What formation occurs when two bifurcations on the same ridge face each other and their branches join?

The correct formation that occurs when two bifurcations on the same ridge face each other and their branches join is known as an enclosure. This term describes a specific configuration of ridges in fingerprinting where the ridges come together to form a closed area, resembling a small oval or loop within the print. An enclosure is significant in the analysis of fingerprint patterns because it can aid in the identification and comparison of prints, making it a critical concept in the field of latent print analysis.

A trifurcation involves a single ridge splitting into three distinct paths, which is different from the scenario where two bifurcations meet and connect. An island refers to a ridge structure that is completely surrounded by other ridges without any direct connection to the main flow, which does not fit the definition provided in the question. Branching describes a simple separation of a ridge into two parts but does not imply the closing of a space or the formation of joins as seen in an enclosure.