Precambrian Crustal Blocks in Minnesota

Precambrian Crustal Blocks in Minnesota PDF Author: S. R. Hemming
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 24

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Book Description
Sm-Nd survey of Precambrian granitic and metasedimentary rocks collected from several geophysically defined blocks in central Minnesota confirms the presence of some fundamental geologic boundaries previously mapped on the basis of structure. The Malmo discontinuity an Early Proterozoic structure separates the Archean Minnesota River Valley ter- ranes from an Early Proterozoic (Penokean magmatic) terrane and the McGrath Gneiss dome of east-central Minnesota North of this boundary, the Penokean fold-and-thrust belt can be divided into fault-bounded terranes that were assembled during the Penokean orogeny. Each terrane within the study area has distinct crust formation ages.

Precambrian Crustal Blocks in Minnesota

Precambrian Crustal Blocks in Minnesota PDF Author: S. R. Hemming
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 24

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Book Description
Sm-Nd survey of Precambrian granitic and metasedimentary rocks collected from several geophysically defined blocks in central Minnesota confirms the presence of some fundamental geologic boundaries previously mapped on the basis of structure. The Malmo discontinuity an Early Proterozoic structure separates the Archean Minnesota River Valley ter- ranes from an Early Proterozoic (Penokean magmatic) terrane and the McGrath Gneiss dome of east-central Minnesota North of this boundary, the Penokean fold-and-thrust belt can be divided into fault-bounded terranes that were assembled during the Penokean orogeny. Each terrane within the study area has distinct crust formation ages.

Precambrian Crustal Blocks in Minnesota--neodymium Isotope Evidence from Basement and Metasedimentary Rocks

Precambrian Crustal Blocks in Minnesota--neodymium Isotope Evidence from Basement and Metasedimentary Rocks PDF Author: S. R. Hemming
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 15

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Book Description


Precambrian Crustal Blocks in Minnesota

Precambrian Crustal Blocks in Minnesota PDF Author: S. R. Hemming
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 15

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Book Description


A Geophysical Study of a Precambrian Crustal Boundary in Minnesota

A Geophysical Study of a Precambrian Crustal Boundary in Minnesota PDF Author: Barbara Wiley Van De Voorde
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 86

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Book Description


U.S. Geological Survey Bulletin

U.S. Geological Survey Bulletin PDF Author:
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 372

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U.S. Geological Survey Bulletin

U.S. Geological Survey Bulletin PDF Author: Paul Kibler Sims
Publisher:
ISBN:
Category : Faults (Geology)
Languages : en
Pages : 268

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Book Description
The Early Proterozoic Michigamme Formation of northern Michigan was deposited in the southeastern part of the Animikie basin. The formation conformably overlies the Goodrich Quartzite and comprises three widespread members a lower member of thin-bedded shale, siltstone, and sandstone; the Bijiki Iron-formation Member; and an upper member of tur- biditic graywacke, siltstone, and mudstone and a few local members. The Goodrich Quartzite is interpreted as having been deposited in a tidally influenced shallow marine environ- ment. The lower member of the Michigamme is interpreted as having been deposited in a tidally influenced environment, the iron-formation member as having been deposited below wave base in somewhat deeper water, and the upper member as having been deposited in still deeper water with turbidity currents being a major depositional mechanism. Several lines of evidence including paleocurrents, paleo- geographic setting, and neodymium isotopes suggest that the graywacke of the southern part of the outcrop area was derived from the south (Early Proterozoic Wisconsin magmatic terranes, Archean miniplates, and older Early Proterozoic sedimentary units formed on the continental margin), and that the graywacke in the northern area was derived from an Archean terrane to the north. The tectonic model that best fits the available data is a northward-migrating foreland basin.

Antarctica

Antarctica PDF Author: Dieter K. Fütterer
Publisher: Springer Science & Business Media
ISBN: 354032934X
Category : Science
Languages : en
Pages : 473

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Book Description
Sixty articles arranged in eight thematic sections refer to most recent geological and geophysical results of Antarctic research. The Precambrian of the East Antarctic shield and its geological history is considered as well as sub-ice topography, geophysics and stratigraphy, sedimentology and geophysics of the surrounding Southern Ocean. Particular emphasis is given to the connection of the Antarctic and the surrounding continents when forming part of Gondwana.

Precambrian: Conterminous U.S.

Precambrian: Conterminous U.S. PDF Author: John C. Reed, Jr.
Publisher: Geological Society of America
ISBN: 081375447X
Category : Science
Languages : en
Pages : 752

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Book Description
This wide-ranging discussion of Precambrian rocks includes contributions from a diverse array of authors actively engaged in investigations of various aspects of U.S. Precambrian geology. Summary discussions by the editors of the five major chapters place these contributions in a logical regional framework.

The Basis for a Continental Drilling Program in Minnesota

The Basis for a Continental Drilling Program in Minnesota PDF Author: G. B. Morey
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 34

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Book Description


Principles of Precambrian Geology

Principles of Precambrian Geology PDF Author: Alan M. Goodwin
Publisher: Elsevier
ISBN: 0080539696
Category : Science
Languages : en
Pages : 339

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Book Description
Principles of Precambrian Geologyis an update to the 1991 book, Precambrian Geology: The Dynamic Evolution of the Continental Crust, by the same author. The new edition covers the same topics in a more concise and accessible format and is replete with explanatory figures, tables, and illustrations. The book serves as a modern comprehensive statement on the Earth's Precambrian crust, covering the main aspects of distribution, lithiostratigraphy, age, and petrogenesis of Precambrian rocks by continent within the context of the Earth's evolving continental crust. Principles of Precambrian Geology provides a suitable framework for assessing various Earth dynamic and biospheric hypotheses, including the modern plate tectonic paradigm and the Gaian hypothesis. Despite the concise format, the new edition provides extensive updated references to support the information presented. It is designed to serve the needs of student, teacher, explorationist and general student of the continental crust. - Updated to provide more concise accessible information - Extensive illustrations, tabulations, and maps - Provides a framework for assessing recent hypothesis on Earth dynamics - Covers main aspects of distribution, lithostratigraphy, age, and protogenesis of Precambrian rocks