8. A new generation of atolls

Some 232-228 million years ago – the late Ladinian – early Carnian era

The Triassic volcanoes eventually ceased erupting and were worn away. There was a return to the optimum conditions for diverse life forms capable of constructing islands to spring up. The gradual sinking of the region drew to a halt and sediment stared to fill up the Triassic Dolomite sea.

The volcanic activity had lasted about a million years and once this ceased, the volcanic complex was worn away by erosion, transporting the finer fragments considerable distances. The tropical tranquillity returned and the island-building organisms resumed their activities.

The number of corals increased and ever more highly evolved species began to appear. The slow, inexorable subsidence of the region slowed down, being more intense to the east than to the west. Almost all the islands, with the exception of the northern-most, grew mainly horizontally, expanding sideways. A great many underwater landslides affected the slopes of these islands and blocks of rock were deposited at their base, among the sediment of the deep sea that surrounded them.

Text by Dolomiti Project

Some rocks and fossils from this era