DETAILED LIST OF SPECIMENS.
The specimens mentioned in the following list have been compared with some of those of England and other countries, principally in the cabinets of the Geological Society, and of Mr. Greenough; and with a collection from part of the confines of the primitive tracts of England and North Wales, formed by Mr. Arthur Aikin, and now in his own possession. Captain King's collection has been presented to the Geological Society; and duplicates of Mr. Brown's specimens are deposited in the British Museum.
RODD'S BAY, on the East Coast, discovered by Captain King, about sixty miles south of Cape Capricorn.* Reddish sandstone, of moderately-fine grain, resembling that which in England occurs in the coal formation, and beneath it (mill-stone grit). A sienitic compound, consisting of a large proportion of reddish felspar, with specks of a green substance, probably mica; resembling a rock from Shap in Cumberland.
(*Footnote. In Captain King's collection are also specimens found on the beach at Port Macquarie, and in the bed of the Hastings River, of common serpentine, and of botryoidal magnesite, from veins in serpentine. The magnesite agrees nearly with that of Baudissero, in Piedmont. (See Cleaveland's Mineralogy 1st edition page 345.)
CAPE CLINTON, between Rodd's Bay and the Percy Islands. Porphyritic conglomerate, with a base of decomposed felspar, enclosing grains of quartz and common felspar, and some fragments of what appears to be compact epidote; very nearly resembling specimens from the trap rocks* of the Wrekin and Breeden Hills in Shropshire. Reddish and yellowish sandy clay, coloured by oxide of iron, and used as pigments by the natives.
(*Footnote. By the terms Trap, and Trap-formation, which I am aware are extremely vague, I intend merely to signify a class of rocks, including several members, which differ from each other considerably in mineralogical character, but agree in some of their principal geological relations; and the origin of which very numerous phenomena concur in referring to some modification of volcanic agency. The term Greenstone also is of very loose application, and includes rocks that exhibit a wide range of characters; the predominant colour being some shade of green, the structure more or less crystalline, and the chief ingredients supposed to be hornblende and felspar, but the components, if they could be accurately determined, probably more numerous and varied, than systematic lists imply.)
PERCY ISLANDS, about one hundred and forty miles north of Cape Capricorn. Compact felspar of a flesh-red hue, enclosing a few small crystals of reddish felspar and of quartz. This specimen is marked "general character of the rocks at Percy Island," and very much resembles the compact felspar of the Pentland Hills near Edinburgh, and of Saxony. Coarse porphyritic conglomerate, of a reddish hue. Serpentine. A trap-like compound, with somewhat the aspect of serpentine, but yielding with difficulty to the knife. This specimen has, at first sight, the appearance of a conglomerate, made up of portions of different hues, purplish, brown, and green; but the coloured parts are not otherwise distinguishable in the fracture: It very strongly resembles a rock which occurs in the trap-formation, near Lyd-Hole, at Pont-y-Pool, in Shropshire. Slaty clay, with particles of mica, like that which frequently occurs immediately beneath beds of coal.
REPULSE ISLAND, in Repulse Bay, about one hundred and twenty miles north-west of the Percy Islands. Indistinct specimens, apparently consisting of decomposed compact felspar. A compound of quartz, mica, and felspar, having the appearance of re-composed granite.
CAPE CLEVELAND, about one hundred and twenty miles north of Repulse Island. Yellowish-grey granite, with brown mica; "from the summit of the hill." Reddish granite, of very fine grain; with the aspect of sandstone. Dark grey porphyritic hornstone, approaching to compact felspar, with imbedded crystals of felspar.
CAPE GRAFTON, about one hundred and eighty miles west of north from Cape Cleveland. Close-grained grey and yellowish-grey granite, with brown mica. A reddish granitic stone, composed of quartz, felspar, and tourmaline.