Orokonui Ecosanctuary/Geology

GEOLOGY

1. 170 million years ago was part of Gondwana the sedimentary rock was heated (350 degrees) and compressed and became metamorphic rock = schist
   • All of the Silverpeaks have a flattish top of schist with younger basalt on top
2. Aotearoa separates from Gondwana 60-85 Million years ago
3. 65 million years ago a comet hit earth and made the dinosaurs extinct
   • First marine sediments (sandstone, mudstone and limestone) appear on top of the schist
     • The sea came in from east of coast and zealandia separated off
4. 14 million years ago there was a volcanic period with hundreds of vents all around Dunedin and thousands of eruptions = basalt (the whole sea floor is made of basalt)
   • The points that we see, eg Double Hill, Mopanui and Mihiwaka, are the roots of the volcanoes that haven’t yet eroded
   • The rocks under Orokonui are from lava flows of phonolite
   • Volcanic rocks often have sediments in them which have fossils
   • Fossils show that in this period the flora was much lusher than now
5. 2 million years ago was an ice age with 9-10 advances during that time and interglacials in between which were even warmer than now
   • Glaciers never reached coastal Otago but very cold long winters with lots of freezing and thawing
   • The habitat was similar to sub-alpine
     • 15,000 years ago was the last ice age

Kōkōwai - Red ochre

• Maori mixed kōkōwai with fish oil.
• The predominant colouring agent and was used to paint large waka taua (war canoe)
  • Ochre prevented the drying out of the wood in canoes and the carvings of meeting houses
    • Estimated to last for 30 years
• Roughly smeared over the face, especially by women, to keep off insects
• Solid chunks of ochre were ground on a flat but rough surfaced rock to produce the powder
• Specialist people within a hapū would be in charge of preparing the tūpāpaku (dead body)
  • They would smear the body with kōkōwai and oil, then sit it up with the knees tucked under the chin and the arms wrapped tightly around the legs
    • The crouched body was wrapped in whāriki (mats), cloaks and other finery