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The boundary between the Triassic and Jurassic periods marks one of the major mass extinction events in the history of life. Recent research suggests that this event, to date the least well-understood of the large extinctions, coincided with an unusual volcanic episode, sudden changes in sea level, and extreme climate warming. The reconstruction of processes of environmental and biotic change, and identifying causes and effects requires acqusition of new data from the scarce global geologic and fossil record of this interval. Only such augmented, multidisciplinary datasets will enable us to model how the Earth system worked during these events some 200 million years ago.
The project will generate integrated paleontological, strat-igraphical, sedimentological, geochemical, geochronologic-al, paleomagnetic, and mineralogical data from Triassic/Jurassic boundary sections globally. Field studies are directed towards previously known localities as well as recently or newly discovered ones. A global database of temporal and spatial distribution of major fossil groups across the boundary will be compiled. Patterns of the end-Triassic extinction and Early Jurassic recovery will be analyzed using the database in order to develop quantitative models. New radiometric ages will be obtained to establish a reliable temporal framework. Environmental perturbations and their role in different extinction scenarios will be assessed using geochemical methods. Further studies of the Central Atlantic Magmatic Province and a search for a hypothetical end-Triassic impact will provide clues to the trigger of global environmental change. Reconstruction of the end-Triassic events will use an Earth systems approach to integrate all new findings into the most plausible model. The level of research activity focusing on Triassic/Jurassic boundary events has started to increase in recent years, although it still considerably lags behind that of the Cretaceous/Tertiary and Permo-Triassic events. Nevertheless, the time is ripe to initiate a major international collaborative research effort, as the problems can now be clearly defined, a suite of modern research methods are available, and diverse studies are already ongoing based on individual initiatives. Deciphering the extinction processes, reconstructing the trajectory of environmental change, and identifying their causes requires a coordinated, multi-disciplinary and global research effort as proposed herein. We have identified nine key areas of study for this project:
(1) The fossil record of the end-Triassic mass extinction;(2) Isotope geochemistry across the Triassic/Jurassic boundary;
(3) Late Triassic to Early Jurassic geochronology;
(4) The Central Atlantic Magmatic Province and related tectonic events;
(5) Search for extraterrestrial impact signatures at the Triassic/Jurassic boundary;
(6) Late Triassic to Early Jurassic paleoclimate reconstructions;
(7) Late Triassic to Early Jurassic magnetostratigraphy;
(8) Late Triassic to Early Jurassic sea level change and sequence stratigraphy;
(9) Global correlation of the base of the Jurassic system, production of scientific data to facilitate GSSP selection.
We look forward to hearing from all interested colleagues who are
willing to participate in this research project.
Jozsef Pálfy palfy@paleo.nhmus.hu
Steve Hesselbo stephen.hesselbo@earth.ox.ac.uk
Chris McRoberts mcroberts@cortland.edu
