If a mineral breaks and leaves a smooth crystal surface, this is said to have cleavage. There are different qualities of cleavage, depending on how smooth the surface of the plane is. For this example, since the mineral breaks cleanly and evenly, it can be described as perfect cleavage.
Answer:
The davis's geomorphic cyclic theory raised some of the problems that the davis's concept of the upliftment creates problem so that is why it is unacceptable as it basically described the rapid change in the rate of the upliftment in the very short duration.
And the concept of the correlation in the upliftment and erosion are erroneous as, according to the concept no erosion occurred unless the upliftment process are completed.