Are Synclines folds symmetrical or asymmetrical?
A syncline is a geologic structure in which the strata are bent into a downfold, like the letter U. The youngest rocks are in the center of the U and the oldest rocks are on the flanks. Synclines may be either symmetrical or asymmetrical. The opposite of a syncline is an anticline, with the folds upward. Both structures are thought to be formed when rock is deformed by pressure from mountain building.