Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea

During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a discontinuous deposition of fine sediments, but net sedimentation rate of about 3mm/y led ultimately to a gradual coverage of the dumped material. During the first decades after the dumping, about half of the originally dumped material was already spread over the surrounding area as a result of sediment dynamics and re-suspension processes. Recent sediments of the historical dump site are still significantly enriched in heavy metals and PAHs. Microbiological toxicity test results were positive, though uptake of contaminants in mussels was found to deviate only slightly from that of a non-contaminated reference station due to a gradual dilution and decrease in bioavailability of the contaminants.     

Diamond Discovered in High-Al Chromitites of the Sartohay Ophiolite, Xinjiang Province, China

In recent years diamonds and other exotic minerals have been recovered from mantle peridotites and high-Cr chromitites of a number of ophiolites of different age and different tectonic environments. Here we report a similar collection of minerals from the Sartohay ophiolite of Xinjiang Province,western China,which is characterized by having high-Al chromitites. Several samples of massive podiform chromitite with an aggregate weight of nearly 900 kg yielded diamonds,moissanite and other highly reduced minerals,as well as common crustal minerals. Thus far,more than 20 grains each of diamond and moissanite have been recovered from heavy mineral separates of the chromitites. The diamonds are all 100-200 μm in size and range in color from pale yellow to reddish-orange to colorless. Most of the grains are anhedral to subhedral octahedra,commonly with elongate forms exhibiting well-developed striations. They all display characteristic Raman spectra with shifts between 1325 cm-1 and 1333 cm-1,mostly 1331.51 cm-1 or 1326.96 cm-1. The moissanite grains are light blue to dark blue,broken crystals,50-150 μm across,commonly occurring as small flakes or fragments. Their typical Raman spectra have shifts at 762 cm-1,785 cm-1,and 966 cm-1. This investigation extends the occurrence of diamonds and moissanite to a Paleozoic ophiolite in the Central Asian Orogenic Belt and demonstrates that these minerals can also occur in high-Al chromitites. We conclude that diamonds and moissanite are likely to be ubiquitous in ophiolitic mantle peridotites and chromitites.     

Sinian Stratigraphy of the Yangtze Valley

INTRODUCTION The term 'Sinian', in its restricted sense, is used to designate asequence of old, sub-metamorphosed or normal sediments, lying unconfor-mably upon the deeply metamorphosed and schistose series of the Wutai,and below the fossiliferous beds of the Lower Cambrian. In the YangtzeValley, it generally comprises a sub-metamorphosed sequence including     

“Subduction Initiation” for the Genesis of Podiform Chromite Deposits

<正>There is a diversity of unusual minerals and mineral inclusions associated with podiform chromitites.The presence of these minerals suggests that grains of amphibolite(plagioclase,amphibole and zircon)and eclogite(coesite,kyanite and garnet)were present in the magmas from which chromite crystallized.Multiphase     

A Bayesian network for analyzing biological acute and long-term impacts of an oil spill in the Gulf of Finland

Knowledge of oil-induced impacts from the literature and experts were used to develop a Bayesian network to evaluate the biological consequences of an oil accident in the low-saline Gulf of Finland (GOF). Analysis was carried out for selected groups of organisms. Subnetworks were divided into subgroups according to a predicted response to oil exposure. Two scenario analyses are presented: the most probable and the worst-case accident.The impact of the most probable accident in the GOF is rather small. In most of the groups studied oil-induced long-term effects are evaluated to be minor at least from the perspective of the whole GOF. After the worst-case accident negative effects are more likely. The model predicts that the most vulnerable groups are auks and ducks. Amphipods, gulls and to a lesser extend littoral fishes and seals may show delayed recovery after an accident. Also annual plant species may be susceptible to oil-induced disturbances.     

Effects of chronic exposure to dispersed oil on selected reproductive processes in adult blue mussels (Mytilus edulis) and the consequences for the early life stages of their larvae

Mussels (Mytilus edulis) were continuously exposed to dispersed crude oil (0.015-0.25 mg/l) for 7 months covering the whole gamete development cycle. After 1 month exposure to 0.25 mg oil/l, the level of alkali-labile phosphates (ALP) and the volume density of atretic oocytes in female gonads were higher than those in the gonads of control females, indicating that oil affected the level of vitellogenin-like proteins and gamete development. Spawning of mussels was induced after 7 months oil exposure. Parental oil exposure did not affect subsequent fertilization success in clean seawater but this was reduced in 0.25 mg oil/l. Parental exposure to 0.25 mg oil/l caused both slow development and a higher percentage of abnormalities in D-shell larvae 2 days post-fertilization; reduced growth 7 days post-fertilization. These effects were greatly enhanced when larval stages were maintained at 0.25 mg oil/l. Similar studies are warranted for risk assessment prognosis.     

喜马拉雅的结构和构造——关于地球物理观测的概略小结

喜马拉雅地区的主要结构和构造与岛弧的相似 ,但被轻的印度陆壳 (不是洋壳 )消亡引起的作用所改造。恒河盆地下的前第三纪基底的表面形态与海洋深海槽的表面形态相似 ,而中印高原是外部地形隆起的追忆记载。印度地盾上的重力异常与朝向海洋的岛弧的重力异常相似 ,并具有岩石圈在深海沟处向下弯曲和在外缘隆起处向上挠曲的模式。断裂面的分解式说明印度岩石圈确实弯曲 ,然后以低角度向喜马拉雅山俯冲。来自印度和岛弧的有关这方面的资料说明了同一个现象。大西洋和印度洋的海洋地球物理资料 ,可以对最后 70 Ma的印度和欧亚地质史加以恢复。一种急剧减缩作用 ,速率大致为 1 0 0 mm/ a。大概在 40 Ma前接近或稍晚于地质上所推定的碰撞时间。印度向巨大深处的消亡作用假定为漂浮的大陆壳所阻碍。印度地壳的浮力可能导致收敛速率的降低 ,但不是停止。虽然与新断裂的产生以及印度板片一个个地向上推置 ,形成山脉带有关 ,但地震记录表明 :沿低角底断裂面 (可在主边界断裂上或紧邻主边界断层 )的俯冲断裂作用 ,使敛合作用继续发生。重力异常与这种解释是一致的。假若喜马拉雅是由印度次大陆古老板片北缘的断裂作用和仰冲板片所建立起来的 ,那么与重力资料说明有 30 0— 40 0 km的缩短是一致的。在喜马拉雅山收缩     

Stratigraphy of Upper Cretaceous──Paleogene deposits of northwestern Zeya──Burya sedimentary basin

In the northwestern Zeya──Bureya sedimentary basin, the authors studied coal deposits, including Ivanovsko-Erkovetskyu brown coal square on which is worked off largest Erkovetsky field of brown coal, extending to south flank of the Mesozoic──Cenozoic Belogor'e depression. The verified stratigraphic scheme of the coalfield sedimentary sequence is substantiated by palynological data on core samples from 18 boreholes sampled in the course of detailed prospecting and by paleobotanical analysis of sections in the Yuzhnyi sector of the coalfield. Sections of the Erkovtsy, Arkhara Boguchan, and Raichikha brown-coal mines are correlated. Stratigraphic subdivisions distinguished in the studied sedimentary succession are the middle and upper Tsagayan subformations (the latter incorporating the Kivda Beds), Raichikha and Mukhino formations.