Endolithische Wurm-Tunnelbauten (Lapispecus cuniculus n. g. n. sp. undDodecaceria [?] sp.) in Brandungsgeröllen der oberen Kreide im nördlichen Harzvorlande

The well known Santonian conglomerates from the area north of the Harz Mountains contain holes due to leached dolomitic pebbles of Kimmeridgian age, in which well preserved casts of “worm”-burrows have been observed. In smaller pebbles - caused by the lack of space — they were burrowed in narrow windings resembling the Serpulid genusGlomerula. However, their mode of winding differs from that of these Serpulids: The convex arches made by the boring organism must be regarded as a behavioural response when approaching the surface of the pebbles. In the loops of the burrows often a “Spreite” is found, but it is also observed in the convex windings and even parallel to the straight cylindrical burrows. That is in contradiction to the conventional definition of the “Spreite”. The burrows which may belong to the Polychaetes are described asLapispecus cuniculus n. g. n. sp. Other rare burrows have been identified asDodecaceria (?) sp.     

Zur Temperatur-Kurve der Oberen kreide in Europa

Zusammenfassung Wenn die auf Grund der¹⁶O¹⁶O-Methode konstruierte Temperatur-Kurve des Oberkreidemeeres (Lowenstam &Epstein 1954,Bowen 1961) richtig ist, welche für die Zeit des Coniac-Santon ein Wärmeoptimum gegenüber niedrigeren Temperaturen im Cenoman und Obermaastricht verzeichnet, so wäre zu erwarten, da\ diese Klimaveränderung auch in der Faunenzusammensetzung der einzelnen Oberkreidestufen deutlich zum Ausdruck kommt. Das ist merkwürdigerweise nicht oder kaum der Fall, wie aus der Verbreitung der mediterranen Faunenelemente in der borealen bzw. zentraleuropäischen Faunenprovinz hervorgeht. Gro\foraminiferen, Riffkorallen, Rudisten und andere Warmwasserformen zeigen zahlenmä\ig ihre grö\te Verbreitung au\erhalb der Tethys im Cenoman und im Obermaastricht. Die Globotruncanen-Verbreitung ergibt kein einheitliches Bild; doch ist die bisherige Vorstellung von einem allmählichen Rückzug der Globotruncanen (s. l.) nach Süden vom Coniac-Santon bis zum Obermaastricht zu revidieren. Die Aufgabe der vorliegenden Arbeit besteht in der Diskussion der sich aus der geochemischen und ökologisch-faunistischen Arbeitsweise ergebenden Resultate, die z. T. erheblich voneinander abweichen. Es ist zu hoffen, da\ es gelingt, die z. Z. noch bestehenden Widersprüche zu klären und sowohl die für die Paläoklimatologie so aussichtsreiche Isotopenmethode als auch die tiergeographisch-ökologische Arbeitsweise weiter zu vervollkommnen.Da mit einer späteren Umkristallisation auch der Belemnitenrostren, auf denen die erwähnten Temperaturmessungen beruhen, zu rechnen sein dürfte, wären neue Untersuchungen unter Berücksichtigung dieser Möglichkeit sehr wünschenswert.

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Summary The curve constructed for the temperatures of the Upper Cretaceous seas (Lowenstam &Epstein 1954,Bowen 1961) based on the¹⁶O¹⁸O ratios shows a temperature optimum in Coniacian-Santonian time, but lower temperatures in Cenomanian and Upper Maastrichtian time. These climatic changes ought to be visible in the faunistic composition within the different stages of the Upper Cretaceous too. Strangely, however, judging from the distribution of mediterranean faunal elements in the boreal and central european faunal provinces respectively, this seems not to be the case. Larger foraminifera, reef corals, rudistids, and other inhabitants of warm water are most widespread outside of the Tethys during Cenomanian and Upper Maastrichtian time. The distribution of Globotruncana gives no uniform picture, but the former conception of their gradual retreat towards the south from Coniacian-Santonian to Upper Maastrichtian time must be revised. The author discusses the results obtained by geochemical and by ecological-faunistical methods, which in part are at considerable variance. Hope is expressed that the present inconsistencies will be cleared up and that both methods will still further be improved that based on animal geography and ecology as well as the isotope method which is so very promising for paleoclimatology.The above-mentioned temperature measurements have been obtained from rostra of belemnoids. New investigations ought to make allowance for the probability of their having been recrystallized

     

Free convection scaling over the ocean derived from buoy measurements during gate

The structure of atmospheric turbulence in the surface layer over the open ocean is examined under conditions of local free convection. The raw data consist of profile and fluctuation measurements of wind and temperature as obtained from a meteorological buoy. For near neutral conditions and for waves running approximately along the wind direction, wave-induced wind fluctuations can be described by a simplified linear theory based on Miles (1957). In this case, the spectrum of wind velocity is given as the sum of two parts; for the turbulent part, the parameterization as obtained by Kaimal et al. (1972) applies, while the wave-induced part is parameterized using a simplification of Miles' linear theory. For cases of local free convection, the measurements of the vertical component of the wind velocity are well described by similarity theory; as expected, _w /(-uw)^1/2 is proportional to (- z/L)^1/3. In order to scale the longitudinal wind velocity component, it seems to be reasonable to extend the list of relevant parameters by the height of the mixed layer z _i. We obtain _u /(- uw)^1/2 (z/z _i)^1/3(- z/L)^1/3 with only a poor correlation coefficient of r = 0.6. Overall, the results of local free convection scaling obtained from direct measurements show good agreement with those obtained from profile measurements. A comparison between direct and indirect determination of turbulent fluxes of momentum shows an unexplained difference of about 20%. This discrepancy is mainly due to a gap in the uw-cospectrum at the swell frequency.     

Microphysical and chemical characteristics of cloud droplet residuals and interstitial particles in continental stratocumulus clouds

During June and July 2003 the Sources and Origins of Atmospheric Cloud Droplets experiment (SOACED) was carried out on a mountain-top site in central Sweden. The main objective of the experiment was to characterise the microphysical and chemical properties of cloud droplet residuals and interstitial aerosol particles in continental clouds and to understand the processes controlling cloud properties at this location.Interstitial and residual aerosol size distributions, cloud liquid water content and species- and size-resolved aerosol mass concentrations are the main variables employed to address questions pertaining to the cloud droplet number concentration and scavenging efficiency during a stratocumulus cloud event observed on July 28, 2003. In this cloud event, about 56% of the aerosol mass was associated with organic species, whilst SO₄ accounted for 23% and NH₄ for 14%. NO₃ and Cl made up about 7% of the total mass.The partitioning of the aerosol particles between cloud droplets and interstitial air has been studied in terms of their microphysical properties. The scavenging efficiency, defined as the fraction of particles activated into cloud elements compared to the total amount of particles, was investigated as a function of size. The scavenging efficiency curves displayed different shapes during the cloud event, from an S-shaped curve, with low scavenging efficiency in the Aitken mode and larger scavenging efficiency in the accumulation mode, to more unusual shapes where Aitken-mode particles were either solely activated or activated in addition to accumulation-mode particles.This study suggests that alterations of the aerosol chemical composition occurred during the measurement period, changing the hygroscopic nature of the CCN and decreasing their activation diameter. It is also hypothesized that entrainment of drier air aloft may have introduced inhomogeneities in the supersaturation field and modified the S-shaped scavenging curves.     

The Rila-Pastra Normal Fault and multi-stage extensional unroofing in the Rila Mountains (SW Bulgaria)

The Rhodope Metamorphic Province represents the core of an Alpine orogen affected by strong syn- and postorogenic extension. We report evidence for multiple phases of extensional unroofing from the western border of the Rila Mountains in the lower Rila valley, SW Bulgaria. The most prominent structure is the Rila-Pastra Normal Fault (RPNF), a major extensional fault and shear zone of Eocene to Early Oligocene age. The fault zone includes, from base to top, mylonites, ultramylonites and cataclasites, indicating deformation under progressively decreasing temperature, from amphibolite-facies to low-temperature brittle deformation. It strikes E–W with a top-to-the-N-to NW-directed sense of shear. Basement rocks in the hanging wall and footwall both display amphibolite-facies conditions. The foliation of the hanging-wall gneisses, however, is discordantly cut by the fault, while the foliation of the footwall gneisses is seen to curve into parallelism with the fault when approaching it. Two ductile splays of the RPNF occur in the footwall, which are subparallel to the foliation of the surrounding gneisses and merge laterally into the mylonites of the main fault zone. The concordance between the foliation in the footwall and the RPNF suggests that deformation and cooling in the footwall occurred simultaneously with extensional shearing, while the hanging-wall gneisses had already been exhumed previously. The RPNF is associated with thick deposits of an Early Oligocene, syntectonic breccia on top of its hanging wall. Integrating our results with previous studies, we distinguish the following stages of extensional faulting: (1) Late Cretaceous NW–SE extension (Gabrov Dol Detachment), exhumation of the present day hanging wall of the RPNF; (2) Eocene to Early Oligocene NW–SE to N–S extension (RPNF); (3) Miocene to Pliocene E–W extension (Western Border Fault), formation of the Djerman Graben; (4) Holocene to recent N–S to NW–SE extension (Stob Fault), reactivating the SW part of the Western Border Fault.     

Land-cover classification and analysis of change using machine-learning classifiers and multi-temporal remote sensing imagery

Frequent human activity and rapid urbanization have led to an assortment of environmental issues. Monitoring land-cover change is critical to efficient environmental management and urban planning. The current study had two objectives. The first was to compare pixel-based random forest (RF) and decision tree (DT) classifier methods and a support vector machine (SVM) algorithm both in pixel-based and object-based approaches for classification of land-cover in a heterogeneous landscape for 2010. The second was to examine spatio-temporal land-cover change over the last two decades (1990–2010) using Landsat data. This study found that the object-based SVM classifier is the most accurate with an overall classification accuracy of 93.54% and a kappa value of 0.88. A post-classification change detection algorithm was used to determine the trend of change between land-cover classes. The most significant change from 1990 to 2010 was caused by the expansion of built-up areas. In addition to the net changes, the rate of annual change for each phenomenon was calculated to obtain a better understanding of the process of change. Between 1990 and 2010, an average of 4.53% of lands turned to the built-up annually and there was an annual decrease of about 0.81% in natural land. If the current trend of change continues, regardless of the actions of sustainable development, drastic declines in natural areas will ensue. The results of this study can be a valuable baseline for land-cover managers in the region to better understand the current situation and adopt appropriate strategies for management of land-cover.     

Some results of a statistical analysis of the S-component of solar radio emission

A statistical treatment of the mean daily solar radio flux between 9400 and 1000 MHz (cm-region) for two solar cycles leads to the following results: No differences have been found between the synodic rotation rates T _mon calculated for different single frequency time series as a whole (rigid rotation of emitting regions). From a piece-wise time series analysis it is concluded that T _mon averaged over all observed frequencies and over times belonging to related years of the two cycles shows a well-expressed dependence on cycle with a maximum of 28.8d following 2 y after the activity minimum and a minimum of 27d shortly after polar magnetic field reversal. Discrete spectral lines with periods smaller than T _mon point on the existence of elementary longitudinal regions of extension between 25° and 33°. The observed facts would support a relation between the sources of the large-scale magnetic field and the S-component.     

Deep reaching fluid flow in the North East German Basin: origin and processes of groundwater salinisation

Major element chemistry, rare-earth element distribution, and H and O isotopes are conjointly used to study the sources of salinisation and interaquifer flow of saline groundwater in the North East German Basin. Chemical analyses from hydrocarbon exploration campaigns showed evidence of the existence of two different groups of brines: halite and halite Ca–Cl brines. Residual brines and leachates are identified by Br^?/Cl^? ratios. Most of the brines are dissolution brines of Permian evaporites. New analyses show that the pattern of rare-earth elements and yttrium (REY) are closely linked to H and O isotope distribution. Thermal brines from deep wells and artesian wells indicate isotopically evaporated brines, which chemically interacted with their aquifer environment. Isotopes and rare-earth element patterns prove that cross flow exists, especially in the post-Rupelian aquifer. However, even at depths exceeding 2,000 m, interaquifer flow takes place. The rare-earth element pattern and H and O isotopes identify locally ascending brines. A large-scale lateral groundwater flow has to be assumed because all pre-Rupelian aquifer systems to a depth of at least 500 m are isotopically characterised by Recent or Pleistocene recharge conditions.