Download or read book Geochemical Characterization of Paleoproterozoic Volcanic and Hypabyssal Igneous Rocks East central Minnesota written by David Leroy Southwick and published by . This book was released on 2001 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report of Investigations written by and published by . This book was released on 2005 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Archean to Anthropocene written by James D. Miller and published by Geological Society of America. This book was released on 2011-01-01 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preliminary Description and Interpretation of the Hattenberger Deep Test Well Carlton County Minnesota written by David L. Southwick and published by . This book was released on 2005 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gneiss Domes in Orogeny written by Donna Whitney and published by Geological Society of America. This book was released on 2004-01-01 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geological Survey Professional Paper written by and published by . This book was released on 1980 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Geological Survey Professional Paper written by and published by . This book was released on 1979 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Refining Paleoproterozoic Sedimentary Sequence Boundaries in East central Minnesota Carlton County written by Scott W. Scheiner and published by . This book was released on 2012 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Animikie Basin in north-eastern Minnesota is usually interpreted as a Penokean (1875-1835 Ma) foredeep deposit consisting mainly of 2 to 5 km thick turbidite sequences underlain by banded iron formations and quartzite conglomerates, all deposited in a foreland basin north of the accreted Penokean arc terrain. Much of the Animikie basin sequence is non-metamorphosed and only mildly deformed. However, along its southern margin in Carlton County, east-central Minnesota, the sedimentary sequence is strongly deformed into refolded nappes. The twice deformed sequence occurs south of a similar sedimentary sequence that has undergone a single deformation. The contact between these sequences, although nowhere exposed, was interpreted by Holst (1985) as a Penokean thrust fault and all of the deformation assumed to be Penokean in age. This contact is commonly referred to at Holst's Line. A wealth of new data collected over the last ~15 years document Yavapai-age magmatism, metamorphism, sedimentation and deformation overprinting the Penokean orogen. Metamorphic ages post-date the Penokean orogeny and detrital zircon ages indicate that some of the Paleoproterozoic sedimentary rocks may be younger than previously thought. Based on this new evidence, I propose Holst's Line to represent an unconformity separating sedimentary foredeep packages of different ages and test this hypothesis using geochemical and Sm/Nd isotopic data. Geochemical analyses were obtained on 10 samples divided into two groups based upon location north or south of Holst's Line. Relative proportions of major elements varied little within and across these groups. Trace element ratio plots of La/Sc vs Ti/Zr, Sc/Cr vs La/Y, Th vs Zr and Sc vs V were created with the hope of distinguishing between different tectonic settings. The results show a concentrated grouping of data from the southern samples and a much larger spread from northern samples, suggesting a more variable source for the northern sedimentary sequence. Neither Sm nor Nd are significantly fractionated compared to each other during surficial processes, and therefore, Nd isotopes are frequently used in sedimentary rocks as an indicator of provenance. Four samples were analyzed, two from north of Holst's Line and two to the south. Using detrital zircon and stratigraphic relationships, ages of 1770 Ma and 1850 Ma were assigned to the northern and southern rocks respectively. [epsilon]Nd (T) was then calculated for each sample with the results indicating the northern rocks were derived from an older Archean crustal source whereas the southern rocks were derived from a younger, possibly arc source. The differences documented here argue against Holst's Line being a tectonic contact. Instead, Holst's Line is reinterpreted as an unconformity separating Penokean foredeep and Yavapai foredeep Paleoproterozoic deposits. This reinterpretation has important ramifications for interpreting structures throughout the upper Great Lakes region. Lastly a new tectonic sequence model for the formation and deformation of the Animikie Basin is proposed.

Download or read book Publications of the Geological Survey written by Geological Survey (U.S.). and published by . This book was released on 1991 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Precambrian Geology of the Tobacco Root Mountains Montana written by John Brady and published by Geological Society of America. This book was released on 2004-01-01 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography and Index of Geology written by and published by . This book was released on 1992 with total page 1544 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plutonism in the Central Part of the Sierra Nevada Batholith California written by Paul C. Bateman and published by . This book was released on 1992 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the structure, composition, and pre-Tertiary history of the Sierra Nevada batholith in the Mariposa 1 by 2 quadrangle.

Download or read book Canadian Journal of Earth Sciences written by and published by . This book was released on 2007 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology and Tectonics of the Lake Superior Basin written by Richard John Wold and published by Geological Society of America. This book was released on 1982-01-01 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tectonic Imbrication and Foredeep Development in the Penokean Orogen East central Minnesota written by David Leroy Southwick and published by . This book was released on 1991 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Igneous Rocks and Processes written by Robin Gill and published by John Wiley & Sons. This book was released on 2010-02-15 with total page 471 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is for geoscience students taking introductory or intermediate-level courses in igneous petrology, to help develop key skills (and confidence) in identifying igneous minerals, interpreting and allocating appropriate names to unknown rocks presented to them. The book thus serves, uniquely, both as a conventional course text and as a practical laboratory manual. Following an introduction reviewing igneous nomenclature, each chapter addresses a specific compositional category of magmatic rocks, covering definition, mineralogy, eruption/ emplacement processes, textures and crystallization processes, geotectonic distribution, geochemistry, and aspects of magma genesis. One chapter is devoted to phase equilibrium experiments and magma evolution; another introduces pyroclastic volcanology. Each chapter concludes with exercises, with the answers being provided at the end of the book. Appendices provide a summary of techniques and optical data for microscope mineral identification, an introduction to petrographic calculations, a glossary of petrological terms, and a list of symbols and units. The book is richly illustrated with line drawings, monochrome pictures and colour plates. Additional resources for this book can be found at: http://www.wiley.com/go/gill/igneous.

Download or read book Information Series Colorado Geological Survey written by Colorado Geological Survey and published by . This book was released on 1976 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: