54 HAYDEN : GEOLOGY OF THE PROVINCES OF TSANG AND 0. 
The Operculina limestone is overlain by a bed, about 150 feet 
thick, of fine-grained greenish, grey and black shale, full of small 
nodular masses of marcasite. It is exposed on the right bank of the 
Kampa stream, at about one mile above the fort, where it is to some 
extent fossiliferous 
The fossils which are poorly preserved and still await deter- 
, . . mination, include chiefly lamellibranchs aiid 
Spondylus shaies. ^ 
gastropods; of the former Spondylus is the 
commonest genus, and is the predominant fossil of the shales, which 
may therefore be conveniently termed the " Spondylus shales:" other 
genera present are Ostrea, Chama and Cardium. 
The gastropods are represented chiefly by Velates schmideltana, 
which extends up from the underlying limestone. 
One echinoid (? Cyphosonia sp.)^ was found, but is too fragmen- 
tary to admit of specific determination. 
Foraminifera, apparently similar to those of the Operculina lime- 
stone, are found in calcareous bands in the shale. 
The Spondylus shales are overlain by a limestone band about 50 
feet thick, the lower layers of which are argil- 
Orbiloliles limestone. . . 
laceous and contain large specimens of Orbi- 
tolites sp. Higher up the limestone has yielded also AlveoHna. 
Under the microscope the rock is found to be composed largely of 
Orbitolites sp. with Alveolina and Miliolina {Quinqueloculina). 
Above this limestone is a bed of sandy micaceous shale with thin 
sandstone flags. The maximum thickness seen 
Sandy shale. 
is about 150 feet. Here the upper beds end, 
being cut off abruptly by an important strike fault which throws them 
beneath older Tertiary horizons (see PI. 3, fig. 2). The shales are to 
some extent fossiliferous, conta'ning lamellibranchs {Solen sp.) in the 
lower layers and lamellibranchs and gastropods in a calcareous band 
about 80 feet above the base. 
The description of the auove sequence., from the Operculina 
! am iiidebted for this determination to my colleague, Mr. E. Vredenburg. 
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