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111.
Dr. Bernd Lammerer 《International Journal of Earth Sciences》1976,65(1):525-535
- Multispectral scanning imageries, revealed from ERTS-1 satellite, show a young lineament pattern in the region of the Northern Calcareous Alps. The statistical distribution of the lineament directions accords well with that of mapped faults. On the other hand, many of these lineaments are not mapped as faults. A more complex type of fracture is supposed for them, composed of many joints and minor faults. With increasing length of the fracture, the acute angle of the shear system increases from about 40° at joints to 70° at faults and 80° at lineaments.
- The satellite imagery shows a relationship between the structures of the folded molasse and the alpine nappes. The mimer and depth of folds, the width of the folded zone, and the lateral limitation of the synclines are related to the amount of thrusting of parts of the nappe system. A model for the genesis of the folded molasse is given.
112.
Hendrik Vogel Giovanni Zanchetta Roberto Sulpizio Bernd Wagner Norbert Nowaczyk 《第四纪科学杂志》2010,25(3):320-338
Here we present a tephrostratigraphic record (core Co1202) recovered from the northeastern part of Lake Ohrid (Republics of Macedonia and Albania) reaching back to Marine Isotope Stage (MIS) 6. Overall ten horizons (OT0702‐1 to OT0702‐10) containing volcanic tephra have been recognised throughout the 14.94 m long sediment succession. Four tephra layers were visible at macroscopic inspection (OT0702‐4, OT0702‐6, OT0702‐8 and OT0702‐9), while the remaining six are cryptotephras (OT0702‐1, OT0702‐2, OT0702‐3, OT0702‐5, OT0702‐7 and OT0702‐10) identified from peaks in K, Zr and Sr intensities, magnetic susceptibility measurements, and washing and sieving of the sediments. Glass shards of tephra layers and cryptotephras were analysed with respect to their major element composition, and correlated to explosive eruptions of Italian volcanoes. The stratigraphy and the major element composition of tephra layers and cryptotephras allowed the correlation of OT0702‐1 to AD 472 or AD 512 eruptions of Somma‐Vesuvius, OT0702‐2 to the FL eruption of Mount Etna, OT0702‐3 to the Mercato from Somma‐Vesuvius, OT0702‐4 to SMP1‐e/Y‐3 eruption from the Campi Flegrei caldera, OT0702‐5 to the Codola eruption (Somma‐Vesuvius or Campi Flegrei), OT0702‐6 to the Campanian Ignimbrite/Y‐5 from the Campi Flegrei caldera, OT0702‐7 to the Green Tuff/Y‐6 eruption from Pantelleria Island, OT0702‐8 to the X‐5 eruption probably originating from the Campi Flegrei caldera, OT0702‐9 to the X‐6 eruption of generic Campanian origin, and OT0702‐10 to the P‐11 eruption from Pantelleria Island. The fairly well‐known ages of these tephra layers and parent eruptions provide new data on the dispersal and deposition of these tephras and, furthermore, allow the establishment of a chronological framework for core Co1202 for a first interpretation of major sedimentological changes. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
113.
Mine tailings are ubiquitous in the landscapes of mined areas. Metal solubilities were compared in two chemically distinct mine tailings from the old Mining District of Cartagena-La Unión (SE Spain). One of the tailings was acidic (pH 3.0) with 5400 mg/kg Zn, 1900 mg/kg As and 7000 mg/kg Pb. The other was neutral (pH 7.4) with 9100 mg/kg Zn, 5200 mg/kg Pb and 350 mg/kg As. In samples from the acidic tailings, more than 15% of the Zn and 55% of the Cd were extractable with 0.1 M NaNO3, and distilled water. In the neutral tailings, using the same reagents, less than 1% of the metals were extractable. A sequential extraction procedure revealed that the sum of the residual and the Fe oxide fractions of Cu, Zn and Pb comprised 80–95% in the acidic tailings and 70–90% in the neutral tailings. The acidic mine tailings had a higher metal solubility, resulting in more metal leaching in the short-term, but also a higher fraction of inert metal. In contrast, in the neutral tailings, the metals were evenly distributed between, oxides and the residual fraction. This implies lower metal mobility in the short-term, but that metal mobility may increase in the long-term. When applied to mine tailings, sequential extractions may provide misleading results because the strong cation exchange capacity of some extractants may induce pH changes and thereby significantly change metal solubility. 相似文献
114.
115.
Altogether 64 predominantly biological traits were coded for more than 600 macroinvertebrate species from European rivers. The main question was: Are biological traits able to reflect “biological functionality” in large rivers and if so, is it possible to deduce an assessment system based on functionality? Analysis of the raw trait structure of all species indicates that these traits are not completely independent from their higher systematic units. To avoid mis-interpretations when judging from mixtures of habitats (β-biocoenosis) we used for our investigations only sample series from -biocoenosis, pre-tested by a mathematical criterion of homogeneity. Within -biocoenosis, traits are shown to be able to compensate for drastic changes with respect to species number and species composition along a river continuum, demonstrating their functional quality. Long-term changes in the trait and species structures of German waterways were studied using multivariate methods, based on an analysis of 142 sampling series. A shift from traits typical for K-strategists to traits typical for r-strategists was detected to be the main background variable. The rK-strategy is regarded as a true functional character of species. We calculated the relative positions of all trait-coded species on this rK-scale, and plotted the functional diversity of our samples against the structural diversity of the species from several river systems. Rivers extremely dominated by r-strategists show a deficit in functional diversity. Rivers dominated by K-strategists also show deficits, possibly in concordance with modern ecological theories such as the intermediate disturbance theory. The quantitative proportions of extreme r- to K-Strategists in -biocoenosis can be used as a general disturbance measure. 相似文献
116.
Lead isotopes of K-feldspars from five granites of the SE-Schwarzwald and from metamorphites are positively correlated in
207/204 as well- as 208/204- vs. 206/204-diagrams.
The linear alignments may be due to correlated laststage lead isotope evolution (lead-lead isochron) and result in a secondary
isochron model age of nearly 3 Ga for the Southern Schwarzwald basement. This calculation implies a long-lasting undisturbed
lead isotope evolution in the Schwarzwald basement since the Archaean. This is not supported however by geochronological studies.
On the other hand the data together with U/Pb-analyses of whole rock samples from metamorphites are consistent with pre-Hercynian
mantle lead addition to the basement. This presumably happened during early Paleozoic polymetamorphism. The interpretation
of the lead isotope correlations as mantle-crust mixing lines needs a rather homogeneous pre-Hercynian mantle lead of the
MORB-type, delivered to the crust probably in part by ascending volatile phases. Thus geodynamical models are supported which
involve subduction of oceanic crust or mantle pluming during the early Paleozoic.
In Part I of this report, the trends in Schwarzwald lead isotopes are discussed as secondary isochrons and as mixing lines.
Constraints are derived for a pre-Hercynian mantlecrust interaction and for lead redistribution by the Hercynian basement
activation. 相似文献
117.
Bernd Wiese Martin Zimmer Martin Nowak Linda Pellizzari Peter Pilz 《Environmental Earth Sciences》2013,70(8):3709-3726
In order to detect hydraulic and geochemical impact on the groundwater directly above the CO2 storage reservoir at the Ketzin pilot site continuous monitoring using an observation well is carried out. The target depth (446 m below ground level, bgl.) of the well is the Exter formation (Upper Triassic, Rhaetian) which is the closest permeable stratigraphic overlying formation to the CO2 storage reservoir (630–636 m bgl. at well location). The monitoring concept comprises evaluation of hydraulic conditions, temperature, water chemistry, gas geochemistry and δ13C values. This is achieved by a tubing inserted inside the well with installed pressure sensors and a U-tube sampling system so that pumping tests or additional wireline logging can be carried out simultaneously with monitoring. The aquifer was examined using a pump test. The observation well is hydraulically connected to the regional aquifer system and the permeability of about 1.8 D is comparatively high. Between Sept. 2011 and Oct. 2012, a pressure increase of 7.4 kPa is observed during monitoring under environmental conditions. Drilling was carried out with drilling mud on carbonate basis. The concentration of residual drilling mud decreases during the pump test, but all samples show a residual concentration of drilling mud. The formation fluid composition is recalculated with PHREEQC and is comparable to the literature values for the Exter formation. The gas partial pressure is below saturation at standard conditions and the composition is dominated by N2 similar to the underlying storage reservoir prior to CO2 injection. The impact of residual drilling mud on dissolved inorganic carbon and the respective δ13C values decreases during the monitoring period. The pristine isotopic composition cannot be determined due to calcite precipitation. No conclusive results indicate a leakage from the underlying CO2 storage reservoir. 相似文献
118.
Soil and sand fine particles, which may be resuspended as fine dust in the atmosphere, contain a variety of anthropogenic
and natural organic components. Samples of fine soil and sand particles (sieved to <125 μM) were collected from the Riyadh
area in the summer of 2003 and extracted with a mixture of dichloromethane and methanol (3:1, v:v). The derivatized total
extracts were analyzed by gas chromatography–mass spectrometry in order to characterize the composition and sources of the
organic components. Both anthropogenic and natural biogenic inputs were the major sources of the organic compounds in these
extracts. Discarded plastics and vehicular emission products were the major anthropogenic sources in the fine particles from
populated areas of the city. Their tracers were plasticizers, UCM, n-alkanes, hopanes and traces of steranes. Vegetation was the major natural source of organic compounds in samples from outside
Riyadh and included n-alkanols, n-alkanoic acids, n-alkanes, methyl alkanoates, sterols and triterpenoids. Carbohydrates had high concentrations (42–54%) in all samples and
indicate sources from decomposition of cellulose and/or the presence of viable microbiota such as bacteria and fungi. The
results were also compared with the data obtained in winter 2002 and showed that anthropogenic inputs were higher in summer
than in winter, whereas the opposite trend was observed for natural inputs. 相似文献
119.
We analysed aftershocks recorded by a temporary digital seismic network following the moderate M w = 5.5 1993, Scotts Mills, Oregon, earthquake. A technique to retrieve source moment tensors from local waveforms was developed, tested, and applied to 41 small earthquakes ( M w ranging from 1.6 to 3.2). The derived focal mechanisms, although well resolved, are highly variable and do not share a common nodal plane. In contrast, the majority of the events, relocated with a joint hypocentre determination algorithm, collapse to a well-focused plane. The incompatibility of the nodal planes of most events with the plane defined by their locations suggests that the aftershocks did not occur on the fault plane, but tightly around it, outlining the rupture area rather than defining it. Furthermore, the moment tensors reveal stable P -axes, whereas T -axes plunges are highly dispersed. We detect a rotation of average T -axis plunge with depth, indicating a change from shallower, predominantly dip-slip mechanisms to deeper strike-slip mechanisms. These characteristics are difficult to explain by remnant stress concentrations on the main-shock rupture plane or asperity- and barrier-type models. We suggest that the aftershocks occurred under the ambient regional stress, triggered by a sudden weakening of the region surrounding the main-shock slip, rather than from a shear stress increase due to the main shock. 相似文献
120.