Tectonics
Amir Shafiei bafti
Abstract
Radon is a radioactive noble gas . The best places for accumulation of radon in groundwater would be geodynamic active areas,deep basement faults and fractures. This paper aims to investigate the relationship between the radon gas concentrations with the behaviors of active tectonic faults. Jorjafk fault ...
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Radon is a radioactive noble gas . The best places for accumulation of radon in groundwater would be geodynamic active areas,deep basement faults and fractures. This paper aims to investigate the relationship between the radon gas concentrations with the behaviors of active tectonic faults. Jorjafk fault with a length of nearly 160 km from North-West to South-East in southern central Iran. This fault shows active tectonics aspects, The distribution of Davaran Mountain seismic centers shows low Seismicity for the region. In addition, the few focus of the events in the south of the mountain and unequal distribution and lack of clear trend is among its seismic properties. For the measurement of radon concentration in water resources leading to the Jorjafk fault,, 35 sampling stations were identified as suitable, and on two occasions the samplings were performed. The highest and lowest concentrations measured in the first stage were 53, 183, and 138 Becquerel's respectively for the stations of 13, 3 and 8, and in the second stage, the highest and lowest concentration were measured with values of 56, 233, and 169 Becquerel's respectively for the stations of 29 and 25. By comparing the obtained concentrations for each station and its compliance with seismic activity in the region, it was observed that in places where seismic activity is higher, the concentration of radon gas is also higher. Therefore, it can be said that the areas with high concentrations of radon gas, have more potential and are more likely to earthquake events
Tectonics
Amir Shafiei bafti
Abstract
. Kouhbanan fault system in south of central Iran is one of the most active and seismic faults, has length of nearly 200km and seismic history from B.C to the present. Epicenter of seismic activities for this fault situated often near fault zone or on the Kouhbanan fault zone branches and other attached ...
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. Kouhbanan fault system in south of central Iran is one of the most active and seismic faults, has length of nearly 200km and seismic history from B.C to the present. Epicenter of seismic activities for this fault situated often near fault zone or on the Kouhbanan fault zone branches and other attached faults. Identify of ruptured and non-ruptured segments can clear the way to finding the areas that have the potential for creating earthquake. Field observation and library data were used for this purpose. According to the spatiotemporal distribution of historical and instrumental earthquakes, may be concluded, the most earthquakes are located where the fault branches or in its bend locations. Earthquake occurred in studied region, often known with absence of high magnitude earthquakes (M≥ 6.5). Interesting point is that in the period of about 160 years ago (Earthquake record time span) along of active faults, especially Kouhbanan fault zone, an area that is less a re-ruptured or be consecutive or earthquake epicenters are few. For earthquake risk assessment, we use Kijko& Sllevoll (1992) method, which show that the earthquake risk and seismicity rate is higher from other regions and earthquake have higher magnitude and less recurrence time. According to the obtained results, for earthquakes (M≥ 7) results should be used with caution.
T. Naderi; M. Pourkermani; A. Shafiei Bafti; M. R. Aminizadeh; S. Bouzari
Abstract
In this study, the permeability of structures associated with Kuhbanan fault zone has been investigated. The Kuhbanan fault zone is one of the most seismically active structural trends in Kerman province. The behaviour of fault zones against groundwater flow (conduit, barrier, or a combination of both) ...
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In this study, the permeability of structures associated with Kuhbanan fault zone has been investigated. The Kuhbanan fault zone is one of the most seismically active structural trends in Kerman province. The behaviour of fault zones against groundwater flow (conduit, barrier, or a combination of both) is relatively controlled by fault core, damage zone, and permeability of fractures and rock units in the fault zone. In this research, qualitative and quantitative data, together with field observations and numerical models have been used. In order to measure the structures in the Kuhbanan fault zone, 23 outcrops were selected for model parameters. Results show that the fault zone acted as barrier in 12 outcrops, conduit in 4 outcrops and a combined barrier-conduit in 6 outcrops. In total, the 61-m-wide southern part of the Kuhbanan fault zone is composed of a fault core of 38 m and a damage zone of 23 m wide, respectively. Therefore, this segment of the Kuhbanan faul zone acts as a combination of conduit and strong barrier for fluid flow. The fault core is well developed but the damage zone is weakly developed , and therefore deformation has been largely localized within the fault core and distributed in the damage zone. To analyze the architecture of the fault zone three Fa, Fs, Fm indices were used. For the southern segment of the Kuhbanan fault zone, the Fa, Fs and Fm were measured as 0.47, 0.73 and 0.51, respectively. The relatively low Fa and high Fs indicate that the Kuhbanan fault zone in this area is not associated with uniform architecture. Also the numerous fault springs in the area are affected by this fault zone.
