Download or read book Petrography and Correlation of Precambrian Clastic Sedimentary Rocks Associated with the Midcontinent Rift System written by Pieter Berendsen and published by . This book was released on 1993 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Petrography and Correlation of Precambrian Clastic Sedimentary Rocks Associated with the Midcontinent Rift System written by Pieter Berendsen and published by . This book was released on 1993 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clastic Rocks Associated with the Midcontinent Rift System in Iowa written by Raymond R. Anderson and published by . This book was released on 1997 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Middle Proterozoic Midcontinent Rift System (MRS) of North America is a failed rift that formed in response to region-wide stresses about 1,100 Ma. In Iowa, the MRS is buried beneath 2,200-3,500 ft of Paleozoic and Mesozoic sedimentary rocks and Quaternary glaciogenic deposits. An extremely large volume of sediments was deposited within basins associated with the rift at several stages during its development. Although the uplift of a rift-axial horst resulted in the erosional removal of most of these clastic rocks from the central region of the MRS in Iowa, thick sequences are preserved in a series of horst-bounding basins. Recent studies incorporating petrographic analysis, geophysical modeling, and other analytical procedures have led to the establishment of a preliminary stratigraphy for these clastic rocks and interpretations of basin geometries. This information has allowed the refinement of existing theories and history of MRS formation in Iowa. Additionally, drill samples previously interpreted as indicating the existence of early Paleozoic basins overlying the Proterozoic MRS basins were re-examined. Samples previously interpreted as deep-lying Paleozoic rocks are now known to have caved from upper levels of the drillhole and were out of stratigraphic position. No deep Paleozoic basins exist in this area. These investigations led to the development of petrographic parameters useful in differentiating the Proterozoic MRS Red clastics from Paleozoic clastic rocks having similar lithologies.
Download or read book Clastic Rocks Associated with the Midcontinent Rift System in Iowa written by Raymond R. Anderson and published by . This book was released on 1997 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Middle Proterozoic Midcontinent Rift System (MRS) of North America is a failed rift that formed in response to region-wide stresses about 1,100 Ma. In Iowa, the MRS is buried beneath 2,200-3,500 ft of Paleozoic and Mesozoic sedimentary rocks and Quaternary glaciogenic deposits. An extremely large volume of sediments was deposited within basins associated with the rift at several stages during its development. Although the uplift of a rift-axial horst resulted in the erosional removal of most of these clastic rocks from the central region of the MRS in Iowa, thick sequences are preserved in a series of horst-bounding basins. Recent studies incorporating petrographic analysis, geophysical modeling, and other analytical procedures have led to the establishment of a preliminary stratigraphy for these clastic rocks and interpretations of basin geometries. This information has allowed the refinement of existing theories and history of MRS formation in Iowa. Additionally, drill samples previously interpreted as indicating the existence of early Paleozoic basins overlying the Proterozoic MRS basins were re-examined. Samples previously interpreted as deep-lying Paleozoic rocks are now known to have caved from upper levels of the drillhole and were out of stratigraphic position. No deep Paleozoic basins exist in this area. These investigations led to the development of petrographic parameters useful in differentiating the Proterozoic MRS Red clastics from Paleozoic clastic rocks having similar lithologies.
Download or read book U S Geological Survey Bulletin written by and published by . This book was released on 1983 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Middle Proterozoic to Cambrian rifting central North America written by Richard W. Ojakangas and published by Geological Society of America. This book was released on 1997-01-01 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the Tenth International Basement Tectonics Conference held at the University of Minnesota-Duluth in August 1992, this volume contains 19 papers, 13 of which focus on the Middle Proterozoic Midcontinent Rift. An introductory essay discussing the Middle Proterozoic to Cambrian rifting in central North America is followed by contributions addressing topics including the Midcontinent Rift in Michigan and Minnesota, the Port Coldwell veins of northern Ontario, and petrography and sedimentation in the western Lake Superior region. The last five papers deal with the pre-Mount Simon basins of Ohio, the English Graben and the newly proposed East Continent Rift Complex, the Reelfoot Rift/Rough Creek Graben in the evolution of the Illinois Basin, and the A-type sheet granites in the Oklahoma Aulacogen of Cambrian age. Bandw illustrations. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book U S Geological Survey Circular written by and published by . This book was released on 1933 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Publications of the U S Geological Survey written by and published by . This book was released on 1993 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book New Publications of the U S Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1993 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Correlation of Precambrian Rocks of the Lake Superior Region United States written by G. B. Morey and published by . This book was released on 1988 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lithology, distribution, correlation, and isotope ages of exposed Precambrian rocks in the Lake Superior region of the north-central United States.
Download or read book The Midcontinent Strategic and Critical Minerals Project written by Walden P. Pratt and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Midcontinent Strategic and Critical Minerals Project written by Douglass E. Owen and published by . This book was released on 1984 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the Geological Survey written by Geological Survey (U.S.) and published by . This book was released on 1993 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies on Ore Deposits Mineral Economics and Applied Mineralogy written by Richard D. Hagni and published by . This book was released on 2001 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precambrian Conterminous U S written by John C. Reed, Jr. and published by Geological Society of America. This book was released on 1993 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Guide to USGS Publications written by and published by . This book was released on 1998 with total page 1660 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sediment hosted Pb Zn Cu Ba Mineralisation Within the Coastal Branches of the Damara Orogen Namibia written by Gregor Borg and published by . This book was released on 2003 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Die vorliegende Studie ist Ergebnis einer in Namibia und Deutschland durchgeführten Literaturrecherche zu sedimentgebundenen Blei-Zink- (Kupfer-Barium)-Vorkommen in den Pan-Afrikanischen Kaoko- und Gariep- Faltengürteln der nördlichen und südlichen Küstenregion Namibias. Die Literaturstudie zeigt, dass metallogenetische Untersuchungen der Buntmetallmineralisationen in diesen orogenen Gürteln Namibias einen aktuellen Forschungsschwerpunkt darstellen. Begründet liegt dies unter anderem in den vergleichsweise begrenzten, derzeit bekannten Rohstoffvorräten an Zink, Blei,Baryt, Silber und Kupfer, die zukünftig einen erhöhten Innovationsbedarf haben und somit verstärkte Explorationsanstrengungen erfordern. Dies wird auch deutlich durch die defizitäre Bilanz aus Zinkproduktion und -nachfrage von 1994 bis 1999 der westlichen Welt. Insbesondere seit den neunziger Jahren wurden in Namibia verstärkt Explorationsinvestitionen durch internationale Explorations- und Bergbaufirmen getätigt. Das Land verfügt über eine lange und erfolgreiche Bergbautradition, deren Wurzeln in einer relativ stabilen politischen Situation, exzellenter Infrastruktur, einem modernen Bergrecht und hochwertigen, gut zugänglichen geologischen und geophysikalischen Daten begründet liegen. - Schlieilich bietet sich die Anwendung der Ga/Ge-Geothermometrie von Sphalerit an und diese sollte in verschiedenen Erzparagenesen der Rosh Pinah Lagerstätte getestet werden. Hierbei verspricht ein kritischer Vergleich der geochemisch ermittelten TGa/Ge mit der mikrothermometrisch bestimmten TF.I. und vor allem der Gebrauch des Verhältnisses TGa/Ge / TF.I. als Proximitätsindikator auch einen positiven Beitrag zur metallogenetischen Grundlagenforschung.
