85 research outputs found
Rock fabrics in palaeoweathering profiles below basement-cover interfaces (AMS-study on drill cores from the Caledonian margin, Central Sweden)
Basement-cover-interfaces are important
crustal boundaries. In many
cases they act as detachment horizons.
Criteria like pre-erosional basement
characteristics, intensity of palaeoweathering
and post-erosional processes
during burial stage lead to a huge variety
of observable alteration and fabric
features of basement-cover-interfaces,
which may influence the shear-strength.
Unconformity-parallel planar fabrics in
the weathering profile were facilitated
by palaeo-alteration and later processes
(Angerer 2005 unpubl. data). Such
fabrics may be a factor for lowering
the shear-strength (e.g. Wintsch et al.
1995). The probably ubiquitous existence
of those fabrics at basement-coverinterfaces
is investigated in case studies
by means of AMS-fabric analysis, which
is a sensitive indicator of rock fabric
changes.
The present case study is based on
sections from two drill cores across
the erosional unconformity between
Fennoscandian Granite (Revsund) and
Cambrian Gärdsjön Fm. (Långviken
SGU 73007 and Hara 79002)
(petrographic descriptions in Gee, 1978
and Gee et al. 1982).conferenc
Electromagnetic radiation (EMR) and its interpretation in terms of stresses in the lithosphere
Electromagnetic radiation (EMR) as
measured at the surface of the lithosphere
or underground shows preferred orientations, which can be related to microcracks
and other brittle structures at
micro and nano scales (see Bahat et al.
2005 and references therein). During
the last years, numerous studies showed
the applicability of EMR measurements
for the determination of active fractures
and stress orientations. EMR is determined
with a ‘Cerescope’, which picks
up EMR signals at frequencies from 5–
50 kHz (Obermeyer, 2005) with a ferrite
aerial and processes them electronically
so that the results can be displayed on
a screen or copied to a computer.
With the help of oriented EMR measurements,
intensity variations are determined,
which can be related to preferred
crack fracture orientations. From
this information, orientations of the
principal stresses can be calculated. In
addition, the intensity of the EMR
is related to stress magnitudes...conferenc
An early Cambrian post-rift basin within the Baltica–Iapetus passive margin (north-central Scandinavian Caledonides)
Long sequence of Quaternary Rocks in the Heidelberg Basin Depocentre
Die neue Forschungs-Kernbohrung aus Heidelberg wird beschrieben und gegliedert. Die Forschungs- und Bohraktivitäten im Heidelberger Becken (HDB) begannen im Jahr 2002; sie erschließen ein kontinentales Sedimentarchiv im Oberrheingraben (URG). Im HDB wird eine der längsten Sedimentabfolgen quartärer Sedimente in Europa erwartet, dank kontinuierlicher Subsidenz des Beckens in Verbindung mit kontinuierlichem Input von Sedimenten unterschiedlicher Herkunft. Das HDB befindet sich auf halber Strecke zwischen dem alpinen Einzugsgebiet des Rheins und seiner Mündung in die Nordsee. Eine kontinuierliche Sedimentation ist hier eher möglich als am Alpenrand mit seinen Schmelzwasser-Erosionsereignissen oder an der Küste mit ihren Meeresspiegelschwankungen. Dieser eher geringe Einfluss des Klimas hat zur Folge, dass die Tektonik eine umso größere Rolle bei der Steuerung der Sedimentation spielt. Die über 500 m mächtige quartäre Abfolge ist daher in erster Linie durch Tektonik kontrolliert, wobei Klimasignale ebenfalls erkannt werden können. Die hier vorgestellte Gliederung der Abfolge beruht auf Provenienz, Lithofazies und wechselnden Verhältnissen von Akkomodationsraum und Sedimentinput (a/s-ratio). Dazu kommen biostratigraphische Zeitmarken. Im skizzierten Sedimentations-Szenario dominieren fluviale Verhältnisse; dazwischen zwei lakustrine Abschnitte. Letztere sind verknüpft mit zunehmendem Akkomodationsraum, der in mindestens einer Zeitscheibe über die Grabenrandstörung hinweg sich bis in die Täler des Odenwalds erstreckt.researc
Dynamic interaction in tropical Africa: IGCP-616Y and IGCP 646 projects and events
The scientific objectives and research program of the IGCP-646 project (2015–2018) cuts across many disciplines and includes various aspects of continental basement geology, resource exploration (mineral, water and hydrocarbons), geohazard mitigation, and climate change, all of which are of critical importance to developing countries, particularly in parts of West Africa where population pressures are on the rise. Considerable emphasis was placed on capacity building, creation of opportunities for young scientists to undertake higher degrees programs, knowledge transfer and training. The SIDA-funded “pilot project” IGCP-616Y (started in 2012), focused on three objects (i) crustal architecture, tectonic evolution and regional geology of Central Africa and the connection with NE Brazil; (ii) the Mesozoic continental rifting and breakup leading to a better integration of the onshore and offshore geology; (iii) clarification and quantification of the links between basement structures, neotectonics, climate change and landscape evolution. The IGCP-616Y and IGCP-646 projects consisted of over 250 researchers, from different countries. In the course of the projects, six annual meetings, four field trips/workshops, as well as several training sessions were organized. Here we provide a summary of the scientific targets of the projects and a summary of the organized activities
Global, local and focused geographic clustering for case-control data with residential histories
BACKGROUND: This paper introduces a new approach for evaluating clustering in case-control data that accounts for residential histories. Although many statistics have been proposed for assessing local, focused and global clustering in health outcomes, few, if any, exist for evaluating clusters when individuals are mobile. METHODS: Local, global and focused tests for residential histories are developed based on sets of matrices of nearest neighbor relationships that reflect the changing topology of cases and controls. Exposure traces are defined that account for the latency between exposure and disease manifestation, and that use exposure windows whose duration may vary. Several of the methods so derived are applied to evaluate clustering of residential histories in a case-control study of bladder cancer in south eastern Michigan. These data are still being collected and the analysis is conducted for demonstration purposes only. RESULTS: Statistically significant clustering of residential histories of cases was found but is likely due to delayed reporting of cases by one of the hospitals participating in the study. CONCLUSION: Data with residential histories are preferable when causative exposures and disease latencies occur on a long enough time span that human mobility matters. To analyze such data, methods are needed that take residential histories into account
Sex differences in short-term mate preferences and behavioral mimicry: A semi-naturalistic experiment
Item does not contain fulltextStudies on short-term mating (STM) yield sex differences regarding preferences for attractiveness (important towomen, very important to men) and social status (very important to women, not to men) in potential mates. Additionally, men generally report a greater desire to engage in STM than women. So far, this evidence is primarily based on studies using vignettes or surveys. The current study extended the findings on sex differences in STM by examining actual behavior and STM-desires towards real people of the opposite sex. It investigated whether (1) sex differences exist in STM-desire, (2) whether this desire was affected by a confederate's attractiveness and status, and (3) if these sex differences were also reflected in interpersonal behavior (mimicry). In a pub-like laboratory, single heterosexual participants performed a task alongside a confederate of the
opposite sex, who differed in attractiveness and social status. Mimicry was observed and explicit STM-desire was assessed. Results showed that men only desired STM more than women in the case of an attractive partner. Women's STMdesire did not vary as a function of status or ttractiveness of the potential partner. Men’s, but not women's, mimicry paralleled these differential STM-desires. These results underline the conditionality of sex differences in STM-desire and provide a useful paradigm to further investigate STM.10 p
A comparison of two orogenic margins : central Scandinavian Caledonides and western Outer Carpathians
The Middle Allochthon in Västerbotten, northern Sweden: tectonostratigraphy and tectonic evolution
A comparison of two orogenic margins: central Scandinavian Caledonides and western Outer Carpathians
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