SOURCES FOR VALLEY-FILL ALLUVIAL SEDIMENTS: BELLA COOLA RIVER BASIN, BRITISH COLUMBIA

Changes in the grain-size distribution and the lithologi-cal I mineralogical properties of sandy-gravel sediments are used to discriminate between sources for the alluvial valley-fill of Bella Coola River, coastal British Columbia. Spatially variable bedrock sources, ranging from highly resistant quartz monzonites to easily weathered basalts, yield sediments that reflect parent rock characteristics. Local increases in the D₉₅ fraction of bulk gravel samples and the D₅₀ fraction of sand samples can be related to inputs from steeper, heavily glaciated tributaries, or those underlain by fractured basalts of the Fraser Plateau. Where there are similarities in the grain-size properties of the source and the sampled deposit, however, grain-size information alone cannot be used to discriminate between sources. The lithology of Bella Coola alluvium shows a close correspondence with the general distribution of rock types in the basin, suggesting proportional contributions from most tributary sources over the long term. However, sand samples from the floodplain have a mostly volcanic affinity, indicating the dominance of sediment derived from headwater tributaries underlain by this rock type. Admixture of plutonic source sediments is evident in lower Bella Coola River adjacent to alluvial fans, heavily glaciated tributary creeks or rock walls comprised mainly of quartz monzonite. Les changements dans la granulometrie et les proprietes lithologiques et mineralogiques des sediments de gravel sablonneux servent d differencier les sources des depéts alluviaux de la Riviere Bella Coola sur la céte de la Colombie-Britannique. La variation spatiale des sources fondamentales donnent des sediments qui refletent les caracteristiques de la roche-mbe variant des quartz rnonzonites très résistants aux basaltes superficiellement altérés par les agents atmospheriques. Les augmentations locales dans la fraction D₉₅ des echantillons de gravel et la fraction D₅₀ des echantillons de sable peuvent être reliees la contribution des tributaires aux pentes plus escarpees et fortement glaciaires ou ceux qui traversent les basaltes fractures du Plateau Fraser. Cependant, quand il y a des similitudes dans la granulometrie de la source et le dépôt-échantillon, l'information granulometrique seule ne peut pas 6tre employee pour differencier les sources. La lithologie des alluvions de Bella Coola montre une correspondance avec la distribution générale des types de roches dans le bassin, suggérant des contributions proportionnelles des sources tributaires a long terme. Cependant, les échantillons de sable des plaines sujettes à inondations ont en grande part une affinité volcanique, indiquant que la dominance du sédiment provient des tributaires qui traversent ce type de roche. Une addition de sediments de sources plutonique est evidente dans le bas de la Riviere Bella Coola adjacent aux eventails alluviaux, aux ruisseaux tributaires affect& par une forte glaciation, ou aux murs de roches qui comprennent principalement des quartz monzonites.     

Bronze Age Globalisation and Eurasian Impacts on Later Jōmon Social Change

Journal of World Prehistory - From northern China, millet agriculture spread to Korea and the Maritime Russian Far East by 3500–2700 BC. While the expansion of agricultural societies across...     

Identifying pre-Hispanic water storages in agricultural areas of south-central Andes through diatom evidence

In the Andes, there are several pre-Hispanic irrigation networks with structures destined for water storage. However, it has not been widely discussed in archaeological research. This is probably due to their being difficult to identify. The aim of this study is to explore the use of diatom assemblage analysis as a methodological tool suitable to help in the identification and characterization of these ancient hydraulic structures. We analyzed two archaeological structures interpreted as water reservoirs from north-western Argentina (EH1 in Antofagasta de la Sierra and U-88R1 in Yocavil) and compared them to current reservoirs. The diatom species composition and the changes in the dominant ecological groups in the studied structures highlight different periods of hydraulic behavior. EH1 contained and stored water, but there were periods of time in which there was a lack of use or abandonment of the structure. However, the U88-R1 structure does not have diatom evidence of containing standing water for a prolonged time but presence of wet soils. Thus, the structure could have been used for other water management strategies. The results show that diatom analysis is a methodological tool with a high potential to study ancestral hydrotechnologies.     

1989: THE CHRONOPOLITICS OF REVOLUTION

A failed effort at “reform from above” or a dramatic reassertion of “people power”? Almost thirty-five years on, studies of the Revolutions of 1989 continue to be framed by these two polarities. However, this historiographical focus has meant that scholars have often overlooked the actual content and character of protest itself. This article argues that one way of reinjecting agency and ideas back into our historical understanding of 1989 is through examining the chronopolitics of revolution: that is to say, by addressing how the control and interpretation of time became a political battlefield, a site of contention and negotiation, between Communist regimes, on the one hand, and political activists and society, on the other. Investigating events in the German Democratic Republic and Czechoslovakia, the article contains two central claims: first, that an interrogation of the concept of “chronopolitics” can provide a new angle by which to grasp the revolutionary character of “1989” and the democratic transformations that resulted and, second, by way of inversion, that a study of the temporal experiences across 1989 and the early 1990s can in turn shed light on the analytical value of “chronopolitics” more generally.