An anticline is a type of fold in sedimentary strata that is arch-like in shape, with its oldest rocks located at the core of the fold. The limbs of an anticline dip away from the center, creating a convex-upward structure. Anticlines are important in petroleum geology because they can serve as traps for oil and natural gas, accumulating hydrocarbons in the crest of the fold.
Source Twiss, R. J., & Moores, E. M. (2007). Structural Geology. W.H. Freeman and Company.