Relations Stratigraphiques entre le Groupe de Pontiac et le Sillon Métavolcanique de Baby au Témiscamingue, Québec

1973 ◽  
Vol 10 (8) ◽  
pp. 1350-1353 ◽  
Author(s):  
L. Imreh
Keyword(s):  
Geological Mapping ◽  
Superior Province ◽  
Satisfactory Solution ◽  
Northern Flank ◽  
Actual Contact ◽  
Age Relation ◽  
Folded Structures

The pre-Kenoran Archean stratigraphy has always been of prime interest to geologists working in the Superior Province. However, one must realize that the problems raised have remained, for the most part, without satisfactory solution. Thus, the respective age relation of the thick lithostratigraphic metavolcanic and metasedimentary units (Pontiac), forming respectively the Baby Rift and its northern flank to the northeast of Ville-Marie in Temiscaming, has not been defined with certainty to date.During a geological mapping project on a scale of 1:12 000, covering the township of Baby and adjacent parts of the townships of Guérin and Guigues, it has become possible for us to remove the uncertainty and to define the age relation of the two units mentioned. We can now state that the metasedimentary unit (Pontiac) forms the stratigraphic base of the metavolcanic unit.To arrive at this conclusion it was first necessary to determine the size of the main folded structures in the region of Rapide des Quinze, then to uncover and let weather the outcrops over several kilometers, in order to define the actual contact of the two units. [Translated by the Journal]

Paleomagnetism, U–Pb geochronology, and geochemistry of Lac Esprit and other dyke swarms, James Bay area, Quebec, and implications for Paleoproterozoic deformation of the Superior Province

2007 ◽  
Vol 44 (5) ◽  
pp. 643-664 ◽  
Author(s):  
Kenneth L Buchan ◽  
Jean Goutier ◽  
Michael A Hamilton ◽  
Richard E Ernst ◽  
William A Matthews
Keyword(s):  
Vertical Axis ◽  
Geological Mapping ◽  
Superior Province ◽  
Hudson Bay ◽  
James Bay ◽  
Common Reference ◽  
Bay Area ◽  
The North ◽  
The Difference ◽  
Dyke Swarms

An extensive set of north- to northwest-trending diabase dykes, termed the Lac Esprit swarm, is identified in the Superior Province east of James Bay based on geological mapping and a distinctive paleomagnetic pole (61.7°N, 169.1°E, dm = 7.7°, dp = 5.5°). The Lac Esprit swarm yields a U–Pb baddeleyite age of 2069 ± 1 Ma similar to that of the 2076+5–4 Ma Fort Frances swarm of the western Superior Province. Their paleomagnetic declinations differ by 23° ± 12° after correction to a common reference locality. The difference is likely due mainly to counterclockwise rotation about a vertical axis of the Fort Frances area relative to the Lac Esprit area. Differential rotation of 10°–20° has been proposed more locally across the Kapuskasing Structural Zone separating the eastern and western Superior Province in earlier paleomagnetic studies of ca. 2450 Ma Matachewan and 2170 Ma Biscotasing dyke swarms. Thus, relative rotation may have involved the entire eastern and western Superior Province, perhaps in response to collisional events associated with the Trans-Hudson Orogen to the north or the Penokean orogen to the south, or in response to rifting beneath Hudson Bay. Other dykes in the study area are interpreted from a combination of paleomagnetism, trend, and geochemistry to belong to the Senneterre, Matachewan, and Mistassini swarms. The 2216 Ma Senneterre dykes form part of a giant swarm that fans across the eastern Superior Province. Paleomagnetic directions and geometry of this swarm rule out substantial block rotations within the eastern Superior Province since dyke emplacement.

Nd-isotope evolution of Archaean plutonic rocks in southeastern Superior Province

1997 ◽  
Vol 34 (3) ◽  
pp. 286-298 ◽  
Author(s):  
L. Paul Bédard ◽  
John N. Ludden
Keyword(s):  
Isotope Composition ◽  
Geological Mapping ◽  
Superior Province ◽  
Nd Isotopes ◽  
Nd Isotope ◽  
The Core ◽  
Plate Margin ◽  
Anatectic Granite ◽  
Plutonic Belt ◽  
Nd Isotope Composition

The Opatica plutonic belt, Abitibi greenstone belt, and Pontiac Subprovince represent a major proportion of the southeastern Superior Province, which was formed and accreted rapidly between approximately 2.9 and 2.8 Ga. Plutons in these belts are grouped into four types: (i) trondhjemite–tonalite–granodiorite (TTG) suite (2.82–2.69 Ga), (ii) monzodiorite (MZD) suite (2.697–2.669 Ga), (iii) late alkaline granitoid (ALK) suite (2.68–2.67 Ga), and (iv) anatectic granite and monzonite (ANA) suite (2.69–2.64 Ga). The four suites are represented in all belts and show similar petrography and geochemistry. In terms of Nd-isotope composition, the TTG, MZD, and ALK suites are typical of destructive plate margin magmatism and have + 1.4 < initial εNd < +3.7, values which are very similar to that of the Abitibi mantle (εNd + 2.5). The lower values for the ANA suites (εNd + 0.1 to + 2.4) result from recycling of crustal components. In the Opatica belt the ANA granitoids fall on the Nd-isotope evolution curve defined by the Opatica TTG plutons, and are thus considered to be melt products of this suite. However, Abitibi and Pontiac ANA suites show a larger range of εNd, from + 0.1 to + 2.4, compared with + 1.0 to + 1.3 for the Opatica, suggesting more heterogeneous crustal source rock. Recent geological mapping and geophysical studies associated with the Lithoprobe project have suggested that the Opatica belt represents a plutonic belt against which the Abitibi was accreted by subduction-related collision and that the Pontiac Subprovince is dominated by imbricated metasediments related to the final stages of collision in the Abitibi region. The Nd-isotope data provide support for these arguments. Early plutonic suites are mantle derived and related to arc-accretion processes. As the collision process progresses, a more evolved isotopic component is introduced, possibly in relation to sediment subduction into the mantle. Anatexis of the crust in the central Opatica belt and the core of the Pontiac Subprovince resulted in the formation of granites with a crustal signature for Nd isotopes.

Angelo Sismonda (1807–1878), pioneer of geological mapping in the Alps of Savoy and the Piedmont: a bibliography

2016 ◽  
Vol 43 (1) ◽  
pp. 119-130 ◽  
Author(s):  
John Hollier ◽  
Virgilio Blardone ◽  
Tullio Basaglia ◽  
Anita Hollier
Keyword(s):  
Geological Mapping ◽  
Short Biography ◽  
The Alps

Angelo Sismonda (Ange Sismonda) was an Italian mineralogist and geologist based in Turin during the Risorgimento who produced pioneering maps of the Alps in the Kingdom of Sardinia. Well known during his lifetime, he is now mentioned only in passing by historians and no comprehensive bibliography of his work exists. To render his work more accessible, we present a short biography and a bibliography.

Geological study in Tal - Talekhu section of Manang District along the Besisahar – Chame Road

2020 ◽  
Vol 22 ◽  
pp. 25-28
Author(s):  
Prakash Luitel ◽  
Suman Panthee
Keyword(s):  
Cross Section ◽  
Geological Mapping ◽  
Igneous Rocks ◽  
Geological Cross Section ◽  
Lowermost Part ◽  
Migmatitic Gneiss

The section between Tal to Talekhu of Manang District lacks the detailed geological study. The geological mapping in the scale of 1:50,000 followed by the preparation of geological cross-section and lithostratigraphic column has been done in the present study. The studied area lies partially in the Higher Himalayan Crystalline and the Tibetan Tethys Sequence. The units of the Higher Himalayan Group from Tal to Talekhu consists mainly of vigorous to faintly calcareous gneiss, migmatitic gneiss, quartzite, granite, etc. They are named as the Calc. Silicate Gneiss and Paragneiss and the Orthogneiss and Granite units. The lowermost part of the Tibetan Tethys consisted of metamorphosed calcareous rocks containing silicates and feldspar, so this unit is termed as the Marble and Calc. Gneiss. The section is about 9 km in thickness and is highly deformed with presence of igneous rocks at many places.

Exploration history and place names of northern East Greenland

1969 ◽  
Vol 21 ◽  
pp. 1-368 ◽  
Author(s):  
Anthony K. Higgins
Keyword(s):  
20Th Century ◽  
19Th Century ◽  
Geological Mapping ◽  
Geological Survey ◽  
The Arctic ◽  
Place Names ◽  
East Greenland ◽  
New Name ◽  
Systematic Compilation

The first recorded landing by Europeans on the coast of northern East Greenland (north of 69°N) was that of William Scoresby Jr., a British whaler, in 1822. This volume includes a chronological summary of the pioneer 19th century exploration voyages made by British, Danish, Norwegian, Swedish, French and German expeditions – all of whom reported that the region had previously been occupied by the Inuit or Eskimo; also included are brief outlines of the increasing number of government and privately sponsored expeditions throughout the 20th century, whose objectives included cartography, geology, zoology, botany, trapping and the ascent of the highest mountain summits. In 1934 the Place Name Committee for Greenland was established, the tasks of which included a review of all place names hitherto recorded on published maps of Greenland, their formal adoption in danicised form, and the approval or rejection of new name proposals. In northern East Greenland, by far the largest numbers of new place names were those proposed by scientists associated with Lauge Koch's geological expeditions that lasted from 1926 until 1958. This volume records the location and origin of more than 3000 officially approved place names as well as about 2650 unapproved names. The author's interest in the exploration history and place names of northern East Greenland started in 1968, when the Geological Survey of Greenland initiated a major five-year geological mapping programme in the Scoresby Sund region. Systematic compilation of names began about 1970, initially with the names given by William Scoresby Jr., and subsequently broadened in scope to include the names proposed by all expeditions to northern East Greenland. The author has participated in 16 summer mapping expeditions with the Survey to northern East Greenland. Publication of this volume represents the culmination of a lifetime working in the Arctic.

Airborne geophysical surveys in Greenland – 1996 update

1997 ◽  
pp. 75-79
Author(s):  
Robert W. Stemp
Keyword(s):  
Mineral Exploration ◽  
Geological Mapping ◽  
Digital Data ◽  
Magnetic Survey ◽  
Aeromagnetic Survey ◽  
West Greenland ◽  
South West ◽  
Geophysical Surveys ◽  
The Government ◽  
Airborne Geophysical Data

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stemp, R. W. (1997). Airborne geophysical surveys in Greenland – 1996 update. Geology of Greenland Survey Bulletin, 176, 75-79. https://doi.org/10.34194/ggub.v176.5069 _______________ Two major airborne geophysical surveys were carried out in 1996, the third year of a planned five-year electromagnetic and magnetic survey programme (project AEM Greenland 1994–1998) financed by the Government of Greenland, and the second year of an aeromagnetic survey programme (project Aeromag) jointly financed by the governments of Denmark and Greenland; both projects are managed by the Geological Survey of Denmark and Greenland (GEUS). The two 1996 surveys were: 1) Project Aeromag 1996 in South-West and southern West Greenland;2) Project AEM Greenland 1996 in South-West Greenland. All areas surveyed and planned for future surveys as of March 1997 are shown in Figure 1. Results of both the 1996 surveys were released in March 1997, as a continuation of a major effort to make high quality airborne geophysical data available for both mineral exploration and geological mapping purposes. The data acquired are included in geoscientific databases at GEUS for public use; digital data and maps may be purchased from the Survey. The main results from the 1996 surveys are described in Thorning & Stemp (1997) and Stemp (1997). Two further new airborne surveys have already been approved for data acquisition during the 1997 field season, with subsequent data release in March 1998. A summary of all surveys completed, in progress or planned since the formal inception of project AEM Greenland 1994–1998 is given in Table 1. The programme was expanded to include a separate regional aeromagnetic survey in 1995, provisionally for 1995–1996, with extension subject to annual confirmation and funding.

The year in focus, 2000

2001 ◽  
pp. 7-10
Author(s):  
Kai Sørensen
Keyword(s):  
Geological Mapping ◽  
Geological Survey ◽  
Seismic Survey ◽  
East Greenland ◽  
Major Field ◽  
Original Series ◽  
West Greenland ◽  
Level Of Activity ◽  
Field Activity ◽  
Year 2000

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Sørensen, K. (2001). The year in focus, 2000. Geology of Greenland Survey Bulletin, 189, 7-10. https://doi.org/10.34194/ggub.v189.5148 _______________ The year 2000 was unusual in that it lacked major field activity directly involved with the systematic geological mapping of Greenland. However, field activities were again many and varied, including a successful highresolution seismic survey offshore central West Greenland, and a joint Geological Survey of Denmark and Greenland (GEUS) – Danish Lithosphere Centre (DLC) project centred on Kangerlussuaq in southern East Greenland. Of the Survey’s 354 personnel, 93 were allocated to Greenland-related activities (Table 1). The Greenland level of activity in 2000, both in Copenhagen and in the field, thus compared favourably with that of 1999.

Sign in / Sign up

Export Citation Format

Share Document