What happened to the Lost Continents?

Recent discoveries on the lost continent of Zealandia have made people begin to wonder if there are more lost continents out there. By dating the Zircons found in Zealandia, there is evidence to suggest that this was a part of the supercontinent Rodina long before Pangea. It aged over 1 billion years ago when Rodina was formed as a supercontinent. Using that as a guide, they recently measured the zircons on the mass under Mauritania and found it was dated earlier than that. Could Mauritania have been part of a supercontinent before the supercontinents that we know of? It is much older even though it sank under the sea after Zealandia did.

So how did we find these lost continents anyway? During the age of exploration, a man called Abel Tasman landed on the South Island of New Zealand. He was looking for a much larger continent but found the island instead. It was an unhappy encounter, and it was not explored again for over a hundred years. James Cook was tasked with finding the eighth continent but didn’t seem to come across anything that would suggest there was one. In 1895, James Hector said that the islands of New Zealand seemed to be a mountain chain of a lost continent. He was the first to suggest that there had been a continent, but it was underwater.

In the age of exploration, when people were still discovering California, there are many stories of a great inland sea that divided the coastal mountains from the desert plains. They had thought that it was the Colorado river changing course, but even the mighty Colorado River couldn’t provide that much water to fill the entire central valley. There is evidence of a beach along the mountains and waterlines on the mountains themselves. Another curious thing is that there are very few dinosaur bones. There are dinosaur bones in Nevada but none in California. This could come from the land going under the water so many times and getting washed away from the Colorado river at the same time. It’s not unheard of to have land submerged and re-emerge. James Hector would have this knowledge when he made this determination.

Even with all this proof, it wasn’t until 1995 that Bruce Luyendyk suggested calling the lost continent Zealandia and supporting the theory of it being a lost continent. They began to search for more evidence of a landmass underwater and new ways of testing for one. They were able to locate some zircons and measure them against zircons found on a landmass above the water. Using this method, they were able to determine that Zealandia was a lost continent and that there were others.

This technique helped them date the land mass suggested under Mauritania. That is when they discovered that the zircons on Mauritania were older than Zealandia. It could mean it was around longer and went through more than one supercontinent. We know that Zealandia was a part of Rodina and Pangea. This makes it a key piece in understanding how these continents moved about. Mauritania could be our key to understanding the time before Rodina. If we could geologically explore this area, we may be able to discover what the land was like before Rodina. The zircons were found to be close to 3 billion years ago, but there may not be enough to indicate core formation. It would be great to see what we could find out about this mass.

Both continents were lost after Pangea broke up. The evidence discovered so far indicates that Mauritania formed first and survived a few supercontinent formations. Zealandia could be the youngest of the lost continents, but it may also be one of those zones that rises and falls in a cycle. The volcanic activity of the ring of fire proves that this theory is possible. It may rise and fall with the movement of the plates. It could be as old as Mauritania but not spent as much time above water. They are now researching new areas around Australia for similar formations. It does make one wonder… were there supercontinents before Rodina? How many lost continents are out there undiscovered? If it’s on a cycle, when is Zealandia due to rise again?