'small cleft' is correct and usable in written English.
It is most typically used to describe a physical feature, like a small gap or fissure, such as in the sentence: "She could feel the cool air coming through the small cleft in the door."
I knew this because a small cleft appeared in his chin.
We are perched in a small cleft at 1,600 meters elevation on the flanks of Veve, the highest point on Kolombangara.
I noted his wavy hair, finely parted, and moist fleshy lips and a small cleft in the center of his chin, which I thought was endearing, because I could see, even in the inadequate street lighting, that he had some trouble shaving there.
Once in a while, a small cleft forms in the mutated protein's core.
Note the small cleft (short arrow) in the superior pole renal cortex and the prominent vessel (long arrow) passing through this.
The region is only accessible via a small cleft in the mountains to the north, leading to a massive stone bridge.
It's perfect for picnics, as large trees and small clefts in the rock provide shade.
Small clefts either side of a large cleft may be missed without gonioscopic visualisation.
Our approach to surgery has generally been cryopexy for small clefts (around one clock hour) and cyclopexy for larger clefts.
The central layer of the interzone undergoes a cavitation process with the appearance of small clefts which extend and coalesce to form the synovial cavity [ 16].
A large pocket surrounds the bound phosphate, with the fido motif R104 lining a smaller cleft on one side of the bound phosphate and a Y132/R107 pair lining a larger cleft on the opposite side (Figure 4B).
