TRANSACTIONS OF THE SECTIONS. 6/ 



Description of a Section across the Silurian Jtocks in Westmoreland^ 

 from the Shap Granite to Casterton Fell. By J. G. Marshall, 

 Esq., F.G.S. 



The object of this paper was to explain the order of superposition of 

 a series of strata exhibited in Westmoreland, and to identify them, by- 

 means of their organic remains, with several members of the Silurian 

 system as defined by Mr. Murchison. The general strike of these 

 strata is from S.W. to N.E., and their prevailing dip toM^ards the S.E., 

 interrupted, however, by many faults and reversals of dip, which are 

 described in detail. The following is the descending order of succes- 

 sion, deduced from the section here described. 



1 . Carboniferous limestone, which at Kirkby Lonsdale overlies con- 

 formably the old red sandstone, and on the E. of Casterton Fell reposes 

 unconformably on the Blawith slate. In Kendal Fell it rests uncon- 

 formably on the Benson Knott rock. 2. Old red sandstone breccia, 

 forming cliffs on the E. side of the Lune. 3. Red or gray tilestones, 

 with nodules of cornstone, occurring in the bed of the Lune from 

 Beckfoot to Killington ; these beds contain but few fossils. 4. The 

 Benson Knott Rock, composing Benson Knott and two other anticlinal 

 ridges on the N.W. of Kirkby Lonsdale, consists of a compact, gray, 

 arenaceous slate with an irregular cleavage chiefly in the direction 

 W.N.W. and E.S.E. It contains numerous fossils, which have been 

 found by Mr. Sowerby to agree with those of the Upper Ludlow rock. 

 5. The Blawith slate, a hard, gray, siliceous slate, with a prevailing 

 cleavage from N.N.E. to S.S.W. This rock is 4000 or 5000 feet thick, 

 and at Blawith on Coniston Lake contains a thin bed of limestone with 

 fossils. 6. The Coniston limestone, consisting of blue flagstone, black 

 slate and blue limestone, the latter with numerous fossils. These beds 

 are much compressed, altered and contorted where they abut upon the 

 Shap granite; but are better displayed towards the S.W. in Sleddale, 

 Kentmere and Coniston, the fossils from which place have been iden- 

 tified by Mr. Sowerby with those of the Caradoc sandstone. Mr. 

 Marshall considers both the Blawith slate and the Coniston rocks to 

 belong to the Lower Silurian series ; and if the Benson Knott rock has 

 been satisfactorily identified with the Upper Ludlow rock, it appears 

 that the Middle Silurian series is wanting in the district here described. 



The Coniston limestone is underlaid by the Cambrian system of 

 Cumberland, which has been described by Professor Sedgwick. 



On a Basaltic Dyke in the Vale of Eden. By J. A. Knipe, Esq. 



The Vale of Eden, or plain of East Cumberland, lying at the base of 

 the carboniferous limestone of the Pennine chain on the east, and the 

 group of primary mountains of the lake district on the west, consists of 

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