210 Bibliographical Notices. 



BIBLIOGRAPHICAL NOTICES. 



A Sketch of the Physical Structure of Australia. By J. Beete 

 Jukes, M.A., F.G.S. London : J. & W. Boone. 



The author of this work, who accompanied as naturahst the explo- 

 ring expedition of H. M. S. Fly, visited, during the voyage, consider- 

 able portions of the coasts of Australia for the purpose of geological 

 investigation, and communicated an abstract of his researches to the 

 British Association in 1846, and to the Geological Society in 1847. 

 Subsequently availing himself of the various facts bearing on the 

 subject collected during the laborious investigations of previous ex- 

 plorers, and to whom full credit is here given, Mr. Jukes has by his 

 own personal examination been better enabled to study and under- 

 stand the diiFerent published accounts of others, and by connecting 

 the various observations together, having himself obtained a tolerably 

 distinct notion of the structure of this region, has endeavoured to 

 convey to the reader a general resume of what is at present known 

 respecting the geology and physical structure of Australia. 



Considering the vast amount of still unexplored country, it might 

 appear at first sight difficult to form any general conclusions as to 

 the peculiar structure of the interior ; but this is to some extent ob- 

 viated by the great uniformity and monotony of those portions 

 hitherto examined. 



The geology of xlustralia (at present known) is somewhat remark- 

 able ; the principal mountain chains consisting chiefly of granitic and 

 metamorphic rocks overlaid by a jjaltEOzoic formation with which are 

 associated masses of porphyry, greenstone and basalt, frequently dis- 

 locating and altering portions of it : tertiary beds occupy considerable 

 areas in the plains, as well as cover the hills to a certain height above 

 the sea ; and with these are associated still more recent igneous rocks. 

 Deposits belonging to the secondary period {i. e. oolitic and creta- 

 ceous), which form so prominent a feature in the geology of portions 

 of the northern hemisphere, have not yet been detected in Australia. 

 " This circumstance inclines us to believe that the country may, 

 most probably, have existed as dry land during the oolitic and cre- 

 taceous periods ; if so, is it not possible that its present fauna and 

 flora may be in some way the descendants and representatives of the 

 fauna and flora that in the oolitic period were common to the whole 

 earth ?" Other points of equal interest are treated of in this volume, 

 such as the peculiar character of the fossil vegetation associated with 

 the Australian coal, as distinguished from that occurring in the car- 

 boniferous deposits of the northern hemisphere. This is a curious 

 fact, inasmuch as, if both deposits are nearly synchronous, (and we 

 quite agree with the author in referring the former to the palaeozoic 

 sera) Australia presents us at this early period with the antitype of a 

 flora which became the characteristic one of the northern hemisphere 

 during the secondary epoch : as, however, no deposits belonging to 

 the latter occur throughout this vast continent, and inferentially no 

 submergence of a large portion of the ancient land, until some part 



