Vol. 67.] THE CARBONIFEROUS SUCCESSION IN GOWER. 



505 



(4) Tabulated Synopses of the Sequence. 



Table I embodies the chief features of the developments in the 

 three districts of Gower, together with the thicknesses, which are 

 also shown graphically in fig. 4 (p. 506). In both table and figure 

 the Eastern District is placed between the two others because, as 

 will be seen, it has relations with both. The differences between the 

 different developments, of which more will be said later, might 

 not be regarded as of importance, were it not that each development 

 could be matched elsewhere in the South- Western Province. 



Table II embodies the features common to much or all of the 

 area, and may be regarded as typical of much of the South- Western 

 Province. 



Table II. 



-Synopsis of the Lithological Sequence in Gower as a whole 

 (generalized prom table i). 



Zone or Subzone. 



2. Chiefly dark non-calcareous shales 

 I. Radiolarian cherts. 



D. 



D 2 or D, 

 D 



' Black lias ' : — soft-weathering, argillaceous limestones with 

 shales and cherts. 



Limestones, including pseudobreccias. 



Chiefly pseudobreccias ; thin coal 2 or coals. 



s. 



c. 



s 9 



c 2 +s, 



c\ 



z. 



3Iodiola phase, characterized especially b} T ' pisolites.' 



Chiefly oolites. 



Limestones of various types. 



3fodicla phase, 3 characterized especially by abundant 

 calcite- and dolomite-mudstones. 



Caninia Oolite. 



Laminosa Dolomites (replacements of crinoidal lime- 

 stones). 



Crinoidal dolomites and limestones: cherts near the bas 



K. 4 



2. Grey shales with thin limestones; a thick oolitic lime- 

 stone, probably between K x & K 2 . 



1. Modiola phase, Km, characterized especially by lime- 

 stones of a type. 



Devonian. 



Upper Old Red Sand>tone. 



Note: — K is equivalent, probably exactly, to the Lower Limestone Shales; the 

 sequence, Z to D 2 inclusive, is termed ' Main Limestone ' by the Geological Survej r ; 

 D 2 _ 3 is termed Upper Limestone Shales; and P is included with the Millstone Grit. 



1 Not known in the North-Western District. 



2 Not known in the South-Western District. 



3 Not developed in the South-Western District. 



4 K is best known in the North-Western District, but there is no reason to believe 

 that the development is different elsewhere. 



