Slide 1

V Rule in sedimentary terrrainTo understand the shapes described by the boundaries of formations on geological maps it is important to realize that they represent a line (horizontal, plunging or curved) produced by the intersection in three dimensions of two surfaces One of these surfaces is the geological surface .The other is the topographic surface the surface of the ground. The topographicsurface is not planar but has features such as hills, valleysand ridges.

A dipping surface that crops out in a valley or on a ridge will give rise to a V-shaped outcrop .

The way the outcrop patterns vee depends on the dip of the geological surface relative to the topography.V-RulesConcept of outcrop of geological contact12Effect of the angle of dip on the sinuosity of a contacts outcrop12Relation between dip and topography has been formalized into a series of statements, collectively called Rule of Vs1.Horizontal BedsThe outcrop traces of real horizontal planes thereforeexactly follow the topographic contours

Therefore, the outcrop pattern Vs upstream, just as the contour lines do2.Beds inclined upstreamAs the attitude departs from the horizontal, with the dip direction in the upstream direction, the pattern made by the traces of the structural planes is progressively modified into a blunter3.Vertical bedThere is no V at all, and thus no control on the pattern by the topography4.Beds inclined downstreamCase A-With beds dip greater than valley gradientThe pattern is V downstreamCase B-Bed dip and valley gradient are sameThere is no V, Bed strip runs parallel to the valley axisBeds inclined downstreamCase C-Bed dip is less than the valley gradient.The pattern of V is upstreamBeds inclined downstreamThank you