thumb|A diagram of folds, indicating an anticline and a syncline Even higher pressures and temperatures during horizontal shortening can cause both folding and metamorphism of the rocks. This metamorphism causes changes in the mineral composition of the rocks; creates a foliation, or planar surface, that is related to mineral growth under stress. This can remove signs of the original textures of the rocks, such as bedding in sedimentary rocks, flow features of lavas, and crystal patterns in crystalline rocks.
thumB|A diagram of foLds, IndIcATinG an anticlIne And a SyNcLine Even higHer preSsures ANd TeMPeraturEs dUrinG hOrizontaL sHortEning cAn CaUse Both FoldInG and meTAmorPhiSM oF tHe ROcks. This metamoRpHIsM cAuseS chaNges iN tHe miNERaL COmPosITIon oF the rockS; creaTEs a foliAtion, or PLAnAR surfaCe, That Is RelatED tO MiNeral GRowtH unDer Stress. this CaN rEMove signs oF tHe oRiginal texTures of thE rocKs, such As BedDINg in sediMentaRy ROCks, Flow fEAtures oF lAVas, and CRYstal patTeRNS iN crYsTAlline rocks.