38 HAYDEN : GEOLOGY OF THE PROVINCES OF TSANG AND 0. 
are dark calcareous shales also containing crinoids^ : near the top 
of the shale a few imiDressions of ammonites were noticed. The 
shale is overlain by massive limestone, apparently unfossiliferous. 
None of the above fossils are determinable, and their horizon is 
consequently unknown; the crinoid limestone is very like that at 
Agang in the Phari plain {supra p. 26) and probably represents the 
same horizon. 
5. Between Khangma and Gyantse the sedimentary rocks are 
disturbed and altered by the intrusive granite 
Gyaotse. 
of Dzamtrang (more familiarly known to mem- 
bers of the late expedition as " Red Idol gorge and by many 
dykes of diabase. The latter are particularly numerous in the imme- 
diate neighbourhood of Gyantse, whilst a thin bed of amygdaloidal 
trap was also found interbedded with the slate in the hills to the 
NE. of the town. The shaly and calcareous beds have thus been 
altered into phyllite and calc-schist. This metamorphism has been 
accompanied by intense folding (see PI. 1 1, fig. i), and the absence of 
determinable fossils is only what might be expected. Among the 
hills to the east of Gyantse, metamorphism is less marked, and some 
imperfect fossils were found near the top of the 15,480 feet peak at 
about 6 miles to E.-SE. of Gyantse, in comparatively unaltered 
beds of shale and sandstone, which are separated by a fault from 
the calc-schists of the plain. The fossils include a fragment of a 
large specimen of Perisphinctes sp. and some badly preserved 
brachiopods and lamellibranchs. " Fucoid" remains were also found 
on th(; high ridge to the N.-NE. of the town. 
Fiom Gyantse on towards Shigatse the Jurassic slates and 
quartjites extend up to and beyond Penang dzong : they are full of 
basic intrusions, including diabase at Drongtse and serpentine at 
Nupuchondzo, a small village on the left bank of the river, about 8 
miles above Penang dzong. 
M am indebted to Captain R. Lloyd, I. M.S., for drawing my attention to 
the fossils in the shale. 
( '59 ) 
