Olorgesailie 2004 Field Season

Posted on 2004-08-14 by Rick Potts

August 14, 2004

About midnight last night, the 14-ton lorry arrived in our camp. The drivers didn't want to wake anybody, so they slept inside the truck. Now it's about to be loaded with all our camping gear to take back to Nairobi. Although there's much to organize this morning, I'm amazed by how quickly our tent city has been dismantled. The kitchen is all packed up. The glassware's wrapped in newspaper for protection during the bumpy ride to Nairobi. And some of our extra food has been given to the local people, who seem happy about it and amused by all our activity.In the photo, you see that the crew is pretty happy, too, even as they carefully load trays and many boxes of this year's discoveries into the…

Posted on 2004-08-13 by Rick Potts

August 13, 2004

Whew! The last day of work for the season. It was tense, but all the sieving of sediment, closing down of excavations, recording of measurements, and packing of specimens has been completed. We're ready to roll to Nairobi tomorrow morning.My last visit to an excavation today was to the hominin fossil site, the one from last year. We've now ended all the digging and sieving of loose sediment beneath the place of discovery, right down to the volcanic bedrock. As for the photo, I'd like to pay tribute to George Mumo (whose head is just poking up from the gully), Kakai ole Milto and Kiluva Nume (who are doing the sieving). They're the three guys in the picture who worked tirelessly all season to look for more…

Posted on 2004-08-12 by Rick Potts

August 12, 2004

It's after dinner; everyone else has turned out their kerosene lamps and has gone to bed. I'll stay up a little longer, and since I have a tent large enough to fit a small table (along with my mattress and a couple cases of clothing and papers on the floor), I can write to you for a little while. I have one lamp on the table fueled by kerosene, the other a headlamp powered by batteries. They give plenty of light to see the keyboard inside my tent on this windy, moonless night. The sky's full of bright stars and the cloudy glow of our galaxy, the Milky Way. I stayed outside for a while to see if I could catch any of the meteor showers (the…

Posted on 2004-08-11 by Rick Potts

August 11, 2004

Today, the excavators, transit fundis, and I completed our final lift of the season at Site 15. This last haul of about 100 fossil bones and stone tools helped a lot in figuring out exactly what happened at this site, about 990,000 years ago. We found several fragments of leg bones with sharp fractures, indicating that the bones had been broken while still fresh. They were found along side stone flakes, a couple cobbles, and teeth of a really old zebra. You can see two of the teeth, with worn chewing surfaces of an incisor (near the top) and a premolar (below), along with some small bone fragments. These finds are similar to something we observed some years ago - the teeth of zebras and antelopes discovered…

Posted on 2004-08-10 by Rick Potts

August 10, 2004

It's the last week of the field season. We'll be breaking camp on Saturday, the 14th, and there's much to do to complete our work by the end of Friday afternoon. One of my goals every season is to look around and figure out a plan for our next excavation season. From the outset this year, I've wanted to find a day to walk across the Ol Keju Nyiro (the dry river near the base of Mt. Olorgesailie) to search the sediments in the southern part of Locality B. I was glad that the Geology Field Course students got over there with Kay, and they did a bit of fossil surveying. I wasn't able to go with them that day, but they focused on exactly the sediments…

Posted on 2004-08-09 by Rick Potts

August 9, 2004

We had a really interesting surprise today. At least once or twice each summer, we find something really neat in our digs we didn't know about before.Today's big job was to carefully remove the hundreds of stones found in excavation Site CL1-1. You may recall that it's the oldest handaxe site known so far at Olorgesailie. The site is nearly 2 meters above a volcanic tuff dated 1.2 million years old (by the argon-argon technique). And about 2 meters beneath a younger tuff that's 992,000 years old. Sandwiched between the two dates, Site CL1-1 is probably a little older than a million years.As you can see in the photo on the left, we discovered a really dense accumulation of Acheulean handaxes. As the excavators unearthed them, we…

Posted on 2004-08-08 by Rick Potts

August 8, 2004

It's the last Sunday of the field season, and we're certainly enjoying our day off. Amanda leaves tomorrow, and today she, John, Alison, and I spent some time reflecting on the season. We talked about the work, the artifacts, and what kept us busy, but we also spent a lot of time talking about the animals we'd seen this season.As every year, there were lots of baboons in the area, both at the baboon cliffs where they sleep each night and across the landscape during the day. We've also heard hyenas frequently, and one night I heard a hyena whooping with satisfaction after it had caused much disturbance with the sleeping baboons. We've spotted Grant's gazelle, gerenuk, and eland, and two female ostriches ran by camp one…

Posted on 2004-08-07 by Rick Potts

August 7, 2004

Alison has started her own excavations in Locality B, across the river and nearer the foothills of Mt. Olorgesailie than either Site 15 or DE 89. Like Locality G, where John has been working, Locality B has exposures of the New Formation and the later Oltepesi Formation, with some Middle Stone Age and Sangoan sites.

Last year, Alison excavated a geology trench down one hill, and found many MSA stone tools, but not many bones. This year, after surveying one area, she found more obsidian flakes and some more bones, and decided to excavate there. In Locality B, it's sometimes hard to tell exactly where on the slope of a hill the artifacts are coming from. Alison spent a day walking up and down the hill…

Posted on 2004-08-06 by Rick Potts

August 6, 2004

The National Museums of Kenya is one of the finest museums (actually a combination of many different museums) in all of Africa. They do a good job of trying to preserve many outdoor museums, including the one at Olorgesailie. During our excavation season here, I often talk to school groups, tourists, and local visitors, all of whom are eager to see the famed concentrations of handaxes that are on display. A couple weeks ago, I talked to the geology students and a group of visitors from a United Nations school in Nairobi, who were tagging along, about one of the most interesting handaxe sites. It's called DE 89, and its original excavation was carried out by Louis Leakey (in the 1940s) and later by Glynn Isaac (in…

Posted on 2004-08-05 by Rick Potts

August 5, 2004

It's important to plan the last week of our excavations with great care. I've also begun to take stock of what we've uncovered so far this season, and how it compares to what we thought we might find. I remember thinking when we started this year's work at Site 15 that we might find another butchery site. The bones and stones that were visible in the wall of the excavation seemed to suggest that a zebra was cut up for meat here by early humans.What we actually found through the season did not paint so clear a picture. We did find many flakes and stone tools, which would have been used in a butchery site. We also found a good number of teeth of a very large…

Posted on 2004-08-04 by Rick Potts

August 4, 2004

Even though today Olorgesailie is a comfortable place, with good water, easy access to towns, and relative safety from animals, in the past it would not have been so. What I find so amazing is that, even during the tumultuous climate changes of the past when populations of other mammals apparently left the area, early humans were able to stick it out. I described earlier how animal species changed through time, and how sometimes dramatic events, like volcanic eruptions or the lake drying up, caused many animals to leave. Throughout all of these big changes, hominins were able to stay in the region (we can tell because their handaxes and other tools are found in almost every stratum) and seemed to thrive, no matter if it was…

Posted on 2004-08-03 by Rick Potts

August 3, 2004

Last week I mentioned the debate about modern human origins - how some people think that modern human behavior originated quite late in prehistory, around the time when biologically modern humans arrived in Europe, while others think it developed earlier and very gradually, particularly in Africa.Alison is a strong proponent of the early, gradual hypothesis. Her work in other places in Africa has shown many cases where early modern humans had more complex behavior than was expected during the Middle Stone Age (MSA). In Botswana, fossil animal bones showed that humans were hunting large, dangerous animals that no one thought they'd have the technology or ability to go after. At Katanda in Zaire (now Democratic Republic of Congo), Alison and John found barbed bone points and many…

Posted on 2004-08-02 by Rick Potts

August 2, 2004

Alison and John returned from their safari today with their children, Elizabeth and Alexander, and Elizabeth's friend Sarah. This is the first time that Elizabeth and Alexander have visited Olorgesailie, but it's certainly not the first time they've visited Africa.

John and Alison have worked in Africa since the 1960s, developing excavations in Botswana, Zaire (now Democratic Republic of Congo), and Ethiopia. In many of these places, they've had to stay for long periods of time, up to a year or more at once. This was far too long to leave their young children with relatives back in the States, so Elizabeth and, later, Alexander came along to some exotic places. It wasn't always easy for them. In fact, the first place where Alison and John…

Posted on 2004-08-01 by Rick Potts

August 1, 2004

In a couple weeks our field season will end. Instead of waiting for the last Saturday evening, I decided that last night was a good time for our annual goat roast and camp party. Every year I buy a goat and present it to our field excavation crew to thank them for their hard work during the season. They, in turn, invite me and the others to join them for dinner - with some music and dancing after the feast.So last night, we all sat around the large campfire and ate roast goat, ugali (a cornmeal dish), and salad. After dinner, the crew called for speeches to mark the occasion - and, as usual, they asked me to start. I thanked them for the work they've done…

Posted on 2004-07-31 by Rick Potts

July 31, 2004

I want to use today's dispatch to describe to you Warren Sharp's research. He joined our group a few days ago, and his work is going along very well. His work is part of a new study to help us find better ways of dating our sites. Like Al Deino, he's collecting samples of rocks from all over the basin. But the kinds of rocks he collects are very different. Al collects bits of volcanic tuff for dating using the argon-argon technique or for chemical correlation. Warren collects rocks in which a different radioactive element, uranium 238, is found. U-238 collects in many different kinds of rocks, but here in the Olorgesailie basin, the main places it collects are in rocks where groundwater has leached through the…