W. JUDD ON THE SECONDARY ROCKS OE SCOTLAND. 



(35 









& 



({d) White Chalk converted into a siliceous rock, with flints, ft. 

 This rock abounds with fragments of Inoceramus and 

 (jlobigerma. It has yielded also Belemnitella mucro- 

 nata Schloth. sp., and some other fossils in a very im- 

 perfect condition 3 



(e) Bed of argillaceous limestone, with many irregularly 



shaped nodules and glauconite grains 1 to 2 



■This bed graduates down into 



(/) Argillaceous greensand,, 4 to 5 



(These beds represent the zone of BeiemniteUa m.u- 

 \ cronata.) 



((g) Coarse white sand, with a few green grains in the upper 



part 10 to 12 



(This bed probably represents, in a greatly diminished 

 condition, the lower of the two Cretaceous estuarine 



V series.) 



(h) Bed of Greensand, becoming calcareous in places and 

 crowded with Eccogyra conica, Sow., Pecten orbicularis, 

 Sow., and Vermicularia (several species), with other 

 common Cenomanian fossils 1 



(J) Greenish argillaceous sand 5? 



(Jc) Blue-lias shales and limestones crowded with the usual 

 fossils — Gryphaa arcuata, Lam., Unicardium cardioides, 

 Phil, sp., Lima pectinoides, Sow. sp., Cardinia Listeri, 



Sow. sp., Pentacrinus, sp., &c (5 



(Lower Lias.) 



(1) Variegated sands, marls, and concretionary limestone, 

 with beds of grit and conglomerate, lie at the base of 

 the series and rest on the old gneiss rocks, but are very 

 imperfectly seen at this point. 



The total thickness of strata lying between the basalt above and 

 the gneiss below in Beinn-y-Hattan is probably from 100 to 120 

 feet in thickness. 



As showing the variation in thickness and character of the beds 

 at short distances, I may cite another section taken at a point not 

 far removed from the last : — 



1. Basalt lava, scoriaceous at its base. ft. in. 



Bed of indurated reddish-brown volcanic ash 10 to 12 



(a) Thin coal-seam lto2 



(b) Underclay 6 in. to 1 



(c) White, highly siliceous chalk with flints 3 



(d) Sandy bed with glauconite grains and irregular con- 



cretionary nodules 3? 



(e) White coarse sand 15? 



Beneath the last bed the representatives of the Upper Greensand, 

 the Lower Lias, and the Poikilitic can be certainly made out ; but 

 the sections are too obscure to enable us to estimate the thickness 

 of the several beds. 



Another interesting section of the Secondary strata is found at 

 the south-east angle of Beinn-y-Hattan, where the succession of beds 

 is as follows : — 



Q. J. G. S. No. 135. 3 c 



