Research Article| March 01, 1989 Nd isotopes and the origin of 1.9-1.7 Ga Penokean continental crust of the Lake Superior region KARIN M. BAROVICH; KARIN M. BAROVICH 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar P. JONATHAN PATCHETT; P. JONATHAN PATCHETT 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar ZELL E. PETERMAN; ZELL E. PETERMAN 2U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar PAUL K. SIMS PAUL K. SIMS 2U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information KARIN M. BAROVICH 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 P. JONATHAN PATCHETT 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721 ZELL E. PETERMAN 2U.S. Geological Survey, Denver, Colorado 80225 PAUL K. SIMS 2U.S. Geological Survey, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1989) 101 (3): 333–338. https://doi.org/10.1130/0016-7606(1989)101<0333:NIATOO>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation KARIN M. BAROVICH, P. JONATHAN PATCHETT, ZELL E. PETERMAN, PAUL K. SIMS; Nd isotopes and the origin of 1.9-1.7 Ga Penokean continental crust of the Lake Superior region. GSA Bulletin 1989;; 101 (3): 333–338. doi: https://doi.org/10.1130/0016-7606(1989)101<0333:NIATOO>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Nd isotopic data on 26 samples demonstrate the origin of the Early Proterozoic crust of the Penokean orogen. The three major components are (1) the Marquette Range Supergroup, a predominantly miogeoclinal continental-margin sequence deposited before 1.85 Ga on Archean basement; (2) ca. 1.88 Ga felsic metavolcanic rocks of the Wisconsin magmatic terrane to the south, of evolved island-arc affinity; and (3) 1.87-1.76 Ga granitoids that intrude the metavolcanic rocks.Initial ϵNd values for the metavolcanic rocks of the magmatic terrane range between 0.0 and +2.4 and TDM ages between 1.9 and 2.2 b.y. The volcanic rocks primarily represent new crustal material that had only a limited Archean input, probably through mixing of subducted sediments into the magma source area. ϵNd (T) values for sedimentary rocks in the lower part of the Marquette Range Supergroup indicate an Archean source, most likely the 2.7 Ga Superior province to the north. On the other hand, the sedimentary rocks in the upper part of the Marquette Range Supergroup (graywackes of the upper Michigamme Formation) have initial ϵNd values between -0.8 and +1.5, indicative of an Early Proterozoic source. These graywackes probably are foredeep deposits derived from the volcanic rocks of the Wisconsin magmatic terrane to the south. Thus, the time of deposition of the upper Michigamme Formation dates the final convergence of the Wisconsin magmatic terrane with the continental margin.The granitoids of the Wisconsin magmatic terrane have a wide range of ϵNd (T) values, from -4.5 to +4.0. They represent mixtures of variable amounts of new crustal material and recycled Archean detritus. The more negative ϵNd (T) values occur in samples close to the northern boundary of the Wisconsin magmatic terrane, which is marked by a mylonitic shear zone (the Niagara fault zone). We suggest that the miogeoclinal lower Marquette Range Supergroup rocks having an Archean Nd signature became involved in magma genesis close to the collisional boundary, whereas increasingly lesser amounts of this older material were available for mixing farther away from the suture. The 1.9-1.7 Ga Penokean events involved major growth of new crust from the mantle. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Research Article| June 01, 1985 Isotopic provenance of sandstones from the Eocene Tyee Formation, Oregon Coast Range PAUL L. HELLER; PAUL L. HELLER 1Laboratory of Geotectonics, Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar ZELL E. PETERMAN; ZELL E. PETERMAN 2U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar JAMES R. O'NEIL; JAMES R. O'NEIL 3U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar MUHAMMAD SHAFIQULLAH MUHAMMAD SHAFIQULLAH 4Department of Geosciences, University of Arizona, Tucson, Arizona 85721 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1985) 96 (6): 770–780. https://doi.org/10.1130/0016-7606(1985)96<770:IPOSFT>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation PAUL L. HELLER, ZELL E. PETERMAN, JAMES R. O'NEIL, MUHAMMAD SHAFIQULLAH; Isotopic provenance of sandstones from the Eocene Tyee Formation, Oregon Coast Range. GSA Bulletin 1985;; 96 (6): 770–780. doi: https://doi.org/10.1130/0016-7606(1985)96<770:IPOSFT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The Tyee Formation of Eocene age in the Oregon Coast Range has been studied by a variety of isotopic techniques in order to determine its provenance. Traditional basin analyses including paleocurrent measurements, lithofacies mapping, and study of sandstone compositions made previously suggest derivation from the Klamath Mountains, which lie to the south. In contrast, the isotopic compositions of whole-rock sandstone samples, white mica, and potassium feldspar separates preclude derivation solely from this local source area. Nd-Sm, Rb-Sr, K-Ar, 18O/16O, and D/H analyses of sandstones from the Tyee and related formations yield the following information about their source areas. (1) Whole-rock ϵNd values between −7.1 and −7.3 at the time of deposition indicate that an old crustal component (∼700 Ma) was incorporated in the source rocks. (2) Whole-rock Rb-Sr systematics implies an older age than those of sandstones clearly derived from the Klamath Mountains. These Rb-Sr values are similar to those of modern sands of the Columbia River that were derived from eastern source areas. (3) Either apparent Rb-Sr ages of potassium feldspars are too old or their initial 87Sr/86Sr ratios are too high to have been derived from plutonic rocks of the Klamath Mountains or Sierra Nevada. (4) White micas have a fairly consistent Late Jurassic Rb-Sr isochron but have K-Ar ages of 68 Ma, an overprint not recognized in the Klamath terranes. (5) White micas have δ18O values of ∼9.5, a value typical of S-type granges such as are found in the Idaho batholith, but too high for normal I-type granites such as in the northern Sierra Nevada and too low for metamorphic rocks in the Klamath Mountains. (6) White micas have δD values consistent with those observed for plutonic white mica in the Idaho batholith, but markedly lower than those of white mica from schist in the Klamath Mountains. (7) Potassium feldspars have δ18O values that vary widely and that mainly are not in oxygen-isotope equilibrium with coexisting white mica, suggesting that these minerals were not derived from the same source area.These results indicate that the provenance of these sandstones included S-type (two-mica) granites that formed in Late Jurassic time from sources that included an old crustal component. Minerals in the granites underwent subsequent thermotectonic age resetting in Late Cretaceous time. Rocks in the Klamath Mountains and northern Sierra Nevada do not possess these features and consequently are precluded from being major source areas for the Tyee Formation. The sandstones most likely were derived from the Idaho batholith. Abundant detritus from that source area is consistent with a model in which the Oregon Coast Range basin lay much farther east, closer to Idaho, during deposition and subsequently moved westward to its present position. Such major displacement is compatible with the tectonic-rotation history documented for the Oregon Coast Range that began during the time of deposition of the Tyee Formation. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
A paper-tape digital recording system is described which has been used to determine the isotopic abundance ratios of strontium from geologic samples. The system costs less than $10 000 and has proved to be highly reliable during its three years of operation. More than 600 analyses have been recorded and the results processed by an IBM-360 computer. This procedure has improved the precision of analyses from this laboratory by a factor of two. Over a period of 11 months, 16 measurements on the M.I.T. strontium carbonate standard gave a mean value for ( 87 Sr/ 86 Sr) n = 0.70797 ± 0.017%. The uncertainty En the results is the standard deviation of the analyses with the 86 Sr/ 88 Sr value normalized to 0.1194. Over shorter periods of time considerably better precision is indicated.
Abstract Precambrian rocks in the Lake Superior region underlie all or parts of Minnesota, Wisconsin, and Michigan, an area along the southern margin of the Superior province of the Canadian Shield (Fig. 1). Except on the north, adjacent to Canada, the Precambrian rocks are overlapped by sedimentary strata of Paleozoic and Mesozoic age, which constitute a thin platform cover of relatively undisturbed rocks that thicken to the west, south, and east. Inliers of Precambrian rocks are exposed locally in southern Minnesota and Wisconsin, mainly in the flat valleys of major rivers, where erosion has cut below the Phanerozoic strata. The present landscape is subdued, and is inherited largely from Pleistocene continental glaciations, which produced a variety of erosional and depositional landforms. The glacier ice scoured the bedrock in the northern parts of the region, in much the same way as throughout most of Canada, and deposited materials of diverse lithology and provenance, as much as 200 m thick, over much of the remainder of the region. The Precambrian rocks in the region record an extended interval of crustal development and evolution that spans nearly 3 b.y. of earth history. This interval of geologic time is not continuously recorded in layered and intrusive units, but instead is punctuated by specific rock-forming and tectonic events that can be deduced from geologic relations and placed in a chronometric framework by isotopic dating. (Fig. 2, also see correlation chart for Precambrian rocks of the Lake Superior region, Morey and Van Schmus, 1986; and Bergstrom and Morey, 1985.)
Research Article| December 01, 1990 Early Proterozoic deformation in the western Superior province, Canadian Shield D. C. KAMINENI; D. C. KAMINENI 1Atomic Energy of Canada Ltd., Pinawa, Manitoba, R0E 1L0, Canada Search for other works by this author on: GSW Google Scholar D. STONE; D. STONE 2Ontario Geological Survey, 77 Grenville Street, Toronto, Ontario, M7A 1W4, Canada Search for other works by this author on: GSW Google Scholar Z. E. PETERMAN Z. E. PETERMAN 3U.S. Geological Survey, Branch of Isotope Geology, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar Author and Article Information D. C. KAMINENI 1Atomic Energy of Canada Ltd., Pinawa, Manitoba, R0E 1L0, Canada D. STONE 2Ontario Geological Survey, 77 Grenville Street, Toronto, Ontario, M7A 1W4, Canada Z. E. PETERMAN 3U.S. Geological Survey, Branch of Isotope Geology, Denver, Colorado 80225 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1990) 102 (12): 1623–1634. https://doi.org/10.1130/0016-7606(1990)102<1623:EPDITW>2.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation D. C. KAMINENI, D. STONE, Z. E. PETERMAN; Early Proterozoic deformation in the western Superior province, Canadian Shield. GSA Bulletin 1990;; 102 (12): 1623–1634. doi: https://doi.org/10.1130/0016-7606(1990)102<1623:EPDITW>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Late Archean granitic plutons (∼2700 to 2665 Ma; U-Pb zircon) of the Superior structural province are cut by a variety of brittle discontinuities, including joints, fractures, and faults, the latter of which show evidence of cataclasis and meter to tens of meters displacements. Fluid circulation, alteration of wall rocks, and neomineralization of epidote, actinolite, and chlorite occurred under greenschist facies conditions in these structures at the time of their formation. The Rb-Sr ages of host rocks are ∼2650 Ma, and the fracture-zone materials are 2300 Ma, indicating that most of this activity occurred long after Archean plutonism and was concentrated in Early Proterozoic time. The brittle structures formed in response to horizontal compression on a regional scale, possibly caused by tectonic processes at margins of the craton. The structures are seen as important clues to the tectonic evolution of the Superior province. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Research Article| January 01, 1970 Sr87/Sr86 Ratios of the Talasea Series, New Britain, Territory of New Guinea Z. E PETERMAN; Z. E PETERMAN U.S. Geological Surrey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar G. G LOWDER; G. G LOWDER University of California, Berkeley, California 94720 Search for other works by this author on: GSW Google Scholar I. S. E CARMICHAEL I. S. E CARMICHAEL University of California, Berkeley, California 94720 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1970) 81 (1): 39–40. https://doi.org/10.1130/0016-7606(1970)81[39:SROTTS]2.0.CO;2 Article history received: 15 Jul 1969 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Z. E PETERMAN, G. G LOWDER, I. S. E CARMICHAEL; Sr87/Sr86 Ratios of the Talasea Series, New Britain, Territory of New Guinea. GSA Bulletin 1970;; 81 (1): 39–40. doi: https://doi.org/10.1130/0016-7606(1970)81[39:SROTTS]2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract No Abstract available This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Precambrian crystalline rocks of the Rocky Mountain region of the United States represent two age provinces.An Archean province (older than 2,600 million years) occupies Wyoming and adjacent parts of Utah, Montana, and South Dakota.A Proterozoic province (about 1,600 to 1,800 million years old), is represented by only sparse exposures west and northwest of the older terrane, and by extensive exposures to the south.The Archean province is mostly felsic gneisses and associated metasedimentary rocks that were metamorphosed about 2,800 million years ago.Tonalitic to granodioritic plutons were emplaced in this terrane 2,500 to 2,760 million years ago.In Colorado, a thick sequence of volcanic and sedimentary rocks was deposited between 2,000 and 1, 750 million years ago.These rocks were metamorphosed and intruded by numerous granodioritic plutons about 1, 700 million years ago.This province was invaded by granitic plutons 1,400 million years ago and again, in central Colorado, 1,015 million years ago.Shelf-type sedimentary sequences were deposited on the older crust during the interval from 2,500 to 1, 700 million years ago and are preserved in a belt from southern Wyoming to the Black Hills.A younger sequence, 1,460 to 1,600 million years in age, is preserved only as the Uncompahgre Formation in southwestern Colorado.A still younger sequence, the miogeoclinal Belt Supergroup, 850 to 1,500 million years in age, is preserved in western Montana and northern Idaho.Rocks roughly equivalent to but isolated from the Belt Supergroup include the Y ellowjacket Formation and Lemhi Group of Idaho and the Uinta Mountain Group of northeastern Utah and northwestern Colorado.Eugeoclinal rocks, including diamictites, were deposited west of the miogeoclinal rocks beginning approximately 860 million years ago.
