Rurutu reconsidered: the development of Makatea topography in the Austral islands

The islands of the southern Cook and Austral groups in
the South Pacific exhibit astonishing differences in geology
and topography, even between closely adjacent islands of
similar ages. Some are sea-level atolls, others have low
fringes of Pleistocene raised reefs, and others substantial
rims of elevated mid-Tertiary limestones, locally known as
makatea. On some islands the relief of the makatea is
subdued, but on others it is dominated by eroded volcanics,
sea-level swamps, and vertical limestone walls. Sixty years
ago there was great controversy over whether the makatea of
Rurutu represented a reef-growth or an erosional topography.
Using insights from Mangaia in the southern Cooks we argue
that the makatea relief of Rurutu is of erosional origin,
and we identify why the Paparai Valley - seen as a key area
in the old arguments, even though none of the protagonists
had seen it - holds a key to the great inter-island differ-
ences which exist in makatea topography in this part of the
Pacific.

Available online

Call Number: [EL]

Physical Description: 20 p.