3D Process-Oriented Gravity Modelling applied north of 49°S on the Argentine continental margin

Authors
Pedraza de Marchi, Ana Carolina; Ghidella de Hurtis, Marta Elba; Tocho, Claudia
Publication Year
2018
Language
English
Format
article
Status
Published version
Description
The Process-Oriented Gravity Modelling (POGM) technique represents a useful way to distinguish the contribution that different geological processes make to the observed gravity in passive margins. The POGM is an innovative gravity modelling approach that can give us information about the role that processes such as sedimentation and magmatic underplating, together with their loading effects, may play in the evolution of a margin. In this work, the POGM methodology has been applied with in a 2D and 3D approach. 2D profiles spaced every one arc-minute in the area of the Argentine continental margin, between 38.5°S and 49°S latitude and 64°W and 50°W longitude, were used to generate the latter. The 3D POGM was also solved and the result was compared with that obtained from 2D profiles. The comparison with the observed anomaly, using the 3D approach from 2D profiles gave results with enhanced resolution. The best fit between the calculated and observed gravity anomaly is given by an effective elastic thickness of 15 km. A cortical thickness map obtained as a result of the POGM calculations shows basin areas characterized by a thinned crust and a structural variation where the continental-oceanic boundary (COB) could be indicated. Besides, results of POGM allow us to detect an alignment between the Valdés and Rawson basins and possibly a third basin as a probable aulacogen. A stretching factor analysis shows that in these basins a stretching period existed but it did not reach the stage of oceanic crust formation. A strong positive residue in the Colorado basin is shown by the flexural isostatic anomaly, suggesting that the basin may continue in subsidence.
Fil: Pedraza de Marchi, Ana Carolina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Ghidella de Hurtis, Marta Elba. Ministerio de Relaciones Exteriores, Comercio Interno y Culto. Dirección Nacional del Antártico. Instituto Antártico Argentino; Argentina
Fil: Tocho, Claudia. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina
Subject
PROCESSES-ORIENTED GRAVITY MODELLING (POGM)
CONTINENTAL-OCEANIC BOUNDARY (COB)
FLEXURAL ISOSTATIC ANOMALY
ELASTIC THICKNESS
Otras Ciencias de la Tierra y relacionadas con el Medio Ambiente
Ciencias de la Tierra y relacionadas con el Medio Ambiente
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-nd/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/49703