Notices of Memoirs — John Ounn — Rocks of Caithness. 31 



The main lines of fault and dip of the strata are also indicated. 



As an outline of the scientific results which were arrived at by the 

 members of the expedition, and which are represented on the map, 

 had already been communicated to the Association, 1 it was not con- 

 sidered necessary to repeat them here, but the author wisbed to add 

 that a topographical and geological map of the Arabah Valley on a 

 scale of about six miles to one inch was in preparation, and would 

 accompany the Geological Eeport now in the press for the Palestine 

 Exploration Society. The topographical survey had been made by 

 Major Kitchener, E.E., and Mr. John Armstrong (formerly sergeant- 

 major, E.E.), and the geological details had been inserted by the 

 author. In addition to these, several longitudinal geological sections 

 illustrating the structure of various parts of this region, and nume- 

 rous drawings would accompany the memoir. 



III. — On the Occurrence of Lower Old Eed Conglomerate in 

 the Promontory of the Fanad, North Donegal. 



By Professor Edward Hull, LL.D., F.E.S., F.G.S., 

 Director of the Geological Survey of Ireland. 



THE district in which the Old Eed Conglomerate occurs is formed 

 of ridges and valleys of metamorphic rocks, consisting of beds 

 of quartzite, schist, crystalline limestone, and trap, chiefly diorite. 

 It lies between Lough Swilly and Mulroy Bay, and is washed on 

 the north by the waters of the Atlantic. The remarkable tract of 

 the Old Eed Conglomerate, recently discovered by the officers of the 

 Geological Survey, is far remote from any mass of the same formation, 

 and it is unrepresented on any geological map hitherto published. 



The beds consist of red and purple sandstones and conglomerates, 

 made up chiefly of quartzite pebbles and blocks, but also containing 

 others of limestone and trap ; all derived from the surrounding 

 metamorphic series. They occupy an area of over two miles in 

 length and half a mile across, extending along the northern base of 

 Knock Alia, a ridge of quartzite which traverses the promontory 

 from side to side. The beds dip against the base of the mountain, 

 against which they are let down by a large fault, and they terminate 

 along their northern edge by an unconformable superposition on 

 beds of quartzite and limestone. They reach a total thickness of 

 about 800 feet. 



From the position of these beds it becomes evident that they are 

 unconnected with any of the recognized basins of Lower Old Eed 

 Sandstone, either in Scotland or Ireland, and may, therefore, be re- 

 garded as having been formed in an isolated basin, which, following 

 the example of Dr. Geikie, I may be allowed to name " Lake Fanad." 

 The tract will be a new feature on geological maps of Ireland. 



IY. — On Eocks of Central Caithness. 

 By John Gunn. 



THE term " Central Caithness " is intended to embrace most of the 

 parish of Halkirk and part of the parish of Watten. The 

 1 Bep. Brit. Assoc. (Montreal Meeting, 1884), Transactions of Sections C and E. 



