Metamorphic and igneous rocks along the northwest border zone of the Idaho Batholith

10.3133/pp344 ◽  
1972 ◽  
Author(s):  
Anna Martta Hietanen
Keyword(s):  
Igneous Rocks ◽  
Border Zone

Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996

1997 ◽  
pp. 66-74
Author(s):  
Henrik Stendal ◽  
Wulf Mueller ◽  
Nicolai Birkedal ◽  
Esben I. Hansen ◽  
Claus Østergaard
Keyword(s):  
Mineral Exploration ◽  
Volcanic Rocks ◽  
Shear Zones ◽  
Field Work ◽  
Igneous Rocks ◽  
Border Zone ◽  
The South ◽  
East Greenland ◽  
North West ◽  
Arc Setting

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Stendal, H., Mueller, W., Birkedal, N., Hansen, E. I., & Østergaard, C. (1997). Mafic igneous rocks and mineralisation in the Palaeoproterozoic Ketilidian orogen, South-East Greenland: project SUPRASYD 1996. Geology of Greenland Survey Bulletin, 176, 66-74. https://doi.org/10.34194/ggub.v176.5064 _______________ The multidisciplinary SUPRASYD project (1992–96) focused on a regional investigation of the Palaeoproterozoic Ketilidian orogenic belt which crosses the southern tip of Greenland. Apart from a broad range of geological and structural studies (Nielsen et al., 1993; Garde & Schønwandt, 1994, 1995; Garde et al., 1997), the project included a mineral resource evaluation of the supracrustal sequences associated with the Ketilidian orogen (e.g. Mosher, 1995). The Ketilidian orogen of southern Greenland can be divided from north-west to south-east into: (1) a border zone in which the crystalline rocks of the Archaean craton are unconformably overlain by Ketilidian supracrustal rocks; (2) a major polyphase pluton, referred to as the Julianehåb batholith; and (3) extensive areas of Ketilidian supracrustal rocks, divided into psammitic and pelitic rocks with subordinate interstratified mafic volcanic rocks (Fig. 1). The Julianehåb batholith is viewed as emplaced in a magmatic arc setting; the supracrustal sequences south of the batholith have been interpreted as either (1) deposited in an intra-arc and fore-arc basin (Chadwick & Garde, 1996), or (2) deposited in a back-arc or intra-arc setting (Stendal & Swager, 1995; Swager, 1995). Both possibilities are plausible and infer subduction-related processes. Regional compilations of geological, geochemical and geophysical data for southern Greenland have been presented by Thorning et al. (1994). Mosher (1995) has recently reviewed the mineral exploration potential of the region. The commercial company Nunaoil A/S has been engaged in gold prospecting in South Greenland since 1990 (e.g. Gowen et al., 1993). A principal goal of the SUPRASYD project was to test the mineral potential of the Ketilidian supracrustal sequences and define the gold potential in the shear zones in the Julianehåb batholith. Previous work has substantiated a gold potential in amphibolitic rocks in the south-west coastal areas (Gowen et al., 1993.), and in the amphibolitic rocks of the Kutseq area (Swager et al., 1995). Field work in 1996 was focused on prospective gold-bearing sites in mafic rocks in South-East Greenland. Three M.Sc. students mapped showings under the supervision of the H. S., while an area on the south side of Kangerluluk fjord was mapped by H. S. and W. M. (Fig. 4).

Magma emplacement in a convergent tectonic orogen, southern Revillagigedo Island, southeastern Alaska

1991 ◽  
Vol 28 (6) ◽  
pp. 929-938 ◽  
Author(s):  
M. L. Crawford ◽  
W. A. Crawford
Keyword(s):  
Shear Zone ◽  
Country Rock ◽  
Shear Zones ◽  
Igneous Rocks ◽  
Border Zone ◽  
Metamorphic Belt ◽  
Lithostratigraphic Units ◽  
Southern Border ◽  
Compressional Deformation ◽  
Oriented Parallel

The western metamorphic belt of the British Columbia – Alaska coastal orogen consists of lithostratigraphic units assigned to the Taku terrane and the Gravina sequence. On Revillagigedo Island and Cleveland Peninsula in the Ketchikan quadrangle of southeastern Alaska, greenschist- and amphibolite-grade schists of the western metamorphic belt are intruded by mid-Cretaceous tonalite and leucotonalite plutons and sills. A number of these igneous bodies are spatially associated with northwest-trending shear zones developed along thrust faults that formed during the main phase of metamorphism of the schists. Observations of field relations and structural fabric in the igneous rocks and the country-rock schist show the following: (i) Along the southern shore of Revillagigedo Island, the Moth Bay pluton was emplaced along a shear zone. Magmatic and submagmatic flow foliation in the southern border zone of the pluton parallels foliations in the sheared country rock; rocks in the interior of the pluton are generally unfoliated. (ii) At Carroll Point a group of sills intrude along the same shear zone. In some of the sills, tabular plagioclase phenocrysts are oriented parallel to the shear fabric. (iii) Foliation-parallel sills lie within a shear zone that separates Gravina sequence and Taku terrane rocks at Point Francis on Cleveland Peninsula. Older sills within the shear zone are deformed, and younger intrusions are unfoliated and cut across the fabric. Based on these and similar observations elsewhere in the area, we suggest the mid-Cretaceous tonalite and leucotonalite magmas in the Ketchikan quadrangle intruded during the regional compressional deformation that formed the shear zones.

Diffusion Weighted MRI Patterns Caused by Acute Border Zone Infarction

2008 ◽  
Vol 58 (1) ◽  
pp. 9 ◽  
Author(s):  
Han Won Jang ◽  
Woo Mok Byun
Keyword(s):  
Border Zone ◽  
Diffusion Weighted Mri ◽  
Diffusion Weighted

“Channeling” the powers of God’s Word

2010 ◽  
Vol 4 (2) ◽  
pp. 135-156 ◽  
Author(s):  
Dorothea E. Schulz
Keyword(s):  
The Other ◽  
Border Zone ◽  
Focus Attention ◽  
Spiritual Power ◽  
New Materials ◽  
God's Word ◽  
Audio Recordings ◽  
Heated Debate ◽  
The Subject ◽  
The One

Starting with the controversial esoteric employment of audio recordings by followers of the charismatic Muslim preacher Sharif Haidara in Mali, the article explores the dynamics emerging at the interface of different technologies and techniques employed by those engaging the realm of the Divine. I focus attention on the “border zone” between, on the one hand, techniques for appropriating scriptures based on long-standing religious conventions, and, on the other, audio recording technologies, whose adoption not yet established authoritative and standardized forms of practice, thereby generating insecurities and becoming the subject of heated debate. I argue that “recyclage” aptly describes the dynamics of this “border zone” because it captures the ways conventional techniques of accessing the Divine are reassessed and reemployed, by integrating new materials and rituals. Historically, appropriations of the Qur’an for esoteric purposes have been widespread in Muslim West Africa. These esoteric appropriations are at the basis of the considerable continuities, overlaps and crossovers, between scripture-related esoteric practices on one side, and the treatment by Sharif Haidara’s followers of audio taped sermons as vessels of his spiritual power, on the other.

Membrane structures in the pulp-dentin border zone A freeze-fracture study of demineralized human teeth

1984 ◽  
Vol 42 (2) ◽  
pp. 73-84 ◽  
Author(s):  
Anders Köling ◽  
Helge Rask-andersen
Keyword(s):  
Freeze Fracture ◽  
Border Zone ◽  
Membrane Structures ◽  
Human Teeth ◽  
Fracture Study

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.

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