566 Notices of Memoirs — J. Lomas — Soidhport Geology. 



lateral torrents, far from contributing to the formation of the lakes, 

 have partly filled them up by their deposits, and have divided into- 

 three what was occasionally a single basin. 



The length of the original lake was remarkable, as it measured 

 no less than 12 kilometres (7^ miles), and it must be borne in 

 mind that though mountain lakes are often very deep their horizontal 

 dimensions are generally limited. 



As to the origin of the lake, the author is of opinion that it cannot 

 be attributed to tectonic movements or to aqueous erosion, and that 

 very probably glacial excavation has come into play. 



IV. — Geology of the Country bound Southport. By J. Lomas, 

 A.R.C.S., F.G.S.i 



LOOKING- towards Southport from the sea, we notice three 

 platforms rising in gigantic steps towards the east. 



The first is low, varying in height from 9 to 20 feet above 

 Ordnance datum, and is fringed on the seaward side by sandhills 

 which rise to an elevation of from 50 to 90 feet. On the north the 

 broad estuary of the Kibble separates this plain from a similar 

 platform known as the Fylde district, and the Mersey on the south 

 cuts off another fragment which forms the north end of the Wirral. 

 Two less significant streams, the Douglas and the Alt, flow across 

 the platform into the Eibble estuary and the Crosb^'^ Channel 

 respectively. 



The whole of this plain is the gift of the Irish Sea glacier, which 

 formerly overrode the district, the solid rocks only reaching the 

 surface in the case of a few islands, while the bulk is below 

 sea-level. 



In the immediate neighbourhood of Southport, Keuper marls 

 occur. These are of great thickness, and contain bands of gypsum 

 and pseudomorphs of rock-salt. To the north, in the Fylde district,, 

 where similar rocks occur, salt is obtained from the beds, and the 

 boulders of gypsum which occur in great profusion in the local drift 

 have evidently come from this formation. 



The Bunter rocks of the Trias succeed to the east, and are in 

 places capped by Keuper sandstones. Where these occur we reach 

 the second platform. 



At Ormskirk, distant about eight miles from Southport, several 

 interesting sections show the Keuper resting on the Upper Bunter. 

 At Scarth Hill, near the Water Tower, the relations between Keuper 

 and Bunter are well displayed, and the quarries are worth visiting. 

 Probably nowhere in the district do the Bunter sandstones display 

 such clear evidence of their seolian origin. They consist of sand- 

 grains perfectly rounded and polished, each bed containing grains of 

 uniform size. So perfect is this sifting that it looks as if the layers 

 had been passed through sieves of varying meshes. In some layers 

 the grains are 2 mm. in diameter, and in others they are exceedingly 

 fine. A comparison of these sands with others from the Sahara and 



1 Abstract of paper read before the British Association, Southport, Section C 

 (Geology), September, 1903. 



