378 



W. A. E. USSHER ON THE TRIASSIC 



the other divisions, and the distinction between natural and faulted 

 boundary-lines became apparent. 



In the correlation of the divisions displayed in the south- coast 

 section with those inland, we should hardly expect to find the same 

 identical lithological characters or identification tests throughout. N or 

 is this the case ; for, with the exception of two divisions, both marls, 

 we find considerable local variations, distinct derivation, and in the 

 members of the lowest division, much horizontal change or replace- 

 ment. 



The subjoined is a rough table of the Triassic beds in four distinct 

 and typical localities, between "Watchet and the south coast of Devon*. 



Coast Section. 



BuELESCOMBE. 



MlLYEETOX. 



WlLEITOX. 



1. (Upper) red variegated 

 marls, veins of gypsum, 

 calcareous in upper and 

 middle beds, loumy and 

 sometimes passing into 

 rock-sand in bottom beds. 



Ditto, but no gypsum 

 observable. 



Ditto. Brickpits in 

 marls at Taunton, 

 and in marl bottom 

 beds at Wellington. 



Ditto. Brickpit at 

 Blue Anchor; gyp- 

 sum veins on coast. 



(Upper) red sandstones 

 and rock-sand, in places 

 with calcareous nodules, 

 mottled greyish, and con- 

 taining bands and poc- 

 kets of red clay ; sligntly 

 conglomeratic at about 50 

 feet from bottom. 



Red rock-sand, some- 

 times buff and grey, 

 and occasionally con- 

 taining seams of 

 clay. 



Eed rock-sand and 

 sandstone with cal- 

 careous nodules in 

 places, and grey 

 mottling in streaks 

 and spots. 



Eed, buff, and grey 

 rock-sand and sand- 

 stones ; between Bi- 

 shop's Lydeard and 

 Williton very cal- 

 careous, almost a 

 marl-stone in places. 



3. Pebble-beds of Budleigh 

 Salterton, large ellipsoidal 

 pebbles, mostly quartzite 

 (foreign derivation) in red- 

 sand matrix, with im per- 

 sistent beds and bands of 

 rock-sand. 



Small quartz pebbles 

 in red- sand matrix, 

 occasional impersis- 

 tent strips of sand, 

 sometimes compac- 

 ted,with grit pebbles 

 locally predominant 



Conglomerate of limestone ^grit and quartz 

 pebbles, in hard sandstone matrix, often 

 thick-bedded. Near Whiteball-Hill tunnel, 

 north of Burlescombe, seems to be passing 

 into pebble-beds. 



Eed variegated marls 

 slightly calcareous above, 

 loamy below, and contain- 

 ing beds of sandstone often 

 impersistent. Brickpits in 

 soil at Exmouth. 



Ditto; structure not 

 observable, owing to 

 a thick loamy clay 

 soil, in Avhich are 

 brickpits. 



Ditto, much faulted; 

 whole thickness not 

 shown by the out- 

 crop. 



Ditto. 



5. Faulted against 4. Brec- 

 cias of angular stones in red 

 rock- sand, as at Exmouth 

 and Dawlish ; with inter- 

 calated rock - sands near 

 the latter, and underlying 

 rock-sands at Dawlish. 

 Hard thick-bedded (com- 

 pare Heavitree) breccias 

 of Teignmouth, breccias, 

 breccio-conglomerates.and 

 variegated sands of Tor- 

 quay and Paignton. (At 

 Exeter brecciated loamy 

 clay with beds of Sand- 

 stone.) 



Either faulted out or 

 concealed by 4. In 

 places a little breccia 

 of shale fragments 

 in sand and dark- 

 coloured sandstones. 

 At Tiverton breccia 

 and breccio-conglo- 

 merate, hard -rock- 

 sand, shale breccia 

 in sand. At Brad- 

 ninch gravelly brec- 

 cia of gritstones with 

 intercalated beds of 

 red rock-sand. Gra- 

 vels near Tiverton,&c . 



Eedand blackish rock- 

 sand,in places slight- 

 ly brecciated in lines 

 of false - bedding. 

 Near Wiveliscombe 

 hard breccia, some- 

 times slightly con- 

 glomeratic, and red 

 sandstones, red and 

 blackish'rock-sands. 



Breccia of angular 

 fragments in red 

 sand ; hard breccias ; 

 red and blackish 

 rock-sand and sand- 

 stone, occasionally 

 slightly calcareous. 

 Breccias of shale 

 fragments in sand 

 and loam. 



* The relations of the divisions in the coast section, Burlescombe district, 

 and the Williton neighbourhood are shown in figs. 1, 2, and 3 respectively, the 

 sections accompanying this paper. The similarity of the Milverton and Wil- 

 liton districts renders a section illustrative of the former unnecessary. 



