Tuesday, January 25, 2011

Geology In Fast Forward

I have always been intensely interested in geology and plate tectonics. For many reasons, I have always been fascinated with the Great Rift Valley of Africa, which begins in the Red Sea and manifests itself in the Afar Depression, where the Northern Nubian Plate is pulling away from the Southern Somalian Plate.
The Rift, course is the agent which produced the Great Lakes of Africa, Lake Tanganyika, Lake Victoria, Lake Malawi are the big ones, but there are many more, including a few Lakes with very unusual chemical concentrations, such as Natron, Magadi and Makati, which are hot spring fed lakes with high Soda content.
The waters of these are noxious to many animals which are not specifically adapted to them. One of the few organisms which have found an successful niche here seem to be a few species of flamingoes, who feed upon the few krill like organisms which flourish in the caustic waters. The tiny shrimplike organisms are very pink and give the flamingoes of the region their intense coloration.
There are eruptions from the volcanoes in these areas which periodically spew caustic hot gas and are deadly to the wild life and humans who are aught in the path.
The Great Rift is a region of intense seismic and volcanic activity. When I was a student and read about them, it was always noted that this was where you could actually see the process of plate tectonics in action.
In the last few years, the processes which were projected to take place in millions of years have rapidly sped up. The volcanic activity has gone from events which would be measured in centuries to almost daily changes. You can read an article and view a very interesting photo gallery in an article in Der Spiegle from last week which documents this rapid acceleration of the African continent splitting process.
The Afar Triangle is beginning to resemble the ocean floor as lava spews from the rifts and the land on either side of the rifts daily moves farther and farther apart. Before our eyes, Africa is splitting into two separate land masses and soon, the ocean will cover the rift floor. What is notable is that the lava spewing from the volcanoes is balsaltic, which is the type of lava which is associated with ocean floor plate movement. Generally, continental lava is granitic or silica based.
As a one time passionate breeder of the unique varieties of Rift Valley Lake Chiclids, I find this all intensely fascinating. When the supply of Rift Valley Chiclids was interrupted by the tribal massacres in Uganda and Rwanda I found myself one of  the main suppliers of three different species to pet stores in Lower Manhattan, but that is another story.

1 comment:

mud_rake said...

An interesting sidelight to the story is that Lakes Malawi and Tanganyika are not only ripe with chiclids, but also extremely dangerous to human swimmers because of a deadly parasite, bilharzia. Once infected, the person has a life span of less than 40 years.

I personally know two Rwandan victims of the parasite who died in their early 40 from schistosomiasis, the medical term for the parasite. It is a long and ugly death!