Middle-Late Devonian age strata in the Canning Basin reef complex, northwestern Australia, record numerous lithological cycles and an extensive extinction among reef formers and invertebrates across the Givetian/ Frasnian boundary. This proposal seeks to develop a geochemical proxy set consisting of 13Corg and biomarker lipids from two locales along the Lennard Shelf with organic rich-facies to assess the timing and duration of this mass extinction.
The goals of this research are three-fold:
1. Assess the detailed Milankovitchian characters of Menyous Gap and within the Pillara Quarry with respect to modern astronomical theory and to discuss the results with respect to timing of the coral extinction events: Was this extinction protracted or relatively sudden?
2. Reconstruct paleoenvironmental change in marine productivity (13Corg) and terrestrial ecosystem conditions (leaf wax-derived n-alkanes).
3. Produce better correlation both within the basin and to similarly aged strata elsewhere using secular trends and low-frequency orbital cycles in 13Corg and n-alkanes.
This research is urgent because of the limited time left within the existing larger Canning Project that combines magnetostratigraphy, conodont biostratigraphy, conodont Sr isotope chronostratigraphy, and biomarker analysis to investigate Middle-Late Devonian paleoenvironmental and biotic change. Gathering these data adds a new dimension (cyclostratigraphy) outside the scope of, but complementary to the existing Canning Project.
