A particular type of cobble spall tool from the Canadian Plains : multi-variant analysis of early-middle period Eldon Unifaces

Eldon unifaces are unifacially flaked stone tool artifacts that are unique to the Canadian Plains of the early-Middle Period (7,500-4,500 ya). They are unique because cortex covers the ventral side. The artifacts also have a suit of traits such as being thinned (or an attempt was made to thin), unifically flaked, and there is a preference for them to be made from large quartzite cobbles. Further morphological traits indicate that there are four related types of these tools: Classic, Corner, Side, and Amorphous; the first two are the focus of this thesis. Design theory and Châine Opératoire are used to study how the artifacts were made and used. Other geographic regions are sought for similar artifact forms: Manitoba, Eastern Woodlands /Maritimes, and British Columbia. It is the cobble spall tools from British Columbia that has the most striking similarity in morphology and manufacturing strategy. There are also important differences like in how Eldon unifaces are more heterogeneous and circumscribed to a shorter period of time than the British Columbia artifacts. A morphological and usewear analysis is undertaken to ascertain the function of Classic and Corner Eldon unifaces. The morphological analysis indicates that the tools were likely used to process medium to hard materials; however, the literature is rife with contraditctions on how to relate morphology with function. This questioned the reliability of a morphological approach to function and indicated that it needed to be supported by a usewear approach. The usewear analysis supported the inferences of the tools working medium to hard materials and also indicated how the tools were used (motion). Further, the usewear and morphological analyses also indicated that the Eldon unifaces were likely hafted

Temporal Variation and Respons of Mangrove Soil on Solar Illumination Changes

Research on soil temperature in mangrove forest is a part of the mangrove ecosystem microclimate research. Studieson microclimate variables interaction, including soil temperature is important and interesting because it is associatedwith ecosystem and environmental changes, and the biota living in it. This study developed a mathematical modelingof soil temperatures and solar illumination in mangrove forest and the surrounding environment. Mathematicalmodeling function was constructed using data measured on three transects which different in ecosystem condition.The results showed that the mathematical modeling parameters produced the parameters of solar illumination andsoil temperatures that were difference for the three transects. Time lag of soil temperature on solar illumination wasalso diference in the three transects due to the difference of penetration of sun radiation and soil inundation by seawater. These parameters also showed the differences between the soil temperature in mangrove with the soiltemperature in terrestrial forest as studied by the former researcher. Our research demonstrated the charachteristicof soil temperature in mangrove, that was not merely controlled by sun radiation, but also it was contribute by thesea water and other factors.[How to Cite: Medellu C, Soemarno, Marsoedi and S Berhimpon. 2012. Temporal Variation and Respons of Mangrove Soil on Solar Illumination Changes. J Trop Soils 17 (2) : 67-74. Doi: 10.5400/jts.2012.17.2.165][Permalink/DOI: www.dx.doi.org/10.540/jts.2012.17.2.165

Vertical Heat flux Analyses over Pasture and Forest in Amazônia using a les Model

As análises de fluxo de calor vertical foram feitas sobre um sítio de pastagem e floresta da Amazônia, usando um dia durante a estação seca (RBLE 3). Depois de uma validação satisfatória, as simulações apresentaram para a pastagem um rápido e mais alto desenvolvimento convectivo, devido ao alto fluxo de calor sensível na superfície e um baixo decaimento, no topo da camada, no final do dia