What evidence supports the Darwin-Dana theory of coral atoll formation?

The Darwin-Dana theory of coral atoll formation is significantly supported by data obtained from deep drilling on coral atolls. This theory posits that atolls develop from fringing reefs that grow around a volcanic island, which eventually erodes and subsides. As the island sinks, the coral continues to grow upwards, resulting in the formation of the atoll.

Deep drilling provides direct geological evidence of the structure and composition of the atolls, revealing layers of coral debris and sediment accumulation over time. This data helps researchers understand the history of the coral atoll's formation and the subsidence of the volcanic island beneath it. It also confirms the age of the coral structures and the processes involved in their development, supporting the theory's premise of atoll formation in conjunction with volcanic activity and gradual sinking.

Visual observations of coral reefs, while informative, do not offer the same depth of geological understanding necessary to validate the erosion and subsidence process described by the Darwin-Dana theory. Additionally, measuring coral growth rates in shallow water may contribute to understanding coral biology but does not encompass the overarching geological mechanisms of atoll formation, and studies of fish populations, while crucial for ecological assessments, do not address the geological history or structural development of atolls. Thus, deep