摘要:

The electrically heated cylindrical probe has often been used to measure the thermal conductivity of materials which allow the contact layer to be small enough to have negligible thermal resistance and negligible thermal mass. The probe method is not widely used in boreholes, mainly because the increased complexity of the theory required by the boundary conditions encountered in typical field situations makes it difficult to design appropriate probes and to interpret the data.This paper deals with the results of a comprehensive series of laboratory and field experiments, using cased and uncased boreholes, to investigate the importance of various design parameters and to compare the relative merits of the many proposed methods of reducing the data.It has been found that there is a surprising degree of latitude in probe design provided an uncertainty of 10% in conductivity values can be tolerated.

ISSN:0008-4077    

DOI:10.1139/e71-001

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

The five arenaceous lithostratigraphic units of the Huronian sequence recognized in the Espanola–Willisville area are the Mississagi, Espanola, Serpent, and the Lorrain Formation, as also the intercalated zone which forms the uppermost subdivision of the Gowganda Formation.The bulk of the Huronian arenites is a mixed assemblage of fine, medium, and coarse subarkose, and arkose which are either poorly sorted, muddy fine-to-medium grained (Mississagi, calcareous Espanola, lower Serpent) and muddy medium-to-coarse grained (lower and middle Lorrain), or, moderately well-sorted, medium-to-coarse grained (middle and upper Serpent and intercalated zone). There is, however, one unit in the upper part of the Huronian sequence (uppermost Lorrain) which is a brilliant white supermature quartzarenite. Among the notable petrographic features are a lower quartz – feldspar ratio, rock fragments of metasedimentary and metavolcanic origin, and occasionally occurring rounded quartz. The feldspathic debris for these arenites was derived largely from the older granitoid rocks similar to the 'Algoman granite' of the Canadian Shield to the north of the study area and partly from the supracrustal rocks infolded in the granitoid terrain. Dominance of plagioclase (oligoclase ?) over potassic feldspar and their overall freshness in the arenites may suggest that the source rocks by and large were not deeply weathered,An integrated analysis of lithologie association and sedimentary characters, including texture and mineralogy of the arenites, possibly indicates a near-shore depositional environment (? fluviatile-deltaic) for several Huronian arenites (Mississagi, Serpent, intercalated zone, and middle and upper Lorrain); some may be deltaic-marine (lower part of lower Lorrain). Calcareous Espanola was perhaps deposited beyond the shoreline partly in deeper waters and partly in shallow turbulent environment. Likewise, clean white quartzarenite of top Lorrain may represent deposition in the turbulent fore-shore zone (beach or shelf).

ISSN:0008-4077    

DOI:10.1139/e71-002

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Earlier studies have shown that the anomaly in geomagnetic variations in the vicinity of Alert at the north end of Ellesmere Island is compatible with a narrow band of induced electric currents flowing in a northeast–southwest direction in the earth's crust or upper mantle. The present analysis of magnetic recordings obtained at 11 sites in Ellesmere Island during 1967 indicates that the Alert anomaly extends to the southwest as far as Eureka, a distance of 475 km. The anomaly has its greatest effect at Alert, and its "strength" diminishes by a factor of 2 or 3, 225 km to the southwest. Its half-width up to this point is about 50 km. The anomalous zone curves to the west near Greely Fjord 300 km southwest of Alert and appears to broaden near Eureka. The path of the anomaly closely follows the structural trends of the near vertical, tightly-folded strata of the Franklinian geosyncline underlying the whole Lake Hazen Plateau region of northern Ellesmere Island. Evidence for the extension of the anomaly through Ellesmere Island includes the near reversal of Wiese vectors on opposite sides of the zone, the confinement of the horizontal magnetic variation and its polarization transverse to the direction of strike, and the large contrast between apparent resistivities observed inside and outside the zone.

ISSN:0008-4077    

DOI:10.1139/e71-003

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Two wells drilled by Pan American in the Grand Banks of Newfoundland gave the first stratigraphic section of Cretaceous and Cenozoic age northeast of Long Island and the only Jurassic and possible Permian sections in the Atlantic Continental Margin of North America.Integrated analysis of lithic and faunal data showed a minimum of seven sequences present. These are Pleistocene, Middle and Upper Miocene, Intra-Eocene, Paleocene and lowest Eocene, Upper Cretaceous, Middle Cretaceous, and Neocomian in age.The rocks range from halite and anhydrite, of possible Permian depositional age, to limestones, in the Upper Jurassic, lower Upper Cretaceous, mid-Eocene and mid-Miocene, and sandstones, which dominate the Neocomian, Upper Eocene, and Middle Miocene. Variable proportions of shale and silty mudstone occur throughout.The microfaunas contain both Tethyan and Boreal elements, and suggest oceanic circulation changes, sea-floor spreading, or both.Depositional environments ranged from subaerial, for the quartz arenites, through very low-land, for stream and swamp deposits, to estuarine, lagoonal, bank and open-shelf warm-marine environments, in which were deposited fine sand to clay-size terrigenous sediment, or, in its absence, skeletal carbonates or lime muds. The first dominant cooling trend appeared in the Late Miocene.All erosional environments of the hiatal episodes appear to have been subaerial and humid.A salt dome intruded the Tors Cove well section, its last movement being in mid-Early Eocene.Periodic interregional tectonic oscillations produced the erosional and depositional episodes of the major baselevel transit cycles. Their total effect is a sedimentary wedge, thickening by preservation toward the continent's edge, and representing one-half or less of Upper Mesozoic and Cenozoic time.

ISSN:0008-4077    

DOI:10.1139/e71-004

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Hellroaring Creek Stock intrudes rocks of the Precambrian Purcell Supergroup which crop out in southeastern British Columbia. Previous K–Ar measurements (Lowdon 1961) indicated a minimum age of 700 m.y. for this stock. Present Rb–Sr isotope measurements indicate an approximate age of 1260 m.y. Cleavage in the contact aureole of the stock indicates a structural event prior to intrusion.

ISSN:0008-4077    

DOI:10.1139/e71-005

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

A light-weight oceanic thermal gradient probe was used for heat flow studies in Bras d'Or Lake, Nova Scotia. The measurements were made in St. Andrew's Channel, an elongated trough 270 m deep and 540 m wide. The heat flux of 1.50 μcal/cm2s (63 mW/m2) is corrected for sedimentation, conductivity contrast, topography, and surface temperature differences.

ISSN:0008-4077    

DOI:10.1139/e71-006

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

This paper reports a parametric study of rainfall–runoff relations for 38 storms in the Eaton basin, southeastern Quebec, between 1950 and 1966. In addition to storm rainfall amounts, water table levels in the vicinity of the channel network, as indicated by baseflow prior to storms, appear to be very important in controlling the amount of response of the basin in different storms. Storm runoff is viewed as the product of direct interception by, and subsurface seepage into, expanded surface water systems in the valley floor areas of the basin. This is in agreement with the variable (partial) source area model developed over the last ten years by a number of hydrologists as an alternative to the Horton theory of runoff production.

ISSN:0008-4077    

DOI:10.1139/e71-007

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Sills in Cambrian sandstone at two localities provide complementary evidence for the magmatic origin of keratophyres near St. Nicolas. The thickest sill has one facies whose solids at the time it was half or somewhat more crystallized had the composition of a hornblende laugenite. The rest magma at this stage gave rise to stellate and trachytoid keratophyre characterized by chlorite and checker-board albite with some quartz. At the other locality magma approximately of the composition of the stellate keratophyre was emplaced as sills up to 4 ft (1.2 m) thick and gave rise to medium-grained keratophyre with, along the selvages or within the sills, a fine-grained variety with chlorite and nodules, up to 1 in. (2.5 cm) diameter, of plagioclase. Illite or its precursor was secreted from the sills and was replaced by a network of veins with cores of quartz and spheroids of plagioclase, of chlorite, and of carbonate.

ISSN:0008-4077    

DOI:10.1139/e71-008

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

Several14C-dated marine shells (and exceptionally even estuarine peat) found at about the present sea level—just below to just above—in different regions of the world suggest a eustatic high stand at about 30 000 B.P.; however, this appears to be incorrect for two main reasons.1. From climatic–glaciologic point of view the interstadial at about 30 000 B.P. (Denekamp, Plum Point, etc.) must correspond to an ocean level far below the present (or roughly corresponding to the Late Glacial one at about 12 000 B.P.).2. Contamination of a sample containing dead or almost dead carbon by 1–5% modern carbon will give the sample an apparent age of 36 000–24 000 B.P.

ISSN:0008-4077    

DOI:10.1139/e71-009

出版商:NRC Research Press    

年代:1971

数据来源: NRC

摘要:

The degree of preferred orientation of hornblende in two boudinage structures is analyzed by means of an X-ray texture goniometer. Relative values of reflected intensity for {110} are plotted on the stereographic net, and contoured at convenient intervals. As in conventional fabric diagrams for hornblende, {110} define a great-circle girdle whose breadth reveals the density of unimodal grouping of [001].The density of grouping of [001] varies throughout both boudinage structures. It decreases with increasing extension in structure A, and seems to have a similar trend in structure B, where the determined variation in degree of grain alignment is of doubtful statistical significance.The inverse relationship between the degree of preferred orientation and the magnitude of extension may be attributed to rotation of the principal directions of finite strain during syntectonic crystallization. Alternatively, reorientation of strained grains by annealing recrystallization may have produced the inverse trend.

ISSN:0008-4077    

DOI:10.1139/e71-010

出版商:NRC Research Press    

年代:1971

数据来源: NRC