ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Spreading-subsidence and generation of ensialic marginal basins: an example from the early Cretaceous of central Chile (1984)
    Geological Society of London
    Details
    Publication Date: 1984-01-01
    Print ISSN: 0305-8719
    Electronic ISSN: 2041-4927
    Topics: Geosciences
    Published by Geological Society of London
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    Low-grade regional metamorphism in the Mesozoic-Cenozoic volcanic sequences of the Central Andes (1989)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of metamorphic geology 7 (1989), S. 0 
    Details
    ISSN: 1525-1314
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: All the Mesozoic and Cenozoic volcanic rocks of the Central Andes (from southern Ecuador to central Chile), except Recent ones, have been affected by episodes of regional metamorphism, without change in texture and structure. The metamorphism, which ranges from low zeolite to greenschist facies, can be classified as burial metamorphism because there is an overall increase in metamorphic grade with stratigraphic depth in the individual volcanic sequences separated by regional unconformities. Some sequences display metamorphic patterns transitional to ocean-floor and to geothermal field types, reflecting variations along and across the Andes in tectonic setting and thermal gradients.Volcanism was closely followed by metamorphism during each cycle characterizing the geological history of the Central Andes. The episodic nature of the metamorphism has led to breaks in metamorphic grade at regional unconformities and repetition of facies series, where strata of higher grade may even overlie those of lower grade. The existence of permeability-controlled distribution patterns of secondary minerals within individual flows shows that gradients of chemical activity, rate of reaction and Pfluid were acting, in addition to temperature and P,tot overall gradients, during the regional metamorphism. The alteration is accompanied by chemical changes and disturbances of the K-Ar and Rb-Sr isotope systems. Similarities between Mesozoic facies series in the western and eastern flanks of the Andes are consistent with a mechanism of ensialic spreading-subsidence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1525-1314.1989.tb00611.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Low-grade metamorphism and geotectonic setting of the Macuchi Formation, Western Cordillera of Ecuador (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of metamorphic geology 5 (1987), S. 0 
    Details
    ISSN: 1525-1314
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Abstract The Cretaceous-Eocene basic to intermediate marine volcanic rocks of the Mucuchi Formation constitute the Western Cordillera in northern Ecuador. Their chemical features mostly correspond to those of tholeiitic basalts with some calc-alkaline affinities and suggest an oceanic island arc setting. The Macuchi rocks are affected by low-grade, non-deformative metamorphism, characterized by zeolite, prehnite-pumpellyite and lower greenschist facies assemblages. Depth-zonation is suggested by the downward mineral sequence: (i) laumontite+ (pistacitic epidote, pumpellyite + prehnite); (ii) pumpellyite+ prehnite + pistacitic epidote; (iii) actinolite+biotite+ pistacitic epidote + chlorite. This broad zonation and the chemistry of individual minerals point to an interaction between the volcanic rocks and sea-water under a moderate to high thermal gradient (= 75° C/km?). Alteration appears to have been dependent primarily on fluid control (volume, pressure, composition), temperature and reaction kinetics which together partly overshadow the role of load-pressure. Compositional variations of a mineral species at the scale of a contiguous flow or even at the scale of a thin section show that intensity of alteration was spatially uneven depending on rock permeability and consequently, metastable equilibrium commonly exists. However, a progressive approximation to equilibrium as a result of P–T control is shown by the mineralogy. A high fo2 of the fluid phase is evident from the mineral chemistry. The metamorphism of the Macuchi volcanics is similar to the hydrothermal-burial type produced during the development of a volcanic arc where lavas and volcanoclastics accumulated in a shallow marine environment. However, some of its characteristics point to a transition toward systems defined by a higher T/P ratio such as those found in ocean-floor metamorphism.A model is proposed in which the Macuchi volcanics are assigned to an oceanic island arc generated contemporaneously with a marginal basin which has opened as the outcome of progressive north-south attenuation of the continental crust due to mantle diapirism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1525-1314.1987.tb00397.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Compositional variations of Cretaceous pumpellyites along the western margin of South America and their relation to an extensional geodynamic setting (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of metamorphic geology 11 (1993), S. 0 
    Details
    ISSN: 1525-1314
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: Abstract Pumpellyites in pervasively altered basic to intermediate rocks from three Cretaceous Andean volcanic sequences, the Colombian Diabasic Group, the Ecuadorian-Peruvian Celica Formation/Casma Group and the Chilean Ocoite Group, were studied to test their compositional behaviour in relation to changes in geodynamic setting. They occur mostly in assemblages of the prehnite-pumpellyite facies filling amygdules and inside plagioclase phenocrysts.(a) Pumpellyites from the three geodynamic settings define three distinct compositional fields in AFM space: (i) those in the Diabasic Group plot closer to the Fe corner; (ii) those in the Ocoite Group plot closer to the Al corner; (iii) those in the Celica Formation/Casma group plot between, and partly overlapping, fields (i) and (ii).(b) Pumpellyites in group (i) formed in T-MORB like, K-poor tholeiites (high Fe/Al), affected by ocean-floor metamorphism in an oceanic back-arc basin. Pumpellyites in group (ii) generated in K-rich, calc-alkaline (low Fe/Al) to shoshonitic metabasites affected by burial metamorphism in an ensialic, aborted, marginal basin with moderate attenuation of the continental crust. Pumpellyites in group (iii) formed in basic and intermediate, calc-alkaline to tholeiitic rocks, metamorphosed in ensialic marginal basins with various degrees of continental crust thinning, from splitting to moderate attenuation. A correlation between pumpellyite and host-rock composition is suggested by these characteristics.(c) Pumpellyites in prehnite-pumpellyite facies assemblages of some of the units studied plot inside higher (and lower) grade reference fields (AFM space) corresponding to different geodynamic settings elsewhere. This anomaly is attributed to the changing characteristics of the marginal basins at the South American margin and emphasizes the need to compare equal facies referred to equal settings.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1525-1314.1993.tb00160.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Late Paleozoic K/Ar ages of blueschists from Pichilemu, Central Chile
    Amsterdam : Elsevier
    Earth and Planetary Science Letters 23 (1974), S. 261-264 
    Details
    ISSN: 0012-821X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0012-821X(74)90200-3
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Rb/Sr ages of rocks from the Chilean metamorphic basement
    Amsterdam : Elsevier
    Earth and Planetary Science Letters 18 (1973), S. 87-92 
    Details
    ISSN: 0012-821X
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0012-821X(73)90038-1
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Closed-loop suppression of chaos in nonlinear driven oscillators (1995)
    Springer
    Journal of nonlinear science 5 (1995), S. 189-206 
    Details
    ISSN: 1432-1467
    Keywords: suppression of chaos ; nonlinear oscillators ; model-based control design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics , Physics
    Notes: Summary This paper discusses the suppression of chaos in nonlinear driven oscillators via the addition of a periodic perturbation. Given a system originally undergoing chaotic motions, it is desired that such a system be driven to some periodic orbit. This can be achieved by the addition of a weak periodic signal to the oscillator input. This is usually accomplished in open loop, but this procedure presents some difficulties which are discussed in the paper. To ensure that this is attained despite uncertainties and possible disturbances on the system, a procedure is suggested to perform control in closed loop. In addition, it is illustrated how a model, estimated from input/output data, can be used in the design. Numerical examples which use the Duffing-Ueda and modified van der Pol oscillators are included to illustrate some of the properties of the new approach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01212954
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    facet.materialart.
    Unknown
    Sensing biofibers with nematic microdroplets [Physics] (2016)
    National Academy of Sciences
    Details
    Publication Date: 2016-02-03
    Description: Probing the surface morphology of microthin fibers such as naturally occurring biofibers is essential for understanding their structural properties, biological function, and mechanical performance. The state-of-the-art methods for studying the surfaces of biofibers are atomic force microscopy imaging and scanning electron microscopy, which well characterize surface geometry of the fibers...
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
    Published by National Academy of Sciences
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Kinematics of Subduction Processes during the Earthquake Cycle in Central Chile (2019)
    Seismological Society of America (SSA)
    Details
    Publication Date: 2019
    Description: 〈span〉〈div〉ABSTRACT〈/div〉Subduction processes at convergent margins produce complex temporal and spatial crustal displacements during different periods of the earthquake cycle. Satellite geodesy observations provide important clues to constrain kinematic models at subduction zones. Here, we analyze geodetic observations in central Chile, where two large earthquakes occurred: 2010 Mw 8.8 Maule and 2015 Mw 8.3 Illapel. We propose a model that considers the motion along both interfaces of the brittle subducting slab as the sources responsible for the movement of the crust in the different periods of the earthquake cycle. Using standard inversion techniques, we provide a consistent framework of the kinematic displacement during each period of the earthquake cycle. We show that during the interseismic period prior to the Maule and Illapel earthquakes, two patches of slip rate on the lower interface are determined. These patches are located just below the future hypocenters. Because the interseismic period corresponds to the loading process and the coseismic to the unloading process, it is interesting to note that the area where loading is stronger corresponds to the area where unloading is also strong. Furthermore, we show that the Maule earthquake causes a significant displacement on the lower interface, just below the epicenter of the future Illapel earthquake to the north, a few years later. We speculate that the interaction between motions along both interfaces is the key to understanding the evolution of stress and the occurrence of earthquakes at subduction zones. This framework improves the understanding of the observed loading and unloading processes and potential triggering between subduction earthquakes.〈/span〉
    Print ISSN: 0895-0695
    Electronic ISSN: 1938-2057
    Topics: Geosciences
    Published by Seismological Society of America (SSA)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Comparative study on the customization of natural language interfaces to databases (2016)
    SpringerOpen
    Details
    Publication Date: 2016-05-02
    Description: In the last decades the popularity of natural language interfaces to databases (NLIDBs) has increased, because in many cases information obtained from them is used for making important business decisions. Unfo...
    Electronic ISSN: 2193-1801
    Topics: Natural Sciences in General
    Published by SpringerOpen
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...