Constraints from 40Ar/39Ar geochronology on the tectonothermal history of the Kapuskasing uplift in the Canadian Superior Province

1994 ◽  
Vol 31 (7) ◽  
pp. 1146-1171 ◽  
Author(s):  
J. A. Hanes ◽  
D. A. Archibald ◽  
M. Queen ◽  
E. Farrar
Keyword(s):  
Fault Zone ◽  
Age Groups ◽  
Fault Zones ◽  
Fault Reactivation ◽  
Superior Province ◽  
Lower Grade ◽  
Upper Limit ◽  
Step Heating ◽  
History Of ◽  
Structural Levels

The Kapuskasing uplift (KU) in the Superior Province of the Canadian Shield has been interpreted as an oblique cross section through the Archean mid-crust. However, the time of juxtaposition of the granulites of the KU against the lower grade rocks of the Abitibi greenstone belt (AGB) along the Ivanhoe Lake fault zone is problematic. To constrain the postmetamorphic tectonothermal history of the KU, we have conducted 57 40Ar/39Ar step-heating analyses on mineral and rock samples collected in a transect across the southern KU and adjacent AGB. The age spectra record a complex thermal history. Amphiboles from the AGB in the footwall of the Ivanhoe Lake fault zone have ca. 2.66 Ga dates, similar to closure ages for amphiboles from farther east in the AGB. Amphibole dates of 2.46–2.52 Ga from the deepest structural levels of the KU place an upper limit on the time of major uplift of the granulites and their juxtaposition with the AGB. Biotite and muscovite dates from the transect cluster into three age groups. The presence in the deepest structural levels of the KU of biotite with 2.40–2.45 Ga dates indicates that significant uplift (15–20 km or more) of the granulites had occurred by this time. Micas with dates in the 2.25–2.30 Ga range are close to fault zones; these dates may indicate a ca. 2.30 Ga episode of fault reactivation. Feldspar, fault-related whole rocks, and some micas record events post 2.1 Ga. These correspond to the emplacement of mafic and lamprophyric dykes and fault reactivation.

Occurrence and possible tectonic significance of high-pressure granulite fragments in the Tulemalu fault zone, District of Keewatin, N.W.T., Canada

1986 ◽  
Vol 23 (12) ◽  
pp. 1950-1962 ◽  
Author(s):  
S. Tella ◽  
K. E. Eade
Keyword(s):  
Fault Zone ◽  
Fault Zones ◽  
Ductile Deformation ◽  
Lower Grade ◽  
Mineral Association ◽  
The West ◽  
High Pressure Granulite ◽  
Tectonic Significance ◽  
Isothermal Decompression ◽  
Textural Evidence

Fragments of garnet–clinopyroxene granulite with corona textures in ductilely deformed lower-amphibolite-grade quartzofeldspathic granitoid gneiss are exposed within the northeast-trending Tulemalu fault zone. The mineral association of the fragments is garnet–clinopyroxene–plagioclase(An20–An22)–quartz–opaques–hornblende–biotite. Textural evidence suggests that hornblende and biotite are late overgrowth minerals. Garnet and clinopyroxene and (or) hornblende are separated by a narrow rim of plagioclase. Pressure–temperature estimates based on currently used geothermobarometers are of the order of 715–789 °C and 10.2–11.4 kbar (1 kbar = 100 MPa) for the garnet–clinopyroxene–plagioclase–quartz assemblage. The fragments are interpreted as relicts of deep-crustal materials, uplifted to higher levels probably as xenolithic rafts in a granitic melt along the fault zone during late Archean or Early Proterozoic ductile displacements. The growth of hornblende and the development of plagioclase reaction rims around garnet are believed to be due to isothermal decompression reactions during uplift.On the basis of limited geological data, paired gravity anomaly patterns, and aeromagnetic interpolation, the Tulemalu fault zone is postulated as representing the northeasterly extension of the Virgin River – Black Lake fault zones of Saskatchewan and represents an approximately 5 km wide ductile deformation zone that separates an Archean granulite terrane to the west from a relatively lower grade terrane composed of Archean supracrustal rocks to the east.

scholarly journals Fluid Inclusions Record Hydrocarbon Charge History in the Shunbei Area, Tarim Basin, NW China

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ziye Lu ◽  
Yingtao Li ◽  
Ning Ye ◽  
Shaonan Zhang ◽  
Chaojin Lu ◽  
...  
Keyword(s):  
Fault Zone ◽  
Fluid Inclusions ◽  
Tarim Basin ◽  
Homogenization Temperature ◽  
Fault Zones ◽  
Carbonate Reservoirs ◽  
Fault System ◽  
Middle Ordovician ◽  
History Of ◽  
Hydrocarbon Charge

The exploration of deeply buried hydrocarbon is still a challenge for the petroleum geology. The Shunbei area is a newly discovered oil fields, located in the center of the Tarim Basin. The oil is mainly yielded from the Middle–Lower Ordovician carbonate reservoirs with depth > 7000  m in the Shunbei No. 1 and No. 5 fault zones. Calcite cements filled in vugs (v-calcite) and fractures (f-calcite) are identified in limestones and dolostones of the carbonate reservoirs. F-calcites in the Shunbei No. 1 fault zone trap secondary inclusions in trails, which comprise liquid-dominated biphase aqueous inclusions, liquid-dominated biphase oil inclusions, and/or oil-bearing triphase inclusions. F-calcite and v-calcite in the No. 5 fault zone trap secondary inclusions in trails, which consist of liquid-only monophase aqueous inclusions, liquid-dominated biphase aqueous inclusions, liquid-dominated biphase oil inclusions, liquid-only monophase oil inclusions, and/or oil-bearing triphase inclusions. The ranges of the homogenization temperature ( T h ) and ice-melting temperature ( T m − ice ) in the Shunbei No. 1 fault zone are, respectively, 130–150°C and -2.1–-1.5°C. The coexistence of liquid-only and liquid-dominated aqueous inclusions in the Shunbei No. 5 fault zone indicates that the aqueous inclusions are trapped at low temperatures. The aqueous inclusions in the Shunbei No. 5 fault zone show a range from -0.4 to -0.2°C in T m − ice which is very close to the meteoric fluid. In the context of the burial-thermal history and the Cambrian source rock evolution, the charging process of hydrocarbon in the Shunbei No. 1 and No. 5 fault zones corresponds to the Silurian and Middle Ordovician, respectively. Results of fluid inclusions indicate a tightly coupling relationship between the hydrocarbon charging process and fault system evolution in the Shunbei area. This study reveals the application of fluid inclusion under the systemically petrographic constraints to decipher the charging history of hydrocarbon, especially for the deeply buried reservoirs.

An experimental and numerical investigation on the hydromechanical behaviour of carbonate fault zones upon reactivation: the impact of carbonate mud sealing layers and overall research outcomes

2019 ◽  
Vol 496 (1) ◽  
pp. 39-73 ◽  
Author(s):  
M. Nogueira Kiewiet ◽  
C. Lima ◽  
A. Giwelli ◽  
C. Delle Piane ◽  
V. Lemiale ◽  
...  
Keyword(s):  
Fault Zone ◽  
Microstructural Analysis ◽  
Fault Zones ◽  
Fault Reactivation ◽  
Two Dimensional ◽  
Direct Shear ◽  
Research Project ◽  
Rock Types ◽  
Particle Hydrodynamics ◽  
The Impact

AbstractTo contribute to the understanding of the impacts of fault reactivation induced by reservoir exploitation, we describe the final series of laboratory experiments, numerical simulations and microstructural analysis conducted during the ‘Fault Reactivation in Carbonates’ research project. In the project, the structure and hydromechanical properties of carbonate-hosted fault zones were investigated. For the analyses here reported, faults were artificially generated by direct shearing composite blocks made of layers of reservoir analogue rocks (outcrop travertine or synthetic grainstone) intercalated with one layer of a sealing analogue rock (synthetic carbonate mudstone). Post-direct shearing, cylindrical plugs containing the fault zone and parts of intact rock were cored out from the blocks and tested in a triaxial test rig, simulating fault reactivation. Varied stress paths and pore-pressure conditions representative of fluid depletion and injection were considered. In parallel, two-dimensional mechanical models representative of the direct shear experiments were developed using smoothed particle hydrodynamics (SPH). We observed a continuous reduction in fault transmissibility during direct shearing, followed by a permeability reduction of 50–80% with increasing mean effective stress in the subsequent fault reactivation tests. Experimental fault zone geometries produced during direct shear were broadly reproduced by the two-dimensional modelling approach. We also detected that the inclusion of the carbonate mud sealing rock into the fault zone caused greater compaction of the fault materials when compared to experiments conducted without carbonate mud layers. We conclude that with fault displacement, increasing incorporation of carbonate mud sealing material into the fault zone and the concomitant development of gouge results in the continuous reduction of fault transmissibility/permeability. This occurs in the two very different limestone host-rock types and for all the stress configurations investigated. Discussions on these results and also on the outcomes of the research project as a whole are presented in the paper.

Depositional history of the southeastern outcrop belt of the Chuckanut Formation: implications for the Darrington – Devil's Mountain and Straight Creek fault zones, Washington (U.S.A.)

1994 ◽  
Vol 31 (12) ◽  
pp. 1727-1743 ◽  
Author(s):  
James E. Evans ◽  
R. John Ristow Jr.
Keyword(s):  
Fault Zone ◽  
Middle Eocene ◽  
Fault Zones ◽  
Early Eocene ◽  
Fluvial System ◽  
Sediment Sources ◽  
Depositional History ◽  
Source Areas ◽  
Depositional System ◽  
History Of

The southeastern outcrop belt of the Eocene Chuckanut Formation contains the erosional remnants of a larger depositional system. In the study area, the Chuckanut Formation can be split into four units based upon differences in age, lithology, sedimentology, paleocurrents, and provenance relationships. The Coal Mountain unit (Early Eocene) represents a southwest-flowing fluvial system that shows no evidence for fault control of drainage. The overlying Higgins Mountain unit (early Middle Eocene) represents a northeast-flowing fluvial system east of the Devil's Mountain fault zone (DMFZ), with lithologies derived from western source areas. The Sperry Peak unit (early Middle Eocene) represents a fluvial system with a wide dispersion of paleocurrent azimuths and a possible mixture of sediment source areas. We believe the Sperry Peak unit was deposited in a fault-wedge graben at the junction of the DMFZ and Straight Creek fault zone (SCFZ), with sediment sources from both east and west. The Grade Creek unit (age unknown) is a fluvial unit found along the trace of the SCFZ with paleo-flow subparallel to the fault zone. The sedimentary evidence suggests that onset of Paleogene faulting on the DMFZ and SCFZ was at about 50–48 Ma, while movement on the Darrington fault zone may have been later (post-42 Ma).

Archean basin–craton complexes and the growth of Precambrian shields

1977 ◽  
Vol 14 (12) ◽  
pp. 2737-2759 ◽  
Author(s):  
Alan M. Goodwin
Keyword(s):  
Mantle Convection ◽  
Age Groups ◽  
Canadian Shield ◽  
Superior Province ◽  
Low Grade ◽  
Lower Grade ◽  
Metamorphic Terranes

Southern Superior Province of the Canadian Shield contains cratonic and basinal elements arranged in high- to low-grade metamorphic terranes such that higher grade gneissic cratons are interpreted to represent primary infrastructure to lower grade volcanic-rich (greenstone) basins. Ensimatic accumulation of volcanic components is favoured with derivation of gneissic (granitic) components by ensuing metamorphic differentiation and granitization processes. Such vertically reconstructed basin–craton complexes which are tentatively ascribed to initial Archean mantle convection, are viewed as building units of growing Precambrian shields.Globally, twenty-seven identified Archean cratons belong to three main age groups based on maximum recorded ages as follows: 3.5–3.8 Ga, 2.9–3.1 Ga, and 2.6–2.7 Ga. The three age groups that correspond to major periods of Archean orogeny may represent accretion superevents (after Moorbath).Most cratons as presently exposed display lithologic characteristics of lower superstructure–upper infrastructure of typical basin–craton complexes thereby suggesting a common degree of crustal buoyancy, hence level of erosion. Archean belts of southern Superior Province provide unique opportunity for reconstruction of the typical basin–craton complex.

Analysis of vitamin D deficiency in patients of different age groups

2020 ◽  
pp. 64-70
Author(s):  
Timur Minasov ◽  
Radik Nurlygayanov ◽  
Angela Vershinina ◽  
Yulia Soboleva ◽  
Damir Akhmeldinov ◽  
...  
Keyword(s):  
Vitamin D ◽  
Blood Serum ◽  
Vitamin D Deficiency ◽  
Russian Federation ◽  
Age Groups ◽  
Upper Limit ◽  
The Russian Federation ◽  
Physiological Values

The results of a study of the concentration of vitamin D in blood serum of 3455 residents of Ufa are presented. Physiological values of 25(OH)D were observed in 34.9 % (274) of men and 31.7 % (847) of women, which is 32.4 % (1121) of all examined. Vitamin D deficiency was detected in 67.1 % of the examined. The level of 25(OH)D in the blood serum of residents is on average 75 nmol/L, which is the upper limit of vitamin D deficiency. Vitamin D deficiency is extremely common among residents of this region of the Russian Federation (67.1 %).

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