OJIT THE STOCKDALE SHALES. 663 



at the base, the Lower Skclgill Beds being entirely faulted out ; but 

 some distance below this wall the Dimorphograptus-confertus Beds are 

 again exposed on the right bank of the stream, which here forms a 

 dip-slope from which the shales of this zone may be broken off in 

 slabs of considerable size. Most of the fossils obtained at the Lower 

 Bridge are found here, and where the shales are unweatbered 

 the Graptolites have been replaced by white calcite, though in the 

 weathered state they occur as yellow-brown impressions, as is the 

 case for the most part with those found at the Lower Bridge. On 

 the opposite side of the stream at this point the section is very 

 similar to that at the Lower Bridge on the same bank, though 

 there is a smaller thickness of shales of the Dimoiyliograptus-confer- 

 tus Zone below the fault. The portion seen is disturbed, a slight 

 disturbance having probably crushed out a portion of the Atryjpa- 

 fleocuosa Limestone, which is here only three inches thick. Above 

 this we find ten inches of calcareous bluish flags, with the usual 

 Graptolites of the DimorpJiograptus-zo-ne, above which is a calcareous 

 pyritous band, apparently in the position of the slickensided divi- 

 sional plane noticed in the section at the Lower Bridge. This band 

 contains badly preserved Graptolites along with numereous Ostracods 

 and small Brachiopods, whose identification it would be too hazardous 

 to attempt. Isolated plates of a species of Turrilepas are also 

 tolerably abundant. 



Lower down the strike-fault is more pronounced, and where there 

 are exposures the Lower Skelgill Beds are again entirely cut out, 

 until we reach the second tributary from the north, on the west 

 bank of which is seen the Atrypa-Jlexuosa band halfway up in a 

 chfi", separating the JDimorj)hograptus-co7ifertus Beds above, with the 

 usual fossils, from the Ashgill Shales below. 



Returning now to the Lower Bridge, and tracing the Lower Skel- 

 gill Beds up stream, we find the Atrypa-jlexuosa Limestone resting on 

 the Ashgill Shales immediately above the bridge ; but the beds above 

 it are here covered with talus. A few yards higher up the stream 

 a dip-fault with a downthrow of a few feet to the north runs in a 

 general E.-W. direction, bringing the Ashgill Shales against the 

 DimorpTiograptus-confertus Beds on the right bank of the stream, 

 and the strike-fault, which has here reached the bed of the stream, 

 has caused the disappearance of a much greater thickness of beds on 

 its north side, so that at the foot of a high precipice, which will be 

 hereafter noticed as containing a magnificent exposure of some of 

 the Middle Skelgill Beds, not only are the Dimorpliograptus-coyifei^tus 

 Beds faulted out, but also the lower part of the Middle Skelgill Beds, 

 which latter rest against the Atrypa-flexuosa Bed. This limestone 

 is here seen in the stream, and after being somewhat displaced again 

 by another dip-fault (which runs up a deep gash on the north-east 

 side of the high cliff, in the same way as the first-named dip-fault 

 runs up a similar gash on the south-west side of the clift), it is well seen 

 resting on the uppermost beds of the Ashgill Shales, at a point where 

 the stream turns a corner and runs down a steep dip-slope. Here 

 the highest Ashgill Shales again contain the calcareous nodules 



