Parallelepiped cooling joint and anisotropy of P-wave velocity in the Takidani granitoid, Japan Alps

Kano, Shingo; Tsuchiya, Noriyoshi

doi:10.1016/s0377-0273(01)00301-8

Cited by 14 publications

(11 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The existence of major quaternary faulting, together with the WNW movement of the Pacific plate during the last 2 Ma, suggests that there exists a compressive tectonic stress field in the region aligned in a WNW to ESE orientation. It has been suggested that this stress field is responsible for the preferred alignment of both joint sets observed in outcrop, and the microcrack fabric [Kano and Tsuchiya, 2002]. Previous work has shown that the microcrack fabric results in an anisotropy of approximately 10% in the P wave velocity measured on laboratory samples, and that the principal anisotropy directions are essentially coincident with the larger-scale jointing [Kano and Tsuchiya, 2002;Benson, 2004].…”

Section: Discussionmentioning

confidence: 99%

“…More importantly, however, the anisotropic stress field within the intrusion has produced an aligned microcrack fabric (Figures 1c and 1d) which, in turn, leads to anisotropy in the physical and transport properties [Benson, 2004]. It is of note that the orientation of the aligned microcrack fabric is approximately colinear with the larger (meter scale) joint fabric observed in outcrop [Kano and Tsuchiya, 2002;Benson, 2004]. These microcrack fabrics were previously verified through 3-D elastic wave anisotropy measurements, in which TDG P wave anisotropy of approximately 10% was measured, with a minimum principal direction aligned subnormal to the microcracking plane [Benson, 2004;Benson et al, 2005].…”

Section: Experimental Equipment and Methodsmentioning

confidence: 99%

“…In contrast, Takidani granite (TDG) is a coarse-grained granodiorite from the Japanese Alps. It was collected from one of the youngest exposed plutons in the world at 1.2 Ma [Kano and Tsuchiya, 2002]. This material formed in an intrusive environment, where the relatively slow cooling rate resulted in a considerably lower crack density than that in the Etnean basalt.…”

Section: Experimental Equipment and Methodsmentioning

confidence: 99%

“…As for the Etnean basalt samples, P wave and S wave velocity measurements for Takidani granite were measured along three orthogonal directions. In addition, since TDG is known to be anisotropic from 3-D velocity measurements [Kano and Tsuchiya, 2002;Benson, 2004;Benson et al, 2005], cores for measurement were taken along the three known principal anisotropy directions. Using this information as a guide and assuming a TI symmetry, four different independent elastic wave measurements were performed, that is, P and S along the axis of symmetry (V 33 and V 31 = V 32 respectively) and P and S in the plane of isotropy (V 11 = V 22 , V 12 respectively).…”

Section: Transversely Isotropic Case (Takidani Granite): Experimentalmentioning

confidence: 99%

See 3 more Smart Citations

Modeling the permeability evolution of microcracked rocks from elastic wave velocity inversion at elevated isostatic pressure

et al. 2006

View full text Add to dashboard Cite

[1] A key consequence of the presence of microcracks within rock is their significant influence upon elastic anisotropy and transport properties. Here two rock types (a basalt and a granite) with contrasting microstructures, dominated by microcracks, have been investigated using an advanced experimental arrangement capable of measuring porosity, P wave velocity, S wave velocity, and permeability contemporaneously at effective pressures up to 100 MPa. Using the Kachanov (1994) noninteractive effective medium theory, the measured elastic wave velocities are inverted using a least squares fit, permitting the recovery of the evolution of crack density and aspect ratio with increasing isostatic pressure. Overall, the agreement between measured and predicted velocities is good, with average error less than 0.05 km/s. At larger scales and above the percolation threshold, macroscopic fluid flow also depends on the crack density and aspect ratio. Using the permeability model of Guéguen and Dienes (1989) and the crack density and aspect ratio recovered from the elastic wave velocity inversion, we successfully predict the evolution of permeability with pressure for direct comparison with the laboratory measurements. We also calculate the evolution of the crack porosity with increasing isostatic pressure, on the basis of the calculated crack density, and compare this directly with the experimentally measured porosity. These combined experimental and modeling results illustrate the importance of understanding the details of how rock microstructures change in response to an external stimulus when predicting the simultaneous evolution of rock physical properties.Citation: Benson, P., A. Schubnel, S. Vinciguerra, C. Trovato, P. Meredith, and R. P. Young (2006), Modeling the permeability evolution of microcracked rocks from elastic wave velocity inversion at elevated isostatic pressure,

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Experimental Equipment and Methodsmentioning

confidence: 99%

Section: Experimental Equipment and Methodsmentioning

confidence: 99%

Section: Transversely Isotropic Case (Takidani Granite): Experimentalmentioning

confidence: 99%

See 2 more Smart Citations

Modeling the permeability evolution of microcracked rocks from elastic wave velocity inversion at elevated isostatic pressure

et al. 2006

View full text Add to dashboard Cite

show abstract

“…The rock exhibits a P wave velocity anisotropy of approximately 8% (Figure 3 and Benson et al [2005]). At the other end of the spectrum, TDG is a crystalline, microcracked granodiorite from a very young pluton (1.2 Ma) in the Japanese age [ Kano and Tsuchiya , 2002]. It has been suggested that both large‐scale joints and these microcracks were formed parallel to the cooling surface during cooling of the pluton [ Kano and Tsuchiya , 2002].…”

Section: Discussionmentioning

confidence: 99%

Role of void space geometry in permeability evolution in crustal rocks at elevated pressure

2006

View full text Add to dashboard Cite

[1] A key consequence of the presence of void space within rock is their significant influence upon fluid transport properties. In this study, we measure changes in elastic wave velocities (P and S) contemporaneously with changes in permeability and porosity at elevated pressure for three rock types with widely different void space geometries: a high-porosity sandstone (Bentheim), a tight sandstone (Crab Orchard), and a microcracked granodiorite (Takidani). Laboratory data are then used with the permeability models of Guéguen and Dienes and Kozeny-Carman to investigate the characteristics that different void space geometries impart to measured permeabilities. Using the Kachanov effective medium theory, elastic wave velocities are inverted, permitting the recovery of crack density evolution with increasing effective pressure. The crack densities are then used as input to the microcrack permeability model of Guéguen and Dienes. The classic Kozeny-Carman approach of Walsh and Brace is also applied to the measured permeability data via a least squares fit in order to extract tortuosity data. We successfully predict the evolution of permeability with increasing effective pressure, as directly measured in experiments, and report the contrast between permeability changes observed in rock where microcracks or equant pores dominate the microstructure. Additionally, we show how these properties are affected by anisotropy of the rock types via the measured anisotropic fabrics in each rock. The combined experimental and modeling results illustrate the importance of understanding the details of how rock microstructure changes in response to an external stimulus in predicting the simultaneous evolution of different rock physical properties.Citation: Benson, P. M., P. G. Meredith, and A. Schubnel (2006), Role of void space geometry in permeability evolution in crustal rocks at elevated pressure,

show abstract

P-Wave Velocity Calculation (PVC) in Rock Mass Without Geophysical-Seismic Field Measurements

et al. 2021

View full text Add to dashboard Cite

Parallelepiped cooling joint and anisotropy of P-wave velocity in the Takidani granitoid, Japan Alps

Cited by 14 publications

References 42 publications

Modeling the permeability evolution of microcracked rocks from elastic wave velocity inversion at elevated isostatic pressure

Modeling the permeability evolution of microcracked rocks from elastic wave velocity inversion at elevated isostatic pressure

Role of void space geometry in permeability evolution in crustal rocks at elevated pressure

P-Wave Velocity Calculation (PVC) in Rock Mass Without Geophysical-Seismic Field Measurements

Contact Info

Product

Resources

About