SON PLATEAU. 225 



ment of the Jurassic group. Here iu their first exposures the Jurassic 

 beds are thin^ faulted, and much concealed. South of Nanga (to 

 the west of Jalar lake) there is a considerable hill (beyond the broken 

 belt of disintegrating- nummulitic limestone) at the base of which 

 carboniferous limestone appears; and further up the triassic Ceratite 

 band, overlaid by a few sandy beds representing the Jurassic rocks, and 

 capped by nummulitic limestone with a southerly dip. 



These beds are cut off by a west-north-west fault bringing them 

 against the carboniferous limestone, here forming a wide hilly tract, 

 its beds dipping both to the north-east and south-west, and its chief 

 lines of hill and valley trending west-north-west. 



South-westward of this tract, and westward from Virgal, is a 



narrow elongated basin formed by a synclinal 

 Virgal. 



curve in the carboniferous limestones, but occupy- 

 ing high ground. Within it, the triassic beds, a few Jurassic layers, 

 and an outlier of the nummulitic limestone, lie, each surrounded by its 

 adjacent lower group, their outcrops forming escarpments on the north- 

 eastern side and south-eastern end of the basin, but being overtopped 

 by higher limestone hills in other directions. The north-east side of 

 the outlier presents the following succession according to Dr. Waagen : — 



Feet. 

 rCompact nummulitic limestone, over yellow nummulitic marl- 



'l stone ... ... ... ... ... .20 



Nummulitic ...^ Gray clays with very much gypsum, hard concretions with 



I fossils ... ... ... ... ... 12 



^Haematite ... ... ... ... ... 4 



f Variegated sands and sandstones ... ... ... 10 



T Brown sandy marls with Twrritella ... ... 5 to 6 



JUEASSIC ,..■{ •' 



I Soft red sandstone with greyish and greenish clays, pyritous 



L and gypseous ... ... ... ... 15 to 20 



f Grey limestone with numerous Bivalves ... ... 2 



Thin -bedded hard sandy limestone, no fossils ... ... 6 



I Ceratite sandstone, thin-bedded soft yellow sandstone with 



"' ' gypsum ; a JBeMero^7<o» bed in the upper region ... 50 



Green Ceratite marls ... ... ... ... 60 to 70 



l_ Thin-bedded limestone with CeraiiVe* ... .- 8 



e2 ( 225 ) 



