Connelly (1979) states: "Geological and geophysical evidence from a number of studies has established that the Papuan Ultramafic Belt is probably an overthrust sheet of oceanic crust and mantle with a thicker crustal section than normal oceanic crust". This hypothesis was first advanced by Thompson in 1957 (see Davies, 1971), and worked out in more detail by Davies (1968, 1971) and Davies and Smith (1971). In 1973 I presented an alternate interpretation of the Papuan Ultramafic Belt. I quote here from the ANZAAS (1973) abstract: "The interpretation advanced and illustrated by cross sections explains the Papuan ultramafic belt as a deeply eroded portion of an uplifted, extinct, west to southwest dipping subduction zone which - after subduction activity ceased in Late Eocene to Oligocene time - rose to the surface and was squeezed out along a major pre-existing shear zone. Owing to the rapid rising of at least 20 kilometres and the concomitant strong erosion of the sprouting orogenic belt, fragments of the oceanic crust and upper mantle from the ancestral subduction zone are now exposed at the surface and form the Papuan ultramafic belt".

The R502 series of maps has been replaced by the National Topographic Map Series (NTMS). The R502 series consists of 542 map sheets and covers Australia at a scale of 1:250,000. It was compiled from aerial photography, but only about one quarter of the series was contoured. The standard sheet size is 1 degree of latitude by 1.5 degrees of longitude. Transverse Mercator map projection and Clark 1858 datum were used. Coverage of the country was completed in 1968.

The R502 series of maps has been replaced by the National Topographic Map Series (NTMS). The R502 series consists of 542 map sheets and covers Australia at a scale of 1:250,000. It was compiled from aerial photography, but only about one quarter of the series was contoured. The standard sheet size is 1 degree of latitude by 1.5 degrees of longitude. Transverse Mercator map projection and Clark 1858 datum were used. Coverage of the country was completed in 1968.

At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

Geoscience Australia`s involvement in Papua New Guinea mapping includes managing the production of maps for select urban areas as part of a MOU between Department of Defence and PNG. In addition, Geoscience Australia distributes some (now aging) 1:100,000 scale maps produced by the Department of Defence for much of Papua New Guinea. At this scale 1cm on the map represents 1km on the ground. Each map covers a minimum area of 0.5 degrees longitude by 0.5 degrees latitude or about 54 kilometres by 54 kilometres. The contour interval is 20 metres. Many maps are supplemented by hill shading.

This series of maps covers the whole of Papua New Guinea at a scale of 1:250 000 (1cm on a map represents 2.5km on the ground). Each standard map covers an area of 1.5 degrees longitude by 1 degree latitude or about 150km from east to west and 110km from north to south. There are more than 50 special maps in the series and these maps cover a non-standard area some also include imagery and additional narrative information. Typically, where a map produced on standard sheet lines is largely ocean it is combined with its landward neighbour. These maps contain natural and constructed features including road and rail infrastructure, vegetation, hydrography, contours (interval 50m), localities and some administrative boundaries. Some maps are supplemented by relief shading.