Rej)orU and Proceedings — Mineralogical Society. 285 



Tertiary Sj'stem in particular. The classification of rocks arrived at 

 is shown in the following table : — 



Feet. 

 Irawadi Series 20,000 (?) Pliocene. 



Arakan Series ( J^^^^^'.^'^P HJJ ?°'''''- 



( Basseiu Group 8,000 Eocene. 



!( Cardita 'BeAs Cretaceous. 



Upper -EfafoSia Limestone Triassic. 



[ Shales and grits (?) 



Lower. Flaggy shales and sandstones (?) 



The oldest rocks, not comprised in the above synopsis, include- 

 representatives of the Silurian, Devonian, and Carboniferous Systems, 

 but little of their detailed geology is known. The Cardita Beds may 

 be correlated with the Cretaceous of India. The ' Chin Shales ' of 

 Dr. Noetling seem to form part of the Bassein Group, of Eocene age, 

 which, is of much, greater thickness than hitherto supposed, and the 

 group rests presumably more or less conformably on the beds below. 

 The fauna is chiefly shallow marine in facies. These rocks flank the 

 Arakan Group on both sides, and in the south form the backbone of the 

 range, where they have been considerably metamorphosed. The I'egu 

 Group probably overlaps the preceding, and is regarded as of Miocene 

 age, although the fauna has many relationships with that of the- 

 French Eocene. Lucina glohulosa is described as the first European 

 Miocene species recorded from Burma. Estuarine conditions came on 

 towards the close of Miocene time, and, in the estuary of the Pliocene 

 precursor of the Irawadi, anticlinal islands of partly consolidated 

 Miocene materials were formed. Around and eventually over these 

 islands a great thickness of fluviatile deposits was laid down, corre- 

 sponding to the Siwalik Beds of the Indian Peninsula. Finally, post-. 

 Pliocene denudation and upheaval revealed the Miocene islands as 

 inliers, while the Irawadi has left its gravels in patches throughout 

 the region. A list of fossils is given, and the species new to Burma, 

 some of them new to science, are described. 



II, — Mineralogical Society. 

 March 17th, 1908.— Prof. H. A. Miers, F.E.S., President, in the Chair. 



(1) On the occurrence of metamorphic minerals in calcareous rocks 

 in the Bodmin and Canielford areas ; by G. Barrow and H. H. Thomas. 

 The pneumatolytic action is not contemporaneous with the thermo- 

 metamorphism produced by granite intrusions ; the gaseous intrusions 

 are later, and often produce their greatest effect beyond the zone of 

 ' contact- action.' The species of mineral produced depends on the 

 nature of the rock penetrated by the gases. In killas, tourmaline is 

 commonly produced ; but in calcareous rocks, axinite and a variety of 

 other minerals result from the pneumatolysis. In the Bodmin area 

 the minerals formed by pneumatolytic action in the calc-flintas are 

 axinite, hedenbergite, epidote, yellow garnet, actinolite, and another 

 amphibole occurring in minute dark-brown needles. In the Camelford 

 area the minerals are mainly due to contact metamorphism. The most 

 conspicuous are yellow garnet, epidote, and idocrase, a mineral which. 



