Notices of Memoirs — Geology of Kimberley, W. Australia. 167 



inland to the Leopold Ranges, and between Port Usborne, and a line 

 running eastward to the south of the Fitzroy River (lat. 16° 35' and 

 18° 30' S., long. 122° 10' and 126° 50' E.), including in all 12,800 

 square miles. 



It may be generally described as a vast undulating plain, rising 

 gradually from the sea-coast to a height of 200 ft., broken by isolated 

 hills and some extensive mountain ranges, the highest reaching 

 2000 ft. above the sea-level. The district is unusually well watered, 

 The geological formations represented over this immense tract of 

 country consist of Recent accumulations, Pliocene sand and gravels, 

 Carboniferous sandstones, grits, and limestone, and Metamorphic 

 rocks. 



The Recent accumulations are — (a.) Wide sand-flats locally termed 

 " Marshes," along the sea-coast, and extending inland for miles, the 

 most striking iustance being the great plain from Roebuck Bay to 

 Barlee Spring. The contained fossils are of recent species. (6.) 

 Alluvium deposited by successive floodings of the rivers, estimated 

 as equal to 3355 square miles, or 2,147,200 acres. But taking into 

 consideration an average thickness of 30 ft., we have the "enormous 

 weight of 103,924,480,000 tons of silt and mud carried down by 

 these rivers" of the Kimberley District, (c.) River-gravels accu- 

 mulated in the upper reaches of many of the streams (notably in the 

 Usborne district), the pebbles often reaching six to nine inches in 

 diameter. These subdivisions comprise the " Recent " formations 

 described by Mr. Hardman. 



Certain deposits of reddish sand, with small pea-like nodules of 

 ironstone, and other rocks, with beds of red and yellow-ochreous 

 earth, are provisionally classed as Pliocene. They are termed the 

 " Pindan " sands and gravels, and occupy a very large area, and have 

 been proved to be at least 30ft. in thickness. They are unfossiliferous, 

 "but there can be little question that they are of comparatively 

 recent age." 



The Carboniferous rocks appear to be separable into an upper and 

 lower series. The upper consists of sandstones, and forms the chief 

 mountain ranges, extending as much as 190 miles into the interior, 

 and are over 1000 ft. in thickness. Lepidodendron, Calamites, and 

 Sigillaria are said to occur in these beds, but no traces of coal have 

 been met with. The apparently overlying Carboniferous Limestone 

 extends in a line N.W. and S.E. directly across the Kimberley district, 

 with a maximum breadth of thirty miles, and an estimated thick- 

 ness of 1000ft. "It is a light-coloured, compact, brittle, splintery, 

 more or less Magnesian Limestone," and bears a strong resemblance 

 to the Upper Carboniferous Limestone of Ireland. It is in places 

 very cavernous. Fossils were met with abundantly at certain 

 localities, and the list of species given by Mr. Hardman clearly bears 

 out the age assigned to the beds. 



The Metamorphic rocks are divided into two classes — the schistose, 

 including gneiss schist and metamorphic granite, and quartzites and 

 altered grits. The former are widely developed along the base of 

 the Leopold Range, and contain quartz veins, and the common garnet 



