Constraints on crustal structure from heat flow measurements in lakes of N.W. Ontario by Richard George Allis

Cover of: Constraints on crustal structure from heat flow measurements in lakes of N.W. Ontario | Richard George Allis

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Written in English

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Subjects:

  • Earth temperature -- Ontario, Northwestern,
  • Heat -- Convection,
  • Water temperature.,
  • Physics Theses

Edition Notes

Book details

Statementby Richard G. Allis.
ContributionsGarland, G. D. (supervisor), Toronto, Ont. University.
The Physical Object
Paginationv, 201 leaves :
Number of Pages201
ID Numbers
Open LibraryOL19771032M

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The constraints brought by heat flow data on crustal structure and lower crustal composition. We then evaluate the THO heat flow in the larger context of the whole North American craton.

Low heat flow areas where the local crustal structure is well-known are used to determine an upper bound for the mantle heat flow. Next, we use a high heat. Crustal Heat Flow: A Guide to Measurement and Modelling is a handbook for geologists and geophysicists who manipulate thermal data, particularly for petroleum exploration.

The book will be regarded as a long-term reference source for professionals and researchers. It will also form the basis of advanced undergraduate and graduate student Cited by:   Crustal Heat Flow: a guide to measurement and modeling G.

Beardsmore & J. Cull, Cambridge University Press,ISBNHardback, £70, and ISBNSoftback, £ Crustal Heat Flow: a guide to measurement and modelingAuthor: Christoph Clauser. Crustal Heat Flow: A Guide to Measurement and Modelling is a handbook for geologists and geophysicists who manipulate thermal data, particularly for petroleum exploration.

In theory and with practical examples, the book discusses the sources of heat within the crust, describes how to maximize the accuracy of temperature data, covers the measurement of the thermal properties of rocks, and. Susan Spangler Nissen, Dennis E. Hayes, Yao Bochu, Weijun Zeng, Yongqin Chen, Xiaupin Nu, Gravity, heat flow, and seismic constraints on the processes of crustal extension: Northern margin of the South China Sea, Journal of Geophysical Research: Solid Earth, Cited by: The predicted mean heat production of the SIC is ± µWm -3, consistent with it being a melt sheet of upper crustal (high heat production) [Darling et al., ] and lower crustal (low.

Heat flow and heat production datasets constrain the crustal thermal structure in the Ga Bundelkhand craton, the oldest cratonic core in northern Indian shield, for the first time and. In well‐sedimented areas, where there is little loss of heat due to hydrothermal circulation, the surface heat flow decays uniformly from values in excess of 6 µcal/cm² s ( mW/m²), for crust younger than 4 Ma (4 m.y.

B.P.), to close to µcal/cm² s (46 mW/m²) through crust between and Ma. Six new heat flow values in this area show that the region of low heat flow associated with the Keweenawan rift in Lake Superior extends northwards along the. The new heat flow values between 31 and 56 mW m-2 are well within the range of values in the eastern part of the Superior and in other Archean t the shallow lake data, the mean.

Heat flow, depth, and crustal thickness of the marginal basins of the South Philippine Sea We present 51 heat flow measurements and two geophysical profiles across the West Philippine and Parece Vela basins.

Klingelhoefer, J.-L. Olivet, D. Aslanian, Crustal structure of a young margin pair: New results across the Liguro–Provencal. These measurements will require drilling into the surface to emplace heat flow probes, as was done for the Apollo measurements on the Moon.

Gravity Field Gravity field measurements on a finer scale than accomplished by MGS can help constrain the subsurface structure of sedimentary basins and variations in crustal thickness (Appendix B: [ A linear relationship relates heat flow (Q) to heat production (A) in which the slope of the curve indicates the distribution of heat producing elements with depth (thermal depth).

In some models, the thermal depth has been equated to the thickness of the granitic layer, since these rocks are commonly enriched in heat producing elements. The heat flow data do not support the proposition that the rift contains significant thicknesses, ~ 15 km, of volcanics.

The comparison of heat flow results with other geophysical methods for studies of major tectonic features shows that measurement of heat flow is an essential part of multidisciplinary geophysical studies.

Granitoid intrusions are the primary heat source of many deep geothermal reservoirs in Tuscany. The depth and shape of these plutons, characterised in this study by a prominent seismic reflector (the K horizon), may vary significantly within the spatial scale of interest. In an exploration field, simulations reveal the mechanisms by which such a heat source influences temperature distribution.

Preliminary report on the stratigraphy and structure of the Bee Lake greenstone belt, Superior Province, northwestern Ontario Article January with 8 Reads How we measure 'reads'. Data on the crustal structure combined with laboratory measurements of heat production in crustal rocks along exposed crustal cross-sections, as well as with petrologic constraints on the total crustal heat production, were used to calculate continental geotherms in the regions with high-quality heat flow data and steady-state thermal regime.

The feasibility of measuring terrestrial heat flow in lakes has been investigated in Lake Superior. The temperature gradient and thermal conductivity of the sediment were measured at each of four stations in water depths exceeding meters. Consideration of the effects of climatic variations suggests that they may not seriously affect the values for heat flow obtained by this method.

The differing average crustal heat generating rates of the KC and the ZC as derived from K, Th and U contents thus broadly agree with the averages of heat flow data from the two cratons, provided that lower crust sections with low K, Th and U contents and basal heat flow values of approximately 20 mW m −2 are assumed.

Geothermometry, calibrated using a conductive geotherm typical of cratonic mantle lithosphere and consistent with regional heat flow measurements (Mareschal et al. ), showed that the garnet suites sampled a wide range of depths within the mantle lithosphere. At Kirkland Lake and Timiskaming, sampling depths ranged from ∼ to – Heat flow has been determined at separate sites, many of which include several separate boreholes or probe casts, within the continental area of Canada, including the continental shelves.

In general, the results show a tendency of lower heat flow with increasing tectonic age of the crust. groundwater flow. The studied area extends between the Eifel mountains and the Maas river in Central Europe.

The total variation due to the- se processes in our study area amounts to tec- tonic events manifested in the studied area 20 mW/m. 2, about 30% of the present day specific heat flow in the region.

Keywords: Crustal Heat Flow; Physical. heat flow density data, and a series of geologically derived constraints are used in the model. Our results are then compared with previous publishe d thermal models proposed by Vernant and Chéry [7] and Tunini et al. [8]. Geological Background The Zagros mountain belt extends for over km from Turkey to SE Iran (Figure 1).

It was. based largely on heat flow, considerable additional information is drawn from seismological studies [e.g.laboratory and theoretical studies of the physical properties of earth materials [e.g.

21, and modeling of convection in the earth [e.g. The measurement of heat flow. crustal flow in response to crustal thickness variations [Gans, ; Block and Royden, ; Kruse et al., ]. In very thick and hot crust, lower crustal flow is very efficient at relieving gravitational stresses, allowing localized upper-crustal extension while the Moho remains flat.

This may be analogous to core complex formation. Abstract. The depth dependence of radioactive heat production in the continental crust was investigated by converting seismic velocity profiles into heat production by means of an experimentally established relationship between heat production (A) and compressional wave velocity (v p).In converting v p to A, the pressure (P) and temperature (T) dependence of wave velocity were considered by an.

The crustal radiogenic component of continental heat flow must lie within the range of and almost certainly lies within the range of. The latter constraints limit the abundances of HPE within the crust (assuming K/U = 10, Th/U =and a crust 41 km thick) to ; Th = ppm, and U = ppm.

Models of crustal composition based. There is an inverse correlation between crustal thickness and heat flow. This correlation is observed both in active regions and on stable platforms. As noted above, stable continental crust is 40 ± 7 km thick with three main crustal layers, each 10–15 km thick.

This crustal type covers the interior of Eurasia, North America, Africa, and. Heat flow at the surface is the observational boundary condition that all acceptable thermal models must satisfy. Throughout his career, Birch has placed a high priority on obtaining additional measurements of heat flow and investigating the various factors that must be considered in reducing raw heat flow.

1 Introduction. The Main Ethiopian Rift (MER) has long been recognized as one of the best places to investigate continental rifting, and, in particular, rift processes leading to seafloor spreading (e.g. Makris & Ginzburg ; Ebinger & Casey ; Bastow & Keir ; Fig. 1).In this paper, we use ambient noise tomography to construct Rayleigh-wave group velocity maps covering most of the MER.

Based on our interpretation of the seismic image, the original volume of the Sudbury Igneous Complex, likely an impact melt sheet, is ∼1 × 10 4 km 3, supporting the claim that the Sudbury Structure represents the eroded and tectonized remanent of one of the largest known impact structure.

Abstract. At least 12 granulite occurrences, ranging in size from a few 10’s tokm2, are exposed in the Archean Superior Province. Primary lithotectonic subdivision of the Superior Province into linear volcano-plutonic and metasedimentary gneiss belts has led to interpretation of these components as magmatic arcs and accretionary prisms respectively, assembled in the interval between.

Axen, ). Thus, lower-crustal flow has been proposed as a mechanism by which lateral pressure gradients within the crust are equilibrated, reduc-ing variations in topography and crustal thickness (e.g., Bird, ).

Lateral variations in topography, crustal thickness, and style of defor. The differences may also be due to the way crustal structure is accounted for, which can have an influence on the retrieved mantle structure (Ferreira et al., ; Lekić et al., ); some groups apply crustal corrections based on existing crustal models (ED16, SL13, and ND08), others model crustal effects using SEM on an existing crustal.

The pattern of residual lineations, shown in Fig. 12 could have formed far from the ice-sheet margin during the final retreat, or during an earlier stage of ice-sheet retreat or advance, either in the Weichselian or during an earlier glacial stage (Tanner, ; Punkari, ; Nordkalott Project, ).

In southwestern Sweden, the residuals show a north-south trend compared with the NE-SW. from the heat flow map. As a result, it is estimated at about 50 mW/m2, that is, the heat flow is normal to slightly low. The crustal temperatures along the east-west cross section of the northeastern part of China (A-A’ in Fig.1) calculated assuming two-dimensional steady state heat conduction show.

In the past 10 years many new heat flow measurements have been reported in the geophysical literature. They have been assembled under the auspices of the International Heat Flow Commission of the International Association of Seis- mology and Physics of the Earth's Interior.

InJessop et. Shop and Discover Books, Journals, Articles and more. The heat flow‐heat production relationship, which provides one method of determining subsurface heat production, has well‐documented limitations.

Allis () and Rybach and Buntebarth (, ), on the basis of laboratory measurements, have proposed quantitative relationships between heat production and rock compositional and physical. This chapter deals with the Basin and Range province defies generalities.

Extension has widened the zone of high elevation, causing minor subsidence in the northern Basin and Range, and major subsidence including the opening of a new ocean basin in the southern range.

This chapter presents the crustal structure, tectonic features, and the basement morphology in the North-East Atlantic. The continental margins were formed during rifting and continental break-up in Cenozoic time, but experi- enced a long history of crustal.

Another indicator of heat flow is the increase in temperature with depth inside deep mines. These measurements of heat flow, however, are all made near the surface. The processes by which heat moves in Earth's deep interior are investigated by computer simulations, which can be compared with seismic and heat flow data that show temperature.Start studying science book 3.

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