Papers by María Sol Raigemborn
PALAIOS, Jul 1, 2015
ABSTRACT
International Journal of Earth Sciences
Palaeogeography, Palaeoclimatology, Palaeoecology
Geosciences, 2021
The Cenomanian Mata Amarilla Formation (MAF) in southern Patagonia (~55° S paleolatitude, Austral... more The Cenomanian Mata Amarilla Formation (MAF) in southern Patagonia (~55° S paleolatitude, Austral-Magallanes Basin, Argentina) is composed mainly of stacked fluvial deposits with intercalated paleosols, which document Cenomanian environments at high-paleolatitudes in the Southern Hemisphere. We performed a multiproxy study of the paleosols and sediments of the MAF in order to (1) understand the composition of the soil- and sediment-derived organic matter (OM), (2) apply carbon isotope stratigraphy as a tool to correlate patterns obtained from the MAF with existing marine and non-marine δ13Corg records worldwide, and (3) investigate the relationship between variations in spore-pollen assemblages of the MAF and the climatic conditions prevailing in the Cenomanian Southern Hemisphere. An integrated dataset was generated, including total organic carbon content, Rock-Eval pyrolysis data, stable isotope (δ13Corg) composition, and palynological data, combined with published paleosol-derive...
Journal of South American Earth Sciences, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of South American Earth Sciences, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Ameghiniana, 2018
Jaw musculature and biomechanical analysis suggest high bite force and scavenger feeding habits f... more Jaw musculature and biomechanical analysis suggest high bite force and scavenger feeding habits for ornithosuchids. Cupressaceae and Podocarpaceae in a diverse assemblage of conifers and bennettitales from the Early Cretaceous of India.
Journal of South American Earth Sciences, 2018
The middle Eocene Koluel-Kaike Formation, located in the San Jorge Basin, Patagonia, Argentina, i... more The middle Eocene Koluel-Kaike Formation, located in the San Jorge Basin, Patagonia, Argentina, is a strongly pedogenically modified succession associated with volcaniclastic input in an aggrading distal eolian-dominated fluvial system, located ∼400 km downwind of the Eocene Andean volcanic arc. The coordinated study of sediments and paleosols of this unit allows (1) reconstruction of environmental conditions and landscape evolution, and (2) determination of the interplay of the main forcing factors in the evolution of the Kokuel-Kaike Formation. The landscape reconstruction attests to the existence of a loessic rolling plain drained by a subordinate fluvial system, composed of both unconfined and confined flows, with locally ponded areas. Over these, thick stacked cumulative paleo-Ultisols and vertic paleo-Ultisols developed with scarce simple and stacked compound vitric Entisols analogues and compound Inceptisols equivalents. This high-resolution sedimentological-pedological analysis of the Kokuel-Kaike Formation indicates that the interplay between episodic volcaniclastic supply and cyclic climate controlled landscape evolution and soil development.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
The Lower Miocene Santa Cruz Formation in southern Patagonia (Austral Basin, Argentina) contains ... more The Lower Miocene Santa Cruz Formation in southern Patagonia (Austral Basin, Argentina) contains several horizons of pedogenic calcretes, which record −17.5 myr old vegetation adapted to a shallow and fluctuating water table at paleolatitude of 56°S. To reconstruct the paleoenvironment, paleoclimate and paleoecosystem, we performed a multiproxy study of the calcretes examining abiotic and biotic components. The calcretes exhibit a variety of morphologies (horizontal and vertical rhizoliths, laminar structure, nodules, massive crusts), microfabrics (Beta-predominant over Alpha-microfabrics), and δ 18 O and δ 13 C values that fluctuate within each morphotype and throughout the analysed interval. Microfossils and phytoliths in the host material of the calcretes indicate fluctuating terrestrial, freshwater, and marine conditions, and record an ecosystem dominated by herbaceous plants and arboreal elements in association with a typical coastal "Santacrucian" vertebrate fauna. We propose that the calcretes developed in soils in a coastal/fluvial setting during pauses in floodplain aggradation that typically lasted between 8-25 ka and 400 ka years. Variable sedimentation rates in different parts of the coastal/fluvial floodplain, the fine texture of the host sediment, and the influence of a fluctuating water table also influenced the formation of the calcrete. A high water table in low relief areas of the floodplain created the conditions necessary to form a horizontally extended rhizolithic system that, jointly with the biotic proxy, can be correlated with a radicular pattern similar to the arboreal elements from coastal settings. Abiotic and biotic proxies of the studied interval attest to environmental fluctuations recorded at different scales that took place under temperate warm and subhumid climates with a marked rainfall seasonality, with a slight increase in the aridity towards the top of the studied interval. Under these conditions a subtropical fauna and a C 3-dominated ecosystem developed coincident with the onset of the Mid-Miocene Climatic Optimum in Patagonia.
Sedimentary Geology, 2018
Although there is general consensus that a global greenhouse climate characterized the mid-Cretac... more Although there is general consensus that a global greenhouse climate characterized the mid-Cretaceous, details of the climate state of the mid-Cretaceous Southern Hemisphere are less clearly understood. In particular, continental paleoclimate reconstructions are scarce and exclusively derived from paleontological records. Using paleosol-derived climofunction studies of the mid-to Upper Cretaceous Mata Amarilla Formation, southern Patagonia, Argentina, we present a reconstruction of the mid-Cretaceous climate of southern South America. Our results indicate that at ~60º south paleolatitude during the Cenomanian-Santonian stages, the climate was subtropical temperate-warm (12ºC ± 2.1ºC) and humid (1404 ± 108 mm/yr) with marked rainfall seasonality. These results are consistent with both previous estimations from the fossil floras of the Mata Amarilla Formation and other units of the Southern Hemisphere, and with the previous observations of the displacement of tropical and subtropical floras towards the poles in both hemispheres. The data presented here show a more marked seasonality and slightly lower mean annual precipitation and mean annual temperature values than those recorded at the same paleolatitudes in the Northern Hemisphere.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2016
Numerous isolated fossil bee cells and other trace fossils are documented from the Santa Cruz For... more Numerous isolated fossil bee cells and other trace fossils are documented from the Santa Cruz Formation (Santa Cruz, Argentina). The trace fossils are described from paleosols of 7 coastal localities. The paleosols are composed of massive to laminated claystone to siltsone or massive to diffuse laminated very fine tuff and reworked tuff. They are poorly developed but include rich trace fossils and root traces assemblages. The isolated bee cells (n=47) are barrel to oval shaped, with one end rounded to flattened and the other flattened. They lack discrete walls and antechambers but have a smooth lining. They are ascribed to Celliforma rosellii (n=28) and to a new ichnospecie, Celliforma argentina (n=19). The new ichnospecies differs from C. rosellii on the shape of the inferior end of the chamber, been the first rounded to flattened and the C. rosellii rounded to pointed, resulting in a final barrel shape in C. argentina and an oval shape in C. rosellii. C. rosellii has an average length and width of 17 mm and 9.8 mm. C. argentina average length and width are 9.2 and 5.1 mm. In some specimens of C. rosellii below the basal mark in the cell, the infill has a strong organic component that has been identified under SEM. This could indicate the exceptional preservation of the fluid deposited by the adult bee for the nutrition of the larva. The trace fossils assemblage shows moderate diversity and abundance. The ichnoassemblage recorded consist in Celliforma rosellii, Celliforma argentina, Palaeophycus tubularis, Planolites beverleyensis, Feoichnus challa, Fictovichnus gobiensis, Taenidium barretti and a variety of root traces. These trace fossils are considered to be part of a Celliforma ichnofacies but with a scarce presence of calcareous components. Considering pedogenic features, compositional aspects and
Se dan a conocer las interpretaciones paleoclimáticas, basadas sobre la estimación de valores de ... more Se dan a conocer las interpretaciones paleoclimáticas, basadas sobre la estimación de valores de precipitación media anual (PMA) y temperatura media anual (TMA) a partir del uso de relaciones moleculares Alúmina/Bases y Bario/ Estroncio y de índices de alteración CIA-K y S en doce pedotipos del Grupo Río Chico, Cuenca San Jorge, Patagonia, Argentina. Los pedotipos de la Formación Las Violetas, Sortem (Ustalf) y Makokattem (Ustept), se desarrollaron bajo un clima húmedo, con PMA ~1000mm y temperatura cálida, con valores de TMA ~12°C-13°C. En el tope de la Formación Peñas Coloradas los pedotipos Colicurá (Udults), Keyoit (Plinthaquult) y Yatenteh (Aquult) sugieren valores de TMA de 15°C-16°C y PMA de ~1200mm-1500mm, indicando climas húmedos y cálidos. Los pedotipos de la Formación Las Flores, Arunkmakotem (Entisol) y Chaishkatch (Ustept) se habrían formado en climas subhúmedos, con PMA de 600mm- 700mm y TMA de 7°C-8°C. En la sección inferior de la Formación Koluel-Kaike los pedotipos Chornk (Fragiaquult) y Kápenk (Plinthaquult) sugieren PMA de 1200mm-1300mm. Los pedotipos Ornek (Vitrand) y Pólnek (Placaquand) de las secciones media y superior, indican condiciones algo más secas, pero aún bajo un clima general húmedo, con una PMA de alrededor de 1000mm. El pedotipo Soorsh (Argialboll), en el tope de la unidad, sugiere un clima subhúmedo a semiárido, caracterizado por un rango de PMA de 600mm-700mm. La paleotemperatura en la Formación Koluel-Kaike muestra una TMA uniforme de 15°C en su sección inferior-media y valores de TMA entre 12 °C y 10°C en su sección media-superior. La tendencia paleoclimática inferida en la unidad muestra una íntima relación con la curva global de valores isotópicos de oxígeno en foraminíferos. Existe un probable vínculo entre los paleo-Ultisoles de la sección superior de la Formación Peñas Coloradas con el Máximo Térmico del Paleoceno-Eoceno y aquellos de la Formación Koluel-Kaike con el Óptimo Climático del Eoceno inferior.Simposio II: El Paleógeno de América del Sur y CentralFacultad de Ciencias Naturales y Muse
Palaeogeography, Palaeoclimatology, Palaeoecology, 2021
Abstract Although interactions between eolian and fluvial systems are well documented in both mod... more Abstract Although interactions between eolian and fluvial systems are well documented in both modern and ancient environments, there are few studies of such deposits that also address the paleosols that developed within them. The Cenomanian Candeleros and Huincul formations of the Neuquen Basin, Northern Patagonia, Argentina, provides an excellent opportunity to do so. These formations preserve mixed fluvial-eolian and fluvial systems, respectively, with associated pedogenesis. We identify five lithofacies associations (fluvial channel deposits [FA1], deposits of unconfined fluvial flows [FA2], floodplain deposits [FA3], eolian-dune deposits [FA4], and wet interdune deposits [FA5]), and five pedotypes (calcic Protosols [P1], Vertisols [P2], vertic and gleyed Protosols [P3a and P3b, respectively], vertic Calcisols [P4], and argillic Protosols [P5]). The lower Candeleros Formation is characterized by eolian dune deposits with calcic Protosols and wet interdune deposits with Vertisols and vertic and gleyed Protosols. The middle part of the formation is dominated by deposits of unconfined fluvial flows with vertic Protosols and, in the upper part of the unit, there are channel deposits with vertic Calcisols. The Huincul Formation is characterized by fluvial deposits with argillic Protosols. Changes in paleosol development have been recorded throughout the two formations. Small-scale changes, recognized in the lower Candeleros Formation, comprise a chrono-toposequence, in which calcic Protosols, Vertisols, vertic and gleyed Protosols are genetically associated with FA4 and FA5. Calcic Protosols developed on the dunes and gleyed Protosols in the inner part of the interdunes subjected to temporal waterlogging. When the dunes were vegetated and pedogenesis promoted dune fixation, the rate of dune mobility was slow and the ancient soils developed into Vertisols. In turn, the absence of vegetation was linked to a relatively high rate of dune migration, the time of soil development was limited, and, as a result, vertic Protosols were preserved. The analysis of soil-forming factors as large-scale controlling factors showed that throughout the succession, variations on the type of paleosol and the sedimentary environment over time were controlled by changes in ancient climate. Mid-Cretaceous global climate reconstructions suggest that the paleosols developed in northern Patagonia were located near the limit between the Southern Mid-latitude Warm Humid Belt and the Southern Hot Arid Belt. Seasonally arid and semi-arid conditions prevailed in this area, although there was a temporal trend towards a temperate subhumid climate.
Latin American journal of sedimentology and basin analysis, 2019
The middle and upper parts of the lower Miocene Santa Cruz Formation (~17–15.9 Ma) in the southea... more The middle and upper parts of the lower Miocene Santa Cruz Formation (~17–15.9 Ma) in the southeastern Austral-Magallanes Basin (southern Patagonia, Argentina) crop out as a fluvial succession that in parts is pedogenically modified. The study of the paleosols of this unit combined with the study of ichnofossils, microremains, and fossil vertebrates present in these allows us to reconstruct past environmental, ecological, and climatic conditions, as well as paleolandscape evolution of the Santa Cruz Formation during ~1 my. These reconstructions demonstrate three different stages during which very weak to moderate pedogenesis took place. The first one (middle part of the unit) is an epiclastic distal floodplain bearing Calcisols or paleo-calcic Inceptisols, which record a relatively dense vegetation integrating trees, shrubs, palms, and short grasses. Soil fauna is scarce and it is in association with a vertebrate fauna typical of coastal “Santacrucian assemblages”. The second landsc...
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Papers by María Sol Raigemborn
important fluvial cycle was developed, whose sediments
have been called the Rio Chico Group. This Group consists
of three formations: Peñas Coloradas, Las Flores and Koluél
Kaike. The sedimentary samples analyzed in this study come
from Lake Colhué Huapi in the Gran Barranca area (45° 43’
26’’ S and 68° 37’ 14’’ W). Two phytolith zones were
identified in core samples from Upper Paleocene-Eocene?
sediments, with phytolith assemblages characterized by an
abundance of dicotyledons phytoliths and palm phytoliths, in
association with Poaceae, Cyperaceae and Podostemaceae
phytoliths. Siliceous sponge spicules, Chrysostomataceae
stomatocycts and diatoms also occured in these assemblages.
Nine plant families and one order were recognized:
Arecaceae, Chrysobalanaceae, Mimosaceae, Magnoliaceae,
Annonaceae, Burseraceae, Zingiberales, Poaceae,
Cyperaceae y Podostemaceae. The two phytolith zones
reflect palaeovegetation patterns consisting of humid tropical
and subtropical forests, with one dominated by woody
dicotyledoneous taxa and the other by palms, and which were
developed under warm and humid climatic conditions. These
interpretations of past climatic conditions are supported by
other lines of evidence, including the nature of the sediments
in the sequences studied and wood identification data.
Key words: Phytoliths, Las Flores Formation, Upper
Paleocene-Eocene?, Arboreal paleocomunities, Chubut,
Argentina