Olorgesailie 2011 Field Season

Posted on 2011-08-04 by Rick Potts

August 4, 2011

The day started like any other day, with breakfast at 6:45. This morning the camp cooks made us a special farewell treat – French toast! – to go with our usual piece of papaya and coffee and tea. After breakfast, we went to our respective tents and spent the next hour packing up belongings.  Within a few hours, the tents had been collapsed, neatly folded, and stowed away. Several truckloads were taken to the Site Museum, where we store some research equipment and tables. The kitchen was disassembled. Several hours passed with everyone milling about, loading trucks, cleaning, and packing. Everyone piled into the cars and eventually began the journey back to Nairobi. And that was the end of our field camp, Kampi Safi, for this field season.  For some…

Posted on 2011-08-03 by Rick Potts

August 3, 2011

After a very productive season of over 2000 artifacts, it’s time to wrap up the excavations at BOK-2.  At one point, it seemed like the artifacts would never stop coming, no matter how far the team dug. Eventually, the excavators hit the grey tuff – you may recall (on Day 27) , Kay helped us determine that the grey tuff is part of an older layer (Member 9 of the Olorgesailie Formation). The team has now reached this older layer in every area of the excavation, and we’ve reached the end of the Middle Stone Age finds at this site.The crew has spent the last few days doing final digs in preparation for the last lift today.  Katie and John were writing bags (each artifact gets its…

Posted on 2011-08-02 by Rick Potts

August 2, 2011

We’re in our last few days of the field season, but research is still going full speed ahead. Joining us for these last few days is our Kenyan friend and paleobotanist, Ms. Rahab Kinyanjui.Rahab was born and raised in Nakuru, Kenya. She attended primary school in Nakuru and high school in Thika.  Her science interests soared at the Kenyan Polytechnic, where she did a dissertation studying the archeology, pollen analysis, and reconstruction of a site in Nakuru called Hyrax Hill. After graduating from the Polytechnic with her 3-year diploma, Rahab began work at the National Museums of Kenya (NMK) studying palynology and paleobotany. It was here where we crossed paths for the first time, in 2001. I worked with a colleague at the NMK for several years…

Posted on 2011-08-01 by Rick Potts

August 1, 2011

I drove back to Nairobi today for a morning with Kenyan teachers who are charged with teaching human evolution in secondary school. Human evolution is a required teaching assignment in Kenya for the Form 1 (9th grade) history course and the Form 4 (12th grade) biology course. I gave the opening keynote speech, and I was asked to relate our experiences at the Smithsonian in presenting human evolution to diverse public audiences in our Museum’s exhibition, website, and public programs. The workshop was held in the National Museums of Kenya auditorium, and was convened by Dr. Kyalo Manthi of the NMK’s Paleontology Division. Kyalo is also the founder of the Prehistory Club of Kenya.It was interesting for me to hear that the teachers face…

Posted on 2011-07-31 by Rick Potts

July 31, 2011

We’re close to the end of the field season – just a few more days left – and we’ve come to the end of one of our excavations, Site 15. If you read my dispatch on July 25th, you may recall that as we reached the base of the artifact layer, we couldn’t quite figure out what the cluster of large cobbles in one area of the dig was all about.  Why were the cobbles where they were – concentrated in one spot? 

The water that rained on, or flowed across, the site as it was forming was probably pretty slow and inadequate to move the cobbles into the position we found them.  We can tell that from the beds of sediment we unearthed at Site…

Posted on 2011-07-30 by Rick Potts

July 30, 2011

Naomi and I took the opportunity today to talk about ancient soils and what they can tell us.  The best way to do it was to take an excursion to the oldest soil we know of in the Olorgesailie region.  It’s at the very bottom of what we call Member 1 of the Olorgesailie Formation, and it’s very likely close to the oldest dated volcanic ash in the record of sediments – about 1.2 million years old.  As you may recall, Naomi is an isotope chemist and geologist, and her research goal here is to find carbonates formed within old soils.  The carbonates are formed by precipitation in the zone of a soil where plant roots grow. The chemistry of the carbonates reflects the woody or…

Posted on 2011-07-29 by Rick Potts

July 29, 2011

The road to becoming human was sometimes a dangerous one, and survival required sophisticated weapons. Here at Olorgesailie, the BOK-2 team has uncovered one of the first kinds of such weapons—the MSA point. The MSA, or Middle Stone Age, is the more recent of the two stone technologies we have a record of here at Olorgesailie. In our digs, the MSA is represented in a younger formation called the Oltulelei Formation, which lies on top of the older Olorgesailie Formation. This time period is the expertise of Alison and John. The MSA is an intriguing time in prehistory characterized by the rise of much more complicated tool kit and ways of manufacturing tools (i.e., stone technologies).  Flake blades and smaller, more sophisticated prepared cores begin to appear, but…

Posted on 2011-07-28 by Rick Potts

July 28, 2011

Kenya is known for its abundant wildlife, so much so that thousands of tourists from around the world travel here every year to see it for themselves. Today we’ll give you a front row seat of our daily safaris, right here at Olorgesailie.              

Posted on 2011-07-27 by Rick Potts

July 27, 2011

Once upon a time, this arid and dusty terrain was once the home of an ancient lake. Observations of the sediments show that water once filled the Olorgesailie basin. The paleo-lake was a major hotspot, attractive to wildlife and hominins. Therefore, reconstructing the lake and its environment is paramount in our understanding of the life that once lived here. 

Actually, we should use the plural ‘environments’ because the lake changed considerably over its history. The person who has helped us understand this visited camp today.  Bernie Owen is an old friend to our project, and he’s spent many summers with us at Olorgesailie as our diatom specialist. He was joined by colleagues Robin Renaut, Tim Lowenstein, and a graduate student Ginette Felske.Diatoms are a…

Posted on 2011-07-26 by Rick Potts

July 26, 2011

One of the big-picture studies we do here at Olorgesailie focuses on how the landscape changed over time, all the way back to the beginning of the sediment record more than 1 million years ago.  This area of the southern Kenya Rift Valley has the most precisely dated record of archeological and fossil remains in the world for the past 1 million years.  There is only one major gap in the time sequence, between the Olorgesailie and Oltulelei Formations – a gap that resulted from widespread erosion in the region between about 490,000 and 340,000 years.  But other than that, Olorgesailie presents a pretty continuous record from the handaxe era up to and beyond the time of the African origin of our species, Homo sapiens.My geologist colleague,…

Posted on 2011-07-25 by Rick Potts

July 25, 2011

You may recall that we have another excavation going on this season besides the Middle Stone Age site called BOK-2. This other excavation, called Site 15, is one made famous by the fossil elephant skeleton found there along with thousands of stone tools. It’s from the handaxe times, which at Olorgesailie extended from 1.2 million to about 490,000 years old.  A newly published article from a site at Lake Turkana, in northern Kenya, shows that handaxe technology (known as the Acheulean) got its start almost 1.8 million years ago.The digging at Site 15 has gone very well – that is, ‘slow but sure.’ Let me give you an update about the questions that have cropped up as our team of seven has dug downward a few centimeters…

Posted on 2011-07-24 by Rick Potts

July 24, 2011

Every Sunday the Kenyan crew takes a break from the usual rigors of excavation.  This season their favorite place to visit is Kiserian, a town about 45 minutes away just outside the Rift Valley, toward Nairobi. Today, Katie decided to join the crew going to Kiserian to see what it’s like, and she offers her thoughts here about the day off: Kiserian is a relaxed place, but not boring! It houses a lively market and plenty of shops.  Here the crew members typically spend the first few hours shopping for miscellaneous needs.  Afterward, they head to their favorite restaurant where they just unwind for the rest of the day.  They also take the opportunity to have a special lunch, a favorite of many East Africans—nyama choma, which is…

Posted on 2011-07-23 by Rick Potts

July 23, 2011

Evolution doesn’t happen overnight. Instead, changes in the environment usually take thousands of years to be represented by evolution in the morphology, or biological form, of organisms. Yet bones and teeth (and other bodily substances, like shells for organisms that have them) can also record information about their immediate surroundings. These bodily tissues grow within the organism’s lifetime, and they’re built up from the foods organisms eat and the water they take in. 

Maybe you’ve never thought about it this way but… food and water are chemicals – and so chemistry offers a way of looking at how an animal’s bodily tissues, such as teeth, or substances made by plants, such as nodules that grow around the roots of plants, reflect the immediate environment of those organisms. 

Posted on 2011-07-22 by Rick Potts

July 22, 2011

Sometimes solving archeological puzzles requires a step back in order to see the big picture.Our second stratigraphic question at hand regards a layer of sediment at BOK-2: is the gray sandy layer at the base of the excavation, part of the Olorgesailie Formation, or is it in the younger Oltulelei Formation? Answering this question is vital if we are to understand the age of the site and the geological context in which the stone tools have been found. To figure out the answer, we had to take a look outside the site.While the BOK-2 excavation focuses on the concentration of stone tools within a relatively small area, our project has pioneered the need to look beyond each specific dig to understand the larger landscape. In this case,…

Posted on 2011-07-21 by Rick Potts

July 21, 2011

It was great to return to Olorgesailie and Kampi Safi today after my trip to western Kenya and Lake Victoria.  In Nairobi, I was joined to two colleagues who are also members of our team, and they accompanied me back to the Rift Valley.  I have known Kay Behrensmeyer for many years, ever since I was getting my start in East Africa as a young graduate student.  Kay, who is a colleague of mine at the Smithsonian’s Natural History Museum, leads our geological studies at Olorgesailie, and she is a font of information about sediments, stratigraphy, and bones.  I’ve known Naomi Levin since 2002 when she first visited Olorgesailie. Naomi is currently  on the faculty at Johns Hopkins University in Baltimore, Maryland, and she specializes in…