Congratulations Professor Anya Reading!
RST Apology to Tasmanian Aboriginal people 2021.
RST Apology to Tasmanian Aboriginal people 2021.
The Tamar Trough, an Early Palaeogene fault structure, contains sedimentaty beds and interleaved basaltic flows that infill the structure along its 70 km length. These infills represent a complex interplay between sedimentation, channel erosion, eruptive dislocations, and even ‘out of trough’ diyersions of the ancestral Tamar drainage. Several areas of resistant basalt flows remain in the south, upper, middle and lower Tamar reaches. Although some palynological control was known, radiometric dating of previously untested basalts now allows close integration and age-pegging for observed palynological biozones. The K-Ar and Ar-Ar ages of the basalt bodies indicate eruptive events at 47, 33-37 and 25 Ma, correlating with Proteacidites asperopolus-Malvacipollis diversus, Nothofagites asperus and Proteacidites tuberculatus biozone age sedimentary beds respectively. Basanite, alkali basalt and hawaiite flows dominate basalt lithology with lesser olivine nephelinite, transitional olivine basalt, olivine tholeiite and quartz tholeiite. Basalt geochemistry suggests derivation from different degrees of partial mande melting (from 7 to 35%), with alkaline and tholeiitic basalts being derived from separate source regions. Most alkaline basalts have high-jl (HIMU) related trace element signatures, which are absent in the tholeiitic rocks. A basalt plug on the trough margin at Loira gave a Jurassic age and has Jurassic dolerite-like geochemistry. The Tamar sequence suggests that the initial fluvio-Iacustrine and
later channel-fill sedimentation from 65(?) to 24(?) Ma was then punctuated in places by periods of alkaline volcanism between 47 to 33(?) Ma, and alkaline and tholeiitic volcanism between 33 to 24(?) Ma. No Neogene fossils are known, so this later period was probably one of net erosion. These contrasting quiet sedimentary and more volcanic intervals are related here to a tectonic model that involves northerly drift of Victorian and Tasmanian lithosphere over several former Tasman metasomatised mantle plume sources.
Royal Society of Tasmania, RST, Van Diemens Land, natural history, science, ecology, taxonomy, botany, zoology, geology, geography, papers & proceedings, Australia, UTAS Library
Published Papers
The Royal Society of Tasmania acknowledges, with deep respect, the traditional owners of this land, and the ongoing custodianship of the Aboriginal people of Tasmania. The Society pays respect to Elders past, present and emerging. We acknowledge that Tasmanian Aboriginal Peoples have survived severe and unjust impacts resulting from invasion and dispossession of their Country. As an institution dedicated to the advancement of knowledge, the Royal Society of Tasmania recognises Aboriginal cultural knowledge and practices and seeks to respect and honour these traditions and the deep understanding they represent.
On 15 February 2021, the Royal Society of Tasmania offered a formal Apology to the Tasmanian Aboriginal people.
