Ifi4 Ranges of Limes to?ie Eock, and Great Faults, described. 



meichiou aud Dyserth, (having in these last places just a contrary 

 fli]) to what I had previously understood, and covering the slate 

 instead of passing under it), then wheeling to the NNE and NE, 

 through Melidon, SE of Prestatyn to Gronant, dipping WNW, 

 NW and at length N. 



Anotlier grand wheel or change in the direction of these Rocks 

 takes place at Gronant, from whence they range nearly SE, in 

 an undulating line, with a NE dip, somewhat varied locally, in 

 the undulated parts, through Llauasa, SW of Whitford, Holy- 

 well and Halkin, to Moel-y-gaer Hill, W of Northope ; where 

 a wheel is made to the SW for about a mile (with a SE dip) and 

 then another to the SSE, passing W of Mould, Nercivys and 

 Llandcgla to Tafarn-Dowyrch, witli an eastern dip, and wheeling 

 then to the SE, it seems to cross the vale and turn N, with first 

 a NE and then a W dip. 



From a point SE of Llandegla, about half a mile, some obser- 

 vations are yet wanting, to satisfactorily connect the range of 

 Limestone (or show the course of the Faults that prevent such 

 (connection) to near Bwlch-y-Gwynt, and the SE side of Minera 

 Chapel, where the Limestone Rock appears again very majesti- 

 callv, with an E dip, and proceeds across Ruabon Mountain and 

 Egiwyseg Rocks, to a great Fatilt, ranging WNW and ESE, 

 which I have traced on the N^of Llangollen, passing just S of 

 the great Aqueduct at Pont-y-Cyssyllte and forwards into the 

 Coal-field. 



By this Fault, the measures on the S are very greatly thrown 

 up, and the denudated edge of the Limestone, in consequence, 

 i>ow apj)ears a mile more eastwai dly : from hence it sets off 

 again SW, with a SE dip, but has not proceeded more than 

 three-quarters of a mile, before another Fault, ranging nearly 

 parallel to the last, again throws the basset to the ^stward, into 

 lower gr(yund, where it is nearly covered by alluvia, and this new 

 range continues, on the W of Chirk-Ca>tle, to another great 

 Fault ranging nearly parallel to the former, on the S of Chirk - 

 Castle and the Town; by which the bassets are again thrown east- 

 ward : anew range of the Limestone then commences and passes 

 W of Selattyn and near Oswestry Race-ground, to Pentrecefn,. 

 where another large E and W Fault, throvvs up very greatly on its 

 S side, and moves the top of the Liuiestone E, to within half a 

 mile of Swinney Hall : from v/hich point it again ranges SSW 

 to Llanyniynech QuarricvS, on the south of which, a still larger 

 Fault than any of those above mentioned, ranges nearly NW and 

 SE, and probably passes forwards, on the S of the Wrekin Hill ?. 



As far as my late hasty view of this part of the Cotmtry would 

 enable me to judge^ the Llanymynech Fault seems to throw up 



greatly 



