Virtual Volcano Vacation #95 WINNERS! – The Barrier

Barrier volcano - The summit caldera of Kakorinya volcano with Lake Turkana further north in the distance. Andrews cone can be seen in the lower left with a young southward lava flow.  - Photo by Martin Smith, 1993 (copyright British Geological Survey, NERC). Image via GVP

Barrier volcano – The summit caldera of Kakorinya volcano with Lake Turkana further north in the distance. Andrews cone can be seen in the lower left with a young southward lava flow. – Photo by Martin Smith, 1993 (copyright British Geological Survey, NERC). Image via GVP

This week’s virtual vacation was chosen quite by random, yet in trying to “get away from it all” I found myself in one of the more likely “birth-places” of humankind…specifically in the East Africa Rift in Kenya upon The Barrier volcano.

The East Africa rift zone - Image via Wikimedia - public domain

The East Africa rift zone – Image via Wikimedia – public domain

The Barrier was so named because it spans a section of the rift valley a bit like a large dam, separating Lake Turkana in the north from the Suguta valley and the small lake Logipi to the south. The Barrier is actually a complex of four volcanoes; Kalolenyang being the westermost, Kakorinya with its large caldera at the center and most directly over the rift zone, and Likaiu West and Likaiu East trending ENE of Kakorinya.

The Barrier volcano - Nabuyatom tuff cone at the edge of Lake Turkana - image via Pinterest - photographer unkown

The Barrier volcano – Nabuyatom tuff cone at the edge of Lake Turkana – image via Pinterest – photographer unkown

Within Kakorinya’s 3.8 km wide caldera, which was formed around 92,000 years ago, there are trachyte and phonolite lava flows and domes covering much of the caldera floor. On Kakorinya’s north and south flanks along an early Holocene fissure there are numerous scoria cones and flows as well as solfataras. The volcano last erupted in 1921 at Teleki cone on the north flank. Other 19th and 20th century eruptions have occurred on Kakoriny’a south flanks at Andrews cone.  (Incidentally, do not let the Google Earth GVP placemark for Andrews cone fool you. It is just south and a little west of the large caldera. You will easily recognize the lava flow.)

The anthropological importance of this region, however, is as fascinating (if not more so) than the volcano. The area has produced a large number of early hominin skeletal remains, some as much as 4 million years old. Perhaps one of the most famous Pleistocene denizens of the area is Nariokotome Boy, formerly and more widely known as Turkana Boy, a 1.5-6 million year old and almost complete skeleton of a homo erectus youth. The same tectonics that created the fertile rift valley that caused early humans to thrive and multiply also produced the volcanism which produced the sediments and tephra layers that so effectively preserved those humans’ remains for us to study.

Congratulations to Granyia for being the first to find me, and Jesper following soon after. As we draw closer to year’s end, the race has become neck-and-neck. Also we are drawing near a major milestone..my 100th volcano!  But first, my 96th virtual adventure begins this Monday at a new volcano. I hope to see some of my lurking Search-Partiers turn out as we head into the holidays.

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