scholarly journals The preserved plume of the Caribbean Large Igneous Plateau revealed by 3D data-integrative models

2020 ◽  
Author(s):  
Ángela María Gómez-García ◽  
Eline Le Breton ◽  
Magdalena Scheck-Wenderoth ◽  
Gaspar Monsalve ◽  
Denis Anikiev
Keyword(s):  
Plate Tectonics ◽  
Positive Density ◽  
Caribbean Plate ◽  
3D Data ◽  
Free Air ◽  
Gravity Measurements ◽  
Crystalline Crust ◽  
The Caribbean ◽  
Free Air Gravity ◽  
First Time

Abstract. Remnants of the Caribbean Large Igneous Plateau (CLIP) are found as thicker than normal oceanic crust in the Caribbean Sea, that formed during rapid pulses of magmatic activity at ~ 91–88 Ma and ~ 76 Ma. Strong geochemical evidence supports the hypothesis that the CLIP formed due to melting of the plume head of the Galápagos hotspot, which interacted with the Farallon (Proto-Caribbean) plate in the east Pacific. Considering the plate tectonics theory, it is expected that the lithospheric portion of the plume-related material migrated within the Proto-Caribbean plate, in a north–north-eastward direction, developing the present-day Caribbean plate. In this research, we used 3D lithospheric-scale, data-integrative models of the current Caribbean plate setting to reveal, for the first time, the presence of positive density anomalies in the uppermost lithospheric mantle. These models are based on the integration of up-to-date geophysical datasets, from the Earth’s surface down to 200 km depth, which are validated using high-resolution free-air gravity measurements. Based on the gravity residuals (modelled minus observed gravity), we derive density heterogeneities both in the crystalline crust and the uppermost oceanic mantle (

scholarly journals The preserved plume of the Caribbean Large Igneous Plateau revealed by 3D data-integrative models

Solid Earth ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 275-298
Author(s):  
Ángela María Gómez-García ◽  
Eline Le Breton ◽  
Magdalena Scheck-Wenderoth ◽  
Gaspar Monsalve ◽  
Denis Anikiev
Keyword(s):  
Plate Tectonics ◽  
Positive Density ◽  
Caribbean Plate ◽  
S Wave ◽  
Tectonic Model ◽  
The North ◽  
3D Data ◽  
Gravity Measurements ◽  
The Caribbean ◽  
Free Air Gravity

Abstract. Remnants of the Caribbean Large Igneous Plateau (C-LIP) are found as thicker than normal oceanic crust in the Caribbean Sea that formed during rapid pulses of magmatic activity at ∼91–88 and ∼76 Ma. Strong geochemical evidence supports the hypothesis that the C-LIP formed due to melting of the plume head of the Galápagos hotspot, which interacted with the Farallon (Proto-Caribbean) plate in the eastern Pacific. Considering plate tectonics theory, it is expected that the lithospheric portion of the plume-related material migrated within the Proto-Caribbean plate in a north–north-eastward direction, developing the present-day Caribbean plate. In this research, we used 3D lithospheric-scale, data-integrative models of the current Caribbean plate setting to reveal, for the first time, the presence of positive density anomalies in the uppermost lithospheric mantle. These models are based on the integration of up-to-date geophysical datasets from the Earth's surface down to 200 km depth, which are validated using high-resolution free-air gravity measurements. Based on the gravity residuals (modelled minus observed gravity), we derive density heterogeneities both in the crystalline crust and the uppermost oceanic mantle (<50 km). Our results reveal the presence of two positive mantle density anomalies beneath the Colombian and the Venezuelan basins, interpreted as the preserved fossil plume conduits associated with the C-LIP formation. Such mantle bodies have never been identified before, but a positive density trend is also indicated by S-wave tomography, at least down to 75 km depth. The interpreted plume conduits spatially correlate with the thinner crustal regions present in both basins; therefore, we propose a modification to the commonly accepted tectonic model of the Caribbean, suggesting that the thinner domains correspond to the centres of uplift due to the inflow of the hot, buoyant plume head. Finally, using six different kinematic models, we test the hypothesis that the C-LIP originated above the Galápagos hotspot; however, misfits of up to ∼3000 km are found between the present-day hotspot location and the mantle anomalies, reconstructed back to 90 Ma. Therefore, we shed light on possible sources of error responsible for this offset and discuss two possible interpretations: (1) the Galápagos hotspot migrated (∼1200–3000 km) westward while the Caribbean plate moved to the north, or (2) the C-LIP was formed by a different plume, which – if considered fixed – would be nowadays located below the South American continent.

Effect of plate motion on plume-induced subduction initiation

2021 ◽  
Author(s):  
Marzieh Baes ◽  
Stephan Sobolev ◽  
Taras Gerya ◽  
Robert Stern ◽  
Sascha Brune
Keyword(s):  
Subduction Zone ◽  
Late Cretaceous ◽  
Subduction Zones ◽  
Plate Tectonics ◽  
Plate Motion ◽  
Cascadia Subduction Zone ◽  
Caribbean Plate ◽  
Subduction Initiation ◽  
Southern Margin ◽  
The Caribbean

&lt;p&gt;Subduction zones are key components of plate tectonics and plate tectonics could not begin until the first subduction zone formed. Plume-induced subduction initiation, which has been proposed as triggering the beginning of plate tectonics (Gerya et al., 2015), is one of the few scenarios that can break the lithosphere and recycle a stagnant lid without requiring any pre-existing weak zones. So far, two natural examples of plume-induced subduction initiation have been recognized. The first was found in southern and western margins of the Caribbean Plate (Whattam and Stern 2014). Initiation of the Cascadia subduction zone in Eocene times has been proposed to be the second example of plume-induced subduction initiation (Stern and Dumitru, 2019).&lt;/p&gt;&lt;p&gt;The focus of previous studies was to inspect plume-lithosphere interaction either for the case of stationary lithosphere (e.g., Gerya et al., 2015) or for moving lithosphere without considering the effect of lithospheric magmatic weakening above the plume head (e.g., Moore et al., 1998). In present study we investigate the response of moving oceanic lithosphere to the arrival of a rising mantle plume head including the effect of magmatic lithospheric weakening. We used 3D numerical thermo-mechanical modeling. Using I3ELVIS code, which is based on finite difference staggered grid and marker-in-cell with an efficient OpenMP multigrid solver (Gerya, 2010), we show that plate motion may affect the plume-induced subduction initiation only if a moderate size plume head (with a radius of 140 km in our experiments) impinges on a young but subductable lithosphere (with the age of 20 Myr). Outcomes indicate that lithospheric strength and plume buoyancy are key parameters in penetration of the plume and subduction initiation and that plate speed has a minor effect. We propose that eastward motion of the Farallon plate in Late Cretaceous time could play a key role in forming new subduction zones along the western and southern margin of the Caribbean plate.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;Gerya, T., 2010,&amp;#160;Introduction to Numerical Geodynamic Modelling.. Cambridge University Press.&lt;/p&gt;&lt;p&gt;Gerya, T.V., Stern, R.J., Baes, M., Sobolev, S.V. and Whattam, S.A., 2015. Plume-induced subduction initiation triggered Plate Tectonics on Earth. Nature, 527, 221&amp;#8211;225.&lt;/p&gt;&lt;p&gt;Moore, W. B., Schubert, G. and Tackley, P., 1998, Three-dimensional simulations of plume-lithosphere interaction at the Hawaiian swell. Science, 279, 1008-1011.&lt;/p&gt;&lt;p&gt;Stern, R.J., and Dumitru, T.A., 2019, Eocene initiation of the Cascadia subduction zone: A second example of plume-induced subduction initiation? Geosphere, v. 15, 659-681.&lt;/p&gt;&lt;p&gt;Whattam, S.A. and Stern, R.J., 2014. Late Cretaceous plume-induced subduction initiation along the southern margin of the Caribbean and NW South America: The first documented example with implications for the onset of plate tectonics. Gondwana Research, 27, doi: 10.1016/j.gr.2014.07.011.&lt;/p&gt;

Gravity data collection with a CG5 gravitymeter for densification of the gravity data around the AUT1 IHRF station

2021 ◽  
Author(s):  
Dimitrios A. Natsiopoulos ◽  
Elisavet G. Mamagiannou ◽  
Eleftherios A. Pitenis ◽  
Georgios S. Vergos ◽  
Ilias N. Tziavos ◽  
...  
Keyword(s):  
Gravity Data ◽  
Gravity Anomalies ◽  
Absolute Gravity ◽  
Dual Frequency ◽  
Height Determination ◽  
Free Air ◽  
Gravity Measurements ◽  
Gravity Database ◽  
Free Air Gravity ◽  
Geological Complexity

&lt;p&gt;Within the GeoGravGOCE project, funded by the Hellenic Foundation for Research Innovation, a main goal has been the densification of the available land gravity database around the eastern part of the city of Thessaloniki, Greece, where the core International Height Reference Frame (IHRF) station AUT1 is located in order to improve regional geoid and potential determination. Hence it was deemed necessary to densify the available gravity data within radiuses of 10 km, 20 km, 50 km and 100 km from the AUT1 core IHRF site. In that frame, and given the geological complexity of the region surrounding Thessaloniki and the significant variations of the terrain, gravity campaigns were appropriately designed and gravity measurements were carried out in order to densify the database and cover as much as possible traverses of varying altitude. The measurements have been carried out with the CG5 gravity meter of the GravLab group and dual-frequency GNSS receivers in RTK mode for orthometric height determination. In this &amp;#160;study we provide details of the gravity campaigns, the measurement principle and the finally derived gravity and free-air gravity anomalies. The mean measurement accuracy achieved was at the ~20 &amp;#956;Gal level for the gravity measurements and ~3 cm for the orthometric heights. In all cases the final derived gravity value was based on the absolute point established by the GravLab team at the AUTH seismological station premises with the A10 (#027) absolute gravity meter.&lt;/p&gt;

scholarly journals Directly ageing the Caribbean spiny lobster, Panulirus argus with validated band counts from gastric mill ossicles

2018 ◽  
Vol 76 (2) ◽  
pp. 442-451 ◽  
Author(s):  
Gaya Gnanalingam ◽  
Mark J Butler ◽  
Thomas R Matthews ◽  
Emily Hutchinson ◽  
Raouf Kilada
Keyword(s):  
Spiny Lobster ◽  
Age Determination ◽  
Florida Keys ◽  
Panulirus Argus ◽  
Gastric Mill ◽  
Coefficients Of Variation ◽  
The Caribbean ◽  
First Time ◽  
Reader Experience

Abstract In crustaceans, ecdysis was long believed to result in the loss and replacement of all calcified structures, precluding the use of conventional ageing methods. However, the discovery of bands in the gastric ossicles of several crustaceans with some correlation with age suggests that direct age estimation may be possible. We applied this method to a tropical spiny lobster, Panulirus argus, one of the most iconic and economically valuable species in the Caribbean. The presence of growth bands was investigated using wild lobsters of unknown age and was validated with captive reared lobsters of known age (1.5–10 years) from the Florida Keys, Florida (USA). Bands were consistently identified in ptero- and zygo-cardiac ossicles of the gastric mill and did not appear to be associated with moulting. Validation with known age animals confirms that bands form annually. Counts between independent readers were reproducible with coefficients of variation ranging from 11% to 26% depending on reader experience and the structure used. This study demonstrates, for the first time, that direct age determination of P. argus is possible.

Structure, age, and origin of the Caribbean Plate unraveled

2021 ◽  
Vol 571 ◽  
pp. 117100
Author(s):  
Andreína García-Reyes ◽  
Jérôme Dyment
Keyword(s):  
Caribbean Plate ◽  
The Caribbean

The preserved plume conduits of the Caribbean Large Igneous Plateau and their relation with the Galápagos hotspot back to 90 Ma

2021 ◽  
Author(s):  
Angela Maria Gomez Garcia ◽  
Eline Le Breton ◽  
Magdalena Scheck-Wenderoth ◽  
Gaspar Monsalve ◽  
Denis Anikiev
Keyword(s):  
Reference Frames ◽  
Thermal Anomaly ◽  
Caribbean Region ◽  
Positive Density ◽  
South American ◽  
Kinematic Models ◽  
Tomographic Data ◽  
The Caribbean ◽  
Moho Depths ◽  
South American Continent

&lt;p&gt;Remnants of the Caribbean Large Igneous Plateau (C-LIP) are found as thickened zones of oceanic crust in the Caribbean Sea, that formed during strong pulses of magmatic activity around 90 Ma. Previous studies have proposed the Gal&amp;#225;pagos hotspot as the origin of the thermal anomaly responsible for the development of this igneous province. Particularly, geochemical signature relates accreted C-LIP fragments along northern South America with the well-known hotspot material.&lt;/p&gt;&lt;p&gt;In this research, we use 3D lithospheric-scale structural and density models of the Caribbean region, in which up-to-date geophysical datasets (i.e.: tomographic data, Moho depths, sedimentary thickness, and bathymetry) have been integrated. Based on the gravity residuals (modelled minus observed EIGEN6C-4 dataset), we reconstruct density heterogeneities both in the crust and the uppermost oceanic mantle (&lt; 50km).&lt;/p&gt;&lt;p&gt;Our results suggest the presence of two positive mantle density anomalies in the Colombian and the Venezuelan basins, interpreted as the preserved plume material which migrated together with the Proto-Caribbean plate from the east Pacific. Such bodies have never been identified before, but a positive density trend is also observed in the mantle tomography, at least down to 75 km depth.&lt;/p&gt;&lt;p&gt;Using recently published regional plate kinematic models and absolute reference frames, we test the hypothesis of the C-LIP origin in the Gal&amp;#225;pagos hotspot. However, misfits of up to ~3000 km between the present hotspot location and the mantle anomalies, reconstructed back to 90 Ma, is observed, as other authors reported in the past.&lt;/p&gt;&lt;p&gt;Therefore, we discuss possible sources of error responsible for this offset and pose two possible interpretations: 1. The Gal&amp;#225;pagos hotspot migrated (~1200-3000 km) westward while the Proto-Caribbean moved to the northeast, or 2. The C-LIP was formed by a different plume, which &amp;#8211; if considered fixed - would be nowadays located below the South American continent.&lt;/p&gt;

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