scholarly journals Nd-isotopic stratigraphy of early Proterozoic Amisk Group metavolcanic rocks from the Flin Flon Belt, Manitoba and Saskatchewan

1992 ◽  
Author(s):  
R A Stern ◽  
E C Syme ◽  
A H Bailes ◽  
A G Galley ◽  
D J Thomas ◽  
...  
Keyword(s):  
Early Proterozoic ◽  
Metavolcanic Rocks ◽  
Flin Flon

Rb–Sr study of metavolcanic rocks from the La Ronge and Flin Flon domains, northern Saskatchewan

1985 ◽  
Vol 22 (3) ◽  
pp. 452-463 ◽  
Author(s):  
B. R. Watters ◽  
R. L. Armstrong
Keyword(s):  
Source Region ◽  
Volcanic Rocks ◽  
Volcanic Arcs ◽  
Magmatic Arc ◽  
Linear Evolution ◽  
Metavolcanic Rocks ◽  
Northern Saskatchewan ◽  
Archean Crust ◽  
Flin Flon ◽  
Lynn Lake

Two whole-rock suites of metavolcanic rocks from separate volcanic belts of the Churchill Province in northern Saskatchewan have been dated by Rb–Sr. Samples from the Amisk Group of the Flin Flon – Snow Lake domain provide an isochron date of 1784 ± 44 Ma; suites from the Waddy Lake and Devil Lake areas of the La Ronge (–Lynn Lake) domain yield isochron dates of 1814 ± 26 and 1854 ± 100 Ma, respectively. All are regarded as minima for, but close approximations to, emplacement ages. The maximum crustal age of any suite cannot greatly exceed 1850 Ma.Previous Rb–Sr and U–Pb isotopic dates together with these new determinations confirm the contemporaneous existence of two volcanic arcs, active during the late Aphebian (1875–1784 Ma) in the Churchill Province.Low initial 87Sr/86Sr ratios (0.7017–0.7022) are consistent with a petrochemically inferred subduction-related origin for the volcanic rocks with no closed-system reworking of Archean crust, and a linear evolution of 87Sr/86Sr ratio in the magmatic-arc mantle source region from 4.55 Ga to the present.

Petrogenesis of the Boundary intrusions in the Flin Flon area of Saskatchewan and Manitoba

1977 ◽  
Vol 14 (3) ◽  
pp. 444-455 ◽  
Author(s):  
Eric C. Syme ◽  
Richard W. Forester
Keyword(s):  
Basaltic Magma ◽  
Molar Ratio ◽  
Chemical Characteristics ◽  
Olivine Gabbro ◽  
Metasedimentary Rocks ◽  
Metavolcanic Rocks ◽  
Flin Flon ◽  
Group 2 ◽  
The Town ◽  
Felsic Rocks

The Aphebian Boundary intrusions are a group of lensoid, ultramafic to felsic rocks which occur in a N–NW trending zone 10 km long by 4 km wide centred on the town of Flin Flon. The intrusions were emplaced into Amisk metavolcanic rocks and Missi metasedimentary rocks. Field relationships, petrography, and chemical characteristics of the Boundary intrusions indicate that they are composed of three compositionally distinct, sequentially emplaced groups. From oldest to youngest, these are (1) a mafic augite- and biotite-bearing mela-dioritic group, (2) a felsic group ranging from leucodiorite to granodiorite, and (3) an olivine-bearing (wehrlite to olivine gabbro) group. The mafic group crystallized at relatively high [Formula: see text] and [Formula: see text], such that successive differentiates have increasing MgO/FeO ratios. Molar ratio diagrams clearly indicate that fractionation of augite, minor magnetite, and possibly subordinate olivine can account for the observed chemical variation of approximately 80% of this group, whereas the olivine-bearing group could only have formed by crystal fractionation of subequal amounts of olivine and clinopyroxene, and minor magnetite. The felsic group is chemically similar to the post-Missi granodioritic plutons and cannot represent SiO2-rich residual liquids produced solely by fractionation of augite and olivine from a basaltic magma.

Early Proterozoic deformation along the southern margin of the Kisseynew gneiss belt, Trans-Hudson Orogen: a 30 Ma progressive deformation cycle

1995 ◽  
Vol 32 (7) ◽  
pp. 875-894 ◽  
Author(s):  
A. R. Norman ◽  
P. F. Williams ◽  
K. M. Ansdell
Keyword(s):  
Time Scales ◽  
Structural Evolution ◽  
Progressive Deformation ◽  
Early Proterozoic ◽  
Movement Vector ◽  
Deformation Cycle ◽  
Southern Margin ◽  
Flin Flon ◽  
Relationship Of ◽  
The Relationship

Fold axes and lineations across the southern margin of the Kisseynew gneiss belt were progressively reoriented from northwesterly to northeasterly during an Early Proterozoic, southwest-directed, compressive deformation cycle. Partitioning of deformation resulted in a concentration of non-coaxial strain along the boundary between the Kisseynew gneiss belt and Flin Flon–Snow Lake belt. The structural evolution was complicated by streamlining of the movement vector around the comparatively rigid Flin Flon–Snow Lake belt. The relationship of metamorphic assemblages to kinematic fabrics indicates that deformation was coeval with a prograde–retrograde metamorphic cycle. Progressive deformation occurred during a period of 30 Ma, which is consistent with Phanerozoic orogenic time scales.

Age and source of detrital zircons from the Missi Formation: a Proterozoic molasse deposit, Trans-Hudson Orogen, Canada

1992 ◽  
Vol 29 (12) ◽  
pp. 2583-2594 ◽  
Author(s):  
Kevin M. Ansdell ◽  
T. Kurtis Kyser ◽  
Mel R. Stauffer ◽  
Garth Edwards
Keyword(s):  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Detrital Zircons ◽  
Early Proterozoic ◽  
Minimum Age ◽  
Granitoid Rocks ◽  
Evaporation Technique ◽  
Single Zircon ◽  
Flin Flon ◽  
Felsic Volcanic

The Missi Formation in the Flin Flon Basin forms part of a discontinuous series of molasse-type sediments found throughout the Early Proterozoic Trans-Hudson Orogen in northern Saskatchewan and Manitoba. The Flin Flon Basin contains a sequence of proximal-fan to braided-stream fluvial conglomerates and sandstones, which unconformably overlie subaerially weathered Amisk Group volcanic rocks. Stratigraphic way-up indicators have been preserved, even though these rocks have undergone greenschist-facies metamorphism and polyphase deformation. The sedimentary rocks are crosscut by intrusive rocks, which provide a minimum age of sedimentation of 1840 ± 7 Ma.Detrital zircons from each of the six stratigraphic subdivisions of the Flin Flon Basin were analyzed using the single-zircon Pb-evaporation technique. Euhedral to slightly rounded zircons dominate each sample, and these zircons give ages of between about 1854 and 1950 Ma. The Missi sediments were thus deposited between 1840 and 1854 Ma. Possible sources for the detrital zircons are Amisk Group felsic volcanic rocks and post-Amisk granitoid rocks and orthogneisses in adjacent domains within the Trans-Hudson Orogen. However, the immature character of the sedimentary rocks, the composition of clasts, the euhedral character of many of the zircons, and the range in ages suggest that most were likely derived from Amisk Group and granitoid rocks in the western Flin Flon Domain. Rounded zircons are uncommon but provide evidence for the reworking of older Proterozoic sedimentary rocks, or a distant Archean or Early Proterozoic granitoid terrane.

Review of isotope data for Precambrian rocks from the Disko Bugt region, West Greenland

1999 ◽  
pp. 41-47 ◽  
Author(s):  
Feiko Kalsbeek ◽  
Paul N. Taylor
Keyword(s):  
Sr Isotope ◽  
Yield Model ◽  
Original Series ◽  
Early Proterozoic ◽  
West Greenland ◽  
Precambrian Rocks ◽  
Isotope Data ◽  
Metavolcanic Rocks ◽  
Granitoid Rocks ◽  
Data Yield

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kalsbeek, F., & Taylor, P. N. (1999). Review of isotope data for Precambrian rocks from the Disko Bugt region, West Greenland. Geology of Greenland Survey Bulletin, 181, 41-47. https://doi.org/10.34194/ggub.v181.5110 _______________ Pb-Pb and Rb-Sr isotope data yield whole-rock isochron ages of c. 2800 Ma for two localities of granitoid rocks in the Disko Bugt region, with little evidence of strong later disturbance. Rb-Sr isotope data on Archaean metasediments from two localities, however, were strongly disturbed during the early Proterozoic. Sm-Nd whole-rock data for acid metavolcanic rocks within Archaean supracrustal sequences yield model ages of c. 2800 Ma. The early Proterozoic age of a younger sequence of supracrustal rocks (the Anap nunâ Group) is confirmed by Sm-Nd data, and Rb-Sr whole-rock data for albitised siltstones show that albitisation took place hundreds of millions of years after the peak of early Proterozoic orogenic activity.

scholarly journals Chemical Stratigraphy and Petrogenesis of the Early Proterozoic Amisk Lake Volcanic Sequence, Flin Flon-Snow Lake Greenstone Belt, Canada

1997 ◽  
Vol 38 (11) ◽  
pp. 1541-1564 ◽  
Author(s):  
M. I. Leybourne ◽  
N. A. Van Wagoner ◽  
L. D. Ayres
Keyword(s):  
Greenstone Belt ◽  
Early Proterozoic ◽  
Volcanic Sequence ◽  
Flin Flon
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