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180 kg CO3 meteorite
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Rocks and hilly ground take the place of "fech fech" and sandy soil. Each of our vehicles carries more than 600 kg of water, gasoline and other materials, a minimum requirement for self-sufficiency in the desert. Descending rocky slopes and driving over soft ground demands a good amount of experience and skill if you do not want to end the day with an overheated motor, or a shovel in your hand. We have to explore all nooks and crannies of this inhospitable desert looking for the "big one". |
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| And a new find makes all our efforts worthwhile, thirty kilometers (nineteen miles) after the discovery of our first small one on the clear area of Dar al Gani... |
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Here it's a hard ground with stone slabs and... fifteen kilo of CO3
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When we find different stones on a same area and all the stones can be put together, we classify them under the same reference number, as it is the impact with the ground which has fragmentated the meteorite. |
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| The first order of business in late afternoon is to wrap a damp cloth around a bottle of sparkling mineral water, our pre-dinner drink. Simple evaporation will lower the water's temperature, providing us with a cool, refreshing drink in half an hour. If three liters of water per person per day is enough at this time of year, in summer the daily requirement could easily exceed five liters. |
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After sunset, we have all the time to study our finds. Here are some meteorites found the preceding days, two are ordinary chondrites, and the small one in my hands is somewhat particular... |
| Some days we take our time preparing and cooking our evening meal and bread, but tonight we are the ones simmering, with understandable excitement! The stars are bright by the time we finally settle into our sleeping bags, full of hope for the next day. |
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24 October 1999 |
| We have been prospecting since the beginning of the day, GPS gives us a localization 10 km (6 miles) north-west of the last find, 15kg scattered. Our motivation drains away with the hours; we have not found a single thing and, worse, the terrain is becoming less favorable. The sand here is everywhere and covers everything. Our chances of discovery "the big one" diminish, but the desert around us is so magnificent, and our pleasure at driving across the sand so great, that we continue mechanically. The formations to my left appear to be covered in a white crust: ancient lake deposits, perhaps. As they are slightly elevated, the sand is absent. The Sun is at its zenith, and I let my thoughts wander... |
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| I am thinking at that extraordinary adventure. We are following the exact trajectory of the CO3 fall and during the last 40 km we have crossed so many different landscapes. Suddenly Roland calls over the radio : "I'm afraid we have a problem, what we feared most has come true!" |
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"In nature... nothing is impossible, one must be prepared for anything, and assume that anything which could be true, is true." |
Carbonaceous chondrite weighing 95kg
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It is a striking image: a pile as black as ink on a background of white. |
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It still remains the largest meteorite ever found in Libya
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| The impact must have been very violent to have shattered the meteorite like this. We cautiously begin a meticulous and laborious recovery operation, recording as much information as possible. The nose of the meteorite has sunk 20 cm into the ground. It is a very fractured block of about 22 kg, the frontal part reduced to powder. The ground alongside is strewn with fragments of all sizes. The largest weighs 25 kg, its buried face, which has been protected from the wind and sand, clearly showing a fusion crust. The surface fragments however, have been exposed to the desert winds for hundreds or thousands of years, and have a polished appearance and blunted shapes. |
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With this discovery, the Dar al Gani 180 kg CO3 becomes the third largest carbonaceous chondrite discovered in the world, after Allende (CV) +2000 kg and Kainsaz (CO) 200 kg. Murchinson (CM) is around 100 kg, and Tagish lake only 10 kilos
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Main mass : 25100gr |
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It's a hard job to be a meticulous prospector !
After a few hours of work, crawling around like ants under the hot sun, we clear the ground of all traces of black, leaving behind a desert of immaculate whiteness. |
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Complete map of Dar al Gani CO3 strewnfield It's 61 finds 184 kg crashed along 43 km |
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CO carbonaceous chondrites are type 3, chondrules are well-defined and plentiful. We have complete thin slices, |
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| Metal droplets inside a chondrule, photo: E. Dransart EMTT |
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| Polyhedral olivine crystal in polarized light, photo: E. Dransart EMTT |
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This type of meteorite holds many clues to the very birth of our Solar System. |
| We want to thank : - Mineral soda water Salvetat, our great support at the end of hot days, perhaps they will send us one free bottle to drink to their health. - Tires BF Goodrich, little worn after 20000 km off road, but good friends in desert. . . We need new ones, please ! - Special thanks to our faithful 4WD's seventeen and fifteen years old ! |
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