﻿52 ME. S. S. BUCKMAN ON CERTAIN [Feb. I9IO, 



3. Certain Jurassic (Lias-Oolite) Strata of South Dorset ; and 

 their Correlation. By S. S. Buckman, F.G.S. (Read November 

 3rd, 1909.) 



Contents. 



Page 

 I. Introduction 52 



(a) Bibliography. 



(b) Chronology. 



II. Description of the Strata 57 



(a) Chideock. 



(b) Burton Bradstock. 



III. Comparison of the Strata 7-t 



(a) Burton and Chideock. 



(b) Other South Dorset Sections. 



(c) Whaddon Hill (Stoke Knap). 



(d) South and North Dot-set. 



IV. Remarks on Hemeral Terms 7& 



Y. ~Pre~striatulus Toarcian 83 



(a) Dorset and Yorkshire Coasts compared. 



(b) Yorkshire and other Districts compared. 



(c) Migration of Areas of Maximum Deposit. 



VI. Summary 80 



I. Introduction. 



The object of the present communication is to show the develop- 

 ment and sequence of certain Jurassic strata on the Dorset coast, 

 and to make some comparisons with strata elsewhere. The range 

 of strata dealt with is from the top of the Middle Lias (Pliens- 

 bachian) to the lower part of the Fullers' Earth (Bathonian,. 

 Yesulian) inclusive. 



The communication is laid before the Society for several reasons: 

 it was promised many years ago ; it forms a sequence to the papers 

 on North Dorset and the Cotteswolds ; it aims to give a detailed 

 account of certain fossiliferous strata of South Dorset, to be used as- 

 a foundation for the dating of the fossils ; and it offers suggestions in 

 the matter of correlation and subdivision as a basis for the work of 

 other investigators. With this stratigraphical paper there is also 

 offered a palseontological paper, to describe some of the new species 

 mentioned, and to figure some other species which are new and 

 illustrative of strata of the same dates. That communication will 

 be alluded to as ' the palseontological paper.' 



The investigations for this paper, which will probably be my last, 

 so far as active field-geology is concerned, were complete in the 

 main several years ago ; it was announced in 1893 as nearly ready 

 for publication. Since then changes of residence have involved 



