Vol. 58. ] JURASSIC OF THE SOUTH WALES DIRECT LINE. gg 
39. On the Jurassic Strata cut through by the SoutH Watzs Direct 
Lins between Fitton and Woorrton Bassett. By Prof. Sipnry 
Hueu Reynoups, M.A., F.G.S., and Arraur Vauenan, Esq., 
B.A., B.Sc., F.G.8. (Read June 18th, 1902.) 
ConTENTs. 
‘ Page 
PARTIC ROC UCLIONN =a ew eM ee cen ere heh eater re Vhawe ss Shane Age (ue 
II. The Liassic Sections West of Sodbury Tunnel ..................0.. 719 
mies he Sodbury umm eles se cree. ccceteees oes vatieniie shee oa asian hela 729 
IV. The Great-Oolite Series Hast of Sodbury Tunnel .................. 742 
Weoethe Horest Marcbleand Cornbrashet slick -.2.0-.-c.dsssceevesonderne 747 
Nene Ene Oxtord ©layszandeC oralliaiis ceces ccvcobetscc5i.ssc0ss ag vadeiaom see 749 
Rome Summary and ComelistOns: 4.50... sect cek secs oeene ie csoeaneanateces 751 
1. IntrRopDUcTION. 
A paper like the following, dealing with a newly-exposed section, 
does not require any long introduction, and naturally the number 
of previous communications on the subject is limited. We know of 
only two, namely :—Mr. H. B. Woodward’s account in the ‘Summary 
of Progress of the Geological Survey for 1898,’ pp. 188-94, and the 
Rey. H. H. Winwood’s Report on the Excursion of the Geologists’ 
Association to the new Great Western Railway-line from Wootton 
Bassett to Filton, Proc. Geol. Assoc. vol. xvii (1901) p. 144.1 
Tl. Tue Lrasstc Sections West oF SopBury Tunne L. 
1. The Main Section. ’ 
(a) The White Lias. 
Resting directly upon a thin bed of typical Cotham Marble is 
a compact, cream-coloured limestone, about 1 foot thick; this 
bed forms a marked horizon, not only by reason of its peculiar 
texture, but also on account of the levelness of its surface. It 
represents the ‘ White Lias’ of the Somerset area and, in particular, 
the ‘ Sun-Bed’ of the Radstock district. 
(6) The Ostrea- and Torus-Beds. 
Immediately above the Sun-Bed is a series of limestones and 
subordinate shales, forming a total thickness of about 5 feet. 
Although no specimen of Psiloceras planorbis was found, the horizon 
of these beds is well marked zonally by Ammonites Johnston 
(= Amm. torus), which is not uncommon in the upper strata. The 
series is, however, chiefly characterized by Ostrea liassica and its 
1 We are much indebted to Mr. A. W. Manton, the agent for Messrs. 
Pearson, and to the contractors, for facilities in the examination of the 
specimens preserved in the office near the Cross Hands, Old Sodbury, and to 
Mr. C. E. Grierson, the engineer for the Great Western Railway, for the loan 
of a map of the line. 
