Geochemistry and lithofacies of Permo-Carboniferous carbonaceous rocks from the southwestern edge of the Bohemian Massif (Germany). A contribution to facies analysis of continental anoxic environments

The Permo-Carboniferous Schmidgaden, Weiden, Erbendorf and Stockheim basins from southern Germany host discontinuous seams of high ash coal and carbargillites which were mined for hard coal, explored for uranium and only recently have proved their source rock potential for gaseous and fluid hydrocarbons. Alteration and facies of these carbonaceous beds were geologically and chemically investigated. During silicification which is exclusively confined to the carbonaceous interbeds of pyroclastic depositions, element depletion prograded except for Zn, Pb, U. The anoxic environments under consideration may be subdivided into fluvial/swamp (Upper Westphalian beds from Schmidgaden, Weiden, Erbendorf and Stockheim) and lacustrine depositions (Upper Stephanian and Upper Autunian carbargillites from Erbendorf, Weiden-Bechtsrieth). SiO₂, MgO, CaO, Mo and Zr have proved to be most suitable for recognition of these environments, whereas, U, K₂O and notably Cu/Zn are less appropriate. In the ternary plots displaying the organic chemistry of extracts of these carbonaceous beds fluvial swamps have low and lacustrine beds high contents of saturated hydrocarbons. All samples show a pronounced OEP (=odd even predominance) of n-alkanes which partly are environment-controlled (terrestrial origin), partly maturity-controlled. The high iso- and cyclo-alkanes of Schmidgaden and bimodal n-alkyl distribution point to a contribution of algal material. Finally four basin types bearing carbonaceous rocks are discussed with respect to their economic potential and compared with basins elsewhere (Cerilly, Lodève, St. Hippolyte, Uinta): type I: intramontane fault-bounded basin (swamp), type II: volcanic-depression with steep relief (swamps), type III: halfgraben (lake), type IV: volcanic-depression with smooth relief (lake). Types I and II are of interest for hard coal, organic-hosted U-deposits and mainly gasprone; types III and IV, however, show good source-rock potential for crude oil.     

Copper, lead and cadmium concentrations in surface water, sediment and fish, C. Carpio, samples from Lake Naivasha: effect of recent anthropogenic activities

Following recent concerns of chemical pollution around Lake Naivasha, especially originating from recent agricultural activities in the catchment, samples of water, sediments, and fish Common carp (Cyprinus carpio) were collected from the Hippo Point, Kasarani, Mouth of Malewa River, Mouth of Karati River, Crescent Island, Sher Karuturi Discharge outlet and Oserian Bay for analysis of Cu, Cd and Pb by FAAS. The mean heavy metal levels ranged from 5.12?C58.11 (Pb), 1.06?C1.73 (Cd), and <0.03?C2.29 (Cu) mg/kg wet weight in C. carpio muscle, <100?C179.83 (Pb), <10.00?C10.06 (Cd) and <30.00?C32.33 (Cu) ??g/L in surface water, and 17.11?C53.07 (Pb), 1.18?C5.58 (Cd) and 3.00?C8.48 (Cu) mg/kg dry weight in sediment and showed a wide variation within and between samples with relatively high concentrations in sediments and fish muscle tissues. The results indicate that Lake Naivasha, in some parts, is polluted with these heavy metals of which relatively higher concentrations are found at the discharge outlets near Sher Karuturi and Oserian Bay. This indicates possible contribution from surrounding horticultural/floricultural activities and the Mouths of the Rivers Malewa and Karati which flow from it??s upper catchment.     

Geography–Internationalisation and the Condition of Forestry in New Zealand

Abstract. Internationalisation is used as a device with which to reexamine geographies of national development and geography in national development in New Zealand. The second half of the paper discusses national and internationalised forestry in New Zealand before considering some of the new possibilities confronting geographers as the New Zealand economy becomes increasingly internationalised.     

Proton acceleration in flares and magnetohydrodynamic solar activity

The possibility of accelerated protons in solar flares having a sharp change in their spectral index is discussed. The analysis is based on the Tsytovich (1982, 1984, 1987a, b, c) acceleration model by MHD turbulence, which is shown to have different resonant conditions for non-relativistic and relativistic particles. The different resonant condition is shown to result in a sharp change in the accelerated proton spectral index, even in the absence of any peculiarity in the spectra of the MHD turbulence. Time scales for accelerated protons to relativistic energies are also derived, and shown to be consistent with observations. We also show that the threshold energy for electron acceleration by low frequency MHD turbulence is much greater than for proton acceleration. The turbulence therefore preferentially accelerates protons.     

The thermophob experiment: Direct investigations of the thermophysical properties of the regolith of phobos

The methodology and the main features of the Thermophob experiment developed for the direct analysis of the thermophysical properties of the surface of the Martian satellite Phobos from the Phobos-Grunt lander are considered. The methodical and engineering aspects of the measurements are discussed, and the design of the instrument and the potential of the interpretation of the measurement results with accounting for the theoretical estimates and the data of the laboratory tests are discussed.     

Tumbling asteroids

We present both a review of earlier data and new results on non-principal axis rotators (tumblers) among asteroids. Among new tumblers found, the best data we have are for 2002 TD₆₀, 2000 WL₁₀₇, and (54789) 2001 MZ₇—each of them shows a lightcurve with two frequencies (full terms with linear combinations of the two frequencies are present in the lightcurve). For 2002 TD₆₀, we have constructed a physical model of the NPA rotation. Other recent objects which have been found to be likely tumblers based on their lightcurves that do not fit with a single periodicity are 2002 NY₄₀, (16067) 1999 RH₂₇, and (5645) 1990 SP. We have done a statistical analysis of the present sample of the population of NPA rotators. It appears that most asteroids larger than ∼0.4 km with estimated damping timescales (Harris, 1994, Icarus 107, 209) of 4.5 byr and longer are NPA rotators. The statistic of two short-period tumblers (D=0.04 and 0.4 km) with non-zero tensile strength suggests that for them the quantity μQ/T, where μ is the mechanical rigidity, Q is the elastic dissipation factor, and T is a spin excitation age (i.e., a time elapsed since the last significant spin excitation event), is greater by two to four orders of magnitude than the larger, likely rubble-pile tumblers. Among observational conditions and selection effects affecting detections of NPA rotations, there is a bias against detection of low-amplitude (small elongation) tumblers.