Monday, October 12, 2015

The Paleogeology of New Zealand

We are now minus two days to our departure for New Zealand and things are falling into place. I have purchased a Nokia GMS phone for use after buying a SIM card at the airport. I have arranged our rental car transfers across the Inter-Island Ferry and have corrected the small error I made in renting inter-island vehicles.

The Avis company will allow a single rental fee so long as you spend at least three days on one island before or after inter-island transfer. Since we required two ferry rides, North to South Island and the returning South to North Island, I mistakenly thought that since we will be on the North Island for 8 days before going to the South Island, I thought that satisfied my three days of being on one island. However, you must satisfy the requirement of three days after each exchange. Since originally we were returning on October 31to the North Island and flying out on November 2, this did not allow three days after the second ferry transit.

I thus quickly readjusted our return from the Milford Sound so that we can get back to Picton for ferry transit on October 30 to satisfy the rental requirements. This will be a couple of long, hard drives for the length of the South Island, but it is doable.


ORIGINAL NEW ZEALAND INHABITANTS

While studying up on the formation of New Zealand and the original habitation by the Maori people, I watched a Netflix movie on the Maori and learned they were cannibals.  Since the Polynesians also inhabited Hawaii and they were not cannibals, I began to wonder why New Zealand, Fiji, New Guinea, etc. developed cannibalism.

http://www.netflix.com/title/80017264

The origin of the Polynesians were from Southeast Asia and they were sea explorers.
During the long voyages, protein must have been scarce and I believe they took to the custom of cannabalism during these transits. The Hawaiians had a custom of saving the bones of certain revered people, such as Captain Cook, but there is no evidence that they were cannibals.

In addition, the Netflix movie also shows some of the weaponry of the Maori people and their warlike posturing with protruding tongue and eyes that is evident today in the Haha Dance.


THE GEOLOGY OF NEW ZEALAND


PALEOGEOLOGY OF NEW ZEALAND

Pangaea was the original land mass of art that began to drift apart about 200 million years ago and formed two super-continents called Laurasia and Gondwanaland. The name comes from the Gondwana region of central India, where geological formations match those of similar ages in the southern hemisphere. At that time plate tectonics were not understood. Now it is thought that these continents float on liquid magma and just split. Gondwana broke up about 180 million years ago and with continual drifting of the continental plates, it split into landmasses we recognize today: Africa, South America, Australia, Antarctica, the Indian subcontinent and the Arabian Peninsula. 

About 45 million years ago, Australia and Anarctica were joined and there was no ice in the south pole. They began to separate and Australia drifted northward. It is thought that there were two tectonic plates that split and one drifted south to become antarctica and another drifted north to become Australia. Between 110 and 80 million years ago, New Zealand broke away from Australia forming the Tasman Sea.


Australia began to fracture about 80 MYA, when the future New Zealand region made its move, splitting away from Australia and Antarctica as the Tasman Sea opened up. Tectonic separation is usually an ‘unzipping’ process and, in terms of today’s maps, the pre-New Zealand rift extended northward from Tasmania through to North Queensland and south along the edge of Antarctica to Marie Byrd Land, splitting off an area about ten times the size of present-day New Zealand; we call this whole continent Zealandia. Full separation took over 20 million years with the Tasman Sea reaching its present width of 2,000 km around 60 MYA.

Zealandia, also known as Tasmantis or the New Zealand Continent, is a nearly submerged continental fragment that sand after breaking away from Australia 60-85 million years ago. It may have completely submerged about 23 million years ago but this is debated since all flora and fauna present in New Zealand today would have had to come from elsewhere and this does not appear to be the case. However, the majority of Zelandia is still submerged under the Pacific Ocean. Only 10% of the Zealandia continent sits above sea level. 

About 25 million years ago, the southern part of Zelandia that is now on the Pacific Tectonic Plate, began to shif relative to the northern part that is on the Indo-Australian tectonic plate. This displacement was about 310 miles and occurs along a fault line known as the Alpine Fault. Compression at this boundary caused uplifting of the Southern Alps in New Zealand. Today’s highth is much reduced from the process of erosion over millions of years. Further north, subduction of the Pacific Plate under the Indo-Australian Plate has led to extensive volcanic activity.




This is apparent in the regions of the Coromandel Peninsula and in the Taupo Volcanic Zone that we are scheduled to visit.













No comments:

Post a Comment