522 Revie^vs — Geological Survey — Sitmmary of Progress. 



f^jninitoid gneiss usually appear as hornblende-schist dykes, ti'aceable 

 for short distances, and tolded with tlie main mass of the rock. Bast 

 and west of the main outcrop of flaky gneiss, but folded with it, are 

 masses of quartzose gneiss belonging probably to the Moine-schist 

 series, but placed in this group on account of the presence of horn- 

 blende-schist dykes. In many parts the rock is indistinguishable 

 from the typical quartzose Moine-schist, whilst in others the 

 occurrence of thin felspathic folia and ' eyes ' associates it with the 

 Acid gneiss." Apparently the grouping of these rocks is made to 

 depend on the presence or absence of hornblende-schist dykes. We 

 would like to know more of these hornblende-schist dykes. Are 

 they of the same age as the Scourie dykes, or what is their age ? 



Under the term " Dalradian or younger schists of the Highlands" 

 are included the rocks of the Central Highlands. The heading 

 suggests that these rocks are newer than those last described. We 

 should like to know the evidence of these being "' newer gneisses." 

 Has any evidence on this point been published ? And if so, where? 



Mr. Barrow draws attention to the identity in structure and 

 appearance of the rocks of the Braemar area with the Moines 

 described above by Mr. Peach and Mr. Home, and he traces their 

 connection with the quartzite and limestone series of the Central 

 Highlands. Mr. Cunningham Craig also describes a series of rocks 

 closely resembling the quartzose phase of the Moine schists or 

 gneisses, and he too connects these with the quartzite and limestone 

 series. 



In the notes on the " younger granites of the Grampian Hills," 

 the large masses of the Central Grampians and the smaller intrusions 

 of much the same age, are described in detail by Messrs. Barrow, 

 Cunningham Craig, and Hinxtnan. Messrs. Hinxman and Craig 

 give evidence showing the thermo-metamorphism produced by these 

 granites. 



Leaving the Dalradian schists we come to accounts of fossils from 

 the Cambrian rocks of Skye. and to records of fossiliferous Silurian 

 rocks in Ireland. Another new genus and species of fossil fish from 

 the Upper Silurian rocks of Lesmahagow, Ateleaspis tessellata, is 

 named by Dr. Traquair. Several good specimens of a new species 

 of JEarypterus of the type of E. scorpoides, Woodw., were collected 

 from the Downtonian rocks of Ayrshire and Lanarkshire. In 

 Caithness, Ross-shire, and the Lome much new information was 

 obtained regarding the Old Red Sandstone, while the granites of 

 Ben Cruachan and Glen Etive and the eifects of contact meta- 

 uiorphism were attentively studied by Mr. Kynaston, aided by 

 Mr. Teali. To the latter we owe the discovery of corundum among 

 the cordierite-bearing rocks of the contact zone round the Ben 

 Cruachan granite. 



The resurvey of the South Wales Coalfield and bordering rocks 

 has been vigorously pursued by Mr. Strahan, Mr. Tiddeman, and 

 Mr. Cantrill, and much new information has been gathered with 

 reference to the structure of the Vale of Neath and of the superficial 

 coverings of Glacial Drift. lu Devonshire and Cornwall, Mr. Ussher, 



