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Microplate modelling paper accepted for publication
Derek Neuharth's paper on the “Formation of continental microplates through rift linkage: Numerical modelling and its application to the Flemish Cap and SaoPaulo Plateau” has just been accepted from publication in AGU's G^3. A pre-print is available on EarthArxiv
Key Points:
- Strike-perpendicular offset and crustal strength control the mode of rift segment linkage (microplate, oblique, or transform).
- Rotating continental microplates form at offsets of >200 km for weak and moderately strong crust.
- Modelled microplate evolution may explain the formation of the Flemish Cap, the Sao Paulo Plateau and other continental promontories.
Abstract:
Continental microplates are enigmatic plate boundary features, which can occur in extensional and compressional regimes. Here we focus on microplate formation and their temporal evolution in continental rift settings. To this aim, we employ the geodynamic finite element software ASPECT to conduct 3D lithospheric-scale numerical models from rift inception to continental breakup. We find that depending on the strike-perpendicular offset and crustal strength, rift segments connect or interact through one of four regimes: (1) an oblique rift, (2) a transform fault, (3) a rotating continental microplate or (4) a rift jump. We highlight that rotating microplates form at offsets >200 km in weak to moderately strong crustal setups. We describe the dynamics of microplate evolution from initial rift propagation, to segment overlap, vertical- axis rotation, and eventually continental breakup. These models may explain microplate size and kinematics of the Flemish Cap, the Sao Paulo Plateau and other continental microplates that formed during continental rifting worldwide.
Oblique annotations in GMT6's colorbar
Since this week, the Generic mapping tools (GMT) have an option to plot colorscale annotations at an angle. After describing my quest to produce annotated geological time scale stages GMT forum post, Paul swiftly implemented the ''-S+a'' option in ''gmt colorbar''. This greatly helps with non-numeric colorscales such as the geological time scale.
Generate UUIDs in ArcGIS Pro
The corporate GIS vehicle is ESRI's ArcGIS Pro. When digitizing new features which are to be used in GPlates, each feature is required to have a UUID-based FEATURE_ID in the form of GPlates-7344d973-6ff1-47f7-93b9-bdb9cf7197ee. In ArcGIS Pro, this can be done easily using the field calculator. The following definition (based on ESRI's website) can be plonked into the Code Block part of the Field Calculator:
def ID(): import uuid return 'GPlates-' + str(uuid.uuid4())
while in the field assignment (FEATURE_ID =) one then simply uses the above definition, assigning FIELD_ID = ID()
Subduction volume paper published
Madison East's paper on subduction volume fluxes over the past 230 Ma is finally published in Gondwana Research.
The supplementary material is available on Zenodo.org. The plate reconstruction model and related digital age grids which were used for the calculations are available for download at the EarthByte FTP site.
Paper on Neuquen Basin
lead by my colleague Daniel Minisini, we have just published a paper on the “Sedimentology, Depositional Model, and Implications for Reservoir Quality” of the Vaca Muerta Unconventional Play in the Neuquen Basin in Argentina. The paper is a chapter in AAPG Memoir 121 "Integrated geology of unconventionals: The case of the Vaca Muerta play, Argentina", edited by Daniel Minisini, Manuel Fantín, Iván Lanusse Noguera, and Héctor A. Leanza,