}<art 2J rAKi{()NiFKUuLs limkstune of s. walks coalfikld. Ill 



G. Tfui CAHm>MFEH()rs Li.MKsroNK Sehies on the Sotrii- 

 Eastekn Maim; in of fhc Sourii Wales Coalfield. By 

 Frank 1)i\kv, M.Si-., F.O.S., and IVof. Thomas Franklin 

 SiiJLV, I). Si.-., F.ii.S., rnivt-r.-ity C'ollei^e of South Wak's A 

 >rouinouth.sliiiv, Canliff. (Head March 2.Sth, 1917.) 



Plates XII XVI.] 



COXTEN'TS. 



Page 



I. lutroauction Ill 



II. Structure aiul Physical Featiiivs of the Outcn ip 114 



III. Note on the Dolomitization 110 



IV. General Account <jf the Snccesjsion ami its Lateral 



Variation 117 



V. Detailed Description of the Succession 124 



(A) Lower Limestone Shales. 



(B) Main Limestone. 



VI. Summary ami Conclusi(ms 157 



I. Inthodlction. 



The outcrop ot' C'arhonlFcrous Liincstoiic which is tlic subject of 

 tliis couununication extends from tlie valley of the Ewenny Kiver 

 al>out 8 miles east t>f Hrids^end ((xlaniori^an) to the valley of the 

 Fhiiw River at Kisca (Monmoutli), a distance of about IJ) miles 

 fi*om west-south-west to east-north-east.^ It lies on the south- 

 eastern marij^in of the Soutli Wales coal-l)asin, and l)elongs in its 

 western |M)i-tion to tlic northern limb of tlie CardifP-Cowbridije 

 inticline (see ma]), Hi^. 1, \i. 112). 



Tlie area witliin wliich this outcro]) is eom])ri.sed was ma|>pe<l l>y 

 tlie otHcers of H..M. (leoloicu.al Survey (Dr. A. Strahan, Mr. H. H. 

 Tiddemaii, and .Mr. '!'. ('. Cantrill), in the course of the re-survey 

 of the Soutli Wales Coallield. aiul the results were emlxxlied in 

 the otlieial ma|)s and memoirs.' Tlie present ])a|)er supplements the 

 dest-riptioii of the Carboniferous Limestone Series ;jfiven in those 

 ]iul)Heations, in the liijht of reet'iit researches on the Carboniferous 

 rocks of this country and MelLrium by the late l>r. .\. ^'auLJ:han 

 and others. 



* Ah ropards the tiold-\V(trk upon which this paper Ih based, all that p«»rtion 

 ■»f the outcrop whirh lies west uf the river Taff has been investipitod by 

 Mr. l>ixey. and the i»ortion ea>t of the Taff by Prof. Sibly. In the absence 

 of Mr. Dixey on military service, the whole paper has been written bv Prof. 

 Sibly. 



■^ Newport sheet (N.S. 1-inch map 24J)) and 'The Country around New- 

 port" ISOO, 2nd ed. ll»o;); Canliff sheet (N.S. 1-inch map '2t;a) and 'The 

 Country around Cardiff' li»ii2. 2nil ed. 1012; Bridjrend sheet (N.S. 1-inch 

 map 2<'>1 \- 2(»2) and 'The Country around Bridgend' IJH>4. These Memoirs 

 will be referred to as the 'Newport Memoir,' the * Canliff Memoir.' and the 

 • lirid^-eiid Memoir,' respei'tively. 



