Southern alps.ppt

Ka Tiritiri o te Moana

Ka Tiritiri o te Moana Ka Tiritiri o te Moana* the

frothing of the ocean. The Ngai Tahu legend of the creation

of the Southern Alps. Raki’s (the Sky father) four sons Aoraki (cloud in sky), Rakiroa (long Raki), Rakirua ( Raki the second) and Rarakiroa (long unbroken line) in their waka, Te Waka o Aoraki ran aground on a reef, listed to the east and turned into stone.

Ka Tiritiri o te Moana

The higher west side of the waka became the Southern Alps. The brothers also turned to stone: Aoraki (Mt Cook), Rakiroa (Mt Dampier), Rakirua (Mt Teichelmann) and Rakiroa (Mt Tasman).

* Legend acknowledged to Te Runanga o Ngai Tahu, Christchurch

Harold Wellman – other knowledge

Harold Wellman born in Liverpool arrived in NZ aged 18 in 1927. He worked as a surveyor and explored widely, living rough in the mountains and wearing out many pairs of boots.

He developed hunches from his many geological observations, arguing relentlessly with his colleagues.

Harold Wellman

Geologists believed that the movement of faults was mainly vertical, with little or no sideways movement.

Wellman in 1949 startled his contemporaries by proposing that matching rocks on the opposite sides of the Alpine Fault in Nelson and Otago had once been joined.

Later they separated by sideways (transcurrent) movement of 480 kilometres.

ALPINE

F AULT Southern Alps faultline - movement along the line of the fault

The Haast schists (green) from Cretaceous era were linked.

The older Pre-cambrian rocks (orange) were linked

Harold Wellman

Wellman recalled that the idea came to him on a wet Sunday afternoon, when he picked up a pair of scissors and cut the newly published geological map of the South Island along the Alpine Fault to see if the opposite sides matched

Wellman DSc FRSNZ (1909–1999) published important scientific papers on a diversity of subjects: active faults, New Zealand coals, archaeology, the Antarctic dry valleys and palaeontology.

Plate tectonics

EarthquakesRED shallow (<40km) Deep (40-300+ km)

Shallow Deep

Harold Wellman

The concept of plate tectonics, developed overseas in the late 1960s, provided a unifying explanation for many key features of New Zealand’s geology.

Wellman began a crusade to change the minds of the unbelievers. In his lifetime there were many arguments about the Alpine Fault and plate tectonics.

Most of what was debated 50 years ago is now accepted.

West New Zealand EastTectonic plate movement

Subduction of Pacific plate under the Australian plate

Harold WellmanA relentless observer and an original thinker with an unusual ability to understand relationships between time and space.

He is generally considered the most influential New Zealand geologist of the twentieth century.

Erosion

Not only are mountains thrust up, but they are worn and broken down by erosion from ice, wind, rain and even earthquakes.

What goes up is slowly ground down.

Single gravel fan from one valley in Southern Alps

Braided rivers carry eroded rock material to the sea

River sediment fans out and deposits on the ocean floor

Aoraki

Wellman’s startling transcurrent theory of lateral movement each side of the Alpine fault was a feature of the 1949 geology Conference. It has stood the exacting tests of proof and taken its place in global tectonic plate theory.

Aoraki stands, piercing the clouds with his three brothers, on the hull of their petrified waka, the tears of Raki bathing them, washing their feet, flowing down the great awanui, Waimakariri, Rakaia and Rangitata to tangaroa the sea.

Alpine Fault

References Barker, M (2006) New Zealand Science

Teacher 113, 27-37 Coates, G. (2002) The rise and fall of the

Southern Alps. Christchurch, New Zealand, Canterbury University Press.

Images for tectonics vulcan.wr.usgs.gov Wikipediaen.wikipedia.org/wiki/Harold_Wellman