New book traces 233-million-year-old Carnian climate crisis

A new book by palaeontologist Alexander Lukeneder examines the Carnian Crisis, a global climate catastrophe caused by massive volcanic eruptions between 233 million and 235 million years ago, ORF reported.

Lukeneder, who works at the Natural History Museum Vienna, brings together 150 years of research and describes how the eruptions released huge amounts of carbon dioxide. The resulting climate change caused much wetter conditions, monsoon-like rainfall and the collapse of marine ecosystems.

The main focus of Lukeneder’s research was Lunz am See in the Scheibbs district of Lower Austria. Its finely layered rocks, formed about 235 million years ago, contain exceptionally well-preserved fossils in black, calcareous to clay-rich marine deposits.

Research at the location and earlier work have produced 20,000 Triassic fossils for the Natural History Museum Vienna, making it the world’s largest collection of its kind, according to ORF.

The volcanic eruptions also deposited a basalt layer more than 1,000 metres thick in Canada and the United States. The rise in atmospheric carbon dioxide triggered pronounced warming during the Late Triassic. Heavy rainfall carried large quantities of sediment into the seas, suffocating reefs in mud.

The Carnian Crisis lasted more than two million years and led to the collapse of entire ecosystems. Researchers drilled a core at Lunz am See into the layers formed during the crisis, recovering chemically unchanged rock that could be examined millimetre by millimetre.

Only a narrow geological zone in Austria contains sedimentary rocks from the Carnian Crisis. It crosses the Lower Austrian and Styrian Limestone Alps, extending from Mödling in Lower Austria to Großreifling in northern Styria, within the area of the Styrian Eisenwurzen Nature and UNESCO Geopark.

The marine deposits of the Reiflinger Basin contain exceptionally well-preserved ammonites, squid, clams, snails, crustaceans, bristle worms, several types of fish, coelacanths and lungfish. The rocks also yielded the world’s first evidence of fossil squid cartilage.

The research also involved citizen scientists Birgitt and Karl Aschauer from Waidhofen an der Ybbs, who excavated hundreds of valuable fossils and made them available to researchers. The work led to the first descriptions of new fossil species of squid and bristle worms.

The 24-chapter book includes contributions from the discoverers of the Carnian Crisis, Alastair Ruffell, Michael Simms and Paul Wignall, as well as 50 other international scientists. Published by Springer, it is available online as an open-access work and in print.