Thank you for your effort. This is really helpful to me. I am currently working in the area having similar structure. The video helped me support my seismic interpretation. Keep up the good work guys!
+geozia you read my mind...this model will definitely be run with a slightly stronger, brittle layer or two within the stratigraphy...sort of like having some carbonate beds within weaker, finer clastics. This trial was run with only sand to expedite gelling, sectioning, and drying, which certainly goes best with consistent porosity/permeability within the model strata. I am backed up with a few strength-contrast compressional models that need editing, but I hope to give strike-slip with varied stratigraphy a try in a week or two. Deformation took several minutes to cross the centimeters of travel here; I am not sure of the exact rate, and from my experience to date, mechanical stratigraphy is the deciding factor on the outcome of the model. I have tried faster and slower experiments, and the nature and arrangement of the layer pack really seem to be the dominant control on model outcome. My models are intended to be illustrative and feasible for class periods or outreach engagements, and I have focused most of my attention on constructing layer packs and controlling layer pack friction with the box floor, a higher friction cover on the floor, or the sidewalls. Strain rate trials would open up a whole new direction, and it's a road I'd like to head down during the summer. Thanks so much for watching and for your question!
A good model for the Bavarian Shear Zone in crystalline basement rocks once buried about 10 km under the surface. .(Pfahl Scherzone Bayerischen Wald Germany) Abstract - Late Variscan Conjugated Shear Zones in the Southern Bohemian Massif (Z. geol. Wiss., Berlin 37 (2009) 4-5: 277 - 292, 19 Abb) Mylonitic fabrics which developed in conjugate shear zones of the Southern Bohemian Massif display dextral shear sense (NW-SE trending systems) and sinistral shear sense (NE-SW trending systems). In most of the shear zones, mylonitization took place under greenschist facies conditions. Lattice preferred orientation of the quartz fabrics, measured with the universal stage and with a x-ray textural goniometer, show glide systems which developed in a temperature range from 300 °C to > 450 °C and in one case (Pfahl Shear Zone) even und > 600 °C. The shear zones are interpreted as a late variscan conjugated system which might have been built up by an in E-W elongated indenter during N-S convergence. Both systems show ages of 288 to 281 Ma with rejuvenations into alpidic ages. All shear zones exhibit an overprint of brittle deformation which probably generated from foreland deformation during alpidic orogeny. With Paleostress analysis principal stresses were reconstructed. All have the same orientation with σ1 in N-S, σ3 in E-W direction and σ2 vertical). The brittle deformation is also caused by an indenter which had a similar shape and orientation as the variscan one.
Thank you for your effort. This is really helpful to me. I am currently working in the area having similar structure. The video helped me support my seismic interpretation. Keep up the good work guys!
There are similar structures along the upper most Cretaceous in subsurface in northern Western Desert, Egypt, great video, thanks
good sandbox trial, I want to ask about the size of the sand and the thickness of the layer, what size do you use?
Great job! Have you thought of trying any ductility contrast in the layers? Also, what is the ~ strain rate?
Thanks!
+geozia you read my mind...this model will definitely be run with a slightly stronger, brittle layer or two within the stratigraphy...sort of like having some carbonate beds within weaker, finer clastics. This trial was run with only sand to expedite gelling, sectioning, and drying, which certainly goes best with consistent porosity/permeability within the model strata. I am backed up with a few strength-contrast compressional models that need editing, but I hope to give strike-slip with varied stratigraphy a try in a week or two.
Deformation took several minutes to cross the centimeters of travel here; I am not sure of the exact rate, and from my experience to date, mechanical stratigraphy is the deciding factor on the outcome of the model. I have tried faster and slower experiments, and the nature and arrangement of the layer pack really seem to be the dominant control on model outcome. My models are intended to be illustrative and feasible for class periods or outreach engagements, and I have focused most of my attention on constructing layer packs and controlling layer pack friction with the box floor, a higher friction cover on the floor, or the sidewalls. Strain rate trials would open up a whole new direction, and it's a road I'd like to head down during the summer.
Thanks so much for watching and for your question!
thank you
Glad you found it useful!
A good model for the Bavarian Shear Zone in crystalline basement rocks once buried about 10 km under the surface. .(Pfahl Scherzone Bayerischen Wald Germany)
Abstract - Late Variscan Conjugated Shear Zones in the Southern Bohemian Massif (Z. geol. Wiss., Berlin 37 (2009) 4-5: 277 - 292, 19 Abb)
Mylonitic fabrics which developed in conjugate shear zones of the Southern Bohemian Massif display dextral shear sense (NW-SE trending systems) and sinistral shear sense (NE-SW trending systems). In most of the shear zones, mylonitization took place under greenschist facies conditions. Lattice preferred orientation of the quartz fabrics, measured with the universal stage and with a x-ray textural goniometer, show glide systems which developed in a temperature range from 300 °C to > 450 °C and in one case (Pfahl Shear Zone) even und > 600 °C. The shear zones are interpreted as a late variscan conjugated system which might have been built up by an in E-W elongated indenter during N-S convergence. Both systems show ages of 288 to 281 Ma with rejuvenations into alpidic ages. All shear zones exhibit an overprint of brittle deformation which probably generated from foreland deformation during alpidic orogeny. With Paleostress analysis principal stresses were reconstructed. All have the same orientation with σ1 in N-S, σ3 in E-W direction and σ2 vertical). The brittle deformation is also caused by an indenter which had a similar shape and orientation as the variscan one.