This is my fourth season working in the caves at Pinnacle Point with Professor Curtis Marean, and it is a little different season this year since it is a small-scale excavation mostly in preparation for a much larger fall dig. We are working at the Pinnacle Point cave 5-6 (PP5-6 for short), which has been excavated for five dig seasons and contains a well-exposed section nearly 15 meters in depth. This is the site that resident field director and IHO employee Kyle Brown lead-authored a paper in the journal Science last fall (2009) outlining the earliest documented evidence for heat-treatment of stone to improve its flaking quality. The stone (called silcrete) is very difficult to work with prior to heating but after being heated above 300° C becomes much more predictable in its breakage and easier to manipulate. We see a rise and fall in the abundance of silcrete used from the top of the PP5-6 sequence to the bottom with a culmination of silcrete abundance at the Howieson’s Poort (HP) levels around 65,000 B.P.
We have two main goals this season: (1) figure out how deep the intact archaeological deposits are exposed along an erosion profile that is currently covered in very recent, mixed-up overburden sediment, and (2) create areas where excavators next season are able to safely access layers with archaeological deposits that are currently under-represented.
The first few weeks are mainly about goal #1, which involves a lot of old fashioned shovel and dry-screen work to remove the recent overburden. We’ve removed about 20m3 of sediment so far. This is in stark contrast to the meticulous methods the project has developed for intact archaeological sediments where we are lucky to excavate down more than a few centimeters a week. Being trained in the very detailed (dental-picks, brushes, and 3D piece-plotting are the norm), I feel a bit uneasy wielding the pick-axe and shovel to remove overburden but we have made 100 percent certain that the sediment we are removing is recent and mixed including a set of optically-stimulated luminescence dates that indicated a mixture of sand grains. Geologically, it’s fairly easy to see that what is being removed is not at all related to the intact archaeological deposits since rocks and debris are uniform throughout (“massive”) without any evidence of layering. After a semester of course work mostly reading, typing, and not going to the gym, I’m not ashamed to say this kind of work is fairly exhausting. However, the view from PP5-6 overlooks the Indian Ocean and dolphin and whale sightings are frequent, which quickly distracts us from thinking about the Sisyphean movement of buckets and sandbags around the site. The most rewarding aspect is being a part of the overall effort to uncover the Middle Stone Age. Sometimes this means big discoveries like the early evidence for heat-treatment, but those discoveries are not possible without first doing the difficult logistical work moving rocks, dirt, and sandbags.
More info/Bio—Benjamin Schoville: Ben just finished his second year in the PhD program of the ASU School of Human Evolution and Social Change studying archaeology under the advising of Professor Curtis Marean. Ben’s interests include the Middle Stone Age in Africa, the origins of modern human behavior, hunter-gatherer ecology, and combining lithic and faunal experimental archaeology. Last fall, he was a teaching assistant for the IHO Hadar Field School in Ethiopia assisting professors Kaye Reed and Chris Campisano. This summer, he is working for the fourth season at Pinnacle Point, South Africa with Professor Marean. Ben recently published a paper describing the taphonomic effects of harvester ant mound building behavior on archaeological deposits, and he currently has a paper in press on the assemblage edge damage distribution of Middle Stone Age points from Pinnacle Point cave 13B, South Africa. When Ben and the Mossel Bay student researchers are not excavating this summer, they are planning a series of experimental butchery and thrusting spear studies to replicate edge wear, breakage frequencies, and possible hafting scenarios of a wide range of Middle Stone Age tools, which will form part of Ben’s dissertation.