Earth Sci

             Folding – The process by which crustal forces deform an area of crust so that layers of rock are pushed into folds.
             Faulting – The process by which crustal forces cause a rock formation to break and slip along a fault.
             Fold – A bent or warped stratum or sequence of strata that was originally horizontal, or neatly so.
             Fault – A planar or gently curved fracture in the earth's crust across which there has been relative displacement of the two blocks of rock parallel to the fracture.
             · It takes 2 measurements to describe the orientation of a layer of rock exposed at a given location:
             · Strike – The direction of the intersection of a rock layer with a horizontal surface.
             · Dip – Measured at right angles to the strike, is simply the amount of tilting – the angle at which the inclines from the horizontal.
             Constructing a Geological Map and Cross Section
             o The dips and strikes of inclined layers
             · 3 types of tectonic forces:
             o Compressive forces – squeeze and shorten a body
             o Tensional forces – stretch a body and tend to pull it apart
             o Shearing forces – push two sides of a body in opposite directions
             What Determines Whether a Rock Bends or Breaks?
             · If subject to tectonic forces near surface, where confining pressure is low it would tend to deform by fracturing and faulting.
             · If deeper than few Km's it would change shape by gradually folding.(also if hot)
             · Brittle rocks – little change, then breaks
             · Ductile rocks – smooth and continuous plastic deformation.
             · Igneous rocks are more brittle (stronger) than sedimentary rocks
             · Basement rocks more brittle than overlaying sedimentar
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Earth Sci . (1969, December 31). In MegaEssays.com. Retrieved 11:25, March 29, 2024, from https://www.megaessays.com/viewpaper/64124.html