j)art 2 i.rMKSTONi: OF I in: [.kickmikhshiuk coai-fiki,!). S7 



is \V(>rk('«l ill (tiic or two small (juarrics in tlic \ iciiiitv of Mi'lltounir. 

 Tilt' Sliak's, wliii'li may W looked u|)<)n as lioiiiotaxial with tin- 

 J'tMulK'sidi- MimIs, ari' always sandy tor a tVw t'l'ct hefoiv they liiially 

 iifivi* piai'c to th«' true Millstoiu* (Jrit. 'riu'ir tliii-kness in tin* area 

 is very small compared with that of tlu* l\'ndleside Hvds in other 

 (listriets, a maximum of ahout ii') feet oecurrinu: in the western 

 inlier of Tieknall ; while farther east at IJreedon CMoud, thes»* 

 shales are prohahlv even thinner, and the horin;^^ at Ton^e passed 

 through no hi-ds that can he referred to this formation. Thus, 

 Ijotli the Millstone (Irit and the Shales rai)idly heeome attenu- 

 ated in an easterly direction. 'I'lie ('arl)oniferous Limestone of 

 the area lias a total thickness of ahout IKK) feet, of which some 

 SoO feet are seen at lireedon-on-the-HiH, tlie remainiui? small 

 thickness oecurrini,' at Tieknall, where the l)eds carry ujiWiirds the 

 Hreedon se<|uence. The hase of the t'arhoniferous Limestone is 

 not seen anywhere in the area, althoui^'h a horin^j^ at Dt'sford in the 

 Whitwick district (1> miles south-east of the Thrin«^stone Fault) has 

 shown that ahout '20 feet of limestone there rests on prc-Cand)rian 

 rocks, a description of which has hcen ju^iven hy Prof. \V. \V. Watts 

 in the (ieoloi^ical Survey Meinoii- on the Leicestershire cV; South 

 Dorhyshire Coalrteld. 



The features of the Ka>tcni and Western series of inlicrs may 

 l)e summarized as follows: — 



The Western Series, includiiii; Tieknall, Calkc Park, and 

 J>imminsdale, consist of earthy, dolomitic, and for the most part 

 highly fossiliferous limestones, exposed along valleys and hollows 

 hy stream-erosion which has removed almost horizontal Iwds of 

 Trias and Millstone (Irit, showing a small thickness of limestone 

 ami * Peiidleside ' Shales. 



The Eastern Scn'ies of inlicrs, including Hrced(»n-on-thc Hill, 

 ih'ecdon Cloud, Harrow Hill, ()sgatlior))e, and (xniee Dicu. are 

 expo.sed hy carth-movi'meiit which has tilted the Carhoniferous 

 Limestone along the Hreedon Fault. The material itself is of a 

 highly dolomitic nature and iM)orly fossiliferous. * IN'iidleside ' 

 Shales are onlv onc»' seen, and the Millstone (Irit i> iievei- \i>i1)le. 



111. TiiK Wk.stkhn I\r,lKHS. 



In addition to their mode of exposure an<l the almost horizontal 

 \\r of the heds aln-ady notitl, the strata exiMjscd at Tieknall. C'alke, 

 and Dinuninsdale have certain eharaeteis in cttnimon. In all cases 

 fossiliferous and dolomitic limestones relatively ]>oor in magnesia, 

 and sejtarati'd hy thin shaly heds, pass uj)wards into yellow and 

 Li'rey d(domit«'s having a |u'recntage of magnesia apjiroximatini; to 

 that of theoretical dolomite. The lower imjuire and less dolomitic 

 limestones yield an ahundant fauna characteristic of a high horizon 

 in the l)ihun(>itlij/llit III Zone, 'i'he *lolomites whiidi rest on them 

 ti-rminate the ('arl)onifcrous Limestone, and the Shales ahov«' are 

 succcedt'd conformahly hy Millstone (irit. 



The strike of the strata is ap]»roximately north and south ; hut 

 till' dip altera: in am<>nnt :n>d din.-tion, owing to t)«.. ...•.•i|ii-.n< f 



