Westpoint Island, Falkland Islands
Today was the last in our 36 day voyage down the Mid-Atlantic Ridge. We left the Ridge when we left Tristan de Cunha and sailed for South Georgia. On the islands of the Ridge we visited some very young rocks, many less than 1 million years old. At Tristan we walked on the lava field from the 1961 eruption. Here in the Falklands the rocks are very much older—the oldest are 1.1 billion years old. We are in West Falkland where these very old rocks are well exposed and today at Westpoint Island we cruised in Zodiacs past these sandstones, which are about 400 million years old. They display the characteristic cross bedding of wind-blown sands and reveal that the area of the Falklands was a hot and arid desert at that time. The Falklands are a remnant of the great super-continent called Gondwana, which began to break up about 250 million years ago. Before the breakup the Falkland microplate was attached to the east side of southern Africa. It rotated 180° and moved to its present position relative to South America. When the Atlantic began to open along the Mid-Atlantic Ridge about 150 million years ago, the Falklands moved west, riding on the South American Plate. Thus as we have moved forward along our course on this voyage we have moved back in time geologically.
The rock shag in the picture was only one of many bird species which abound in the Falklands. The many penguins, albatross, geese, and johnny rooks share these remote outer islands with a few hardy sheep farmers and we have visited three of these farms in the past two days. The quiet solitude of West Falkland provided a fine opportunity to meditate in these final days about all we have seen on these Forgotten Islands.
Today was the last in our 36 day voyage down the Mid-Atlantic Ridge. We left the Ridge when we left Tristan de Cunha and sailed for South Georgia. On the islands of the Ridge we visited some very young rocks, many less than 1 million years old. At Tristan we walked on the lava field from the 1961 eruption. Here in the Falklands the rocks are very much older—the oldest are 1.1 billion years old. We are in West Falkland where these very old rocks are well exposed and today at Westpoint Island we cruised in Zodiacs past these sandstones, which are about 400 million years old. They display the characteristic cross bedding of wind-blown sands and reveal that the area of the Falklands was a hot and arid desert at that time. The Falklands are a remnant of the great super-continent called Gondwana, which began to break up about 250 million years ago. Before the breakup the Falkland microplate was attached to the east side of southern Africa. It rotated 180° and moved to its present position relative to South America. When the Atlantic began to open along the Mid-Atlantic Ridge about 150 million years ago, the Falklands moved west, riding on the South American Plate. Thus as we have moved forward along our course on this voyage we have moved back in time geologically.
The rock shag in the picture was only one of many bird species which abound in the Falklands. The many penguins, albatross, geese, and johnny rooks share these remote outer islands with a few hardy sheep farmers and we have visited three of these farms in the past two days. The quiet solitude of West Falkland provided a fine opportunity to meditate in these final days about all we have seen on these Forgotten Islands.
