Sasha Say's - Gondwana - a podcast by Whitestone Geopark

....Geoeducator: So we've got an activity there that's actually a puzzle. So let me start at the beginning. Long time ago, back in the Triassic, which is very long time ago. We're talking, you know, 200 odd million years ago, there was a continent called Pangea. Now Pangea was the land masses of the world and then that separated up into two separate supercontinents. There's Laurasia, which is mostly the northern hemisphere continents of today (there are some exceptions of course), and Gondwana, which is mainly the southern continents (of course there are a couple of exceptions there as well). And so that broke up into those two continents, and New Zealand formed off the edge of Gondwana. So that's part of the southern continents. Now, Gondwana was in a different area on the globe than New Zealand is today. Now, Gondwana itself, then started to break up in the Jurassic. So round about 160 odd million years ago, it started to break up. And New Zealand then started to break away from Gondwana around about 80 million years ago. Now, you know, this took a very, very, very long time. So we're talking millions of years to break away and it's slowly opened up, scissor like, separating from Australia and Antarctica. And actually, interesting fact, Zealandia (which is the continent that New Zealand sits on) is only separated from Australia by a trough called the Cato trough, and it's only 25 kilometres across. Believe it or not. So pretty narrow when you're looking at the actual continental crust as opposed to what's sticking up above the land (sea). So this activity that we've got is all the different puzzle pieces, if you like, that make up Gondwana. So you can print it out, colour them and cut them at the edges of the continents and then try and piece them back together to get an idea of what Gondwana looked like. Have a go identifying the various countries that are there as well. How does it relate to the Geopark? Well, Gondwana is reflected in the Geopark through our basement rock. So we've got our greywackes (which is the Torlesse Terrane), and we've got our Otago schists, which I like to call, you know, the stripy metamorphic rocks. They are schists. And so they were formed before New Zealand broke away from Gondwana. And then all of our subsequent sediments and marine sediments terrestrial sediments, our fossils, all that were deposited after New Zealand broke away from Gondwana. So the GeoPark has this wonderful history that we've got recorded in the rocks and the landscape right from Gondwana time right through to the present day. What's happening now is we've got a lot of erosion happening, we've still got deposition happening in the rivers. So we've got this huge record right here to see. And when we travel around the Geopark at different sites, you're seeing different parts of that history. So in some areas you might see more recent, like the glaciation and some areas you'll see older, like the limestone or the volcanism. So you can get snapshots, different periods of time of our history that's linked to Gondwana. So cool activity, cool way to find out some new facts about our Geopark and how it links to the past right through to the present.

Radio Announcer: And that's all on the website at www.whitestonegeopark.nz.....

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