[1] Its European name was given when, after sailing around Groote Eylandt between 5 and 14 January 1803, Matthew Flinders and his accompanying scientific party landed on the small island to take bearings and found that deep chasms in the cliffs made it difficult to reach the top.

[2] The island is significant for the millennia-old rock art found there that include paintings and engravings observed and recorded by Flinders; the first documented by Europeans.

[3] Chasm Island covers 3.2 square kilometres and the topography is flat but rugged, with frequently encountered deep crevices and fissures in the sandstone running roughly WSW to ENE crossed by others in a North-South orientation.

The island is within the McArthur Basin formed during widespread extension and thermal subsidence, and was subsequently deformed during thrust tectonics events affecting the North Australian Craton during the Proterozoic.

Ancestral entities traversed the land and oceans during this creative time, shaping natural features, altering the seascape, and imbuing them with spiritual significance.

[8] They relate how the geography of the small islands; their rocky formations, steep cliffs, and submerged rocks, were shaped in ancient times by three mythical beings: the Baler-shells known as Yukana, the dolphins called Amatuana, and the tiger-shark Bangudja.

Later, they relocated northward to Chasm Island where they formed a harmonious relationship with a pair of dolphins, with whom they lead a joyful coexistence, gathering abundant marine resources and playing in the warm waters.

The third person of the band was twice the height of the others, and held in his hand something resembling the whaddie, or wooden sword of the natives of Port Jackson; and was probably intended to represent a chief.

In the early months of 1948, he dedicated a span of 14 weeks on the Groote archipelago, meticulously surveying and documenting rock art sites, as well as conducting excavation work.

Collaborating with his American counterpart, Frank Setzler (Head Curator of Anthropology at the Smithsonian Institution), they scoured Groote Eylandt for sites of significance, with McCarthy meticulously recording around 2400 motifs of rock art across three pivotal complexes: Chasm Island, Angoroko, and Junduruna.

[18] His thorough record-keeping of rock art allowed McCarthy to provide detailed descriptions of the motifs and to outline a framework showcasing the evolution of artistic styles over time.

McCarthy[10] and later Chaloupka[12] note petroglyphs also found on the island that embody the labour of countless generations of Aboriginal artists spanning thousands of years.