Contribute to Ol Doinyo Lengai Research
 

Lava sample collection: Dr. Roger Mitchell of Lakehead University in Ontario, Canada, is a geologist who is particularly interested in carbonatites.  He has analyzed the crystalline structure and chemical composition of many specimens collected at Lengai. Since Ol Doinyo Lengai is the only volcano in the world that erupts natrocarbonatite lavas, he would like to obtain specimens from the crater as often as possible, since the lava can change its composition over time.  Dr. Mitchell would greatly appreciate receiving any specimens of Lengai’s lava from you if you are willing to collect it from the crater and post it to Canada once you have returned home. Your contribution will be acknowledged if any publishable research includes data from your specimen.

Here are some guidelines for collecting Lengai lava specimens:

(1) Remember the lavas on eruption are HOT -. They can remain hot for quite a long time even when solidified.  Do not attempt to collect flowing lavas!
(2) Use gloves if you are collecting freshly erupted lavas.
(3) The best samples to collect are obtained as soon as the lava has cooled and solidified completely. These will be brown or black in colour. Do not collect white rocks. These represent lavas which are not fresh as they have been altered by interaction with moisture. This process destroys the original mineralogy.
(4) Break off a small piece of solid lava (2-4 inches in size). Large pieces are not required for our purposes. If you do not have a geological hammer this can usually be done with the heel of your hiking boots.
(5)  Place the sample in a plastic bag. Note: if the lava has just been erupted and is still fairly hot this will cause the plastic to partially-melt or soften. This is actually very useful as the plastic will adhere to the sample and keep out moisture. Don’t be concerned if the plastic does not stick to the sample. Place the first bag inside a second plastic bag and squeeze out as much air as possible. Wrap the two bags in side a third bag, keeping the contained air to a minimum. The objective is to keep moisture from interacting with the sample. Moisture interactions ruin the fresh sample and make it useless for assessing the character of the eruption products.  Please do not use paper bags or newspaper to wrap samples as this absorbs moisture.
(6) You might want to collect several samples of lavas which are obviously different in their appearance. If you do this place each sample in a separate bag.
(7) Please label your sample(s) with the Lengai cone designation number if you know it and add your name and address.
(8)  Mail your sample(s) as soon as possible to:

Dr. Roger H. Mitchell
Department of Geology
Lakehead University,
955 Oliver Road,
Thunder Bay,
Ontario
CANADA
 P7B 5E1
 
 Please do not send any samples which have turned white.

Photographs: Many people who climb Ol Doinyo Lengai on a day-trip do not go all the way to the true summit, but if you do, please make a photo or two of the crater from the summit. A very useful summit picture could be made by using a telephoto lens to zoom in on the crater.  Center the picture on the cones in the central part of the crater.  If you walk around in the crater, try to photograph any erupting or black cones from a couple of different directions.  Also make a picture of the active cones from some distance away and try to include part of the crater rim or the summit in the background if possible.

Description of activity: If you visit the crater, make notes about the number of cones you see erupting, if any, and the type of eruptions that are occurring, for example, lava lakes, lava flows, or lava splashing from the tops of cones. If you take a map of the crater try to identify the active cone(s) or the general area of the activity.  If you hear anything of interest about Lengai’s activity from people in Ngare Sero village or from other tourists in the campsite, please make note of them.  Of particular interest are reports of eruptions large enough to be visible from the village, explosion sounds, or any earthquakes or tremors.

Please send your observations to me at the email address given on my home page.  If you have a large number of photographs to email please contact me first so that I can be sure my mailbox has sufficient space to receive them.

Back to Ol Doinyo Lengai home page