Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
The aim of the present work is to demonstrate the preliminary results of the study of the arsenic... more The aim of the present work is to demonstrate the preliminary results of the study of the arsenic concentrations in the sediments of the Claromecó river basin. A variation of As content related to lithogenic factors is presented in the study: the Miocene-Pliocene fluvial facies have a reduced arsenic concentration (∿2.6 mg/kg) compared with the Late Pleistocene fluvial facies (∿11.6 mg/kg). These differences are probably attributed to a major hydraulic gradient during the Pliocene, which is reflected in grain size and in fluvial structures that probably washed out the sediments. Volcanic glass shards probably represent one of the main arsenic sources, especially in the fine silt grain size. On the other hand, different paleosols show different As concentrations due to the presence of amorphous Fe-Mn oxides-hydroxides. Topography is controlling the As concentrations as shown by the increasing of this element in sediments and groundwater in the downgradient of the basin.
Central Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents ... more Central Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. Combined with previous research focused on coastal sediments, this actualistic provenance study uses framework petrography and heavy‐mineral data to trace multistep dispersal of volcaniclastic detritus first eastwards across central Argentina for up to ca. 1,500 km and next northwards for another 760 km along the Atlantic coast. Although detritus generated in the Andes is largely derived from mesosilicic volcanic rocks of the cordillera, its compositional signatures reflect different tectono‐stratigraphic levels of the orogen uplifted along strike in response to varying subduction geometry as well as different character and crystallization condition of arc magmas through time and space. River sand, thus, changes from feldspatho‐litho‐quartzose or litho‐feldspatho‐quartzose in the north, where sedimentary detritus is more common, to mostly quartzo‐feldspatho‐lithic in the centre and to feldspatho‐lithic in the south, where volcanic detritus is dominant. The transparent‐heavy‐mineral suite changes markedly from amphibole ≫ clinopyroxene > orthopyroxene in the north, to amphibole ≈ clinopyroxene ≈ orthopyroxene in the centre and to orthopyroxene ≥ clinopyroxene ≫ amphibole in the south. In the presently dry climate, fluvial discharge is drastically reduced to the point that even the Desaguadero trunk river has become endorheic and orogenic detritus is dumped in the retroarc basin, reworked by winds and temporarily accumulated in dune fields. During the Quaternary, instead, much larger amounts of water were released by melting of the Cordilleran ice sheet or during pluvial events. The sediment‐laden waters of the Desaguadero and Colorado rivers then rushed from the tract of the Andes with greatest topographic and structural elevation, fostering alluvial fans inland and flowing in much larger valleys than today towards the Atlantic Ocean. Sand and gravel supply to the coast was high enough not only to promote rapid progradation of large deltaic lobes but also to feed a cell of littoral sediment transport extending as far north as the Río de la Plata estuary.
El propósito de esta tesis doctoral es analizar el contenido de arsénico (As) en los depósitos de... more El propósito de esta tesis doctoral es analizar el contenido de arsénico (As) en los depósitos del Cenozoico tardío de la llanura pampeana y establecer los controles litogénicos que derivan en altas concentraciones de As en las aguas subterráneas. Para este fin, se plantearon objetivos específicos dirigidos a identificar los principales minerales de As, óxidos e hidróxidos de Fe autígenos, amorfos o cristalinos en los sedimentos, suelos y paleosuelos; incrementar el conocimiento de la variabilidad del As en relación con los procesos depositacionales y postdepositacionales; y contribuir al conocimiento de los factores que controlan los procesos geoquímicos e hidroquímicos y que determinan altas concentraciones de As en las aguas subterráneas. De acuerdo con los objetivos propuestos, se realizó un estudio a partir de una aproximación de escala de análisis jerárquico (llanura pampeana, cuenca de drenaje, perfil geológico, grano-partícula) que responden a diferentes factores de control....
Large sediment masses are transferred over many hundreds of kilometres along the coast of passive... more Large sediment masses are transferred over many hundreds of kilometres along the coast of passive continental margins worldwide. The relevance of such a phenomenon for source‐to‐sink studies, environmental issues, and coastal management remains largely unperceived. This study traces the paths of volcaniclastic sand along ca 2170 km of the Argentine coast and documents a 760 km long cell of littoral transport extending from the formerly larger Río Colorado delta to the edge of the Río de la Plata mouth. During deglaciation stages and humid periods of the Pleistocene, a much greater sediment volume than today was transferred by the Desaguadero and Colorado rivers from the highest‐relief tract of the Andean Cordillera to the Atlantic Ocean. Amphibole‐rich sand originally supplied by the Río Desaguadero is being recycled today from Pampean lowlands to feed the beaches along Río de la Plata southern shores, whereas pure quartzose sand of Río Paraná is found only adjacent to its prograding delta. Augite‐rich sand supplied by the Río Colorado is dominant along the coast of the Buenos Aires Province, where it mixes locally with coarser‐grained quartz‐rich detritus recycled in the urbanized Mar del Plata area. Hypersthene‐rich sand of the Río Negro is dispersed both north and south of the mouth, where heavy‐mineral‐rich lag deposits are formed in areas of accelerated erosion and retreating sea cliffs. Changes of mineralogical signatures during long‐distance littoral transport are largely ascribed to local supply from coastal erosion or hydrodynamic effects rather than to selective breakdown of labile grains. Whereas the relative abundance of amphibole and pyroxene is largely independent of transport distance, olivine is depleted both in the northern part of the Colorado littoral cell and south of the Río Negro mouth, which is chiefly ascribed to dilution by recycling of Neogene sediments that have undergone early intrastratal dissolution rather than to mechanical loss.
Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
Latin American journal of sedimentology and basin analysis, 2017
The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province ha... more The Neogene to Quaternary continental sedimentary record of the southern Buenos Aires province has been the object of numerous stratigraphic and biostratigraphic studies. However, much has to be done concerning the evolution and sedimentary dynamics of this area. To this end, the Claromeco creek basin (CCB) was chosen as a case study. The aim of this work is to analyze the Neogene to Quaternary sedimentary record to understand the geological evolution of the basin. To reach this objective, a preliminary geomorphological study was carried out. Then, facies and facies associations were defined in order to identify the sedimentary environment and to establish the ratio between accommodation space and sediment supply. This information was subsequently used to interpret the main controls on the sedimentation of the CCB. The CCB is located in the center of the southern Buenos Aires province. It covers an area of 3017.18 km 2 , from the northwestern flank of the Tandilia range to the Atlan...
The aim of the present work is to demonstrate the preliminary results of the study of the arsenic... more The aim of the present work is to demonstrate the preliminary results of the study of the arsenic concentrations in the sediments of the Claromecó river basin. A variation of As content related to lithogenic factors is presented in the study: the Miocene-Pliocene fluvial facies have a reduced arsenic concentration (∿2.6 mg/kg) compared with the Late Pleistocene fluvial facies (∿11.6 mg/kg). These differences are probably attributed to a major hydraulic gradient during the Pliocene, which is reflected in grain size and in fluvial structures that probably washed out the sediments. Volcanic glass shards probably represent one of the main arsenic sources, especially in the fine silt grain size. On the other hand, different paleosols show different As concentrations due to the presence of amorphous Fe-Mn oxides-hydroxides. Topography is controlling the As concentrations as shown by the increasing of this element in sediments and groundwater in the downgradient of the basin.
Central Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents ... more Central Argentina from the Pampean flat‐slab segment to northern Patagonia (27°–41°S) represents a classic example of a broken retroarc basin with strong tectonic and climatic control on fluvial sediment transport. Combined with previous research focused on coastal sediments, this actualistic provenance study uses framework petrography and heavy‐mineral data to trace multistep dispersal of volcaniclastic detritus first eastwards across central Argentina for up to ca. 1,500 km and next northwards for another 760 km along the Atlantic coast. Although detritus generated in the Andes is largely derived from mesosilicic volcanic rocks of the cordillera, its compositional signatures reflect different tectono‐stratigraphic levels of the orogen uplifted along strike in response to varying subduction geometry as well as different character and crystallization condition of arc magmas through time and space. River sand, thus, changes from feldspatho‐litho‐quartzose or litho‐feldspatho‐quartzose in the north, where sedimentary detritus is more common, to mostly quartzo‐feldspatho‐lithic in the centre and to feldspatho‐lithic in the south, where volcanic detritus is dominant. The transparent‐heavy‐mineral suite changes markedly from amphibole ≫ clinopyroxene > orthopyroxene in the north, to amphibole ≈ clinopyroxene ≈ orthopyroxene in the centre and to orthopyroxene ≥ clinopyroxene ≫ amphibole in the south. In the presently dry climate, fluvial discharge is drastically reduced to the point that even the Desaguadero trunk river has become endorheic and orogenic detritus is dumped in the retroarc basin, reworked by winds and temporarily accumulated in dune fields. During the Quaternary, instead, much larger amounts of water were released by melting of the Cordilleran ice sheet or during pluvial events. The sediment‐laden waters of the Desaguadero and Colorado rivers then rushed from the tract of the Andes with greatest topographic and structural elevation, fostering alluvial fans inland and flowing in much larger valleys than today towards the Atlantic Ocean. Sand and gravel supply to the coast was high enough not only to promote rapid progradation of large deltaic lobes but also to feed a cell of littoral sediment transport extending as far north as the Río de la Plata estuary.
El propósito de esta tesis doctoral es analizar el contenido de arsénico (As) en los depósitos de... more El propósito de esta tesis doctoral es analizar el contenido de arsénico (As) en los depósitos del Cenozoico tardío de la llanura pampeana y establecer los controles litogénicos que derivan en altas concentraciones de As en las aguas subterráneas. Para este fin, se plantearon objetivos específicos dirigidos a identificar los principales minerales de As, óxidos e hidróxidos de Fe autígenos, amorfos o cristalinos en los sedimentos, suelos y paleosuelos; incrementar el conocimiento de la variabilidad del As en relación con los procesos depositacionales y postdepositacionales; y contribuir al conocimiento de los factores que controlan los procesos geoquímicos e hidroquímicos y que determinan altas concentraciones de As en las aguas subterráneas. De acuerdo con los objetivos propuestos, se realizó un estudio a partir de una aproximación de escala de análisis jerárquico (llanura pampeana, cuenca de drenaje, perfil geológico, grano-partícula) que responden a diferentes factores de control....
Large sediment masses are transferred over many hundreds of kilometres along the coast of passive... more Large sediment masses are transferred over many hundreds of kilometres along the coast of passive continental margins worldwide. The relevance of such a phenomenon for source‐to‐sink studies, environmental issues, and coastal management remains largely unperceived. This study traces the paths of volcaniclastic sand along ca 2170 km of the Argentine coast and documents a 760 km long cell of littoral transport extending from the formerly larger Río Colorado delta to the edge of the Río de la Plata mouth. During deglaciation stages and humid periods of the Pleistocene, a much greater sediment volume than today was transferred by the Desaguadero and Colorado rivers from the highest‐relief tract of the Andean Cordillera to the Atlantic Ocean. Amphibole‐rich sand originally supplied by the Río Desaguadero is being recycled today from Pampean lowlands to feed the beaches along Río de la Plata southern shores, whereas pure quartzose sand of Río Paraná is found only adjacent to its prograding delta. Augite‐rich sand supplied by the Río Colorado is dominant along the coast of the Buenos Aires Province, where it mixes locally with coarser‐grained quartz‐rich detritus recycled in the urbanized Mar del Plata area. Hypersthene‐rich sand of the Río Negro is dispersed both north and south of the mouth, where heavy‐mineral‐rich lag deposits are formed in areas of accelerated erosion and retreating sea cliffs. Changes of mineralogical signatures during long‐distance littoral transport are largely ascribed to local supply from coastal erosion or hydrodynamic effects rather than to selective breakdown of labile grains. Whereas the relative abundance of amphibole and pyroxene is largely independent of transport distance, olivine is depleted both in the northern part of the Colorado littoral cell and south of the Río Negro mouth, which is chiefly ascribed to dilution by recycling of Neogene sediments that have undergone early intrastratal dissolution rather than to mechanical loss.
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