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PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jail. 8, 



2. On the Estuary Beds and the Oxford Clay at Loch Staffin, 

 in Skye. By Professor Edward Forres, F.R.S., V.P.G.S. &c. 



The purpose of the following brief notice is to put on record some 

 observations made in the island of Skye in August 1850, by which 

 the true geological horizon of the so-called "Wealden" of Loch 

 Staffin was determined, and the Oxford Clay added to the series of 

 oolitic strata in the Hebrides. 



Sir Roderick Murchison, in his " Supplementary Remarks on the 

 Strata of the Oolitic Series and the Rocks associated with them in 

 the Counties of Sutherland and Ross, and in the Hebrides," read 

 before the Geological Society in November 1827, states that "in the 

 low and ruinous cliff of blue shale, associated with zeolitic and amyg- 

 daloidal trap on the north-eastern shores of Loch Staffin, were found, 

 during my late excursion with Professor Sedgwick, flattened masses 

 of shelly limestone containing five species of Cyclas, one Paludina, one 

 Neritina, one Ostrea, one Mytilns, and some undescribed bivalves," 

 and remarks that "it adds materially to the interest of these remains, 

 that two species of the Cyclas, the Paludina, and the Ostrea prove to 

 be identical with the fossils of one of the upper beds of the Weald 

 clay described by Dr. Fitton as occurring in Swanage Bay, Dorset- 

 shire, and in the Isle of Wight." Of these fossils a list is appended 

 to the paper, drawn up by Mr. Sowerby ; and besides the references 

 to Weald Clay species, one Cyclas is considered identical with a Barton 

 Cliff shell, and the Nerita is compared with a Woolwich species. 



When the Duke of Argyll announced his important discovery of 

 tertiary strata, probably of freshwater origin, associated with traps in 

 the island of Mull, it occurred to me that possibly the Loch Staffin 

 beds might prove to be tertiaries also ; the more likely since some 

 of their fossils had been referred to tertiary species. At the same 

 time I felt very anxious to ascertain whether on the other hand they 

 might really be Wealden strata, or what was more probable, as Mr. 

 Robertson had suggested in his interesting paper on Brora, equiva- 

 lents of the estuary strata associated with the Brora oolitic coal. 

 My recent researches among the Purbecks had led me to distrust all 

 the older determinations and comparisons of freshwater fossils, and I 

 felt that it was of great consequence to the special work in which I 

 was officially engaged in my duties as a member of the Geological 

 Survey, that before publishing the full account of the palaeontology 

 of the Purbecks now in course of preparation, I should examine the 

 Loch Staffin fossils, and, if possible, personally inspect their locality. 

 This I felt to be the more necessary, since I had been told by Sir 

 Roderick Murchison that the fossils in question were taken from 

 loose blocks of stone, the exact position of which in situ had not 

 been seen. 



Many of the Hebridean localities are so out of the way of travelling 

 that it is by no means easy to visit them. Loch Staffin and Loch 

 Laigh (the latter in the neighbourhood of the Duke of Argyll's leaf- 

 beds) were of this kind. But all difficulty was removed by a pro- 

 posal from my excellent friend Mr. Mac Andrew to accompany him 



