Hawkes Bay is final piece in NZ map jigsaw

GNS Science has published a new map detailing the geology of Hawke's Bay - the final map completed in a series of 21 that document the whole of New Zealand.

The QMAP series was created using a computer program that allows it to be updated when new information is obtained, replacing previous maps that were published in the 1960s.

Accompanying the Hawke's Bay map is a 97-page book that includes photos, illustrations and diagrams.

It is thought the map will benefit organisations such as the Department of Conservation, regional councils, engineers, and mineral and petroleum exploration companies, as well as keen fossil hunters.

GNS Science geologist Kyle Bland said the mapping process required "an awful lot of walking", as well as the compilation of lots of previous work, such as PhD and thesis research.

"A nice part of it was it gave you the excuse to get into areas that you wouldn't normally," he said. "The previous maps were done before the concept of plate tectonics was really accepted. So the new maps are able to take that into account to explain a lot of the geology of the area. The map information is also digital ... that is the real big advance."

Among the oldest rocks in the 1:250,000 scale map are the Ruahine, Kaweka, and Ahimanawa ranges and the Kaimanawa mountains. These rocks were deposited on the ocean floor between 200 million and 145 million years ago during the Jurassic Period, and have since been uplifted.

Hills of limestone and sandstone now exposed near Napier, Hastings, Waipukurau and the eastern margin of the Kaweka Range accumulated within a seaway that stretched from the Manawatu Gorge to Cape Kidnappers between 1-3 million years ago.

Geoscience Society of New Zealand president Scott Nodder said the maps were useful for identifying resources.

But they could also be used to satisfy the curiosity of locals, who could check to see what the "hills behind your house" were made of, or identifying where fossils are found.

"I think the key thing is the level of detail that is in them, they've been mapped at a particular scale that is useful for a wide range of applications," he said.