How does a global flood explain angular unconformities?

Creationists will tell you that all the sedimentary layers were put down in one flood event, but they have a problem; Angular Unconformities. These are where one set of layers of sediments have been extensively modified (e.g., tilted) and eroded before a second set of layers were deposited on top. They thus seem to require at least two periods of deposition (more, where there is more than one unconformity) with long periods of time in between to account for the deformation, erosion, and weathering observed.