Characterization of traditional raw materials used in housing construction in Huambo Region - Angola

The sustainability of buildings associated to the use of raw earth has motivated the studies and the development of techniques and methods in the context of this type of construction. In the region of Huambo, Angola, these construction techniques are widely used, especially for low-income families who represent the majority of the population. Much of the buildings in Huambo province are built with adobe. Due to the climate in this region, subtropical, hot and humid, with altitudes above 1000 meters and extensive river system, these buildings are particularly vulnerable to the action of water and develop, in many situations, early degradation. The Huambo Province is located in central Angola, has 36 km2 area and approximately 2 million inhabitants. This work aims to evaluate, by conducting in-situ tests, physical and mechanical properties of adobe blocks typically used in the construction of those buildings. The methodology is based on field campaigns where in-situ expeditious tests were performed in soils (smell test, color, touch, brightness, sedimentation, ball, hardness, etc.) and tests on adobes blocks made with traditional procedures, particularly in terms of durability and erodibility (erosion test at Geelong method; evaluation test of wet / dry cycle, applying the New Zealand standards 4297: 1998; 4297: 1998 and 4297: 1999). The results will contribute to the characterization of the geomaterials and methods used in construction with earth in Huambo Province, contributing to the improvement of these sustainable solutions, with a strong presence in this region. The results of this study will also contribute to the proposal of constructive solutions with improved performance characteristics, comfort, safety and durability.

Lithic economy and territory of Epipaleolithic hunter–gatherers in the Middle Tagus: The case of Pena d'Água (Portugal)

In Central Portugal (westernmost Eurasia) the transition from the traditional Pleistocene hunter–gatherer societies to the complex Mesolithic societies of the Holocene has been debated for decades. While some argue that these differences were a progressive phenomenon that started with the shift from the Pleistocene to the Holocene, others defend that the Late Pleistocene patterns were fairly similar to those of the Epipaleolithic and that the major shift was rapid, dramatic and triggered by the necessary adaptation to the 8.2 ka cal BP (8.09–8.25 ka cal BP) climatic event. The study of lithic raw material provenance might be useful for this discussion, since it has been suggested that the Magdalenian and Epipaleolithic populations from this region were collecting this resources within a close range territory, whereas the Mesolithic populations were acquiring them at longer distances. In this paper, we present the results from p-XRF, VP-SEM-EDS and μ-XRD analysis done on the Epipaleolithic lithic assemblage from Pena d'Água Rockshelter, and in some geological samples from secondary sources located ∼14 km from this site. This layer is of major relevance for this debate since it is dated from 8.19 ka cal BP. If the transition was gradual, it would be expected that this assemblage would show some traits of higher-complexity seen in the Mesolithic, namely of longer distance acquisition. However, our results indicate correspondence between the archaeological chert types and some of the geological sources. The differences seen between the archaeological specimens and geological samples are mostly present in traits that can be related with manufacture, handling and post-depositional phenomena. The results suggest that, in what concerns to the economy of abiotic resources, the Epipaleolithic populations living at the time of the dramatic 8.2 ka cal BP cold event, were performing a short range acquisition of lithic raw materials which reinforces the idea of continuity from the Late Pleistocene to the 8.2 ka cal BP event and an abrupt and dramatic shift soon after this phenomena.