238 PR0CKEDIXG3 OF THE GEOLOGICAL SOCIETY. [Feb. 22, 



eroding power through the Silurian area in their course to the river 

 Eden. 



The Lower Silurian rocks and the strata which bound them have 

 been referred to in a memoir by Dr. Buckland *. This, however, 

 was at a time long antecedent to Sir Roderick Murchison's labours 

 among the older rocks ; and consequently the relations described by 

 Dr. Buckland are such as are inapplicable to the present state of our 

 knowledge of the older Palaeozoic series. Professor Phillips, in his 

 ' Geology of Yorkshire,' has also alluded to the rocks of this district 

 as forming the base upon which the Old Red Sandstones and the 

 Carboniferoiis strata of the north of England repose. 



2. The Lower Silurian Rocks of the South-east of Cumherland. — 

 It has been already stated that the extreme northern limit of the 

 Lower Silurian rocks in the south-east of Cumberland is in the 

 township of Melmerby. In this locality these rocks are exhibited, 

 flanked on their western side by the Upper Permian sandstones, 

 which have been brought into contact with the older Palaeozoic rocks 

 by the Great Pennine Eault. On the north and north-east the 

 Upper Old Red sandstones are seen bordering the Lower Silurian 

 rocks, reposing unconformably upon them, and dipping towards the 

 north-east at a low angle. Immediately contiguous to the Lower Silu- 

 rian strata, on their western side, as seen in Rake Beck, about a mile 

 east of Melmerby village, is a mass of trap which sends veins into 

 them. This trap soon disappears from the old rocks southward 

 from Rake Beck ; it can, however, be seen north of the extreme 

 northern limits of the Silurian strata, forming low hummocky hil- 

 locks along the base of the Pennine escarpment ; and it is probably 

 a portion of that line of igneous rock which intersects the Permian 

 strata in the centre of Cumberland, cutting across them from Ren- 

 wick, in a W.N.W direction, through Barrock FeU to Petterell 

 Crooks, near Wreay Station, on the Lancaster and Carhsle Railway. 



The Lower Silurian rocks are exposed in the upper portion of 

 Rake Beck, in the parish of Melmerby, and in the streams which join 

 this rivulet. They compose a hiU called Mickle Aw Fell, on the north 

 side of Rake Beck ; and in its neighbourhood the strata have been 

 extensively worked for diking purposes. 



The rocks, as seen here, are hard flaggy slates, usuallj^ of a dark- 

 grey colour, but having occasional green bands among them. At 

 Mickle Aw Fell they dip S.S.E. about 50°, and possess all the characters 

 of the flaggy beds of the Skidd aw slates. The evidence of the occur- 

 ence of fossils in them is imperfect, consisting only of impressions 

 and elevations having a Gorr/onia-hke aspect, and possessing a dis- 

 tinct central axis, which sends off from each side a reticrdated struc- 

 ture with interspaces. Impressions and elevations of a like nature 

 are also seen among the Skiddaw slates of the Lake-country. In the 

 course of Rake Beck, below the junctions of the streams flowing from 

 Mickle Aw FeU, the Skiddaw slates are also seen ; but they have a 

 different mineral character from the flaggy slates of Mickle Aw Fell. 



They are black in colour and soft in nature, in which features 

 * G-eol. Trans. 1st series, vol. iv. p. 105 et seq. 



