Mineral resources of Wilderness Study Areas: north-central Colorado

10.3133/b1717 ◽  
1985 ◽  
Keyword(s):  
Mineral Resources ◽  
North Central

scholarly journals Precambrian faulting episodes and insights into the tectonothermal history of North Australia: Microstructural evidence and K–Ar, <sup>40</sup>Ar–<sup>39</sup>Ar, and Rb–Sr dating of syntectonic illite from the intracratonic Millungera Basin

2020 ◽  
Author(s):  
I. Tonguç Uysal ◽  
Claudio Delle Piane ◽  
Andrew Todd ◽  
Horst Zwingmann
Keyword(s):  
Large Scale ◽  
Active Tectonics ◽  
Mineral Resources ◽  
Sedimentary Basins ◽  
Integrated Approach ◽  
Space Distribution ◽  
Seismic Survey ◽  
North Central ◽  
Time Space ◽  
Central Australia

Abstract. Australian terranes concealed beneath Mesozoic cover record complex Precambrian tectonic histories involving a successive development of several Proterozoic to Paleozoic orogenic systems. This study presents an integrated approach combining K–Ar, 40Ar–39Ar, and Rb–Sr geochronology of Precambrian authigenic illites from the recently discovered Millungera Basin in north-central Australia. Brittle deformation and repeated fault activity are evident from the sampled cores and their microstructures, probably associated with the large-scale faults inferred from interpretations of seismic survey. Rb–Sr isochron, 40Ar–39Ar total gas, and K–Ar ages are largely consistent indicating late Mesoproterozoic and early Proterozoic episodes (~ 1115 ± 26 Ma, ~ 1070 ± 25 Ma, ~ 1040 ± 24 Ma, ~ 1000 ± 23 Ma, and ~ 905 ± 21 Ma) of active tectonics in north-central Australia. K–Ar results show that illites from fault gouges and authigenic matrix illites in undeformed adjacent sandstones precipitated contemporaneously, indicating that advection of tectonically mobilised fluids extended into the undeformed wall rocks above or below the fracture and shear (fault gouge) zones. This study provides insight into the enigmatic time-space distribution of Precambrian tectonic zones in central Australia, which are responsible for the formation of a number of sedimentary basins with significant energy and mineral resources.

scholarly journals Precambrian faulting episodes and insights into the tectonothermal history of north Australia: microstructural evidence and K–Ar, <sup>40</sup>Ar–<sup>39</sup>Ar, and Rb–Sr dating of syntectonic illite from the intracratonic Millungera Basin

Solid Earth ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 1653-1679
Author(s):  
I. Tonguç Uysal ◽  
Claudio Delle Piane ◽  
Andrew James Todd ◽  
Horst Zwingmann
Keyword(s):  
Large Scale ◽  
Active Tectonics ◽  
Mineral Resources ◽  
Sedimentary Basins ◽  
Integrated Approach ◽  
Space Distribution ◽  
North Central ◽  
Time Space ◽  
Minimum Age ◽  
Central Australia

Abstract. Australian terranes concealed beneath Mesozoic cover record complex Precambrian tectonic histories involving a successive development of several Proterozoic to Palaeozoic orogenic systems. This study presents an integrated approach combining K–Ar, 40Ar–39Ar, and Rb–Sr geochronologies of Precambrian authigenic illites from the recently discovered Millungera Basin in north-central Australia. Brittle deformation and repeated fault activity are evident from the sampled cores and their microstructures, probably associated with the large-scale faults inferred from interpretations of seismic surveys. Rb–Sr isochron, 40Ar–39Ar total gas, and K–Ar ages are largely consistent in indicating late Mesoproterozoic and early Proterozoic episodes (∼1115±26, ∼ 1070±25, ∼1040±24, ∼1000±23, and ∼905±21 Ma) of active tectonics in north-central Australia. K–Ar results show that illites from fault gouges and authigenic matrix illites in undeformed adjacent sandstones precipitated contemporaneously, indicating that advection of tectonically mobilized fluids extended into the undeformed wall rocks above or below the fracture and shear (fault gouge) zones. Isotopic age data clearly indicate a Mesoproterozoic minimum age for the Millungera Basin and thus previously unrecorded late Mesoproterozoic–early Neoproterozoic tectonic events in north-central Australia. This study provides insight into the enigmatic time–space distribution of Precambrian tectonic zones in central Australia, which are responsible for the formation of a number of sedimentary basins with significant energy and mineral resources.

Stromatoporoids from the Famennian (Devonian) Wabamun Formation, Normandville oilfield, north–central Alberta, Canada

1988 ◽  
Vol 62 (03) ◽  
pp. 411-419 ◽  
Author(s):  
Colin W. Stearn
Keyword(s):  
Patch Reef ◽  
Abundant Species ◽  
The Other ◽  
North Central ◽  
Biotic Crisis

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species isStylostroma sinense(Dong) butLabechia palliseriStearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described areClathrostromacf.C. jukkenseYavorsky,Gerronostromasp. (a columnar species), andStromatoporasp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

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