Y'S ISLAND, are of the same
materials as Groote Eylandt: and sandstone was found also on the western
shore of BLUE-MUD BAY.

On the shore of the mainland, opposite to Groote Eylandt, a little north
of latitude 14 degrees, Mr. Brown observed the common sandy calcareous
stone, projecting here and there in ragged fragments.

MORGAN'S ISLAND, in Blue-Mud Bay, north-west of Groote Eylandt, is
composed principally of clink-stone, sometimes indistinctly columnar. But
among the specimens are also a coarse conglomerate of a dull purplish
colour, including pebbles of granular quartz and a fragment of a slaty
rock like potstone: the hue and aspect of the compound being precisely
those of the oldest sandstones. Reddish quartzose sandstone, of uniform
and fine grain. A concretion of rounded quartz pebbles, cemented by
ferruginous matter, apparently of recent formation.

ROUND HILL, near Cape Grindall, a prominence east of north from Blue-Mud
Bay, was found by Captain Flinders to consist, at the upper part, of
sandstone. The specimens of the rocks in its vicinity are, dark grey
granite, somewhat approaching to gneiss, with a few specks of garnet; and
a calcareous, probably concretional stone, enclosing the remains of
shells, with cavities lined with crystals of calcareous spar.

MOUNT CALEDON, on the mainland, west of Caledon Bay, consists of grey
granite, with dark brown mica in small quantity; and on the sides and top
of the hill large loose blocks of that rock were observed, resting upon
other blocks.

A small island, near Cape Arnhem, is also composed of granite, in which
the felspar has a bluish hue.

Smaller of the MELVILLE ISLANDS, north-east of Melville Bay.* A
botryoidal mass of ferruginous oxide of manganese, approaching to
hematite; the fissures in some places occupied by carbonate of lime.

(*Footnote. The relative position of the islands and bays on this part of
the coast is represented in the enlarged Map.)

MELVILLE BAY. Granite, composed of grey and somewhat bluish felspar, dark
brown mica, and a little quartz; containing minute disseminated specks of
molybdena, and indistinct crystals of pale red garnet.

RED CLIFFS, south-west of Arnhem Bay; on the line of the first chain of
islands mentioned by Captain Flinders. (See the Map, figure 3.) Friable
conglomerate, of a full brick-red colour, consisting of minute grains of
quartz, with a large proportion of ochreous matter.

MALLISON'S ISLAND. (Map, figure 4.)