Tectonic shear zone

Skempton, A.W. 1966. Some observations on tectonic shear zones. Proc. 1st Congr. Int. Soc. Rock. Mech. Lisbon, Vol. 1, pp. 329-385. 

The Tisdale rocks were deformed by two tectonic events that resulted in superposition of east-west isoclinal folds on older north-south open folds. Five camp- to regional-scale faults, including the Hollinger Shear Zone (HSZ), have offset all these rocks. The HSZ is a reverse fault ( 140 m offset) that passes through the Hollinger-Mcintyre mine, strikes 57°, dips 65°S, extends to a depth of >1,500m and formed synchronous with the east-west folds. Most gold mineralization in the HMC deposit is associated with rocks in and above the HSZ. 

With the advent of stable isotope paleoaltimetry towards the turn of the millennium the stable isotope and tectonics communities have witnessed an increasing number of isotopic mineral proxies developed to address the long-term topographic histories of orogenic belts and continental plateaus. These proxies include calcite from paleosols (see for example Quade et al. 2007, this volume and references therein), fluvial and lacustrine rocks the phosphate and carbonate component of mammal teeth (Kohn and Dettman 2007, this volume and references therein), smectite and kaolinite from paleosols, weathered sediments and volcanic ashes (e.g., Chamberlain et al. 1999 Takeuchi and Larson 2005 Mulch et al. 2006a) as well as white mica from extensional shear zones and fluid inclusions in hydrothermal veins (e.g., Mulch et al. 

The long time scales (104 to 10s m.y.) involved in deformation and synkinematic isotope exchange in white mica provide a robust, long-term average of meteoric water-rock interaction, characteristic for the time scales of major readjustments in surface elevation. Thus the hydrogen isotope record in recrystallized muscovite provides a direct link between the tectonic and fluid flow history in the shear zone and temporal variations in meteoric water composition due to changing surface elevation. 

Scharer U, Tapponier P, Lacassin R, Leloup PH, Dalai Z, Shaocheng J (1990) Intraplate tectonics in Asia A precise age for large-scale Miocene movement along the Ailao Shan-Red River shear zone, China. Earth Planet Sci Lett 97 65-77... 

Pankhurst RJ, Storey BC, Millar IL, Macdonald DIM, Vennum WR (1988) Cambrian-Ordovician magmatism in the Thiel Mountains, Transantarctic Mountains, and implications for the Beardmore Orogeny. Geology 16(3) 246-249 Peacock SM, Goodge JW (1995) Eclogite facies metamorphism preserved in tectonic blocks from a lower crustal shear zone, central Transantarctic Mountains, Antarctica. Lithos 36 12-13... 

A reel steadily puUs and simulates the steady plate tectonic motions far from the plate boundaries, wooden blocks having different thickness simulates different shear zones of the fault which are connected with a rubber band that furnishes the elastic property of the crust. Friction is simulated by sandpaper stacked on a wooden plank using pins slightly rising from the board when the blocks simulating the fault get stuck on the pin we can also discuss asperity of the fault. The use of wooden blocks and sandpaper (Fig. 17.2) instead of the rocky blocks and the porcelain surface suggested by Linton and Stein (2012) is meant to emphasize the... 

Cored Upper Jurassic claystones from a well located within the Lindesnes trend display both dila-tional and shear fractures (Fig. 9). Although both shear and dilational fractures can be produced by hydraulic fracturing (Lockner and Byerlee, 1977), the location of this well within a major wrench zone suggests tectonic breaching as the most likely cause. 

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