Notebook resting on an Ice Age or the transition from the Tonian Skillogallee and Myrtle Springs Formations to the overlying Cryogenian Sturt Formation (Sturt Glaciation, marked by the notebook) in the Willouran Ranges, Adnyamathanha Country, South Australia. Image: Alan Collins ARC Future Fellow Dr Adriana Dutkiewicz from the EarthByte Group and colleagues have used NCRIS … Read more…
Earth’s topography and bathymetry with revised boundaries between continental and ocean crust overlain as thin red lines. We have released a refined data set of the boundaries between continental and ocean crust (COBs). The data can be downloaded from zenodo as GPlates-compatible gpmlz and as ESRI shapefile. The COBs are based on the data set … Read more…
8 February 2024, University of Sydney Media release Historically low volcanic emissions and weathering events seem likely cause Dr Adriana Dutkiewicz was inspired during a field trip to the Flinders Ranges to find out how volcanic activity turned our blue dot to an ice covered planet. Together with Professor Dietmar Muller and the EarthByte group, … Read more…
The termination of Neoproterozoic “Snowball Earth” glaciations is marked globally by laterally extensive neritic cap carbonates directly overlying glacial diamictites. The formation of these unique deposits on deglaciation calls for anomalously high CaCO3 saturation. A popular mechanism to account for the source of requisite ocean alkalinity is the shallow-ridge hypothesis, in which initial spreading ridges … Read more…
The long-term diversification of the biosphere responds to changes in the physical environment. Yet, over the continents, the nearly monotonic expansion of life started later in the early part of the Phanerozoic eon1 than the expansion in the marine realm, where instead the number of genera waxed and waned over time2. A comprehensive evaluation of … Read more…
Kimberlites are sourced from thermochemical upwellings which can transport diamonds to the surface of the crust. The majority of kimberlites preserved at the Earth’s surface erupted between 250 and 50 million years ago, and have been attributed to changes in plate velocity or mantle plumes. However, these mechanisms fail to explain the presence of strong … Read more…
11 July 2023 Tectonic changes alter sea levels that can create breeding grounds for life Movement in the Earth’s tectonic plates indirectly triggers bursts of biodiversity in 36-million-year cycles by forcing sea levels to rise and fall, new research has shown. Dinosaur Stampede exhibit at Dinosaur Canyon, located in Queensland’s Winton Formation which was formed … Read more…
The fossil record reveals that biotic diversity has fluctuated quasi-cyclically through geological time. However, the causal mechanisms of biotic diversity cycles remain unexplained. Here, we highlight a common, correlatable 36 ± 1 Myr (million years) cycle in the diversity of marine genera as well as in tectonic, sea-level, and macrostratigraphic data over the past 250 … Read more…
The evolving mosaic of tectonic plates across the surface of the Earth sets boundary conditions for the evolution of biotic and abiotic processes and helps shape the dynamics of its interior. Reconstructing plate tectonics back through time allows scientists from a range of disciplines (such as palaeobiology, palaeoclimate, geodynamics and seismology) to investigate Earth evolution … Read more…
Understanding the long-term evolution of Earth’s plate-mantle system is reliant on absolute plate motion models in a mantle reference frame, but such models are both difficult to construct and controversial. We present a tectonic rules-based optimisation approach to construct a plate motion model in a mantle reference frame covering the last billion years and use … Read more…
Carbonatites have formed for at least the past three billion years. But over the past 700 My the incidence of carbonatites have significantly increased. We compile an updated list of 609 carbonatite occurrences and plot 387 of known age on plate tectonic reconstructions. Plate reconstructions from Devonian to present show that 75% of carbonatites are … Read more…
A drastic change in plate tectonics and mantle convection occurred around 50 Ma as exemplified by the prominent Hawaiian– Emperor Bend. Both an abrupt Pacific Plate motion change and a change in mantle plume dynamics have been proposed to account for the Hawaiian–Emperor Bend, but debates surround the relative contribution of the two mechanisms. Here … Read more…
Significance We report the discovery of anomalously high 3He/4He in “cold” geothermal fluids of central Panama, far from any active volcanoes. Combined with independent constraints from lava geochemistry, mantle source geochemical anomalies in Central America require a Galapagos plume contribution that is not derived from hotspot track recycling. Instead, these signals likely originate from large-scale … Read more…
The plate tectonic theory says that Earth’s surface is made up of slabs of rock that are slowly shifting right under our feet. Because of this constant movement, today’s Earth looks a lot different from what it did millions of years ago. In 1912, German scientist Alfred Wegener proposed that Earth’s continents once formed a … Read more…
Assessing the size of a former ocean of which only remnants are found in mountain belts is challenging but crucial to understanding subduction and exhumation processes. Here we present new constraints on the opening and width of the Piemont–Liguria (PL) Ocean, known as the Alpine Tethys together with the Valais Basin. We use a regional … Read more…