The southern parts of its course must be much younger because the areas where the Finke now flows near the southern edge of the Northern Territory , and further south , were under the sea during the Mesozoic Era , part of the Great Artesian Basin . But southern parts of its course must be much younger because the areas where the Finke now flows near the southern edge of the Northern Territory , and further south , were under the sea during the Mesozoic Era , part of the Great Artesian Basin .