Mechanical Properties of Some Japanese Sedimentary Rocks under Confining Pressure (1)

Hoshino, Kazuo

doi:10.5110/jjseg.8.151

Cited by 33 publications

(42 citation statements)

References 7 publications

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“…The natural cohesion of crustal materials is in the range of 10 5 to 10 7 Pa (e.g. Hoshino et al 1972), while the cohesion of the analogue material is 70 Pa. Considering a scaling factor of 2.5×10 -5 , cohesion in our experiments is thus properly scaled.…”

Section: Experimental Setup and Scalingmentioning

confidence: 99%

Propagation, linkage, and interaction of caldera ring-faults: comparison between analogue experiments and caldera collapse at Miyakejima, Japan, in 2000

Burchardt

Walter

2009

Bull Volcanol

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The formation of ring faults yields important implications for understanding the structural and dynamic evolution of collapse calderas and potentially associated ash-flow eruptions. Caldera collapse occurred in 2000 at Miyakejima Island (Japan) in response to a lateral intrusion. Based on geophysical data it is inferred that a set of caldera ring faults was propagating upward. To understand the kinematics of ring-fault propagation, linkage, and interaction, we describe new laboratory sand-box experiments that were analyzed through Digital Image Correlation (DIC) and post-processed using 2D strain analysis. The results help us gain a better understanding of the processes occurring during caldera subsidence at Miyakejima. We show that magma chamber evacuation induces strain localization at the lateral chamber margin in the form of a set of reverse faults that sequentially develops and propagates upwards. Then a set of normal faults initiates from tension fractures at the surface, propagating downwards to link with the reverse faults at depth. With increasing amounts of subsidence, interaction between the reverse-and normalfault segments results in a deactivation of the reverse faults, while displacement becomes focused on the outer normal faults. Modeling results show that the area of faulting and collapse migrates successively outward, as peak displacement transfers from the inner ring faults to later developed outer ring faults. The final structural architecture of the faults bounding the subsiding piston-like block is hence a consequence of the amount of subsidence, in agreement with other caldera structures observed in nature. The experimental simulations provide an analogy to the observations and seismic records of caldera collapse at Miyakejima volcano, but are also applicable to caldera collapse in general.

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Section: Experimental Setup and Scalingmentioning

confidence: 99%

Propagation, linkage, and interaction of caldera ring-faults: comparison between analogue experiments and caldera collapse at Miyakejima, Japan, in 2000

Burchardt

Walter

2009

Bull Volcanol

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“…As the density of analog materials is smaller than that of natural rocks by a factor of ∼2 (i.e., density ratio-ρ * = 0.5), and gravitational acceleration is the same in both model and nature (i.e., gravity ratio-g * = 1), the required stress ratio for a geometric scaling factor of 10 −4 is σ * = 5 × 10 −5 . As the cohesion of natural rocks lies in the range 10 5 -10 7 Pa (Hoshino et al, 1972Glicken et al, 1980, a suitable cohesion for the analog material needs to be in the range 5-500 Pa. Higher values of 10 7 Pa, in nature, are representative of small laboratory samples (Schultz, 1996) or intact rock (Handin, 1966;Jaeger and Cook, 1971).…”

Section: Scaling Proceduresmentioning

confidence: 99%

“…In our experiments, h corresponds to the thickness of the substratum (500 m scaled to 5 cm in the model) and 4 ranges from 1.19 to 119, with a cohesion for the analog material in the range 5-500 Pa; we used an analog material with a cohesion of about 150 Pa. An average density for natural rocks is about 2500 kg/m 3 , but the range for sedimentary and magmatic rocks is from 2300 to 2900 kg/m 3 and their typical cohesion is between 10 5 and 10 7 Pa (Hoshino et al, 1972;Glicken et al, 1980). Thus, overall values of 4 in nature range from 1.22 to 122, with a fixed density of 2500 kg/m 3 and varying the cohesion (10 5 and 10 7 Pa).…”

Section: = Gf Length/thickness Of the Substratummentioning

confidence: 99%

Interaction between Transform Faults and Rift Systems: A Combined Field and Experimental Approach

2016

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We present a detailed field structural survey of the area of interaction between the active NW-striking transform Husavik-Flatey Fault (HFF) and the N-S Theystareykir Fissure Swarm (TFS), in North Iceland, integrated by analog scaled models. Field data contribute to a better understanding of how transform faults work, at a much higher detail than classical marine geophysical studies. Analog experiments are conducted to analyse the fracture patterns resulting from different possible cases where transform faulting accompanies or postpones the rift motions. Different tectonic block configurations are also considered and results are compared with field data in order to study as thoroughly as possible the interaction between the HFF and the TFS as well as the possible prolongation of the HFF into the TFS. West of the intersection between the transform fault (HFF) and the rift zone (TFS), the former splays with a gradual bending giving rise to a leading extensional imbricate fan. The westernmost structure of the rift, the N-S Gudfinnugja Fault (GF), is divided into two segments: the southern segment makes a junction with the HFF and is part of the imbricate fan; north of the junction instead, the northern GF appears right-laterally offset by about 20 m. Southeast of the junction, along the possible prolongation of the HFF across the TFS, the strike of the rift faults rotates in an anticlockwise direction, attaining a NNW-SSE orientation. Moreover, the TFS faults north of the HFF prolongation are fewer and have smaller offsets than those located to the south. Through the comparison between the structural data collected in the field at the HFF-TFS connection zone and a set of scaled experiments, we confirm a prolongation of the HFF through the rift, although here the transform fault has a much lower slip-rate than west of the junction. Our data suggest that transform fault terminations may be more complex than previously known, and propagate across a rift through a modification of the rift pattern.

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“…The cohesive term is important wherever the wedge is sufficiently thin that S 0 /(l -\)pgz, the ratio of the cohesive strength over the effective overburden, is not much less than one. Throughout most of the Barbados wedge, the depth-dependent term predominates, assuming that the cohesive strength and internal friction are consistent with laboratory measurements of typical sedimentary rocks (Hoshino et al, 1972). The assumption of Coulomb behavior is reasonable in light of the current understanding of stress in the upper part of the crust.…”

Section: S O (3)mentioning

confidence: 86%

“…The magnitude we attribute to that shear stress depends upon the assumptions we make about rock strength. Laboratory measurements of rock strength under brittle deformation (Byerlee, 1978;Hoshino et al, 1972) and ductile flow (Goetze, 1978;Heard and Carter, 1968) at typical geological strain rates (Pfiffner and Ramsay, 1982) suggest that friction-dominated deformation controls the state of stress in the upper 10-15 km of the crust (Brace and Kohlstedt, 1980). Above the brittle-ductile transition, time-independent friction may be assumed to govern sliding along pre-existing faults, except very near the deformation front and at very shallow depths, where sediments are most likely to be unlithified.…”

Section: Coulomb Wedge Modelmentioning

confidence: 99%

The Compressive Mechanics of Accretionary Wedges Applied to the Leg 78A Study Area near Barbados

Davis¹

1984

Initial Reports of the Deep Sea Drilling Project

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Sites 541 and 542 of DSDP Leg 78A are very near the front of a large wedge of accreted sediments at the eastern edge of the Caribbean Plate where it overthrusts the downgoing crust of the Altantic Ocean. The mechanics of this wedge are considered in light of the Coulomb-wedge hypothesis of Davis et al. (1983), which regards the sediments of the wedge as analogous to soil being pushed by a bulldozer. The wedge deforms in order to attain and maintain its critical taper, at which it could stably ride over the downgoing plate. If it were allowed to maintain that taper without any erosion or accretion, then no significant internal deformation would be required for the wedge to ride over its décolle-ment. The magnitude of this critical taper is a function of fluid pressures and the mechanical properties of the wedge and décollement. The narrow taper of the Barbados wedge is consistent with the evidence of high fluid pressures for the region, suggesting that its behavior is dominated by horizontal compression resulting from plate convergence. The hypothesis that the wedge is at or near compressive failure permits a description of the state of stress in the wedge. The borehole stability problems experienced at Sites 541 and 542 are consistent with the view (Hottman et al., 1979) that boreholes act as stress concentrators. The resulting stress concentration can initiate compressive failure of the borehole wall, and may have contributed to the borehole instability observed on Leg 78A.

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Mechanical Properties of Some Japanese Sedimentary Rocks under Confining Pressure (1)

Cited by 33 publications

References 7 publications

Propagation, linkage, and interaction of caldera ring-faults: comparison between analogue experiments and caldera collapse at Miyakejima, Japan, in 2000

Propagation, linkage, and interaction of caldera ring-faults: comparison between analogue experiments and caldera collapse at Miyakejima, Japan, in 2000

Interaction between Transform Faults and Rift Systems: A Combined Field and Experimental Approach

The Compressive Mechanics of Accretionary Wedges Applied to the Leg 78A Study Area near Barbados

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