I came across this question while studying in my text book: What does the existence of strata containing a reverse fault and above them parallel strata refer to? I thought that referred to an angular unconformity, thinking that the fault should make a tilt in the layers, and that the tilts which appear in angular unconformity happen by a fault or a fold, but I found that the answer is "disconformity", so I became confused. Would that reverse fault present only a crack not a tilt? Or was the strata where the fault appeared was parallel so the movement didn't affect the angle of the layers? Would the tilt which appears in angular unconformities happens by other factors more than a fault and a fold?. I would like anyone to help me understand this, because I didn't get help searching in many websites but some definitions and concepts which made me more perplexed.