Vertical migration ofcentropages typicus (copepoda) in Chesapeake Bay,with some thoughts on migration studies

Centropages typicus was collected at two hour intervals over a diel cycle at a station near the Chesapeake Bay mouth. The species migrated upward at dusk and downward at dawn. Neither light, temperature, salinity, nor density appeared to cue the migration. Attention is drawn to the need for information on the extent and regularity of migration by individual organisms, and how the lack of such information may lead to poor interpretations of migration data.     

Channel constituents in beryl

The electronic absorption spectra of Fe²⁺ in non-chromium beryls are examined. Fe²⁺ in the Al-rich six-coordinate site produces absorption bands at about 820 nm and 970 nm polarizedE‖c. Fe²⁺ in the channel produces bands at 820 nm (⊥c) and 2100 nm (‖c). Some blue beryls which are more intensely colored than most aquamarines, have an absorption band at ～700 nm (‖c) which is suggested to arise from an Fe²⁺/Fe³⁺ intervalence interaction. Fe²⁺ in both the six-coordinate site and the channel is identified in the Mössbauer spectra. The Mössbauer spectra of deep blue beryls are unusual and have not been satisfactorily explained. Color changes which accompany heating and irradiation are strongly influenced by the channel iron.     

Pollution studies in the Firth of Forth

The Firth of Forth, on the east coast of Scotland has hitherto received the untreated wastes of the city of Edinburgh. Some areas of the southern side of the Firth are heavily polluted in consequence. A new sewage treatment scheme will be introduced early in 1976 and a six-year monitoring programme is in progress to measure the efficiency of the new scheme. It is hoped that this work will eventually contribute to a better understanding of the influence of domestic and industrial sewage on the marine and estuarine environment.     

First cosmogenic 10Be age constraint on the timing of Younger Dryas glaciation and ice cap thickness,western Scottish Highlands

We use cosmogenic ¹⁰Be surface exposure age techniques at a locality close to Rannoch Moor, western Scottish Highlands, in order to establish the age and chronology of its most recent glaciation. Glacial erratics and an in situ bedrock quartz vein sampled from this site—the summit of Beinn Inverveigh—have yielded zero‐erosion exposure ages of 12.9 ± 1.5 ka to 11.6 ± 1.0 ka, implying complete ice cover of the mountain during the Younger Dryas, or Loch Lomond Stadial. These results fit closely with published ¹⁴C dates that bracket the maximum (lateral) extent of ice cap outlet glaciers, and are the first internally consistent ages to specifically address this period of glaciation in Scotland. Furthermore, the dates imply that previous palaeoglaciological reconstructions for this area may have underestimated both the thickness of the former ice cap and, by implication, its volume. © British Geological Survey/Natural Environment Research Council copyright 2007. Reproduced with the permission of BGS/NERC. Published by John Wiley & Sons, Ltd.     

A Geoarchaeological Study of the Middle and Upper Pleistocene Levels at Canteen Kopje,Northern Cape Province,South Africa

Canteen Kopje, situated in the Northern Cape Province of South Africa, has two main archaeological deposits: alluvial gravels and a mantle of overlying fine sediments known locally as the “Hutton Sands.” This paper focuses on the fine sediments, the three industries contained within them, and the interface with the underlying gravels in an attempt to clarify their formation and transformation. A Fauresmith assemblage is found at this interface; it is thus crucial to understand the processes of deposition and modification at this poorly understood boundary. The methods used in this study involved the analysis of artifact depositional (dip and orientation) and spatial data, artifact condition, raw materials, and assemblage size profiles. Data presented document the mixing between the lowest levels of the fine sediments and the underlying alluvial gravels. This study thus provides important contextual information for the Fauresmith industry at Canteen Kopje.     

Controls on biochemical oxygen demand in the upper Klamath River,Oregon

A series of 30-day biochemical oxygen demand (BOD) experiments were conducted on water column samples from a reach of the upper Klamath River that experiences hypoxia and anoxia in summer. Samples were incubated with added nitrification inhibitor to measure carbonaceous BOD (CBOD), untreated to measure total BOD, which included demand from nitrogenous BOD (NBOD), and coarse-filtered to examine the effect of removing large particulate matter. All BOD data were fit well with a two-group model, so named because it considered contributions from both labile and refractory pools of carbon: BOD_t = a₁(1 ? e^? a₀t) + a₂t. Site-average labile first-order decay rates a₀ ranged from 0.15 to 0.22/day for CBOD and 0.11 to 0.29/day for BOD. Site-average values of refractory zero-order decay rates a₂ ranged from 0.13 to 0.25 mg/L/day for CBOD and 0.01 to 0.45 mg/L/day for BOD; the zero-order CBOD decay rate increased from early- to mid-summer. Values of ultimate CBOD for the labile component a₁ ranged from 5.5 to 28.8 mg/L for CBOD, and 7.6 to 30.8 mg/L for BOD. Two upstream sites had higher CBOD compared to those downstream. Maximum measured total BOD₅ and BOD₃₀ during the study were 26.5 and 55.4 mg/L; minimums were 4.2 and 13.6 mg/L. For most samples, the oxygen demand from the three components considered here were: labile CBOD > NBOD > refractory CBOD, though the relative importance of refractory CBOD to oxygen demand increased over time. Coarse-filtering reduced CBOD for samples with high particulate carbon and high biovolumes of Aphanizomenon flos-aquae. There was a strong positive correlation between BOD, CBOD, and the labile component of CBOD to particulate C and N, with weaker positive correlation to field pH, field dissolved oxygen, and total N. The refractory component of CBOD was not correlated to particulate matter, instead showing weak but statistically significant correlation to dissolved organic carbon, UV absorbance at 254 nm, and total N. Particulate organic matter, especially the alga A.flos-aquae, is an important component of oxygen demand in this reach of the Klamath River, though refractory dissolved organic matter would continue to exert an oxygen demand over longer time periods and as water travels downstream.