عنوان

Structure, metamorphism and tectonic setting of a gneissic terrane, the Sagan Afelata area, southern Ethiopia

Number

TLpq303968567

.Language of Text, Soundtrack etc

انگلیسی

Title Proper

Structure, metamorphism and tectonic setting of a gneissic terrane, the Sagan Afelata area, southern Ethiopia

General Material Designation

[Thesis]

First Statement of Responsibility

S. Gichile

Subsequent Statement of Responsibility

W. K. Fyson

Name of Publisher, Distributor, etc.

University of Ottawa (Canada)

Date of Publication, Distribution, etc.

1991

Specific Material Designation and Extent of Item

265

Dissertation or thesis details and type of degree

M.Sc.

Body granting the degree

University of Ottawa (Canada)

Text preceding or following the note

1991

Text of Note

The Sagan-Afelata area, which extends east approximately 100 km from the Main Ethiopian Rift towards the Adola gold fields, is underlain by high-grade rocks, dominantly biotite and quartzofeldspathic gneiss. The gneissic rocks are characteristically of K-rich mineralogy and appear to form a Proterozoic supracrustal sequence rather than Archean basement as thought earlier. The gneissic rocks were subjected to at least three distinct phases of deformation. The first, D, to which probably several generations of structures are attributed, formed migmatitic layering then isoclinal folds that transposed the layers parallel to flat-lying regional foliation (S), during amphibolite to granulite facies metamorphism. The second, D2, formed upright folds in S and parallel layers with subhorizontal NNW to NNE trending axes, accompanied by amphibolite facies metamorphism that overprinted most rocks. D3, resulted in local E-W trending, open, upright folds that are confined to the eastern part of the area. (Abstract shortened by UMI.)

Earth sciences

Geology

S. Gichile

W. K. Fyson

Electronic name

p

[Thesis]

276903

a

Y