MORTE SLATES. 12/ 



Morte Slates. 



This division, termed the Morte Slates by the Rev. D. Williams, 

 derives its name from Morte Point, on the north-west coast of 

 Devon. The term Mortehoe Group, from the village of that name, 

 was used by John Phillips. 



The Morte Slates, or "grey slates," comprise pale greenish-grey 

 and silvery grey glossy slates, much veined with quartz, and having 

 a thickness estimated at from 3000 to 4000 feet. No fossils have 

 been found ; nor have any limestone bands been recognized in 

 them. The beds rest on the Ilfracombe Beds at Lee Bay, and the 

 Subdivisions which can be traced are noted by ]Mr. Etheridge (in 

 ascending order) as the Lee, Rockham Bay, and Mortehoe Beds. 

 The Morte Slates pass downwards into the Ilfracombe Beds, 

 and in Mr. Ussher's opinion they are simply an upper unfossili- 

 ferous portion of this lower division, since it is impossible to fix 

 any definite boundary between them.^ Simonsbath is situated in the 

 valley of the Barle between the Ilfracombe and Morte Beds. 

 Eastwards they extend to near Wiveliscombe, where they are 

 exposed at the Oakhampton Slate quarry, north of that town. The 

 slaty beds of Hestercombe, north of Taunton, are probably on the 

 horizon of the Morte Slates. The valuable spathose iron-ore of 

 the Brendon Hills occurs in these beds. 



UPPER DEVONIAN. 



Pickwell Down Sandstones. 



These beds, which derive their name from Pickwell Down on 

 the borders of Morte Bay, consist in the upper part of red or lilac 

 slates, resting on red, brown, purple, and green grits, and red 

 micaceous sandstones. They pass downwards, according to Mr. 

 Ussher, into the Morte Slates on Exmoor, by intercalation with 

 buff and greenish slates. The thickness of the Pickwell Down 

 Sandstones has been estimated at about 3000 feet. 



The beds extend from Pickwell Down and Woolacombe (Wolla- 

 combe Sandstone of the Rev. D. Williams), by Molland and Haddon 

 Downs, to Main Down, near Wiveliscombe. 



In many respects the beds resemble the Upper Old Red Sand- 

 stone. No fossils have been found in them. 



The upper part of the Pickwell Down Sandstones has been 

 distinguished by Mr. Etheridge under the name of the Vention 

 Series, from Vention, west of Pickwell, on Morte Bay. This 

 division consists of red slates. The name Upcot Flags was given 

 by Prof. Hull to the beds east of Upcot, north of Braunton. 



1 G. Mag 1879, p. 94. 



