22 G ANNUAL OF SCIENTIFIC DISCOVERT. 



relatively in Australian geology, and that the strata (so ably 

 mapped by the surveyors) which are above the carbonaceous 

 sandstones should be called Cainozoic. The term Lower Cainozoic 

 would refer to all the deposits beneath the Mount-Gambler series, 

 the Middle to the deposit, and the Upper to all above/ 



" At present all that can be arrived at concerning 1 the relative 

 position of the Australian fossiliferous tertiaries and their physical 

 geology may be quickly summed up. They formed on a sea- 

 bottom of the oldest rocks, in increasingly deep water, during a 

 period when the denudation of the neighboring coast line to the 

 east and north-east was rapid. They were very distant from the 

 reef-area of the period; and the physical conditions of such an 

 area were never present during the deposition of the madrepo- 

 raria, polyzoa, eehinodermata and mollusca, which have a facies 

 characteristic of all the European marine tertiary deposits above 

 the Nummulitic. They were subjected to frequent volcanic 

 outbursts, which covered large areas with basalt and ash, and 

 they were covered, after the general upheaval of the centre of 

 Australia, with lacustrine, dune, river, and torrent deposits, whose 

 depth testifies to the enormous denudation of the older rocks. 

 The condition of the high land on the extreme east and west of 

 Australia was probably that of dry land during the whole Caino- 

 zoic period, and these districts bounded the tertiary sea." 

 Quar. Jour. Geol. &oc. t xxvi. (1870), 313. 



ABYSSINIAN GEOLOGY. 



From the report of Mr. W. T. Blanford, late geologist to the 

 Abyssinian expedition (1867-68), we learn that the formations met 

 with throughout the region traversed were : 1. Recent, consist- 

 ing of soils of the highlands, including regur, or cotton soil, 

 similar to that found in India, and alluvial deposits on the coast. 

 2. The volcanic series which skirt both coasts in the southern 

 portion of the Red Sea. This group, which is but poorly developed 

 on the west coast of Annesley Bay, Mr. Blanford proposes to call 

 the Aden Volcanic Lines. 3. Trappean. series. This grand col- 

 lection of beds, which forms the Abyssinian highlands, including 

 Magdala and the Ashangi groups, consists of two divisions, 

 which are unconformable to each other, the former (the Magdala 

 group) consisting of trachytes and dolerites, and the latter 

 (the Ashangi group), entirely composed of dolerites of great 

 thickness and bedded volcanic rocks, lavas, and ashes. Through 

 this Ircqipean series near Bethor, not far from Magdala itself, the 

 Jitta river has cut its way, and now runs at a depth of 3,500 feet, 

 in a valley probably more than a mile in width. The sides are 

 extremely steep, often perpendicular. The beds on both sides 

 appear exactly to correspond. A well-marked river-terrace half 

 way down, indicated on both sides of the stream, records the 

 fluviatilc origin of the gorge. " Of all the grand scenery," says 

 Mr. Blanford, " met with in Abyssinia, none equalled this won- 

 derful gorge." His descriptions remind one of the Grand Canons 



