We present a series of 12 OSL/IRSL dates that revise and complete the chronology of the important Middle (MSA) and Later Stone Age (LSA) site Umbeli Belli in KwaZulu-Natal, South Africa. These dates shift the previous radiometric ages thousands of years older than earlier measurements and play a key role in revising the cultural stratigraphy of KwaZulu-Natal. We also discuss how these dates bring the chrono- and cultural stratigraphy of southern Africa into clearer focus. The Robberg sequence of Umbeli Belli is now firmly dated to 21 ± 2 ka, whereas the preceding Early LSA assemblage dates to ~32 ka, representing one of the earliest dates for this cultural expression in the broader region. The final MSA assemblages from Layer 7 to 9 now date to between 35 ka and 40 ka, overlapping more tightly with comparable assemblages from Sibhudu, Umhlatuzana and other sites. Layer 10, which was previously also assigned to the final MSA, now dates to ~47-54 ka, placing the assemblage within the temporal range of the Late MSA. The new dates provide a good explanation for the clear differences in material culture between Layer 10 and the younger layers. We also present two new ages for the deeper horizons 11b and 12 at Umbeli Belli, dating to 76 ± 9 ka and 80 ± 9 ka, respectively. SIGNIFICANCE: • Revised and new age estimates are given for the Middle and Later Stone Age sequence of Umbeli Belli. • These age changes allow new comparisons with nearby prehistoric sites. • They change our view of the regional variability of technologies and cultures between ca. 80 and 20 ka on the east coast of South Africa.

ABSTRACT A comprehensive tectono-stratigraphic and sedimentological investigation of Early to Middle Devonian rocks was conducted in the southern Floresta Massif and adjacent regions in the Northern Andes of Colombia. A substantially reduced thickness of the Floresta Formation compared to prior studies is suggested here, attributable to pronounced stratal deformation and the prevalence of recumbent folds throughout the area. The deformation in the Floresta Formation manifests as atypical recumbent folds, diverging from the structural behavior observed in the underlying and overlying strata of the El Tibet and Cuche formations respectively, which exhibit minimal deformation. Our findings also reveal that the Floresta Formation accumulated under shallow-water platform conditions, subject to eustatic sea-level fluctuations. This resulted in distinct episodes of carbonate and siliciclastic deposition, with terrigenous sediments sourced from continental origins, potentially encompassing a combination of cratonic areas and uplifted blocks. The identification of a plausible stage of carbonate silicification signifies a post-diagenetic transformation. The sedimentary rocks of the Floresta Formation reached the upper epizone conditions, in proximity to the transition between the epizone and the upper anchizone, which suggests a maximum depth and temperature of ~5-7 km and ~300 °C, respectively. This contribution provides new insights into the geological history of the region, emphasizing the importance of scrutinizing Early to Middle Devonian rocks within the broader geological context of the Northern Andes.

RESUMEN Este trabajo presenta una exhaustiva investigación tectono-estratigráfica y sedimentológica de las rocas del Devónico temprano a Medio en el sur del Macizo de Floresta y regiones adyacentes, Andes del Norte, Colombia. Se sugiere un espesor sustancialmente reducido para la Formación Floresta en comparación con estudios previos, atribuible a una deformación pronunciada de los estratos y a la prevalencia de pliegues recumbentes en toda el área. La deformación en la Formación Floresta se manifiesta mediante pliegues recumbentes atípicos, a diferencia del comportamiento estructural observado en los estratos subyacentes y sobreyacentes de las formaciones El Tíbet y Cuche, respectivamente, que muestran una deformación mínima. Se revela también que la Formación Floresta se acumuló en condiciones de plataforma de aguas someras, sujeta a fluctuaciones eustáticas del nivel del mar. Esto resultó en variados episodios de depositación carbonática y siliciclástica, con aportes de sedimentos terrígenos provenientes de fuentes continentales, los que posiblemente abarcaron una combinación de áreas cratónicas y bloques levantados. La identificación de una posible etapa de silicificación carbonática indica una transformación postdiagenética. Las rocas sedimentarias de la Formación Floresta alcanzaron las condiciones de la epizona superior, en proximidad a la transición entre la epizona y la anquizona superior, lo cual sugiere una profundidad y temperatura máximas de ~5-7 km y ~300 °C, respectivamente. Esta investigación aporta nueva información acerca de la compleja historia geológica de la región, enfatizando la importancia de examinar las rocas del Devónico Temprano a Medio en el contexto geológico más amplio de los Andes del Norte.

ABSTRACT Objective: This study was aimed at analyzing and disseminating the fossil wood collection data stored in the thin sections of the paleobotany collection of the Department of Paleontology and Stratigraphy of the Institute of Geosciences at the Federal University of Rio Grande do Sul. Thin sections of petrified wood are described. Research data used in geosciences specifically seek to develop a model for the use of this type of sheet in paleobotany, enabling visualization of its representativeness in studies published over 40 years to obtain the anatomical characteristics of fossil woods and define their systematic affinities as a specific typology of research data in geosciences. Methods: The methodology involved interviewing a paleobotanical specialist and using different techniques applied in metric studies to map scientific production in petrified wood. Thus, a dataset of (20) thin slide sections of petrified fossil wood used in “Stressing environmental conditions in the ‘petrified forest’ from the Mata Sequence in the Triassic context of the Paraná Basin,” a paper published by the Journal of South American Earth Sciences (DOI:10.1016/j.jsames.2023.104415), was used. Depending on the methodology, these thin sections petrified wood can reveal systematic paleoclimatic signatures based on the anatomical characteristics of the fossil wood. In addition to this case study, which represents a collection of more than (2.000) thousand blades of fossil wood and approximately 40 years of research, the paleobotanical collection of the department is reused in methodology classes. The collection comprises a database created by research physicists that provides information on anatomical features, systematic affinities, paleoclimatic conditions, and paleoenvironmental insights. Potential for reuse: The reuse, registration, storage, identification, and preservation of thin sections as a type of research data used in paleobotany aims to improve the methodology associated with the organization of the physical database of the institution. The research data and blades of fossil wood are being digitized. They will soon be available under CC BY 4.0, according to the sample described in this data paper (DOI Mendeley: 10.17632/b8phfcsync.3). Furthermore, the data can be reused in optical and electronic scanning microscopy software. Objective Sul 4 Methods Thus 20 (20 Stressing forest Basin, Basin DOI10.1016/j.jsames.2023.104415, DOI101016jjsames2023104415 DOIjjsames DOI 10.1016/j.jsames.2023.104415 , 10 1016 j jsames 2023 104415 (DOI:10.1016/j.jsames.2023.104415) 2.000 2000 2 000 (2.000 classes features insights reuse registration storage identification institution digitized 0 4.0 Mendeley 10.17632/b8phfcsync.3. 1017632b8phfcsync3 bphfcsync 10.17632/b8phfcsync.3 . 17632 b8phfcsync 3 b phfcsync 10.17632/b8phfcsync.3) Furthermore software (2 DOI10 DOI10.1016/j.jsames.2023.104415 jjsames DOI101016jjsames202310441 101016jjsames2023104415 10.1016/j.jsames.2023.10441 1 101 202 10441 (DOI:10.1016/j.jsames.2023.104415 2.00 200 00 (2.00 4. 1017632b8phfcsync 10.17632/b8phfcsync. 1763 ( DOI1 DOI10.1016/j.jsames.2023.10441 DOI101016jjsames20231044 101016jjsames202310441 10.1016/j.jsames.2023.1044 1044 (DOI:10.1016/j.jsames.2023.10441 2.0 (2.0 10.17632/b8phfcsync 176 DOI10.1016/j.jsames.2023.1044 DOI101016jjsames2023104 101016jjsames20231044 10.1016/j.jsames.2023.104 104 (DOI:10.1016/j.jsames.2023.1044 2. (2. 17 DOI10.1016/j.jsames.2023.104 DOI101016jjsames202310 101016jjsames2023104 10.1016/j.jsames.2023.10 (DOI:10.1016/j.jsames.2023.104 DOI10.1016/j.jsames.2023.10 DOI101016jjsames20231 101016jjsames202310 10.1016/j.jsames.2023.1 (DOI:10.1016/j.jsames.2023.10 DOI10.1016/j.jsames.2023.1 DOI101016jjsames2023 101016jjsames20231 10.1016/j.jsames.2023. (DOI:10.1016/j.jsames.2023.1 DOI10.1016/j.jsames.2023. DOI101016jjsames202 101016jjsames2023 10.1016/j.jsames.2023 (DOI:10.1016/j.jsames.2023. DOI10.1016/j.jsames.2023 DOI101016jjsames20 101016jjsames202 10.1016/j.jsames.202 (DOI:10.1016/j.jsames.2023 DOI10.1016/j.jsames.202 DOI101016jjsames2 101016jjsames20 10.1016/j.jsames.20 (DOI:10.1016/j.jsames.202 DOI10.1016/j.jsames.20 DOI101016jjsames 101016jjsames2 10.1016/j.jsames.2 (DOI:10.1016/j.jsames.20 DOI10.1016/j.jsames.2 101016jjsames 10.1016/j.jsames. (DOI:10.1016/j.jsames.2 DOI10.1016/j.jsames. 10.1016/j.jsames (DOI:10.1016/j.jsames. DOI10.1016/j.jsames (DOI:10.1016/j.jsames

RESUMO Objetivo: O estudo visa divulgar e analisar a coleção de lenhos fósseis armazenadas no acervo de lâminas delgadas da coleção de paleobotânica do Departamento de Paleontologia e Estratigrafia do Instituto de Geociências da Universidade Federal do Rio Grande do Sul. Descrevem-se lâminas delgadas de madeira petrificada, enquanto dados de pesquisa utilizados para investigação em Geociências, em específico, busca-se compor um modelo para utilização deste tipo de lâmina na paleobotânica o que permite visualizar sua representatividade em estudos publicados durante 40 anos. Assim, obter-se-á as características anatômicas de laminas de lenhos fósseis com vistas a definir suas afinidades sistemáticas como uma tipologia específica de dados de pesquisa em Geociências. Métodos: A metodologia envolve entrevista com um especialista em paleobotânica e a utilização de diferentes técnicas aplicadas em estudos métricos para mapear a sua produção científica em lenhos fósseis. Nesse sentido, como exemplo descrevem-se um conjunto de dados de (20) lâminas delgadas de lenhos fósseis petrificados utilizados no paper Stressing environmental conditions in the “petrified forest” from the Mata Sequence in the Triassic context of the Paraná Basin publicados pelo periódico Journal of South American Earth Sciences, conforme DOI: 10.1016/j.jsames.2023.104415. A metodologia de utilização dessas lâminas no paper permite a identificação de assinaturas paleoclimáticas, com base em características anatômicas de lenhos fósseis. Além desse estudo de caso, esse data paper serve para representar uma coleção de mais de (2.000) mil lâminas de lenhos fósseis, cerca de 40 anos de pesquisa em paleobotânica que é reutilizada em aulas de metodologia e compõem uma base de dados de pesquisa que fornece informações sobre características anatômicas, afinidades sistemáticas, condições paleoclimáticas e percepções paleoambientais. Potencial de reutilização: A reutilização desse conjunto de dados permite o registro, o armazenamento, a identificação e a preservação de lâminas delgadas de lenhos fósseis enquanto um tipo de dado de pesquisa em Geociências, também objetiva aprimorar a organização de um banco de dados. Esses dados da pesquisa estão sendo digitalizados e em breve todos estarão disponíveis sob a licença CC BY 4.0, conforme a amostra descrita nesse data paper. (Mendeley DOI: 10.17632/b8phfcsync.3) os quais poderão ser reutilizados por softwares de microscopia óptica e de varredura eletrônica. Objetivo Sul Descrevemse Descrevem se petrificada específico buscase busca 4 Assim obterseá obter á Métodos sentido descrevemse descrevem 20 (20 petrified forest Sciences DOI 101016jjsames2023104415 jjsames 10 1016 j jsames 2023 104415 10.1016/j.jsames.2023.104415 caso 2.000 2000 2 000 (2.000 paleoambientais registro armazenamento 0 4.0 Mendeley 10.17632/b8phfcsync.3 1017632b8phfcsync3 bphfcsync 17632 b8phfcsync 3 b phfcsync eletrônica (2 101016jjsames202310441 1 101 202 10441 10.1016/j.jsames.2023.10441 2.00 200 00 (2.00 4. 10.17632/b8phfcsync. 1017632b8phfcsync 1763 ( 101016jjsames20231044 1044 10.1016/j.jsames.2023.1044 2.0 (2.0 10.17632/b8phfcsync 176 101016jjsames2023104 104 10.1016/j.jsames.2023.104 2. (2. 17 101016jjsames202310 10.1016/j.jsames.2023.10 101016jjsames20231 10.1016/j.jsames.2023.1 101016jjsames2023 10.1016/j.jsames.2023. 101016jjsames202 10.1016/j.jsames.2023 101016jjsames20 10.1016/j.jsames.202 101016jjsames2 10.1016/j.jsames.20 101016jjsames 10.1016/j.jsames.2 10.1016/j.jsames. 10.1016/j.jsames

Abstract This research aims to obtain tomographic images to interpret the seismic stratigraphic profile around the San Rafael (SR) knickpoint using seismic tomography. The SR waterfall on the Coca River sinkhole in February 2020 caused regressive soil erosion, suggesting that the knickpoint is highly unstable. Seismic tomography for the P-wave velocity model, utilizing data from 14 stations in the permanent Ecuadorian seismic network, produced vertical cross-sections at azimuths of 0°, 45°, 90°, and 80°. These sections reveal geological formations and their transition to volcanic deposits, while a horizontal cross-section illustrates the extent of the volcanic deposits. The tomographic images facilitated the identification and correlation of seismic stratigraphy with the area's geological features. The most unstable materials for erosion lie from 0 km to 1.5 km with velocities of up to 3.5 km/s. The erosive process impacts the population and infrastructure settled on the banks of the Coca River with a high susceptibility to erosion in zone 1, with velocities of 3 km/s and a 10 km extension. The Coca Codo Sinclair Dam (CCSD) is located in zone 2, with velocities of 3.8 km/s extending up to 40 km with medium susceptibility to erosion. (SR 202 Pwave P wave model 1 network crosssections cross 0° 45 45° 90 90° 80 80° deposits crosssection section areas area s features 15 5 1. 35 3. kms extension CCSD (CCSD 2 38 8 4 20 9

Abstract The settlement is a critical factor in foundation selection. To ensure the safety and stability of a structure, engineers must accurately predict settlement and design the foundation accordingly. However, in cases where the soil stratigraphy is complex, a more detailed analysis is necessary to determine safe and cost-effective solutions for a building's foundation. This paper presents a case study in which settlement monitoring was performed on a 23-story building with spread footings laid on a stiff rock layer of limited thickness overlying more compressible layers of clay and sand. The building was monitored through four construction stages, during which data on vertical displacements and stress distribution on the soil were obtained. To improve the accuracy of the results, a methodology for calibrating the thicknesses of the soil strata was applied, based on the measured settlements, soil-structure interaction, and estimates from semi-empirical methods. Furthermore, a numerical analysis was performed using the finite element method, where more conservative displacements were observed. Finally, the safety of the building was evaluated by verifying angular distortions. selection structure accordingly However complex costeffective cost effective buildings s 23story story 23 sand stages obtained results applied settlements soilstructure interaction semiempirical semi empirical methods Furthermore method observed Finally distortions 2

Resumo O recalque é um fator crucial na escolha de uma fundação. Para garantir a segurança e estabilidade de uma estrutura, os engenheiros precisam prever os recalques com um grau razoável de precisão e projetar a fundação de acordo. Entretanto, em casos em que a estratigrafia do solo é complexa, é necessária uma análise mais detalhada para determinar soluções seguras e econômicas para a fundação de uma edificação. Este artigo apresenta um estudo de caso no qual foi realizado o monitoramento de recalques de um prédio de 23 andares com sapatas assentadas em uma fina camada rochosa, sobrejacente a camadas mais compressíveis de argila e areia. O prédio foi monitorado através de quatro estágios de construção, para os quais foram obtidos valores de deslocamentos verticais e distribuição de tensões no solo. Buscando resultados mais precisos, uma metodologia para calibrar as espessuras das camadas de solo foi aplicada, com base nos recalques medidos, na interação solo-estrutura e nas estimativas de métodos semi-empíricos. Também foi realizada uma análise numérica pelo método dos elementos finitos, em que foram observados deslocamentos mais conservadores. Por fim, a segurança do prédio foi avaliada por meio da verificação de distorções angulares. estrutura acordo Entretanto complexa edificação 2 rochosa areia construção precisos aplicada medidos soloestrutura semiempíricos. semiempíricos semi empíricos. empíricos semi-empíricos finitos conservadores fim angulares

Abstract We combined detailed field work with whole-rock geochemistry of samples from both surface exposures and rock chips from a ~300 m pile of basalt retrieved from a groundwater borehole in the Jaú region (central part of the state of São Paulo) to contribute to the stratigraphic knowledge of the northern Paraná Magmatic Province. The P2O5 content was used as the first guide to flow identification, always combined with other minor and trace elements (mostly Ti, Zr, Sr, and Cu). This approach allowed the establishment of a stratigraphic column with 16 flows, which were tentatively divided into three sequences. Regional correlations show that the lower portion of these basalt flows (Sequence 1) has good correspondence with the flow-by-flow succession identified at the border of the Paraná Basin by previous regional works. The upper eight flows, occurring at the top of the plateau where the thickness of basalt reaches up to 300 m, should have their continuity westward (toward the center of the Paraná Basin), where the volcanic pile thickens. The local preservation of these upper flows may result from significant (up to 170 m) displacements along the ENE-directed Jaú fault, identified from stratigraphic relations here defined in the basalt pile. wholerock whole ~30 central Paulo Province PO P O P2O identification mostly Ti Zr Sr Cu. Cu . Cu) 1 sequences Sequence flowbyflow works 30 toward Basin, , Basin) thickens 17 ENEdirected ENE directed fault ~3 3 ~

Resumen Antecedentes: Históricamente en biología ha habido discrepancias a la hora de considerar a ciertos taxones dentro de las categorías “nativo” o “exótico” en determinadas áreas geográficas. Preguntas y/o hipótesis: ¿Tienen los taxones cualidades inherentes que permitan establecer formalismos concordantes con un principio de prioridad como criterio para resolver los problemas derivados de la categorización “nativo-exótico”? Especies de estudio/Descripción de datos/Modelo matemático: Se utilizaron Eucalyptus globulus, Phytolacca dioica, Prosopis alba, Schinus longifolius y Tipuana tipu como especies de referencia para aplicar los modelos matemáticos denominados “Índices de Ancestralidad” que permitan formalizar el grado de cualidad ancestral de un taxón en un área determinada, Sitio y años de estudio: Tres áreas asociadas geográficamente pero con características discordantes fueron seleccionadas. Este trabajo se realizó entre 2017 y 2022. Métodos: Se proponen dos tipos de índices complementarios. El “Índice de Ancestralidad Binario”, que parte de la distinción clásica de especie “nativa-exótica” y se codifica en forma binaria. El “Índice de Ancestralidad Escalar”, que se basa en el desarrollo de dos criterios: uno espacial (“distancia al área de origen”) y otro temporal (“tiempo de permanencia”). Resultado: Se obtuvieron tablas con los índices mencionados para las especies y áreas elegidas. Conclusiones: Estos índices resultarán útiles, por ejemplo, cuando sea necesario tomar decisiones que puedan afectar negativamente a los ecosistemas, considerando la historia e identidad del sitio. Los índices también serían fundamentales como estímulo a investigaciones de temáticas asociadas y para componerlo que se propone como estratigrafía ecológica de un área.

Abstract Background: Historically, in biology, there have been discrepancies when considering certain taxa within the “native” or “exotic” categories in particular geographic areas. Questions and/or Hypotheses: Do the taxa have inherent qualities that allow establishing formalisms consistent with a principle of priority as a criterion to solve problems derivates of the categorization "native-exotic"? Studied species/ Data description /Mathematical model: Eucalyptus globulus, Phytolacca dioica, Prosopis alba, Schinus longifolius and Tipuana tipu were used as reference species to apply mathematical models called “Ancestrality Indices” that allow formalizing the degree of ancestral quality of a taxon in a given area. Site and years of study: Three areas geographically associated but with discordant characteristics were selected. This work was carried out between 2017 and 2022. Methods: Two types of complementary indices are proposed. The "Índice de Ancestralidad Binario", which starts from the classic distinction of "native-exotic" species and is coded in binary form. The “Scalar Ancestry Index”, which is based on the development of two criteria: a spatial one (“distance to the area of origin”) and a temporal one (“permanence time”). Results: Tables were obtained with the indices mentioned for the species and areas chosen. Conclusions: These indices will be useful, for example, when it is necessary to make decisions that may negatively affect ecosystems, considering the history and identity of the site. The indices would also be fundamental as a stimulus to research on associated themes and to compose the ecological stratigraphy of an area.

ABSTRACT Revision of the La Veteada Formation in its stratotype (La Rioja, Argentina): age, stratigraphy and paleoenvironmental significance. The La Veteada Formation, in the Sierra de Famatina (west of Argentina), is one of the few records of Early Triassic age in South America verified by isotopic age and palynological assemblages. This unit is composed of sandstones, mudstones, shales, limestones, and marls, with some levels of gypsum, chert, and tuff levels. In its stratotype, the La Veteada Formation rests on Late Permian red beds of the Talampaya Formation and is covered by Neogene breccias and conglomerates belonging to the Del Crestón Formation. The unit is divided into three associations of sedimentary facies. Facies association A (80 m thick) is a red bed succession composed of mudstone and fine-grained sandstone, together with some levels of chert and gypsum. Facies association B (58 m thick) is greenish-gray to yellowish-gray and comprises limestones, marls, shales, and fine- to coarse-grained sandstones. This facies includes stromatolites and several levels of shales and marls where rich palynological assemblages were recovered. Finally, facies association C (24 m thick) is made up of yellowish-gray marls, mudstones, and sandstones. In this section, stromatolites are missing, thin levels of gypsum appear, and evidence of subaerial exposition as mud cracks and raindrop imprints are frequent at the top of the facies. The lithology, sedimentary structures, and vertical stacking of facies suggest that the La Veteada Formation was deposited in a lacustrine environment, which evolved from a shallow ephemeral playa lake system (facies association A) to a perennial lake, in which carbonate production increased compared to clastic sedimentation (facies association B). Regarding the facies association C, the increase in clastic supply, the missing stromatolites, and the presence of gypsum levels suggest a progressive shallowing of the lake and the likely transition to a palustrine environment. The Early Triassic age of the La Veteada Formation is indicated from two different lines of research. Firstly, a zircon U-Pb age of 249.66±0.11 Ma obtained from a tuff level at the middle part of the facies association A. Secondly, the presence of palynological species identified in other Early Triassic units worldwide. The La Veteada Formation records the filling of the embryonic extensional basins formed at the earliest Triassic. Moreover, this unit shows the evolution of depositional environments after the late Permian massive extinction event.

RESUMEN La Formación La Veteada, en la sierra de Famatina (oeste de Argentina), es uno de los pocos registros de edad triásica temprana en América del Sur comprobada por dataciones radiométricas y asociaciones palinológicas. Esta unidad está compuesta por areniscas, lutitas, fangolitas, calizas y margas, con algunas intercalaciones de yeso, chert y toba. En su estratotipo, descansa sobre bancos rojos de la Formación Talampaya (Pérmico tardío) y está cubierta por brechas y conglomerados del Neógeno pertenecientes a la Formación Del Crestón. La unidad es dividida en tres asociaciones de facies sedimentarias. La asociación de facies A (80 m de espesor) es una sucesión de capas rojas compuestas por fangolitas y areniscas de grano fino, junto con algunos niveles de chert y yeso. La asociación de facies B (58 m de espesor) es de color gris verdoso a gris amarillento y comprende calizas, margas, lutitas y areniscas de grano fino a grueso. Esta facies incluye estromatolitos y varios niveles de lutitas y margas donde se recuperaron ricas asociaciones palinológicas. Finalmente, la asociación de facies C (24 m de espesor) está compuesta por margas, lutitas y areniscas de color gris amarillento. En esta sección, faltan estromatolitos, aparecen niveles delgados de yeso y son frecuentes las evidencias de exposición subaérea, como grietas de desecación e impresiones de gotas de lluvia, especialmente en la parte superior de la facies. La litología, las estructuras sedimentarias y el apilamiento vertical de facies sugieren que la Formación La Veteada se depositó en un ambiente lacustre, que evolucionó de un sistema lacustre efímero poco profundo (asociación de facies A) a un lago perenne, en el que la producción de carbonato aumentó en comparación con la sedimentación clástica (asociación de facies B). En la asociación de facies C, el aumento en el suministro clástico, la ausencia de estromatolitos y la presencia de niveles de yeso indicarían una progresiva somerización del lago y la probable transición a un ambiente palustre. La edad triásica temprana de la Formación La Veteada es determinada desde dos líneas de investigación diferentes. En primer lugar, una edad U-Pb sobre circón de 249,66±0,11 Ma obtenida a partir de un nivel de toba en la parte media de la asociación de facies A. En segundo lugar, la presencia de especies palinológicas identificadas en otras unidades del Triásico temprano a nivel mundial. La unidad registra el relleno de las embrionarias cuencas extensionales formadas a comienzos del Triásico. Por otro lado, la Formación La Veteada muestra la evolución de los ambientes depositacionales con posterioridad al evento de extinción masiva ocurrido a fines del Pérmico.

ABSTRACT: ln the inland of the northern Fueguian steppe, the archaeological stratigraphic evidence is scarce, being the presence of surface contexts with variable densities of lithic artifacts, occasionally associated with bone remains, among the most ubiquitous characteristics of the record. These contexts are exposed to erosive processes and natural additions of bones, causing low resolution and integrity and therefore hindering the construction of a chronological scheme as well as the discussion on the different patterns of faunal exploitation. The archaeological signal shows a greater intensity of occupations during the late Holocene, with little evidence for earlier times. Within this framework, our study results of the assemblages from the Yowen Ko and Amalia 6 sites are presented and discussed, the first one in stratigraphy and the second one on the surface, both with a marked prevalence of their faunal component. The zooarchaeological and taphonomic analyzes carried out on these assemblages, in combination with other studies and experiments from a geoarchaeological perspective, allows us to assess the degree of integrity and the processes involved in the formation of both sites. Moreover, the chronology and composition of these contexts, in particular the Yowen Ko ones, represent a significant contribution to the discussion on the use of space in the area of brackish shallow lakes within the steppe landscape since late middle Holocene, a period from which there is not much information, and the use of fauna by human groups in the brackish shallow lakes area in the Fuegian inland.

RESUMEN: En el interior estepario del norte fueguino la evidencia arqueológica en estratigrafía es escasa y entre las características más ubicuas del registro se cuenta la presencia de contextos de superficie con densidades variables de artefactos líticos, eventualmente asociados con restos óseos. Estos contextos están expuestos a procesos erosivos y lluvia natural de huesos, que generan situaciones de baja resolución e integridad, dificultando la construcción de un esquema cronológico y la discusión sobre las pautas de explotación faunística. La señal arqueológica indica una mayor intensidad de ocupaciones durante el Holoceno tardío, con escasa evidencia para momentos previos. En este marco, se presentan y discuten los resultados del análisis de los conjuntos procedentes de los sitios Yowen Ko y Amalia 6, el primero en estratigrafía y el segundo en superficie, ambos con marcado predominio de su componente faunístico. Los análisis zooarqueológicos y tafonómicos desarrollados sobre estos conjuntos, en combinación con estudios y experimentaciones desde una perspectiva geoarqueológica, permiten evaluar el grado de integridad y los procesos implicados en la formación de ambos sitios. A su vez, la cronología y composición de estos contextos, en particular Yowen Ko, brindan un aporte valioso para la discusión sobre uso del espacio dentro del paisaje estepario desde finales del Holoceno medio -periodo para el cual no se cuenta con mucha información- y el aprovechamiento de la fauna por los grupos humanos en el sector de lagunas salobres del interior fueguino.

RESUMEN: Se presentan los resultados de la primera excavación del sitio El Rincón, en la península de San Julián, provincia de Santa Cruz. Se analizan los distintos conjuntos materiales recuperados en la secuencia estratigráfica con el objetivo de examinar las prácticas vinculadas a la producción y uso de artefactos líticos, así como el aprovechamiento de los recursos faunísticos terrestres y marinos. Aunque, se enfatiza el estudio del componente inferior que posee el registro más numeroso y conforma la primera ocupación identificada, datada en ca. 700 años AP. El examen arqueomalacológico señala que la especie preferentemente consumida por los grupos, en los seis componentes de ocupación, corresponde a Mytilus edulis colectada en bancos cercanos; mientras que el análisis zooarqueológico sugiere el consumo de mamíferos terrestres, en especial guanacos. Por su parte, el estudio de la tecnología lítica sugiere actividades orientadas a la formatización final de instrumentos, vinculados al procesamiento de recursos como a la captura de presas. Estos patrones permitieron profundizar el estado de conocimiento sobre el modo de ocupación y las prácticas desarrolladas en la península. La ocupación del sitio corresponde a un espacio donde se instalaron campamentos de actividades múltiples, a lo largo de períodos cortos o más extensos. Probablemente este sector de costa, hacia el segmento final del Holoceno tardío, formara parte de los circuitos de movilidad y de explotación de los recursos disponibles, durante las estaciones de primavera y verano.

ABSTRACT: Results of the first excavation carried out at El Rincón site, in San Julián peninsula, Santa Cruz province, are presented. Different material assemblages recovered from the stratigraphic sequence are analyzed with the aim of examining the practices related to the production and use of lithic artifacts, as well as the use of terrestrial and marine faunal resources. Although, emphasis is placed in the study of the lower component, which has the most numerous record and forms the first identified occupation, dated to ca. 700 years BP. Archaeomalacological examination indicates that Mytilus edulis was the preferably consumed species in the six stratigraphic components, these were collected in nearby banks. Zooarchaeological analysis suggests consumption of terrestrial mammals, especially guanacos. Study of lithic technology allows inferring activities aimed at the final trimming of instruments, related to the processing of resources and capture of preys. These patterns allowed to deepen the state of knowledge about human occupations and practices developed at the peninsula. The occupation of the site corresponds to a space where multi-activity camps were installed, over short or longer periods. Probably this sector of the coast, towards the final of the late Holocene, was part of the mobility circuits and exploitation of the available resources, during the spring and summer seasons.

RESUMEN Los estratos del Mioceno de la Formación Qom Formation en la sección Ghalibaf, Irán Central (NO Semnan), documentan una alta diversidad de microfacies marinas someras. Estos depósitos, en la sección Ghalibaf, con un espesor total de 445 m, se caracterizan por veitiún microfacies. Las microfacies de carbonatosfueron depositadas en cinco cinturones de facies, incluyendo laguna, pendiente superior, pendiente inferior, bancos de arena de margen de plataforma y facies marginales en una plataforma carbonatada bordeada. La presencia de barreras de arrecifes, intraclastos, oncoides, The presence of barrier reefs, intraclasts, oncoids, y calizas granulares de carga agregada, junto con la ausencia de vastas areas de planicie de mareas, logran distinguirse. De acuerdo a las evidencias antes mencionadas, estos sedimentos fueron depositados en una plataforma carbonatada marginada. Adicionalmente, el carácter heterolítico de depósitos de calcirrudita muestran que las secuencias fueron despositadas en el tipo de plataforma citado. Con base en los datos disponibles de análisis de estratigrafía secuencial, setentaytres órdenes de secuencias deposicionales se caracterizan por límites de secuencia topoe-1 y tipo. Los cambios de nivel del mar relativos entre los límites de secuencia superior e inferior, de acuerdo a las curvas del nivel global del mar, revelan una correlación razonable. Sin embargo, algunas diferencias en otros límites de secuencia pueden deberse a actividad tectónica local en la cuenca sedimentaria de la Formación Qom, lo que produciría cambios locales del nivel del mar. Adicionalmente, datos bioestratigráficos basados en grandes foraminíferos, marcadores índice, que incluyen Praebullalveolina curdica, Borelis melo, Dendritina rangi, Meandropsina iranica, Elphidium sp. 14, Neorotalia viennoti y Miogypsina sp., sugieren las Zonas Bénticas Someras del Mioceno SBZ24-SBZ25, las cuales son equivalentes al lapso temporal del Aquitanian tardío-Burdigalian.

ABSTRACT The Miocene strata of the Qom Formation from the Ghalibaf section, Central Iran (NW Semnan) documented a high diversity of shallow-marine microfacies. These deposits in the Ghalibaf section, with a total thickness of 445 m, are characterized by twenty-one microfacies. The carbonate microfacies are deposited into five facies belts, including a lagoon, upper slope, lower slope, platform-margin sand shoals and margin facies. The presence of barrier reefs, intraclasts, oncoids, and grainstone aggregates, along with the absence of vast tidal flat areas, are distinguished. According to the aforementioned evidences, these sediments were deposited on a rimmed carbonate platform. In addition, the heterolithic calciturbidite deposits also show that the carbonate sequences were sedimented on a rimmed carbonate platform. Based on the available data of sequence stratigraphy analysis, seven third-order depositional sequences are bounded by type-1 and type-2 sequence boundaries. The relative sea-level changes between the upper and lower sequence boundaries in accord with the global sea-level curves reveal a reasonable correlation. However, some differences in other sequence boundaries might be due to local tectonic activities in the Qom Formation sedimentary basin, thereby leading to local sea-level changes. Moreover, biostratigraphic data based on the larger foraminifera index markers, including Praebullalveolina curdica, Borelis melo, Dendritina rangi, Meandropsina iranica, Elphidium sp. 14, Neorotalia viennoti, and Miogypsina sp. suggests the Miocene Shallow Benthic Zones, SBZ24-SBZ25 equivalent to the late Aquitanian-Burdigalian timespan.

RESUMEN El Grupo Sierra Madre de Chiapas tiene informalidades en su nomenclatura estratigráfica que han sido transmitidas a través de la literatura geológica. Este trabajo describe las características de tres sucesiones litoestratigráficas que hacen comprensible la división tripartita del Grupo Sierra Madre. Una litología particular, que aquí se define sucesión El Chango, separa las sucesiones Cantelhá y Cintalapa para integrar a este grupo. Adicionalmente, la sucesión El Chango hace posible realizar una cartografía apropiada y su correlación permite interpretar la distribución regional de facies sedimentarias que presentan estas sucesiones. La epifluorescencia de rocas de la sucesión El Chango (Cenomaniano) exhibe compuestos orgánicos. Datos de pirólisis indican ⁓0.22% de carbón orgánico total en roca carbonatada, su reflectancia equivalente es 0.7 y 1.0, que ubica a la roca en la ventana de generación del aceite y gas metagénico, los valores de S2 menores de 0.2 mg HC/g hacen cuestionable el bajo potencial de expulsión de hidrocarburos, por lo que se requieren análisis adicionales. La porosidad impregnada con asfalto en rocas del Grupo Sierra Madre sugiere la existencia de roca almacén, cubierta regionalmente por rocas pelíticas como sello y los cambios de facies y deformación indica la existencia de trampas potenciales. Los datos de este trabajo proponen explorar un play hipotético petrolero en esta región.

ABSTRACT The Sierra Madre Group of Chiapas has informalities in its stratigraphic nomenclature that have been transmitted through geological literature. This work describes the characteristics of three lithostratigraphic successions that make the tripartite division of the Sierra Madre Group understandable. A particular lithology, which here is defined as the El Chango succession, separates the Cantelhá and Cintalapa successions to integrate this group. Additionally, the El Chango succession makes it possible to do an appropriate mapping and its correlation allows interpreting the regional distribution of sedimentary facies that these successions. Epifluorescence of rocks from the El Chango succession (Cenomanian) exhibits organic compounds. Pyrolysis data indicate ⁓0.22% of total organic carbon in carbonate rock, its equivalent reflectance is 0.7 and 1.0, which places the rock in the generation window of metagenic oil and gas, S2 values less than 0.2 mg HC/g make the low hydrocarbon expulsion potential questionable, so additional analyzes are required. The porosity impregnated with asphalt in rocks of the Sierra Madre Group suggests the existence of reservoir rock, regionally covered by pelitic rocks as a seal, and the changes in facies and deformation indicate the existence of potential traps. The data from this work proposes to explore a hypothetical oil play in this region.

Abstract Discussions about the Anthropocene produced by Earth System Science (ESS) and stratigraphy have resulted in texts that make use of data and models, but that also produce historical narratives through which an attempt is made to offer a new unified meaning for humanity. In this article I take these statements as “propositions” which have the potential to transform historiographical practice. The objective is to offer a more detailed picture of the contributions of these “anthropocenologists” in order to enable a better assessment of the possibilities of reception of these propositions by the historians’community. Therefore, this article aims to review some recent criticisms of the narratives produced by these scientists. As a conclusion, I demonstrate that the literature produced by the ESS cannot be easily reduced to the idea of a “metanarrative”, due to the plurality of positions it encompasses, as well as I point to the need for a pluralization of the historiographical onto-epistemic perspectives so that it can contribute to the multiple ways of inhabiting and giving meaning to the experience in the post-Holocene. (ESS models humanity “propositions practice anthropocenologists “anthropocenologists historianscommunity. historianscommunity historians community. community historians’community Therefore scientists conclusion metanarrative, metanarrative , “metanarrative” encompasses ontoepistemic onto epistemic postHolocene. postHolocene post Holocene. Holocene post-Holocene “metanarrative

Resumo As discussões sobre o Antropoceno produzidas pela Ciência do Sistema Terra (CST) e pela estratigrafia têm resultado em textos que lançam mão de dados e modelos, mas que também produzem narrativas históricas por meio das quais se tenta oferecer um novo sentido unificado para a humanidade. Neste artigo tomo esses enunciados como “proposições” com o potencial de transformar a prática historiográfica. O objetivo é oferecer um quadro mais detalhado das contribuições desses e dessas “antropocenologistas” a fim de possibilitar uma melhor avaliação das possibilidades de acolhimento dessas proposições pela comunidade de historiadores e historiadoras. Para tanto, este artigo tem o objetivo de revisar algumas críticas recentes às narrativas produzidas por esses e essas cientistas. Como conclusão, demonstro que a literatura produzida pela CST não pode ser reduzida facilmente à ideia de uma “metanarrativa”, devido à pluralidade de posições que ela abarca, bem como aponto para a necessidade de uma pluralização das perspectivas ontoepistêmicas da historiografia a fim de que ela possa contribuir com as múltiplas formas de habitar e de conferir sentido para a experiência no pós-Holoceno. (CST modelos humanidade “proposições historiográfica antropocenologistas “antropocenologistas historiadoras tanto cientistas conclusão metanarrativa, metanarrativa , “metanarrativa” abarca pósHoloceno. pósHoloceno pós Holoceno. Holoceno pós-Holoceno “metanarrativa

Resumen La perforación del pozo hidrogeológico Alejandrina a los 209 m bbp, muy por debajo de la profundidad habitual de los pozos de agua de la zona, alcanzó un nivel areniscoso de la Formación Zapallal con contenido gasífero inesperado que determinó un fuerte venteo, licuefacción de la plataforma de perforación, colapso del equipo de perforación y la contaminación de los niveles tradicionalmente productores del acuífero confinado. Para mitigar esta invasión de gas y surgencia a superficie, se perforaron los pozos: i) de alivio Papayal, para efectuar maniobras de captura y cementación donde se requirieron 5 intentos de perforación direccional hasta interceptar el pozo Alejandrina y ii) exploratorio Curumuy 1X para disminuir la presión de la invasión de gas y conocer sus posibles orígenes anormales a esas profundidades tan someras. El objetivo del trabajo es informar la estratigrafía de este sector potencialmente exploratorio con probada presencia de recursos de gas de la cuenca Sechura y describir la secuencia de acontecimientos de la interferencia en el manejo y producción entre los recursos hidrogeológicos y gasíferos que comparten los mismos reservorios areniscosos de la Formación Zapallal. Para ello, se aportan datos petrofísicos a partir de los registros de perforación de los pozos Alejandrina, Papayal y Curumuy 1X y un modelo simulado de carga y manejo del gas responsable de la contaminación. De esta manera, se presenta un caso de interferencia de objetivos del subsuelo con la intención de preservar y restablecer el comportamiento de los pozos productores del acuífero y a la vez producir gas.

Abstract The drilling of the Alejandrina hydrogeological well at 209 m bbp, below the usual depth of water wells in the area, reached a sandy level of the Zapallal Formation with unexpected gas content that caused strong blow-up, venting, liquefaction of the ground, collapse of the drilling equipment and contamination of the traditionally producing levels of the confined aquifer. To mitigate this invasion of gas and it upwelling to the surface, the following wells were drilled: i) Papayal interference well, to carry out capture and cementing maneuvers with 5 horizontal attempts until intercepting the Alejandrina well, and ii) Curumuy 1X exploratory well to reduce the pressure of the gas invasion and discover its possible abnormal origins at such shallow depths. The objective of the work is to present the stratigraphy of this potentially exploratory sector with proved gas resources of the Sechura basin and to describe the sequence of events of the interference in the management and relationships between the hydrogeological and gas resources that share the same sandstone reservoirs of the Zapallal Formation. For this, petrophysical data are provided from the drilling records of the Alejandrina, Papayal and Curumuy 1X wells and a simulated model of loading and handling of the gas responsible for the contamination. In this way, a case of interference of different subsoil objectives is presented with the intention of preserving and reestablishing the behavior of the producing wells of the aquifer and at the same time producing gas.

Resumen La hoja Monterrey se ubica al noroeste de Costa Rica en el límite del arco volcánico activo y la cuenca de San Carlos (CSC), asociado con la sedimentación, el vulcanismo y la tectónica de la región tras-arco de América Central meridional. El objetivo y método de trabajo fue desarrollar el cartografiado geológico de los depósitos sedimentarios y volcánicos, la tectónica y el muestreo para dataciones radiométricas, geoquímica y petrografía de las diferentes unidades geológicas. Las rocas más antiguas de la Hoja Monterrey están constituidas por los sedimentos clásticos de la Formación Venado depositados en un ambiente de plataforma y transición continental de edad Mioceno Medio - Superior. La geocronología U-Pb del grupo de zircones detríticos más jóvenes en estos sedimentos, registran una edad de sedimentación máxima de 6,9 ± 0,2 Ma, sugiriendo una edad del Mioceno tardío y Plioceno de los sedimentos en esta región de la cuenca de San Carlos, correlacionable con dataciones previas de microforaminíferos, palinología y una edad radiométrica 40K/40Ar del vulcanismo que sobreyace estos sedimentos. La sedimentación del Plioceno en el área se interpreta como la colmatación de la cuenca asociado al cierre del istmo Centroamericano, registrado por una discordancia angular posiblemente asociado al evento tectónico registrado durante el final del Mioceno e inicios del Plioceno. El vulcanismo del Mioceno Superior es sub-alcalino de marcada afinidad toleítica y calco-alcalina y de transición a ambas series, variando de basaltos hasta dacitas. Los análisis geoquímicos sugieren una fuerte diferenciación de estos magmas a partir de fuentes de transición de tipo OIB (para las rocas de afinidad calco-alcalina/alcalina) a fuentes de tipo MORB (para los basaltos de afinidad toleítica) modificadas por los procesos de subducción. El vulcanismo piroclástico del Plio-Pleistoceno se asocia a ignimbritas de composición dacítica-andesítica calco-alcalina. En relación con magmas primarios, los análisis sugieren mayores o altos grados de la fusión parcial con un aporte de fluidos y sedimentos pelágicos carbonatados de la placa subducida al metasomatismo del manto. La normalización al manto primitivo indica enriquecimiento en LILE y deficiencias en HFSE asociado al aporte de fluidos y deshidratación de sedimentos marinos de la placa subducida al metasomatismo del manto, típico del vulcanismo de arco con una componente alcalina que puede estar más relacionada al vulcanismo del tras-arco que al vulcanismo del intra-arco del norte de Costa Rica. La Formación Monteverde de edad Pleistoceno inferior, abarca la mayor parte del área cerca del 78%, mayormente formando suelos de transición y residuales, constituido principalmente por andesitas, asociado también con un vulcanismo piroclástico y volcano-sedimentario presente en el sector suroeste de la hoja. La Formación Buena Vista conforma la actividad volcánica posterior a la Formación Monteverde y está constituido por depósitos volcaniclásticos (lahares) que forman brechas volcánicas muy endurecidas. Los depósitos piroclásticos Holocénicos del volcán Arenal (tefras) son de composición andesítica-andesítica basáltica calco-alcalina y se distribuyen al sur de la hoja. La tectónica compresiva del Mioceno Medio-Superior en el área está registrada por la deformación tectónica de fallas inversas en los sedimentos de la Formación Venado y la tectónica transtensiva del Plioceno y Pleistoceno por fallas principalmente de desplazamiento de rumbo consideradas activas. Las edades Cenozoicas y Mesozoicas obtenidas en zircones detríticos de la Formación Venado, registran el desarrollo y evolución del arco de islas de América Central meridional. En tanto, las edades Proterozoicas y Paleozoicas registran una posible conexión con el norte de América Central o sur de México, o un posible origen Gondwanico o Laurenciano. Sin embargo, podrían indicar también la presencia de fragmentos de corteza continental por debajo de América Central meridional. Estas edades de zircones primordiales son un aporte nuevo al conocimiento geocronológico y evolutivo de estos complejos continentales y proveen un paradigma para futuros estudios sobre la evolución geológica y geotectónica del istmo Centroamericano.

Abstract The Monterrey sheet is located in the northwest of Costa Rica in the limit of the active volcanic arc and the San Carlos basin (SCB), associated with the sedimentation, the volcanism and the tectonic of the back-arc region of southern Central America. The objective and methods were to develop the geological mapping of the sedimentary and volcanic deposits, the tectonic and the sampling for radiometric dating, geochemistry and petrography of the different units. The older rocks are conformed by clastic sediments belonging to Venado Formation, deposited in a shelf and transitional continental environment of Middle-Upper Miocene age. U-Pb geochronology for the youngest group of detrital zircons in these sediments constrained to a maximum depositional age of 6,9 ± 0,2 Ma, suggesting a late Miocene to Pliocene age sedimentation of the basin in this region of the SCB, which is in agreement with previous microforaminiferal and palynological dating and one 40K/40Ar radiometric age of the overlying volcanism on this sediments. The Pliocene sedimentation corresponds to the sealing of the basin associated with the Central American isthmus closure, recognized by an angular discordance associated with the tectonic event registered at the end of the Miocene and the beginning of the Pliocene. The Upper Miocene volcanism is subalkaline of marked tholeiitic and calc-alkaline afinity and transition to both series, varying from basalts to dacites. The geochemical analysis suggest a strong differentiation of these magmas from OIB type source (calc-alkaline/alkaline rocks) to MORB type source (tholeiitic basalts) modified by the subduction processes. The Plio-Pleistocene pyroclastic volcanism is associated to ignimbrites of calc-alkaline dacitic-andesitic composition. Related to primary magmas, the analysis suggest greater or high degrades of partial melting with an input of fluids and carbonate pelagic sediments from the subducting slab to the mantle metasomatism. The primitive mantle normalization shows LILE enrichments and HFSE depletions associated with the input of marine fluids and sediments dehydration of the subducted slab to the mantle metasomatism, typical of arc volcanism with an alkaline component that may be more related to the back-arc rather than the intra-arc volcanism of northern Costa Rica. The Monteverde Formation of the lower Pleistocene, cover most of the area of about 78%, forming transitional and sedentary soils mainly of andesite composition, associated also to a pyroclastic and volcaniclastic volcanism in the southwest of the sheet area. The Buena Vista Formation conform the subsequent volcanism of Monteverde Formation and is constituted by volcaniclastic deposits (lahars) of very indurate volcanic breccia. The pyroclastic Holocene deposits of Arenal volcano (tephra) are calc-alkaline of andesitic-basaltic andesite composition and are distributed to the south of the sheet. The compressive tectonic of the Middle to Upper Miocene is registered in the area by the tectonic deformation of thrusting faults in the sediments of the Venado Formation and the transtensive tectonic of the Plio-Pleistocene by mainly strike-slip faults considered active. The Cenozoic and Mesozoic detrital zircon ages of the Venado Formation, they register the development and evolution of the southern Central America volcanic arc, meanwhile, the Proterozoic and Paleozoic detrital zircon ages a possible connection with northern Central America or southern Mexico, or a possible Gondwanic or Laurentian origin. However, it could also indicate the presence of hidden continental crust fragments underneath southern Central America. These ancient detrital zircons ages constitute a new contribution to the geochronological knowledge and evolution of these continental complexes and provide a paradigm for future studies about the geologic and geotectonic evolution of the Central America isthmus.