Gulf of Carpentaria, is so low,
that for a space of nearly six hundred miles--from Endeavour Strait to a
range of hills on the mainland, west of Wellesley Islands, at the bottom
of the gulf--no part of the coast is higher than a ship's masthead.* Some
of the land in Wellesley islands is higher than the main; but the largest
island is, probably, not more than one hundred and fifty feet in
height;** and low-wooded hills occur on the mainland, from thence to Sir
Edward Pellew's group. The rock observed on the shore at Coen River, the
only point on the eastern side of the Gulf where Captain Flinders landed,
was calcareous sandstone of recent concretional formation.

(*Footnote. Flinders Charts Plate 14.)

(**Footnote. Flinders Volume 2 page 158.)

In Sweer's Island, one of Wellesley's Isles, a hill of about fifty or
sixty feet in height was covered with a sandy calcareous stone, having
the appearance of concretions rising irregularly about a foot above the
general surface, without any distinct ramifications. The specimens from
this place have evidently the structure of stalactites, which seem to
have been formed in sand; and the reddish carbonate of lime, by which the
sand has been agglutinated, is of the same character with that of the
west coast, where a similar concreted limestone occurs in great
abundance.

The western shore of the Gulf of Carpentaria is somewhat higher, and from
Limmen's Bight to the latitude of Groote Eylandt, is lined by a range of
low hills. On the north of the latter place, the coast becomes irregular
and broken; the base of the country apparently consisting of primitive
rocks, and the upper part of the hills of a reddish sandstone; some of
the specimens of which are identical with that which occurs at Goulburn
and Sims Islands on the north coast, and is very widely distributed on
the north-west. The shore at the bottom of Melville Bay is stated by
Captain Flinders to consist of low cliffs of pipe-clay, for a space of
about eight miles in extent from east to west; and similar cliffs of
pipe-clay are described as occurring at Goulburn Islands (see the plate,
volume 1) and at Lethbridge Bay, on the north of Melville Island: both of
which places are considerably to the west of the Gulf of Carpentaria.

Morgan's Island, a small islet in Blue-Mud Bay, on the north-west of
Groote Eylandt, is composed of clink-stone; and other rocks of the
trap-formation occur in several places on this coast.

The