188 Scientijic Intelligence — Geology and Mineralogy^ 



Esq., M.A., F.G.S. — In a memoir by Mr Jukes, he gives a short 

 abstract of all the information collected by various travellers regard- 

 ing the Australian continent, including his own observations. 



The eastern coast is occupied by a great range of high land, ap- 

 pearing like a continuous chain of mountains when seen from the sea, 

 and rising in several places to 5000 feet or more above the sea-level. 

 The chain has an axis of granite, with occasional large masses of 

 greenstone, basalt, and other igneous rocks. It is flanked on both 

 sides by thick beds of palseozoic formations, chiefly sandstone, but 

 also containing limestone and coal. In the northern portion of the 

 chain, Dr Leichardt found similar formations, and especially trap 

 and granite near the Burdekin river. In the Port-Philip district 

 there are similar igneous rocks, and on the coast tertiary formations, 

 which Mr Jukes found resting on the edges of upturned palaeozoic 

 beds. In West Australia, the Darling range consists of granite 

 below, covered by metamorphic rocks ; and between it and the sea 

 is a plain composed of tertiary beds. In the colony of North Aus- 

 tralia, there is a great sandstone plateau, rising about 18U0 feet above 

 the sea, and probably of palasozoic age ; whilst on the immediate shore, 

 and round the gulf of Carpentaria are beds supposed to belong to the 

 tertiary pei'iod. Similar formations constitute the substratum of the 

 central desert, in which Captain Sturt was compelled to turn when 

 halfway to the Gulf of Carpentaria, from the southern coast. Hence 

 Mr Jukes conjectures that these tertiary rocks are probably continuous 

 through the whole central region, and that, during the tertiary pe- 

 riod, all this portion of the country was submerged, whilst the high 

 lands on the coast rose like four groups of islands from a shallow sea. 

 In confirmation of this view, he remarked that a greater diflerence 

 existed between the plants and animals of New iSouth Wales and 

 Western Australia, though in the same latitude, than between those 

 at the southern and nox'thern extremities of the eastern chain of 

 mountains, distant 20° of latitude from each other. — (^Geological 

 Jouriial, No. 14, vol. iv., p. 142.) 



15. Present and Former Extent of the Island of Heligoland. By 

 M. Wiehel. — It appears (1.), that the well-known map of Heligoland 

 by Meyer, according to which the island once contained nine parishes, 

 is entirely a work of the imagination ; (2.) that, on comparing the map 

 made in the year 1793 by the Danish engineer, Wessel, of which, how- 

 ever, only a three-inch reduction remains, with the author's own mea- 

 surements, " the co-efficient of destruction in a century for the whole 

 circumference of the rock washed by the sea, does not on the average 

 amount to more than three feet ;" (3.), that, in the time of Adam 

 of Bremen (an extended description by whom is still in existence), 

 and of Charlemagne, the island was only a little larger than at pre- 

 gent. — {Geological Journal, vol. iv., No. 14.) 



