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Folds new
Folds are bends or curvatures in rock layers caused by stresses in the Earth's history. The shape of a fold depends on factors like the nature, magnitude, and direction of forces, and the type of rock. Folds have key parts like limbs, the sides of the fold, a hinge where curvature is greatest, and a hinge line or axial plane connecting all hinge points. Folds also have a crest at the top of an upfold or a trough at the bottom of a downfold. There are several types of folds including anticlines that bend upward, synclines that bend downward, symmetrical folds with equal limbs, and asymmetrical folds with unequal limbs.
Folds new
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- 2. FOLD:- itmay be defined as UNDULATIONS OR BENDS OR CURVATURES developed in a rocks because of STRESSES witch are acting on rocks from time to time in past history of the earth. The shape and extent of a folds depends upon a no. of factors;- - nature - magnitude - direction and duration of forces act upon the rocks - and on nature of the rocks.
- 3. PARTS OF FOLDSLIMBS :- these are the sides or flanks of the folds. HINGE :- in folded layer a point at curvature is maximum is called hinge point. HINGE LINE :- rocks occur in a sequence and their all hinge points are joined together, they make a line called hinge line. AXIAL PLAIN :- an axial plane is that imaginary plane that passes through all the points of maximum curvature in a folded sequence PLUNGE OF FOLD :- plunge is angle which axis line makes with a horizontal plane.
- 4. PARTS OF FOLDS CREST AND TROUGH :- the line running through the highest points in an up arched fold defines as CREST. THE line running through the lowest point in a down arched fold make its THROUGH.
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- 6. Types of FOLDS:-- 1)Anticline fold 2) syncline fold 3) Symmetrical Folds 4) Asymmetrical fold 5) overturned fold 6) Isoclinal fold 7) Recumbent Fold
- 7. 1) Anticline fold:- inthis fold strata are convex upwards. 2) syncline fold:-- in this fold strata are convex downward.
- 8. 3) Symmetrical fold:- thisare also called normal folds . Axial plane is essentially vertical. The limbs are equal in length and dip equaly in in opposite directions. 4) Asymmetrical fold:- in this folds limbs are unequal in length and dip are of different angle. Are termed as Asymmetrical folds. 5) Overturned fold:- these are folds with inclined axial plains in witch both limbs are dipping essentially in the same general direction. 6)Isoclinal folds:- these are group of folds in witch all the axial plains are parallel. They may b made up of series of anticlines and synclines.
- 9. 7) Recumbent fold:- thismay be described as extreme types of overturned fold in witch the axial plain acquires an almost horizontal attitude.
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