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Topic: Mesoproterozoic

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	Palaeos Proterozoic: The Mesoproterozoic Era
		The Mesoproterozoic was the first period of Earth's history with a respectable geological record.
		The subdivisions of the Mesoproterozoic are, obviously, arbitrary divisions based on time.
		The base of the Mesoproterozoic is defined chronometrically, in terms of years, rather than by the appearance or disappearance of some organism.
	www.palaeos.com /Proterozoic/Mesoproterozoic.html (669 words)

	Project title: Mesoproterozoic anorogenic granitoid magmatism in active shear zones
		The Mesoproterozoic period between 1.6 and 1.4 Ga is commonly thought to be one of crustal stabilization in the almost entire North Atlantic realm.
		Mesoproterozoic active shear zones controlling anorogenic magmatism in the western part of the East European Craton, EUG10, Strasbourg, pp.
		The Stenshuvud and Tåghusa granites: new representatives of the Mesoproterozoic granitic magmatism in southern Sweden.
	www.geol.lu.se /personal/asc/Project.htm (1320 words)

	Tectonics Special Research Centre - About IGCP 440 Project
		Amalgamation of the Rodinia Supercontinent is the major geodynamic event during the Mesoproterozoic era.
		The record of amalgamation and break-up of Rodinia is preserved in Mesoproterozoic mobile belts and Neoproterozoic basins present at the margins of most Paleoproterozoic cratons.
		The objective of the project is to obtain a robust database and framework for interpretation of the geodynamic evolution of the continental lithosphere during the late Mesoproterozoic and Neoproterozoic.
	www.tsrc.uwa.edu.au /440project (210 words)

	SIGEP: Sitio 093-FAZENDA CRISTAL (BAHIA)- MESOPROTEROZOIC STROMATOLITES (Site not responding. Last check: 2007-10-16)
		The spherical and domal carbonate bioherms of about six meters in diameter are composed of non- branching or ramified columnar stromatolites of upto ten centimeters in height and three centimeters in diameter.
		The nature of these outcrops, allied to the presence of caves and collapse structures, in an area of easy access and low demographic density, together with their importance for mesoproterozoic geology and paleontology of Brazil, justify that the suitable measures may be undertaken for their preservation.
		In the area of Fazenda Cristal are exposed the sedimentary rocks of Caboclo Formation of Chapada Diamantina Group, which is na integral part of the Espinhaso Supergroup of Mesoproterozoic age.
	www.unb.br /ig/sigep/sitio093/sitio093english.htm (1975 words)

	Acritarchs and microfossils from the Mesoproterozoic Bandemall Group, Northwestern Australia Journal of Paleontology - ... (Site not responding. Last check: 2007-10-16)
		The three assemblages have typical Mesoproterozoic aspects: peritidal benthic habitats were dominated by Siphonophycus-Sphaerophvcus-Eosvnechococciis-Mx-,vococcoides-Palaeopleurocapsa, shallow subtidal settings were occupied by Siphonophvcus-Leiosphaeridia-Pterospermopsimorpha-Safka, and offshore plankton consisted solely of very large chuarid acritarchs.
		Most other Mesoproterozoic assemblages consist of benthic prokaryotes permineralized in chert from peritidal carbonate platforms or planktonic eukaryotes compressed in shale from shallow-marine shelves, giving a restricted view of biological and ecological diversity at the time.
		Third, it includes chuarid fossils permineralized in concretions, an unusual mode of preservation for such large fossils that reveals substantially more information about their wall ultrastructure and shows that the Bangemall specimens are incontrovertible eukaryotes, amongst the oldest known.
	www.findarticles.com /p/articles/mi_qa3790/is_199909/ai_n8860540 (820 words)

	Metallogenic evolution of Mesoproterozoic sedimentary rocks in Idaho and Montana
		A major emphasis of this Project will be to refine the known Mesoproterozoic geologic framework of the region, both in terms of stratigraphy and sedimentalogy as well as tectonics of basin development.
		The Mesoproterozoic deposits in this region host important syngenetic stratabound as well as younger epigenetic mineral deposits; the integration of stratigraphic, tectonic, magmatic, and geochronologic studies will assist in the development of mineral deposit models that will further enhance our ability to predict potential for undiscovered deposits.
		Key to the success of this Project and the accomplishment of the proposed objectives is the synthesis of as much previously accumulated geologic knowledge as possible—stratigraphic, structural, tectonic, geochronologic—that has been obtained, in large part, by the Headwaters Project.
	minerals.cr.usgs.gov /projects/mesoproterozoic_seds/index.html (335 words)

	Government of Saskatchewan - Mesoproterozoic
		Mesoproterozoic Athabasca Basin and the underlying deep crustal tectonic...
		Mesoproterozoic Diabase, gabbro: fl to brown grey, medium to coarse grained, massive dyk es; 75−80% pyroxene and amphibole, 15−20% plagioclase, 1−5...
		Mesoproterozoic D iabase, gabbro: fl to brown grey, medium to coarse grained, massive dykes; 75-80% pyroxene and amphibole, 15-20% plagioclase, 1-5...
	www.gov.sk.ca /topics/keyword/keyword?topic=nature-environment&keyword=4160 (507 words)

	Mesoproterozoic basement in the Carolina slate belt (Site not responding. Last check: 2007-10-16)
		Evidence for Mesoproterozoic basement in the Carolina slate belt and speculations on its origin
		The combination of Neoproterozoic magmatic activity and Mesoproterozoic basement suggests that the Carolina terrane may have a distinct history relative to many other circum-Atlantic, Neoproterozoic arc terranes.
		In particular, the chronologic and isotopic similarity of the inferred Carolina arc basement to that of the nearby Blue Ridge province suggests the possibility that the Carolina terrane may be allochthonous, but not exotic.
	www.geology.ufl.edu /manuscripts/csb.abst.html (214 words)

	[No title]
		Rock units within the thrust stack range in age from Archean to late Mesoproterozoic, with older units occupying the lower levels of the thrust stack, and the younger units the higher levels to the southeast.
		Protolith ages of granitoids are entirely Mesoproterozoic (1.465-1.300 Ga), and Nd model ages are 1.64-1.46 Ga. Eclogites record the oldest metamorphic ages (1.12 Ga) but peak metamorphism could be as young as 1.08 Ga. If the Algonquin and Shawanaga slices are separate terranes, they were stitched by the 1.16 Ga metagabbro suite.
		Recognition of the approximately 300 million year duration of the Mesoproterozoic convergent margin of southeastern Laurentia suggests that there may be useful parallels with the evolution of the Andes, which has been a convergent margin since the early Paleozoic.
	instruct.uwo.ca /earth-sci/300b-001/grenv.htm (10682 words)

	EarthRef.org Reference Database (ERR) -- Kah et al. 2001
		This hypothesized Mesoproterozoic oxygenation event may be recorded in the geologic record by the appearance of the oldest preserved.
		An upsection increase in delta S-34 of Society Cliffs gypsum (from +22 parts per thousand to +32 parts per thousand VCDT) is therefore interpreted to reflect primary variation in Mesoproterozoic marine sulfate compositions, although the inferred rapidity of isotopic change requires a marine sulfate reservoir significantly smaller than that of the modern ocean.
		Examination of the maximum fractionation between coeval sulfide and sulfate reservoirs, however, indicates that Mesoproterozoic oceans were not sulfate-limited with respect to bacterial sulfate reduction either before or after the hypothesized 1.3 Ga oxygenation event.
	earthref.org /cgi-bin/err.cgi?n=654 (463 words)

	The Detrital Record of Orogenic Evolution I - Tectonophysics [T]
		The significant features of this detrital zircon record with respect to the temporal and spatial paleogeographic evolution of northeast Laurentia are the variable distribution of Mesoproterozoic detritus in Group 1 and 2 units as well as the general paucity of Archean detritus is Group 2 sequences.
		The absence of Mesoproterozoic detritus in the Stoer Group is consistent with its inferred depositional age of around 1.2 Ga, predating Grenville orogenesis whereas metasedimentary sequences in the Composite Arc Belt are interstratified with metavolcanic sequences and contain Mesoproterozoic detritus related to accretionary assembly of the Grenville orogen, but predate final collisional orogenesis.
		The strong input of Mesoproterozoic detritus in Group 2 and 3 units indicates development of the Grenville orogenic welt during assembly of Rodinian and its subsequent maintenance as a source region during development of the passive margin succession along the East Laurentia margin that faced an open Iapetus Ocean.
	www.agu.org /meetings/fm04/fm04-sessions/fm04_T51D.html (3044 words)

	Significance of the Nova Brasilândia metasedimentary belt in western Brazil: Redefining the Mesoproterozoic ...
		The NBMB marks the Mesoproterozoic limit of the SW Amazon craton.
		The discordance of the NBMB to the NNW structural trend of the younger Aguapeí belt (200 km SE of NBMB), together with marked differences between the two belts in sedimentary environment, metamorphic grade, and timing of deformation, signify that these two belts are not geologically continuous.
		Citation: Tohver, E. van der Pluijm, K. Mezger, E. Essene, J. Scandolara, and G. Rizzotto (2004), Significance of the Nova Brasilândia metasedimentary belt in western Brazil: Redefining the Mesoproterozoic boundary of the Amazon craton, Tectonics, 23, TC6004, doi:10.1029/2003TC001563.
	www.agu.org /pubs/crossref/2004/2003TC001563.shtml (511 words)

	Slides: Proterozoic Eon
		Mesoproterozoic Castner Marble (1.2 – 1.4 Ga) exposed in the
		Quarry in Mesoproterozoic Keweenawan basalts associated with the 1 to 1.2 Ga Mid-Continent Rift Zone; near Houghton on the
		Dike cutting dipping beds of the Mesoproterozoic Hakati Shale (1.1 Ga), Unkar Group in the
	www.austincc.edu /rblodget/Slides1.htm (185 words)

	The Mesoproterozoic event within the Rehoboth Basement Inlier of Namibia: review and new aspects of stratigraphy, ...
		The Mesoproterozoic event within the Rehoboth Basement Inlier of Namibia: review and new aspects of stratigraphy, geochemistry, structure and plate tectonic setting -- Becker et al.
		The Mesoproterozoic event within the Rehoboth Basement Inlier of Namibia: review and new aspects of stratigraphy, geochemistry, structure and plate tectonic setting
		suggests Mesoproterozoic evolution of this area in three stages.
	sajg.geoscienceworld.org /cgi/content/abstract/108/4/465 (390 words)

	julian menuge publications
		Brewer, T.S., Åhäll, K.-I., Menuge, J.F., Storey, C.D. and Parrish, R.R. Mesoproterozoic bimodal volcanism in SW Norway, evidence for recurring pre-Sveconorwegian continental margin tectonism.
		Menuge, J.F., Brewer, T.S. and Seeger, C.M. Petrogenesis of metaluminous A-type rhyolites from the St Francois Mountains, Missouri and the Mesoproterozoic evolution of the southern Laurentian margin.
		Menuge, J.F. and Brewer, T.S. Mesoproterozoic anorogenic magmatism in southern Norway.
	www.ucd.ie /geology/geologyinfo/personnel/academic/menuge/pubs.htm (470 words)

	Tectonics and Geobiology of the Paleo- and Mesoproterozoic (Site not responding. Last check: 2007-10-16)
		Tectonics and Geobiology of the Paleo- and Mesoproterozoic
		Determining the apparent polar wander paths for different cratonic blocks of Laurentia and Australia during early Precambrian times can reveal the opening and closure of ancient oceans, and indicate whether the style of plate tectonics earlier in Earth's history was similar to or radically different from its style on today's globe.
		Some geochemical and geobiological records, like the appearance of the first fossilized eukaryotes and the record of strontium isotopes, can only be understood in a holistic fashion by taking into account the pattern of global tectonics at that time.
	www.yale.edu /ceo/Projects/Students/paleotectonics.html (131 words)

	Nilanjan Chatterjee's professional and research interests
		The CGC has witnessed three distinct episodes of anorthositic magmatism ranging in age from Late Paleoproterozoic to the Early Mesoproterozoic in association with metamorphosed layered mafic-ultramafic sequence, as a product of differentiated gabbro, and massif anorthosite.
		The present study aims to focus the characteristic petrological and chemical features of these metamorphosed mafic and ultramafic intrusives in the high-grade gneiss-migmatite terrain in tracing the tectonic setting of magma generation, their relationship with the mantle composition and probable heat source.
		The Eastern Ghats belt (EGB) is a Mesoproterozoic amphibolite-granulite terrain that can be traced through to Australia, Madagascar, southern Africa and eastern Antarctica.
	web.mit.edu /nchat/www/research2d.html (399 words)

	Geological Map of Canada (CD-ROM)
		Elsewhere letters only are used to designate special types of sedimentary rocks such as Mesoproterozoic marble in the southwestern Grenville Province north and south of Ottawa, Paleoproterozoic conglomerate and sandstone west and north of Hudson Bay, and mélange in the Appalachian and Cordilleran orogens.
		Clusters of Mesoproterozoic mega-breccias or diatremes cut Paleoproterozoic units north and east of Dawson, Yukon.
		Pearya Terrane on northernmost Ellesmere Island in the Arctic is a fault-bounded composite continental fragment probably derived from the Caledonides.
	instruct.uwo.ca /earth-sci/505/gscmap.htm (2680 words)

	Palaeos Proterozoic: The Stenian Period
		The Stenian Period of the Mesoproterozoic Era: 1200 to 1000 million years ago
		Most of the important events we mentioned in the Mesoproterozoic actually occurred in the Stenian, the last Period of the Mesoproterozoic Era.
		This stop is Rodonia Central on the Time Line.
	www.palaeos.com /Proterozoic/Stenian.html (713 words)

	Shuhai Xiao
		Alan J. Kaufman and I are currenlty working to measure the carbon isotopic compositions of individual acritarchs from Mesoproterozoic shales.
		Our preliminary measurements of Dictyosphaera delicata from the Mesoproterozoic Ruyang Group of North China indicate that atmospheric CO levels in the Mesoproterozoic was at least 10-200 times today's level.
		Xiao, A. Knoll, and M. R.Walter, Early eukaryotes in Paleoproterozoic and Mesoproterozoic oceans.
	www.geol.vt.edu /paleo/Xiao (2523 words)

	A review of the Mesoproterozoic to early Palaeozoic magmatic and tectonothermal history of south-central Africa: ...
		A review of the Mesoproterozoic to early Palaeozoic magmatic and tectonothermal history of south-central Africa: implications for Rodinia and Gondwana -- Johnson et al.
		A review of the Mesoproterozoic to early Palaeozoic magmatic and tectonothermal history of south–central Africa: implications for Rodinia and Gondwana
		Block and Irumide Belt are not components of the same orogen,
	jgs.geoscienceworld.org /cgi/content/abstract/162/3/433 (262 words)

	Mesoproterozoic Reworking of Palaeoproterozoic Ultrahigh-temperature Granulites in the Central Indian Tectonic Zone and ... (Site not responding. Last check: 2007-10-16)
		Mesoproterozoic Reworking of Palaeoproterozoic Ultrahigh-temperature Granulites in the Central Indian Tectonic Zone and its Implications -- BHOWMIK et al.
		Mesoproterozoic Reworking of Palaeoproterozoic Ultrahigh-temperature Granulites in the Central Indian Tectonic Zone and its Implications
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	dx.doi.org.cob-web.org:8888 /10.1093/petrology/egi011 (298 words)

	Hanson: Research Interests
		Southern Africa is of crucial importance in understanding global Proterozoic plate dynamics and supercontinent configurations, both with regard to assembly and breakup of the Mesoproterozoic Rodinia supercontinent, and with regard to the assembly of Gondwana near the end of the Neoproterozoic.
		Our work suggests that the African igneous province is temporally and perhaps spatially linked to widespread, coeval within-plate magmatism in North America (including the Midcontinent rift).
		This linkage has important implications for proposed reconstructions of the Mesoproterozoic Rodinia supercontinent, and for relations between mantle convection and supercontinent assembly and dispersal.
	geowww.geo.tcu.edu /faculty/hanson/Hanson3.html (2091 words)

	ILSG - Nipigon 2005
		Please note that this trip is dependent on weather and lake conditions.
		The area is underlain by Neoarchean metasedimentary and granitoid rocks of the Quetico Subprovince, overlain by Mesoproterozoic Sibley Group sedimentary rocks and mafic to ultramafic intrusive rocks related to the Midcontinent Rift.
		Archean granitoid rocks of the Quetico Subprovince (on right) are in fault-bounded contact with Mesoproterozoic Sibley Group sedimentary rocks and Keweenawan diabase sills (on left).
	www.lakesuperiorgeology.org /nipigon2005/fieldtrips.html (875 words)

	Geosciences
		Sears, J.W., and Price, R.A., 2002, Hypothetical Mesoproterozoic supercontinent Columbia: Implications of the Siberian-west Laurentian connection: Gondwana Research, v.
		Sears, J.W., 2001, Emplacement and Denudation History of the Lewis-Eldorado-Hoadley thrust slab in the northern Montana Cordillera, USA: Implications For Steady-State Orogenic Processes: American Journal of Science, p.
		Sears, J.W., 2001, Icosahedral fracture tessellation of early Mesoproterozoic Laurentia: Geology, v.
	www.umt.edu /geosciences/faculty/sears/sears.htm (662 words)

	Geologic map of Idaho county
		East of the suture are the Clearwater Mountains, underlain by Proterozoic and Paleozoic rocks with affinity to North America, and intruded by the Cretaceous Idaho batholith.
		Many of these strata are Mesoproterozoic Belt Supergroup, though some have uncertain affinity.
		On the southeast and along the eastern border with Montana in the Bitterroot Mountains are Eocene intrusive rocks, associated with the Challis magmatic episode.
	imnh.isu.edu /digitalatlas/counties/idaho/geomap.htm (467 words)

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