This is unbelievably good! I wish I had this resource back in college about 20 years ago! You have a gift for breaking down complex ideas, thank you for uploading these.
@soroush67882 жыл бұрын
Thanks Rob. this video was very useful for me to find out finally how the shear zone is.
@robbutler20952 жыл бұрын
thanks - glad you found this useful.
@张宏远-z8t Жыл бұрын
I think 45 degrees (αf) may not be always true. The congugate angle 2αf should be random, sometimes 110degrees in middle to lower crust, then less than 90 degrees in most shallow crust, according to quartzofeldspar rocks.
@robbutler2095 Жыл бұрын
Hi - not so - this is basic geometry for simple shear. Of course rocks can deform in different ways but then it isn't ideal simple shear. There are of course lots of studies - in naturally deformed rocks, in numerical simulations and in theory that deal with general shear - but simple shear (the game for "Ramsay & Graham" shear zone0s is defined as in the video.
@张宏远-z8t Жыл бұрын
@@robbutler2095 Thanks a lot. Your talk makes me understand that simple shear is the principle mechanism for shear zones of different levels. Maybe what I talk is just in line with a pure shear environment or Anderson model.