Kinney Pool: Defining the western boundary of the Edwards (Balcones Fault Zone) Aquifer, Texas

The role of oroclinal bending in the structural evolution of the Central Anatolian Plateau: evidence of a regional changeover from shortening to extensionThe NW-SE striking extensional Inönü-Eskişehir Fault System is one of the most important active shear zones in Central Anatolia. This shear zone is comprised of semi-independent fault segments that constitute an integral array of crustal-scale faults that transverse the interior of the Anatolian plateau region. The WNW striking Eskişehir Fault Zone constitutes the western to central part of the system. Toward the southeast, this system splays into three fault zones. The NW striking Ilıca Fault Zone defines the northern branch of this splay. The middle and southern branches are the Yeniceoba and Cihanbeyli Fault Zones, which also constitute the western boundary of the tectonically active extensional Tuzgölü Basin. The Sultanhanı Fault Zone is the southeastern part of the system and also controls the southewestern margin of the Tuzgölü Basin. Structural observations and kinematic analysis of mesoscale faults in the Yeniceoba and Cihanbeyli Fault Zones clearly indicate a two-stage deformation history and kinematic changeover from contraction to extension. N-S compression was responsible for the development of the dextral Yeniceoba Fault Zone. Activity along this structure was superseded by normal faulting driven by NNE-SSW oriented tension that was accompanied by the reactivation of the Yeniceoba Fault Zone and the formation of the Cihanbeyli Fault Zone. The branching of the Inönü-Eskişehir Fault System into three fault zones (aligned with the apex of the Isparta Angle) and the formation of graben and halfgraben in the southeastern part of this system suggest ongoing asymmetric extension in the Anatolian Plateau. This extension is compatible with a clockwise rotation of the area, which may be associated with the eastern sector of the Isparta Angle, an oroclinal structure in the western central part of the plateau. As the initiation of extension in the central to southeastern part of the Inönü-Eskişehir Fault System has similarities with structures associated with the Isparta Angle, there may be a possible relationship between the active deformation and bending of the orocline and adjacent areas.

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RECONNAISSANCE AEROMAGNETIC PROFILES, NORTHEAST TEXAS

Geophysics ◽

10.1190/1.1439178 ◽

1963 ◽

Vol 28 (2) ◽

pp. 306-308

Author(s):

R. J. Brod ◽

R. H. Hammons ◽

F. W. Hinrichs

Keyword(s):

Fault Zone ◽

Gulf Coast ◽

Red River ◽

Montgomery County ◽

Western Boundary ◽

East Texas ◽

East Texas Basin ◽

Northerly Direction ◽

Northern Portion ◽

Llano Uplift

The three aeromagnetic traverses of Figure 1, in East Texas, demonstrate the applicability of the conventional aeromagnetic method in this area. Flight line AA′ extends from the Sabine uplift across the East Texas Basin, Mexia‐Talco Fault zone, Balcones Fault zone, and Ouachita front to the Llano Uplift. Line BB′ extends from the Sabine Uplift through the northern portion of the East Texas Basin, across the Mexia‐Talco Fault zone to a point near the western boundary of Ellis County. Line CC′ extends in a northerly direction from the center of Montgomery County on the northern flank of the Gulf Coast Geosyncline through the East Texas Basin across the Mexia‐Talco Fault zone to the Red River.

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Deformation of continental blocks within convergent plates: Anatolia as a case study

10.5194/egusphere-egu2020-18856 ◽

2020 ◽

Author(s):

Cengiz Zabcı ◽

Taylan Sançar ◽

Müge Yazıcı ◽

Anke M. Friedrich ◽

Naki Akçar

Keyword(s):

Fault Zone ◽

Plate Boundary ◽

Slip Rate ◽

Shear Zones ◽

Strike Slip ◽

Central Anatolia ◽

Western Boundary ◽

The West ◽

Secondary Importance ◽

Continental Block

<p>Anatolia is part of the west-central Alpide plate-boundary zone, particularly where the deformation is characterized by the westward extrusion of this continental block between the Arabian-Eurasian collision in the east and the Hellenic Subduction in the west. Although, this motion mostly happens along the boundary structures, i.e., the North Anatolian and East Anatolian shear zones, there are multiple studies documenting the active deformation along NE-striking sinistral and NW-striking dextral strike-slip faults within the central and eastern parts of Anatolia. These secondary faults slice Anatolia into several pieces giving formation of the Malatya-Erzincan, Cappadocian and Central Anatolian slices from east to west, where their boundary geometries are strongly controlled by the weak zones, the Tethyan Suture Zones.</p><p>We compiled all geological slip-rate and palaeoseismological studies, which point out inhomogeneous magnitude of deformation along different sections of these secondary structures. The Central Anatolian Fault Zone, the westernmost NE-striking sinistral strike-slip structure and the western boundary between the Central Anatolia and Cappadocian slices, has an average horizontal slip-rate of about 1 to 1.5 mm/a for the last few tens of thousands of years. The earthquake recurrence of about 4500 years between two events revealed on the northern sections of the CAFZ also support this rate of deformation. However, the Malatya-Ovac&#305;k Fault Zone has a bimodal behaviour in terms of deformation rate, which is 2.5 times higher along its northern member, the Ovac&#305;k Fault (OF) than the southern one, the Malatya Fault (MF) (2.5 to 1 mm/a), respectively. This velocity difference between two distinct members of the same fault zone can be explained by the relative westward motion of slices where the OF makes the direct contact between the Central Anatolian and Malatya-Erzincan, and the MF delimits Cappadocian and Malatya-Erzincan slices. Although these structures, which are shallow and probably deform only the upper crust, are of having secondary importance, yet they are still capable of producing infrequent but strong earthquakes within this highly deforming convergent setting. This study is supported by T&#220;B&#304;TAK projects no. 114Y227 and 114Y580.</p>

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