Testing the “shift in the balance of power” hypothesis at Swartkrans, South Africa: Hominid cave use and subsistence behavior in the Early Pleistocene

C.K. Brain documented two interesting patterns in the Pleistocene faunas of Swartkrans Cave, South Africa: (1) The earliest depositional units, Members 1 and 2, preserve high numbers of hominid fossils, while the numbers drop sharply in the more recent Member 3. (2) Burned bone specimens, which seem to have been altered in fires tended by hominids, appear for the first time in Member 3. It was suggested that mastery of fire provided a “shift in the balance of power”, allowing hominids to carry out activities in the cave for the first time unmolested by predators. A lack of butchered bones in Members 1 and 2 and their presence in Member 3 provided support for the hypothesis. However, we have now identified butchered bones in all three units. Further, our findings reveal a lack of variability in butchery patterns through time at Swartkrans; in all cases hominids appear to have been proficient carcass foragers. The real “shift” at Swartkrans does not appear to be one of eventual hominid dominance over carnivores, but rather one of a predominance of leopards at Swartkrans in Member 1 times to the alternating presence of leopards and hyenas in Members 2 and 3. Consistent leopard presence in Member 1 seems to have discouraged hominid activity in the vicinity of the cave. In contrast, by the time Members 2 and 3 were forming hominids may have temporarily used the cave, taking advantage of those periods of carnivore absence.     

Agricultural slope management and soil erosion at La Laguna,Tlaxcala, Mexico

Several superimposed systems of agricultural terracing are preserved at the archaeological site of La Laguna in central Mexico. Excavations uncovered complex stratigraphic sequences of terrace fills and colluvial deposits. Their chronology was established by radiocarbon, optically stimulated luminescence (OSL), and the presence of diagnostic features and artifacts. The Formative occupations of the site (ca. 600–400 BC and 100 BC–AD 100) resulted in severe erosion and exposure of indurated subsoil horizons. In the Middle to Late Postclassic (AD 1150–1520) stone-walled terraces were built to recover the degraded slopes for cultivation. Renewed reclamation works have been undertaken since the Colonial period, eventually taking the form of sloping-field terraces with berms planted in maguey. The reconstructed sequence of local land use underscores the risks of dating agricultural features by association with sherd scatters, as well as the complexity of the relationships between demographic variables, agricultural intensity and terracing.     

The mystery of plague in medieval Iceland

This article is aimed at encouraging scholars to continue to take critical, interdisciplinary approaches to understanding the cause and scale of historic plague outbreaks. It does this by reinvestigating two recorded outbreaks of plague in Iceland in 1402–4 and 1494–5. It is argued that these were episodes of pneumonic plague, caused by Yersinia pestis, and that the likely mortality was no more than 25% of the population in both cases. This contrasts with the higher rates (50–60% and 30–50%) postulated elsewhere. Although it is recognised there are other explanations for plague in Iceland, greater caution needs to be taken in interpreting the direct and indirect evidence for its demographic effects. A lower mortality rate fits better with a less widespread and more fragmented epidemic. The numbers and types of Icelandic farms which might have been vacant during the fifteenth and early sixteenth centuries are given more detailed consideration than in previous accounts. ‘Farm abandonment’ in the fifteenth century was continually driven by a series of environmental and economic factors and need not be interpreted as a demographic collapse caused solely by the plague. Greater attention is also given to understanding how plague could have reached Iceland and the biological, ecological and sociological factors which might then have sustained it.     

Macusani obsidian from southern Peru: A characterization of its elemental composition with a demonstration of its ancient use

Transparent obsidian artifacts have been reported for the northern Lake Titicaca Basin. Based on instrumental neutron activation analysis (INAA) of these artifacts a distinct chemical group was identified. Yet, the location of the source of transparent obsidian in the southern Andes remained unreported in the archaeological literature. This paper reports on the chemical composition and geographic location of a source of transparent obsidian from the Macusani region of Peru. Through the use of INAA and portable X-ray fluorescence (PXRF) we demonstrate that Macusani obsidian or macusanite comprises (at least) two chemical groups. One of these groups was used for making artifacts during the Archaic Period. Artifacts made of this obsidian were found more than 120 km from the source and yet, one-third of the obsidian artifacts encountered at Macusani were from the non-local source of Chivay which is 215 km to the southwest.