Heat Transport Processes in the Earth’s Crust     

Christoph Clauser 《Surveys in Geophysics》2009,30(3):163-191

The heat of the Earth derives from internal and external sources. A heat balance shows that most of the heat provided by external sources is re-emitted by long-wavelength heat radiation and that the dominant internal sources are original heat and heat generated by decay of unstable radioactive isotopes. Understanding of the thermal regime of the Earth requires appreciation of properties and mechanisms for heat generation, storage, and transport. Both experimental and indirect methods are available for inferring the corresponding rock properties. Heat conduction is the dominant transport process in the Earth’s crust, except for settings where appreciable fluid flow provides a mechanism for heat advection. For most crustal and mantle rocks, heat radiation becomes significant only at temperatures above 1200°C.

Christoph ClauserEmail:

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Chronology building using objective identification of annual signals in trace element profiles of stalagmites     

Claire L. Smith  Ian J. Fairchild  Christoph Spötl  Silvia Frisia  Andrea Borsato  Steven G. Moreton  Peter M. Wynn 《Quaternary Geochronology》2009,4(1):11-21

Determination of annual lamination provides important additional constraints to radiometric dates on speleothems, both for dating the duration of specific growth intervals and optimizing growth models. In the absence of visible laminae, however, speleothem age models are reliant upon curve fitting through discretely dated points and are therefore inherently more uncertain than annual chronologies from laminae. Given that the impact of seasonality on speleothems is expected to be strong enough to generate an annual pulse in trace element chemistry regardless of whether or not visible or fluorescent growth laminae are visible, we demonstrate the potential for deriving high-resolution stalagmite chronologies from non-laminated samples using annual chemical variations in stalagmites from two Alpine caves (Obir, Austria and Ernesto, NE Italy). Trace element data were obtained by ion microprobe analyses for H, P, Mg, Na, Sr and Ba and the annual signal was sought using spectral and wavelet analysis. An automated chemical peak-counting software tool was developed in MATLAB^©. It counts significant annual peaks using criteria of minimum amplitude in relation to the local standard deviation of signal variation and minimum separation between peaks determined by the thickness of the preceding layers. Verification of the tool using visibly laminated samples suggests the software is a reliable and accurate method of chronology building, with hit ratios greater than 0.93 and less than 0.75% false alarm occurrences. Used in conjunction with other dating methods such as radiocarbon, U–Th and sulphur peak dating, the automated chemical laminae chronology-building approach provides a more meaningful alternative to simple age-depth curve fitting for non-laminated samples.  相似文献   

Hans Cloos in seinen Breslauer Jahren     

Martin Schwarzbach 《International Journal of Earth Sciences》1986,75(3):515-523

Ohne Zusammenfassung  相似文献   

Geological setting, mining and reduction of mercury vapor contamination in the gold-silver district of Vetas-Calofornia （Santander, Colombia）     

Erwin Wolff Carreno Juan Manuel Pinzon Angel Rodolfo Contreras Moreno Christoph Bernardy 《《幕》》2005,28(4):252-256

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Nocturnal Near-Surface Temperature,but not Flow Dynamics,can be Predicted by Microtopography in a Mid-Range Mountain Valley     

Lena Pfister  Armin Sigmund  Johannes Olesch  Christoph K. Thomas 《Boundary-Layer Meteorology》2017,165(2):333-348

We investigate nocturnal flow dynamics and temperature behaviour near the surface of a 170-m long gentle slope in a mid-range mountain valley. In contrast to many existing studies focusing on locations with significant topographic variations, gentle slopes cover a greater spatial extent of the Earth’s surface. Air temperatures were measured using the high-resolution distributed-temperature-sensing method within a two-dimensional fibre-optic array in the lowest metre above the surface. The main objectives are to characterize the spatio-temporal patterns in the near-surface temperature and flow dynamics, and quantify their responses to the microtopography and land cover. For the duration of the experiment, including even clear-sky nights with weak winds and strong radiative forcing, the classical cold-air drainage predicted by theory could not be detected. In contrast, we show that the airflow for the two dominant flow modes originates non-locally. The most abundant flow mode is characterized by vertically-decoupled layers featuring a near-surface flow perpendicular to the slope and strong stable stratification, which contradicts the expectation of a gravity-driven downslope flow of locally produced cold air. Differences in microtopography and land cover clearly affect spatio-temporal temperature perturbations. The second most abundant flow mode is characterized by strong mixing, leading to vertical coupling with airflow directed down the local slope. Here variations of microtopography and land cover lead to negligible near-surface temperature perturbations. We conclude that spatio-temporal temperature perturbations, but not flow dynamics, can be predicted by microtopography, which complicates the prediction of advective-heat components and the existence and dynamics of cold-air pools in gently sloped terrain in the absence of observations.  相似文献   

Erratum to: Evaluation of Urban Local-Scale Aerodynamic Parameters: Implications for the Vertical Profile of Wind Speed and for Source Areas     

Christoph W. Kent  Sue Grimmond  Janet Barlow  David Gatey  Simone Kotthaus  Fredrik Lindberg  Christos H. Halios 《Boundary-Layer Meteorology》2017,164(2):215-215

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COMBINED EXPERIMENTAL AND NUMERICAL INVESTIGATION OF FORMULAE FOR EROSION AND DEPOSITION OF COHESIVE SEDIMENTS     

Christoph SCHWEIM Jorn V. PROCHNOW  Jurgen KONGETER Institute of Hydraulic Engineering  Water Resources Management  Aachen University of Technology  Germany. E-Mail: schweim@iww.rwth-aachen.de 《国际泥沙研究》2001,16(2)

1 mTsonvCTIoxTIansport of fine cOhesive sedinds inevitably leads to the develoPment of sediment deposits inreservoirs or zones with small flow velocihes in lowland rivers. Such sediment dePosits often conshtUte aconsiderable ecological danger, as cOhesive sediInnts have the ability to bind POllutants like heavymetals, polycyclic aromatic hydrocrtons or chlorinated hydrocaIbons (F6f8iner, l989). In the case of anextreme hydraUlic event like a flood or a reservoir dePlehon, erosion of cone…  相似文献   

Fractional crystallization in open systems of variable composition: Correlations between element concentrations     

G. Christoph 《Earth and Planetary Science Letters》1990,101(1)

Fractional crystallization in open systems is modelled in a general mathematical form. The estimation of element concentrations in liquid and solid phases is done by means of a system of coupled nonlinear first order differential equations. With special, physically founded assumptions on distribution coefficients and source terms in the equations several special cases can be derived which are known in the literature.As an application, correlations between solid-phase concentrations of major elements, trace elements and isotopes are derived which can be used for the interpretation of geological processes. Especially the changes of strontium and rubidium concentrations of magmatic rocks are discussed in the progression of magma differentiation. In a second example the evolution of trace elements in the West-Erzgebirge (G.D.R.) as an open crystallizing magmatic system is discussed.  相似文献   

Swelling of Clay-Sulfate Rocks: A Review of Processes and Controls     

Christoph Butscher  Thomas Mutschler  Philipp Blum 《Rock Mechanics and Rock Engineering》2016,49(4):1533-1549

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A Comparison of In Situ Analytical Methods for Trace Element Measurement in Gold Samples from Various South African Gold Deposits          下载免费PDF全文

Christoph Gauert  Mathias Schannor  Lutz Hecht  Martin Radtke  Uwe Reinholz 《Geostandards and Geoanalytical Research》2016,40(2):267-289

Trace element concentrations in gold grains from various geological units in South Africa were measured in situ by field emission‐electron probe microanalysis (FE‐EPMA), laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and synchrotron micro X‐ray fluorescence spectroscopy (SR‐μ‐XRF). This study assesses the accuracy, precision and detection limits of these mostly non‐destructive analytical methods using certified reference materials and discusses their application in natural sample measurement. FE‐EPMA point analyses yielded reproducible and discernible concentrations for Au and trace concentrations of S, Cu, Ti, Hg, Fe and Ni, with detection limits well below the actual concentrations in the gold. LA‐ICP‐MS analyses required larger gold particles (> 60 μm) to avoid contamination during measurement. Elements that measured above detection limits included Ag, Cu, Ti, Fe, Pt, Pd, Mn, Cr, Ni, Sn, Hg, Pb, As and Te, which can be used for geochemical characterisation and gold fingerprinting. Although LA‐ICP‐MS measurements had lower detection limits, precision was lower than FE‐EPMA and SR‐μ‐XRF. The higher variability in absolute values measured by LA‐ICP‐MS, possibly due to micro‐inclusions, had to be critically assessed. Non‐destructive point analyses of gold alloys by SR‐μ‐XRF revealed Ag, Fe, Cu, Ni, Pb, Ti, Sb, U, Cr, Co, As, Y and Zr in the various gold samples. Detection limits were mostly lower than those for elements measured by FE‐EPMA, but higher than those for elements measured by LA‐ICP‐MS.  相似文献