YORKSHIRE NATURALISTS UNION IN UPPER SWALEDALE, 207 
some observations upon the plain of the fell tops, as seen from the 
high ground, and gave his reasons for regarding it as the modified 
descendant of the old surface on which the New Red Rocks 
(= Magnesian Limestone and Trias) formerly reposed. Its present 
upheaval and part of its present inclination date from Oligocene or 
Miocene times, and are coeval with the close of the volcanic period 
of the Antrim and Western Island Basalts, and with the filling of 
the metalliferous veins. 
Arrived at the Buttertubs the naturalists made a long halt for the 
. purpose of examining these singularly beautiful natural features. 
Several persons made the descent to near the bottom of one or two 
of the shafts. The Buttertubs commence at the very top of gi 
Main Limestone, where the insoluble Main Chert comes on, and a 
copious springs, heavily charged with calcareous matter in solution. 
As the rock wastes, the places where the water enters the limestone 
recede radially from the starting-point, so that the limestone is eaten 
away to every point of the compass, provided the water enters on all 
sides. Of course, the limestone ceases to be fretted away along any 
direction where the water ceases to flow. Some good examples of 
rotten-stone, resulting from the removal of the calcareous constituents 
of the Main Chert, were examined. Specimens of the more interesting 
of these are placed in the Edinburgh Museum of Science and Art. 
On leaving the Buttertubs, the general features of the beds 
forming the fell-tops were described. Liunasit (misspelt Lovely Seat 
by Phillips and others since) consists of the three lower subdivisions 
of the Kinder Scout Grit, which retain their several characteristics 
over a very large area in this part 
Nearer Wensleydale the chief alhanpe visible on the way were 
named and their geological composition briefly referred to. When 
the party were sufficiently near to Wensleydale to see the broader 
features of the dale itself, Mr. Goodchild gave some account of the 
origin of the remarkable scars and terraces of limestone seen there. 
He showed that their present form does not admit of explanation by 
ordinary subaérial denudation, while it is exactly of the nature that 
would result from prolonged glacial action. ‘The subject is more 
fully dealt with in the Quart. Journ. Geol. Soc. for Feb. 1875 (read 
in June 1874), pp. 71 et seq.; Geol. Mag., Dec. ii, vol. 1 and 2; and 
Trans. Cumb. and West. Assoc., No. xi (1887), pp. 155 et seq. 
July 1891. 
