Leda Sánchez Bettucci | Universidad de la República (original) (raw)
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Papers by Leda Sánchez Bettucci
Precambrian research, Aug 1, 2024
Precambrian research, Aug 1, 2024
A compilation of available data about the geology of Uruguay allowed the definition of its main e... more A compilation of available data about the geology of Uruguay allowed the definition of its main events and tectonic units. Based on a critical revision of different tectonic hypothesis found in the literature, a parsimonious tectonic evolution schema is presented, in the context of Western Gondwana. The tectonic map illustrates the general features of the structure and main tectonic units
AGU Spring Meeting Abstracts, May 1, 2007
A paleomagnetic study was performed on three Neoproterozoic sedimentary successions exposed in Ur... more A paleomagnetic study was performed on three Neoproterozoic sedimentary successions exposed in Uruguay in order to better define the paleogeographic evolution of the Rio de la Plata craton prior to and during the assembly of Gondwana. These units comprise the latest Ediacaran to Early Cambrian calcareous Cerro Victoria Fm, the late Ediacaran clastic Yerbal Fm and the calcareous Polanco Fm
AGU Spring Meeting Abstracts, May 1, 2013
ABSTRACT The paleomagnetic studies in Uruguay have been applied as a complementary tool to geolog... more ABSTRACT The paleomagnetic studies in Uruguay have been applied as a complementary tool to geological studies. Paleomagnetic data can be very useful for geodynamic reconstructions, fundamentally for determine the latitudinal tectonic transport, rotations of crustal blocks. This technique has been applied to Paleoproterozoic, Neoproterozoic and Paleozoic units. The geology of the Uruguayan territory is divided into four tectonic units of Uruguay that include a) the Piedra Alta tectonostratigraphic terrane (PATT) and b) Nico Pérez tectonostratigraphic terrane (NPTT), separated by the Sarandí del Yí high-strain zone. Both terranes are well exposed in the Río de La Plata craton (RPC) and have paleoproterozoic ages, the last was reworked in Neoproterozoic times (metacraton). The most thoroughly investigated Neoproterozoic sections are located in the eastern and southeastern regions of Uruguay. The c) Dom Feliciano Belt shows a tectonic evolution from back-arc to foreland basin characterized by fold-and-thrust, thick-skinned belts developed during the Brasiliano/Pan-African orogenic cycle. And finally d) The high metamorphic grade Punta del Este terrane where its most notable feature is their African affinity. There is a significant shortage of geochemical and geochronological data for the existing geological complexity.
Journal of South American Earth Sciences
EGU General Assembly Conference Abstracts, Apr 1, 2016
In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of d... more In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of developing the Geosciences. The Astronomical and Geophysical Observatory Aiguá (OAGA) is located within the Cerro Catedral Tourist Farm (-34 ° 20 ’0 .89 ‘S/-54 ° 42 ’44.72′ W, h: 270m). This has the distinction of being located in the center of the South Atlantic Magnetic Anomaly. Geologically is emplaced in a Neoproterozoic basement, in a region with scarce anthropogenic interference. The OAGA has, since 2012, with a GSM-90FD dIdD v7.0 and GSM-90F Overhauser, both of GEM Systems. In addition has a super-SID receiver provided by the Stanford University SOLAR Center, as a complement for educational purposes. Likewise the installation of a seismograph REF TEK-151-120A and VLF antenna is being done since the beginning of 2013.
Preliminary results on the magnetostratigraphy of three Neogene formations from SW Uruguay are pr... more Preliminary results on the magnetostratigraphy of three Neogene formations from SW Uruguay are presented: Camacho, Raigón and Libertad, and a relative age from the record of reversions in the Earth's magnetic field polarity is proposed. The sediments outcrop in the SW region of Uruguay,and have been received attention due to their fossil contents. The oldest is the late Miocene-Pliocene Camacho
Earth, Planets and Space, 2006
We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks... more We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0 ± 1.9 to 25.4 ± 2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7×1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Córdoba lavas agree remarkably well with those obtained from the Paraná Magmatic Province (133–132 Ma). This reinforces the hypothesis a...
Journal of Geophysical Research: Solid Earth, 2019
The Tunguska event was an explosion of a bolide that occurred in the Russian Siberia on June 30, ... more The Tunguska event was an explosion of a bolide that occurred in the Russian Siberia on June 30, 1908. This phenomenon generated diverse hypothesis related to its origin. No crater was formed in the epicenter and obtained particles are scarce and of great uncertainty. Almost one hundred years after, Italian scientists suggest that the Cheko Lake, located five kilometers from the epicenter, may correspond to the crater produced by the bolide.
Precambrian research, Aug 1, 2024
Precambrian research, Aug 1, 2024
A compilation of available data about the geology of Uruguay allowed the definition of its main e... more A compilation of available data about the geology of Uruguay allowed the definition of its main events and tectonic units. Based on a critical revision of different tectonic hypothesis found in the literature, a parsimonious tectonic evolution schema is presented, in the context of Western Gondwana. The tectonic map illustrates the general features of the structure and main tectonic units
AGU Spring Meeting Abstracts, May 1, 2007
A paleomagnetic study was performed on three Neoproterozoic sedimentary successions exposed in Ur... more A paleomagnetic study was performed on three Neoproterozoic sedimentary successions exposed in Uruguay in order to better define the paleogeographic evolution of the Rio de la Plata craton prior to and during the assembly of Gondwana. These units comprise the latest Ediacaran to Early Cambrian calcareous Cerro Victoria Fm, the late Ediacaran clastic Yerbal Fm and the calcareous Polanco Fm
AGU Spring Meeting Abstracts, May 1, 2013
ABSTRACT The paleomagnetic studies in Uruguay have been applied as a complementary tool to geolog... more ABSTRACT The paleomagnetic studies in Uruguay have been applied as a complementary tool to geological studies. Paleomagnetic data can be very useful for geodynamic reconstructions, fundamentally for determine the latitudinal tectonic transport, rotations of crustal blocks. This technique has been applied to Paleoproterozoic, Neoproterozoic and Paleozoic units. The geology of the Uruguayan territory is divided into four tectonic units of Uruguay that include a) the Piedra Alta tectonostratigraphic terrane (PATT) and b) Nico Pérez tectonostratigraphic terrane (NPTT), separated by the Sarandí del Yí high-strain zone. Both terranes are well exposed in the Río de La Plata craton (RPC) and have paleoproterozoic ages, the last was reworked in Neoproterozoic times (metacraton). The most thoroughly investigated Neoproterozoic sections are located in the eastern and southeastern regions of Uruguay. The c) Dom Feliciano Belt shows a tectonic evolution from back-arc to foreland basin characterized by fold-and-thrust, thick-skinned belts developed during the Brasiliano/Pan-African orogenic cycle. And finally d) The high metamorphic grade Punta del Este terrane where its most notable feature is their African affinity. There is a significant shortage of geochemical and geochronological data for the existing geological complexity.
Journal of South American Earth Sciences
EGU General Assembly Conference Abstracts, Apr 1, 2016
In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of d... more In 2011 began the installation of the first geophysical observatory in Uruguay, with the aim of developing the Geosciences. The Astronomical and Geophysical Observatory Aiguá (OAGA) is located within the Cerro Catedral Tourist Farm (-34 ° 20 ’0 .89 ‘S/-54 ° 42 ’44.72′ W, h: 270m). This has the distinction of being located in the center of the South Atlantic Magnetic Anomaly. Geologically is emplaced in a Neoproterozoic basement, in a region with scarce anthropogenic interference. The OAGA has, since 2012, with a GSM-90FD dIdD v7.0 and GSM-90F Overhauser, both of GEM Systems. In addition has a super-SID receiver provided by the Stanford University SOLAR Center, as a complement for educational purposes. Likewise the installation of a seismograph REF TEK-151-120A and VLF antenna is being done since the beginning of 2013.
Preliminary results on the magnetostratigraphy of three Neogene formations from SW Uruguay are pr... more Preliminary results on the magnetostratigraphy of three Neogene formations from SW Uruguay are presented: Camacho, Raigón and Libertad, and a relative age from the record of reversions in the Earth's magnetic field polarity is proposed. The sediments outcrop in the SW region of Uruguay,and have been received attention due to their fossil contents. The oldest is the late Miocene-Pliocene Camacho
Earth, Planets and Space, 2006
We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks... more We present here new paleointensity and geochronology results from Early Cretaceous volcanic rocks of Sierra Chica de Cordoba (Argentina). The new K-Ar isotopic ages of 5 samples range from 136 to 122 Ma. Twenty five samples from 7 individual flows yielded acceptable paleointensity estimates. The mean paleointensity values per flow are ranging from 53.0 ± 1.9 to 25.4 ± 2.6 μT and the corresponding Virtual Dipole Moments (VDMs) are ranging from 9.3±1.3 to 4.6±0.5 (1022 Am2). This corresponds to the mean value of 7.3±1.7×1022 Am2, which is compatible to the present geomagnetic axial dipole. Currently available selected paleointensity data from 80 to 130 Ma suggest that geomagnetic field strength frequently fluctuated before and during the Cretaceous Normal Superchron while the magnetic polarity maintained stable. The mean paleointensities derived from Córdoba lavas agree remarkably well with those obtained from the Paraná Magmatic Province (133–132 Ma). This reinforces the hypothesis a...
Journal of Geophysical Research: Solid Earth, 2019
The Tunguska event was an explosion of a bolide that occurred in the Russian Siberia on June 30, ... more The Tunguska event was an explosion of a bolide that occurred in the Russian Siberia on June 30, 1908. This phenomenon generated diverse hypothesis related to its origin. No crater was formed in the epicenter and obtained particles are scarce and of great uncertainty. Almost one hundred years after, Italian scientists suggest that the Cheko Lake, located five kilometers from the epicenter, may correspond to the crater produced by the bolide.