Brittle faulting in the Thor–Odin culmination, Monashee complex, southern Canadian Cordillera: constraints on geometry and kinematics

2005 ◽  
Vol 42 (12) ◽  
pp. 2141-2160 ◽  
Author(s):  
Stefan Kruse ◽  
Paul F Williams
Keyword(s):  
Strike Slip ◽  
Normal Faults ◽  
Canadian Cordillera ◽  
The West ◽  
West Side ◽  
The North ◽  
Monashee Complex ◽  
Dextral Strike Slip Fault ◽  
Brittle Faulting ◽  
Dextral Strike Slip

Regionally recognized dextral strike-slip faulting is present in the Monashee complex of the southern Canadian Cordillera but is overprinted and partially obscured by subsequent extension. Eocene brittle faults and fractures within the Thor–Odin culmination of the Monashee complex are divisible into three distinct sets. Initial 340°–010° trending strike-slip faults (set 1) were locally overprinted and reactivated by normal faults with a 325°–020° trend (set 2). A third set of 255°–275° trending fractures (set 3) are interpreted as conjugates to set 1, reactivated as transfer faults to the set 2 normal faults. Large regional faults weather recessively, forming topographic lineaments that transect the Monashee complex. The Victor Creek Fault defines one such lineament. Detailed mapping within the northern Thor–Odin culmination reveals piercement points (fold hinges) on the east side of the fault that are not readily matched on the west side. The minimum displacement required on the Victor Creek Fault to down-drop the fold hinge below the level of exposure on the west side is 1370 m, assuming normal down-to-the-west displacement. The geometry of the fault is consistent with a set 1 dextral strike-slip fault, however. Matching the piercement points in the study area with possible equivalents to the north indicates 55–60 km of dextral strike-slip displacement.

Tertiary extension in the central British Columbia Intermontane Belt: magnetic and paleomagnetic evidence from the Endako region

2001 ◽  
Vol 38 (4) ◽  
pp. 657-678 ◽  
Author(s):  
Carmel Lowe ◽  
Randolph J Enkin ◽  
Lambertus C Struik
Keyword(s):  
British Columbia ◽  
Strike Slip ◽  
Paleomagnetic Data ◽  
Magnetic Data ◽  
Euler Deconvolution ◽  
The West ◽  
Near Surface ◽  
Dextral Strike Slip Fault ◽  
Slip Displacement ◽  
Dextral Strike Slip

New magnetic and paleomagnetic data for central British Columbia support and quantify the hypothesis that the area underwent significant Tertiary-age transtensional deformation. Paleomagnetically determined tilts in Eocene rocks indicate that four fault-bounded pits, which constitute the Endako molybdenum mine, were displaced on a series of normal (probably listric) faults that have separations of less than a kilometre. The interpretation also suggests there can be little vertical offset on the Denak West Fault, which separates the Denak East and Denak West pits. Regional paleomagnetic data indicate a predominance of easterly directed tilts to the east of the Casey Fault, but to the west a large variation in the orientation and magnitude of tilts is observed. Results at one site proximal to the Casey Fault indicate a component of dip-slip displacement on this dominantly dextral strike-slip fault. Mapped northeast- and northwest-trending faults commonly correspond to linear zones of steep magnetic gradient and near-surface magnetic sources. Several additional northwest- and northeast-trending lineaments are imaged in the magnetic data where no faults are mapped (particularly over massive and lithologically homogeneous phases of the Endako batholith). Euler deconvolution solutions confirm most such lineaments are also associated with shallow magnetic sources. In profile, they have either a fault or dyke character and are interpreted to be unmapped faults, some locally intruded by mafic dykes, which cut the region into a series of fault-bounded blocks.

scholarly journals The role of the 'Zvornik suture' for assessing the number of Neotethyan oceans: Surface - subsurface constraints on the fossil plate margin (Vardar Zone vs. Inner Dinarides)

2020 ◽  
Vol 81 (2) ◽  
pp. 63-86
Author(s):  
Darko Spahic ◽  
Tivadar Gaudenyi
Keyword(s):  
Oceanic Lithosphere ◽  
Ocean Model ◽  
Strike Slip ◽  
Fault System ◽  
The West ◽  
Vardar Zone ◽  
Slip Activity ◽  
Dextral Strike Slip Fault ◽  
Dextral Strike Slip

The balancing exercise of the ?single-ocean model? and reexa - mination of Jurassic paleogeographic conditions and tectonic interaction allowed the reconstruction of the mosaic of independent microplate margins and sutured northwestern Tethyan realm (Vardar Ocean). The overprinted Mesozoic convergent margin referred to as the ?Zvornik suture? was of special interest in the reconstruction of the displaced ophiolite belts of Dinarides and Vardar Zone. The surface?subsurface constraints of these mixed crustal units, in particular the polyphase strike-slip character of the ?Zvornik suture? yields the presence of at least two of Neotethyan basins extrapolated in the vicinity of the northwestern segment of this paleosuture - related fault system. The restoration and synopsis shows a limited capability for obduction-related emplacement of the Vardar oceanic lithosphere (West Vardar Zone) accounting the polyphased strike-slip tectonics. The balancing and the proposed tectonic/paleogeographic recon struction does not exclude obduction, but it shows a limited capability with much shorter across-strike width of the highlydeformed West Vardar ophio lite. The presence of the two distinct autochthonous Tethyan oceans divided by this important dextral strike-slip fault zone is suggested: The Inner Dina ric?(Mirdita?Pindos) Ocean or Dinaric Tethys (identified by the Inner Dinaric Ophiolite Belt) and the Vardar Ocean (identified by the West Vardar Zone). The West Vardar Zone remains to be a subzone of the principal composite Neotethyan suture referred to as the Vardar Zone s.s., whereas the Dinaric Tethys have been (re)incorporated to the area of Dinarides (Adria microplate). The northern segments of these two landlocked basins were on both sides of the Inner Dinaridic continental ridge (referred to as the Drina-Ivanjica block), divided by the protracted strike-slip activity of the ?Zvornik suture?.

scholarly journals Coseismic fault-slip distribution of the 2019 Ridgecrest Mw6.4 and Mw7.1 earthquakes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yang Gao ◽  
HuRong Duan ◽  
YongZhi Zhang ◽  
JiaYing Chen ◽  
HeTing Jian ◽  
...  
Keyword(s):  
Strike Slip ◽  
Fault Slip ◽  
Slip Distribution ◽  
Synthetic Aperture ◽  
Seismic Events ◽  
Interferometric Synthetic Aperture Radar ◽  
The Past ◽  
Dextral Strike Slip Fault ◽  
Fault Slip Distribution ◽  
Dextral Strike Slip

AbstractThe 2019 Ridgecrest, California seismic sequence, including an Mw6.4 foreshock and Mw7.1 mainshock, represent the largest regional seismic events within the past 20 years. To obtain accurate coseismic fault-slip distribution, we used precise positioning data of small earthquakes from January 2019 to October 2020 to determine the dip parameters of the eight fault geometry, and used the Interferometric Synthetic Aperture Radar (InSAR) data processed by Xu et al. (Seismol Res Lett 91(4):1979–1985, 2020) at UCSD to constrain inversion of the fault-slip distribution of both earthquakes. The results showed that all faults were sinistral strike-slips with minor dip-slip components, exception for dextral strike-slip fault F2. Fault-slip mainly occurred at depths of 0–12 km, with a maximum slip of 3.0 m. The F1 fault contained two slip peaks located at 2 km of fault S4 and 6 km of fault S5 depth, the latter being located directly above the Mw7.1hypocenter. Two slip peaks with maximum slip of 1.5 m located 8 and 20 km from the SW endpoint of the F2 fault were also identified, and the latter corresponds to the Mw6.4 earthquake. We also analyzed the influence of different inversion parameters on the fault slip distribution, and found that the slip momentum smoothing condition was more suitable for the inversion of the earthquakes slip distribution than the stress-drop smoothing condition.

Rampart seismic zone of central Alaska

1983 ◽  
Vol 73 (3) ◽  
pp. 813-829
Author(s):  
P. Yi-Fa Huang ◽  
N. N. Biswas
Keyword(s):  
Main Shock ◽  
Fault Plane ◽  
B Value ◽  
Aftershock Sequence ◽  
Strike Slip ◽  
Lithospheric Plate ◽  
Normal Faults ◽  
Seismic Zone ◽  
The West ◽  
Fault Plane Solutions

abstract This paper describes the characteristics of the Rampart seismic zone by means of the aftershock sequence of the Rampart earthquake (ML = 6.8) which occurred in central Alaska on 29 October 1968. The magnitudes of the aftershocks ranged from about 1.6 to 4.4 which yielded a b value of 0.96 ± 0.09. The locations of the aftershocks outline a NNE-SSW trending aftershock zone about 50 km long which coincides with the offset of the Kaltag fault from the Victoria Creek fault. The rupture zone dips steeply (≈80°) to the west and extends from the surface to a depth of about 10 km. Fault plane solutions for a group of selected aftershocks, which occurred over a period of 22 days after the main shock, show simultaneous occurrences of strike-slip and normal faults. A comparison of the trends in seismicity between the neighboring areas shows that the Rampart seismic zone lies outside the area of underthrusting of the lithospheric plate in southcentral and central Alaska. The seismic zone outlined by the aftershock sequence appears to represent the formation of an intraplate fracture caused by regional northwest compression.

Miocene to Messinian deformation and hydrothermal activity in a pre-Alpine basement massif of the French western Alps: new U-Th-Pb and argon ages from the Lauzière massif

2010 ◽  
Vol 181 (3) ◽  
pp. 227-241 ◽  
Author(s):  
Dominique Gasquet ◽  
Jean-Michel Bertrand ◽  
Jean-Louis Paquette ◽  
Jérémie Lehmann ◽  
Gueorgui Ratzov ◽  
...  
Keyword(s):  
Late Miocene ◽  
Shear Zones ◽  
Hydrothermal Activity ◽  
Western Alps ◽  
Strike Slip ◽  
Quartz Veins ◽  
The North ◽  
Slip Regime ◽  
Tectonically Active ◽  
Dextral Strike Slip

Abstract U-Pb and Th-Pb dating of monazite from hydrothermal quartz veins (“Alpine veins”) from the Lauzière massif (North Belledonne) together with Ar/Ar ages of adularias from the same veins constrain the age of the last tectono-metamorphic events that affected the External Crystalline Massifs (ECM). Ages obtained are surprisingly young. The study of the structural context of the veins combined with our chronological data, allow us to propose a tectonic scenario of the northern ECM for the 15-5 Ma period, which was poorly documented so far. The quartz veins are of two types: (i) the oldest are poorly mineralized (chlorite and epidote), flat-lying veins. The quartz fibres (= extension direction) are near vertical and seem to be associated with a subvertical dissolution schistosity superimposed upon an early Alpine deformation underlined by “mini-biotite”. They bear a sub-horizontal stretching lineation; (ii) the youngest veins are very rich in various minerals (anatase, rutile, phénacite, meneghinite, beryl, synchysite, ….). They are almost vertical. Their “en echelon” geometry as well as the horizontal attitude of their quartz fibres show a dextral strike-slip regime. Two groups of Th-Pb ages have been obtained: 11 to 10 Ma and 7 to 5 Ma. They were obtained from the most recent veins (vertical veins) sampled in different areas of the massif. The ca. 10 Ma ages are related to veins in the Lauzière granite and its metamorphic country-rocks at about 2 km from the eastern contact of the massif, while the ages of ca. 5 Ma correspond to veins occurring in mylonites along this contact. Adularias provided Ar/Ar ages at ca. 7 Ma. By contrast, a monazite from a vein of the Pelvoux massif (Plan du Lac) yielded a Th-Pb age of 17.6 Ma but in a different structural setting. Except fission track ages, there are very little ages of this range published in the recent literature on the Alps. The latter concern always gold mineralized veins (NE Mont Blanc and SW Lepontine dome). The last compressive tectonic regime dated between 15 and 12 Ma is coeval with (i) the late “Roselend thrust” event, which is recorded in the Mont Blanc by shear-zones with vertical lineation, (ii) the last movements in the basal mylonites of the Swiss Nappes, (iii) the horizontal Alpine veins from the Mont Blanc and Belledonne massifs (with vertical quartz fibres), which are similar to the early veins of the Lauzière. On the contrary, the vertical veins of the Lauzière, dated between 11 and 5 Ma, correspond to a dextral strike slip regime. This suggests that most of the strike-slip tectonics along the ECM took place during two stages (ca. 10 Ma and ca. 7-5 Ma) and not only at 18 Ma as had been proposed previously. Our ages are consistent with the late Miocene-Pliocene overlap of the Digne thrust to the South and to part of the normal movement along the Simplon fault to the North. Thus, all the external crystalline massifs were tectonically active during the late Miocene. This suggests that tectonic events in the external alpine belt may have contributed to some extent to the geodynamical causes of the Messinian crisis.

scholarly journals Structural analysis of S-wave seismics around an urban sinkhole; evidence of enhanced subrosion in a strike-slip fault zone

2017 ◽  
Author(s):  
Sonja H. Wadas ◽  
David C. Tanner ◽  
Ulrich Polom ◽  
Charlotte M. Krawczyk
Keyword(s):  
Strike Slip ◽  
Strike Slip Fault ◽  
Key Factors ◽  
S Wave ◽  
Seismic Profiles ◽  
Reflection Seismic ◽  
Dextral Strike Slip Fault ◽  
Seismic Sections ◽  
The Town ◽  
Dextral Strike Slip

Abstract. In November 2010, a large sinkhole opened up in the urban area of Schmalkalden, Germany. To determine the key factors which benefited the development of this collapse structure and therefore the subrosion, we carried out several shear wave reflection seismic profiles around the sinkhole. In the seismic sections we see evidence of the Mesozoic tectonic movement, in the form of a NW–SE striking, dextral strike-slip fault, known as the Heßleser Fault, which faulted and fractured the subsurface below the town. The strike-slip faulting created a zone of small blocks (

The Early Expansion of the Kingdom of Mithridates VI

2020 ◽  
pp. 111-124
Author(s):  
Duane W. Roller
Keyword(s):  
Black Sea ◽  
Economic Benefits ◽  
The Black Sea ◽  
The West ◽  
West Side ◽  
The North ◽  
North Side

Mithridates VI the Great began his solidified rule by expanding his kingdom, seemingly with the goal of encircling the Black Sea. He gained possession of the ancient territory of Colchis and then strengthened his predecessors’ control of the Bosporos, on the north side of the sea. He also established a presence on the west side of the sea. The locals on the north side of the sea welcomed the king because they were constantly subject to barbarian pressures. There were also economic benefits to the Pontic kingdom in acquisition of the new territories. Mithridates also established a Pontic presence south and west of his kingdom, in Paphlagonia and Galatia. Yet such aggressive actions by the king were noticed by the Romans, even though the northern Black Sea was not in any region of their direct interest.

Charles Edward Inglis, 1875 - 1952

1953 ◽  
Vol 8 (22) ◽  
pp. 444-457
Keyword(s):  
The South ◽  
Art Gallery ◽  
The West ◽  
West Side ◽  
The North ◽  
The Right

Charles Edward Inglis was the second surviving son of Dr Alexander Inglis, M.D., M.R.C.S.E., of Auchindinny and Redhall, and of his first wife, Florence, the second daughter of John Frederick Feeney, proprietor of the Birmingham Daily Post, whose family founded the Feeney Art Gallery in that city. The Inglis family of Auchindinny appear first as tenants and afterwards owners of the farm of Langbyres, which adjoins the west side of Murdostoun in the parish of Shotts, Lanarkshire. The first mention of them in connexion with the place is found in the Lord High Treasurer’s accounts for 1543 when John Inglis in Langbyres and James Kneland in Swyntre had to pay £13 6s. 8d. to redeem their movable goods, which had been escheated as a penalty for their absence from the army, mustered by James V to invade England, which was routed at Solway Moss. The estate of Auchindinny, about 730 acres, was purchased in 1702 by one John Inglis, a Writer to the Signet, who had succeeded to Langbyres in 1685. Auchindinny lies about eight miles south of Edinburgh, on the right bank of the North Esk and at the south end of the parish of Lasswade. The house, completed in 1707, is a severe substantial sandstone building. John Inglis had eleven children. One of his grand-daughters, Barbara, co-heiress of Archibald, Laird of Auchindinny, married in 1777 her cousin, Captain, afterwards Admiral, John Inglis, R.N., of Redhall, whose father had left Scotland and settled in Philadelphia as a merchant about 1736. Captain Inglis commanded H.M.S. Belliqueux at the battle of Camperdown. The ship took a conspicuous share in the fighting, there being a hundred and three casualties out of a complement of four hundred and ninety-one, and quite redeemed the character which she had lost in the Mutiny at the Nore a few months earlier. It is said that the Captain was puzzled in the battle by his Admiral’s frequent signals and at last threw his signal book on deck exclaiming, ‘Damn the signals; up wi’ the hellem and gang into the middle o’ it’. He thus anticipated Nelson’s celebrated memorandum that ‘when a captain should be at a loss he cannot do very wrong if he lay his ship alongside of the enemy’.

scholarly journals First evidence of active transpressive surface faulting at the front of the eastern Southern Alps, northeastern Italy. Insight on the 1511 earthquake seismotectonics

2018 ◽  
Author(s):  
Emanuela Falcucci ◽  
Maria Eliana Poli ◽  
Fabrizio Galadini ◽  
Giancarlo Scardia ◽  
Giovanni Paiero ◽  
...  
Keyword(s):  
Strike Slip ◽  
Southern Alps ◽  
Strike Slip Fault ◽  
Fault System ◽  
The Past ◽  
Fold And Thrust Belt ◽  
Northeastern Italy ◽  
Dextral Strike Slip Fault ◽  
Seismic Lines ◽  
Dextral Strike Slip

Abstract. We investigated the eastern corner of northeastern Italy, where the NW-SE trending dextral strike-slip fault systems of western Slovenia intersects the south-verging fold and thrust belt of the eastern Southern Alps . The area suffered the largest earthquakes of the region, among which are the 1511 (Mw 6.3) event and the two major shocks of the 1976 seismic sequence, with Mw = 6.4 and 6.1 respectively. The Colle Villano thrust and the Borgo Faris-Cividale strike-slip fault have been first analyzed by interpreting industrial seismic lines and then by performing morpho-tectonic and paleoseismological analyses. These different datasets indicate that the two structures define an active, coherent transpressive fault system that activated twice in the past two millennia, with the last event occurring around the 15th–17th century. The chronological information, and the location of the investigated fault system suggest its activation during the 1511 earthquake.

IV.—The Upper Trias of Leicestershire

1913 ◽  
Vol 10 (5) ◽  
pp. 205-215 ◽  
Author(s):  
A. R. Horwood
Keyword(s):  
Black Shales ◽  
The South ◽  
The West ◽  
West Side ◽  
North West ◽  
The North ◽  
Eastern Boundary ◽  
East End

Although the Rhætic beds are not exposed continuously along the eastern boundary of the Keuper outcrop, they have been proved at many points from the River Trent in the north on the Nottinghamshire border to Glen Parva in the south. South of this point there is so much drift, and borings within the Liassic outcrop have been so isolated or shallow, that there is a gap in our knowledge of the intervening ground between the last point and the Rugby district. The Countesthorpe boring, carried to a depth of over 600 feet, encountered Upper Keuper beneath the Drift, with no intervening Rhætics. Commencing in the north in the Gotham district the two outliers are capped above the Red Marl and Tea-green Marl with Rhætic beds, and Lower Lias Limestone (Ps. planorbe zone) above. At Ash Spinney at the south end of the southern outlier, and at the east end of Crownend Wood, Black Shales with Avicula contorta crop out; and on the west side septaria are seen. On the north-west side of the northern outlier at Cottager's Hill Protocardium phillipianum has been found in a well-section near the lane. Rhætic shales are seen in the shafts driven for gypsum works about Gotham.

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