ;* scattered over the lime- 

 stone on several points are patches of lias, in which 

 fossils have been found, notably at Intrepid Inlet, Arnott 

 Bay, Bathurst Island, and on Exmouth Island north of 

 Grinnell Land. 



North Devon.— From Cape Osborne to Cape Warrender 

 graphic granite occurs, passing into laminated gneiss 

 consisting of black mica and transparent felspar, inter- 

 stratified with garnetiferous mica-slate, traversed by 

 epidote hornstone overlaid by red sandstone, similar to 

 that of Wolstenholme Sound. 



Dr. Sutherland describes the crevasses of the glaciers 

 of Petowak, on the south coast of Jones Sound, as often 

 being filled with mud, which becomes frozen in, and the 

 whole mass breaks off in bergs. 



North Somerset. — Granite of grey quartz, red felspar, 

 and green chloritic mica occurs on the west coast. East- 

 ward, the island consists of the Upper Silurian sand- 

 stones and limestones, the junction of which occurs in 

 Transition Valley. In Bellot Straits granite and syenite 

 rise to a height of i,6oo feet. The base of the Silurian 

 consists of red sandstone and coarse grit, resembling 

 those of Cape Warrender rnd Wolstenholme Sound, over- 

 laid by ferruginous limestones with quartz grains, earthy 

 limestones, occasionally cream-coloured, dipping from 

 0° to 5° to the N.N.W. ; a few high cliffs occur, but the 

 country is generally low and terraced, the limestone 

 standing out as steps and buttresses, particularly at Port 

 Leopold, where the alternation of hard limestone and soft 

 shales, so well known in European limestone districts, is 

 well shown in Beechey's sketch, at p. 35 of Parry's First 

 Voyage. Amongst the fossils from Port Leopold Dr. 

 Haughton records Loxonema APClintoclcii, and specimens 

 of carnelian and selenite. 



Prince of Wales Island. — Eruptive syenite occurs at 

 Cape M'Clure. The western coast consists of Silurian 

 limestone with fossils, overlaid by bright red ferruginous 

 limestones, and a few beds of bright red sandstones, like 

 the Transition Valley sandstone. 



Banks Land— \J pper Silurian rocks are succeeded by 

 close-grained sandstone, striking N.E. to E.N.E., of 

 Lower Carboniferous age, and containing thin coal seams, 

 discovered first in Parry Islands by Parry, and afterwards 

 by Austin and Belcher in Melville Island and Bathurst 

 Island. The fossils from this series are similar to those 

 from the Irish Calp series, and from the Eifel. Silicilied 

 steins of plants were discovered by M'Clure on the coast 

 of Banks Land, and on those of Wellington Channel by 

 Belcher. The southern entrance to this channel was dis- 

 covered by Sir Edward Parry in 1S19. The lamented 

 Sir John Franklin sailed up it 150 miles in 1845, before 

 being beset with ice at Beechey Island in September 1846. 



In Drift on the Coxcomb Range, Banks Land, M'Clure 

 found fine specimens of Cyprina Islandica, 500 feet above 

 the sea. In 78° N., Belcher found whale bones on high 

 ground ; and marine shells are described by Parry as 

 occurring in clay in the ravines of Byam Martin's Island. 



From the coast of Princess Royal Island the Esquimaux 

 procure native copper in large masses. The rocks consist 

 of greyish-yellow sandstone, with Terehratnla aspersa. 



r of North Dcvoti, not tlie large tract west of Ken- 



