NITRATE-NITROGEN FLUX AND UTILIZATION IN A STREAM ECOSYSTEM DURING LOW SUMMER FLOWS

Analysis of nitrate transport in the downstream reaches of Duffin Creek, Ontario, revealed an average daily loss of 45 kg nitrate-N during low summer flows. The nitrate loss represents 50 per cent of the average daily input of total nitrogen and 75 per cent of the nitrate input received by these channel reaches. Nitrate uptake by benthic algae appears to account for a small portion of the NO₃^- removal. Laboratory experiments suggest that most of the nitrate disappearance from the river reaches is caused by bacterial denitrification and nitrate reduction in stream sediments. L'analyse du transport de nitrate dans l'étendue en aval de Duffin Creek, Ontario, a révélé une perte journalière moyenne de 45 kg de nitrate-N durant l'écoulement affaibli des flots du ruisseau en été. Cette perte de nitrate représente 50 pourcent de la moyenne journalière du total d'azote fourni et 75 pourcent du nitrate reçu par l'étendue de ce canal. Les algues agrostides ne semblent être responsable que d'une faible partie de ladisparition du NO₃^-. Des experiences en laboratoire suggèrent que presque toute la disparition du nitrate dans la riviere est causée par la dénitrification bactérienne et la réduction d'azote dans les sédiments du cours d'eau.     

THE ORIGIN OF BLACK‐FIGURE GREEK CERAMICS FOUND IN NAUCRATIS (NILE DELTA)*

At the site of the Greek trading port of Naucratis, located on the Canopic mouth of the Nile inland from Alexandria, Flinders Petrie and later archaeologists encountered sherds of Classical Greek black‐figure pottery. We have characterized the pastes of 14 of these specimens, drawn from the collections of the British Museum and the Ashmolean Museum at Oxford, by neutron activation analysis and numerical taxonomy. The ceramics agree in composition with a reference group centred on Athens. We also investigated a small number of additional black‐figure sherds from other sites. One specimen, from Ruvo di Puglia (Italy), actually originated in or near Marseilles. There was no evidence for local manufacture of black‐figure pottery at Naucratis.     

NEUTRON ACTIVATION ANALYSIS AT THE BRITISH MUSEUM,LONDON

Neutron activation analysis was used at the British Museum from 1978 until 2002 for provenance studies on ceramics and marble. Significant numbers of the items analysed were of high quality and value, and careful sampling was necessary to avoid damage to the object. An in‐house British Museum Standard Pottery was established and inter‐calibrated with a number of standards used by other archaeometry laboratories. The results of the projects have been published in many papers, and the databases established will be of use to future scholars interested in the ceramic groups represented. Projects on Greek and Near Eastern pottery have been undertaken. Relatively large numbers of north European medieval and post‐medieval pottery samples were analysed, as well as the tin‐glazed ceramics of Spain and Italy. Classical marble has also formed the subject of another project and a database of quarry material has been established.     

GEOMETRIC SQUARES

Summary: One type of male figure on Attic Late Geometric vases has a rectangular rather than triangular torso. the general interpretation of this shape as a square shield is not valid, and it is already recognised that we have some examples which represent a bell-corslet and a chiton. the warriors on the chariots in the main frieze of an amphora by the Anavysos painter in the British Museum appear to be wearing non-metallic corslets. A review of extant material suggests we should be cautious in interpreting square-bodies since artists availed themselves of the convention for a number of purposes. the extent of the use of non-metallic corslets in the eighth and seventh centuries cannot be judged from this evidence, but its very use is a significant factor in the debate over the introduction of hoplite armour and tactics in Greek society.