@article{10272/28549,
year = {2026},
url = {https://hdl.handle.net/10272/28549},
abstract = {This study analyzes both the texture and foraminiferal and ostracod assemblages of recent (Quaternary) sediments from the Carrizal Bajo wetland, in the southern Atacama Desert of northern Chile. A transect carried out from the infralittoral zone to the landward margin of the active wetland allowed four coastal sectors to be differentiated based on the distribution and abundance of these faunal groups. The infralittoral, shallow marine areas (sector 1) are composed of bioclastic sandy sediments extremely rich in foraminifera and ostracods, which contrast with their marked scarcity or absence in the very fine sands and very coarse muds of the adjacent intertidal-supratidal zones and washover fans (sector 2). Scarce resedimented shells of ostracods and the gastropod Heleobia copiapoensis characterize the  peaty sandy muds of the lagoon bottom (sector 3), a hostile environment for the groups studied due to intermittent anoxic conditions and frequent changes in salinity. The innermost (landward) margin of the wetland (sector 4) is characterized by sandy silts with a rich freshwater fauna in the vicinity of springs, as well as an unexpected occurrence of resedimented marine foraminifera ~650 m inland. These results can be applied in future research related to investigating: 1) the environmental degradation of the system, should the density and diversity of these faunal groups decrease or even disappear over time; 2) the reconstruction of paleoenvironments in recent Quaternary deposits, in case the taxa determined are present in the fossil record; or 3) the identification of recent Quaternary tsunamigenic layers along this coastline,  characterized by the presence of infralittoral species within aeolian or wetland sedimentary sequences.
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},
abstract = {En este trabajo se presenta un análisis de la textura y meiofauna (foraminíferos y ostrácodos) en los sedimentos recientes (cuaternarios) del humedal costero de Carrizal Bajo (zona sur del desierto de Atacama, norte de Chile). Un transecto realizado desde la zona infralitoral hasta el margen interior del humedal activo ha permitido diferenciar cuatro sectores en función de la distribución y abundancia de estos grupos faunísticos. Las zonas marinas someras del ambiente infralitoral (sector 1) están compuestas por sedimentos arenosos bioclásticos extremadamente ricos en foraminíferos y ostrácodos, lo que contrasta con la marcada escasez, o incluso ausencia, de estos grupos en las arenas muy finas y limos muy gruesos de las zonas intermareal y supramareal adyacentes (sector 2). Escasas conchas resedimentadas de ostrácodos y del gasterópodo Heleobia copiapoensis caracterizan los fangos arenosos turbosos del fondo de la laguna (sector 3), un medio hostil para los grupos estudiados debido a un ambiente anóxico intermitente y frecuentes cambios de salinidad. El margen interior del humedal (sector 4) está formado por limos arenosos con una rica fauna dulceacuícola próxima a manantiales, así como por un sorpresivo registro de foraminíferos marinos resedimentados ~650 m tierra adentro. Los resultados obtenidos en este estudio pueden aplicarse en investigaciones futuras relacionadas con: 1) la degradación ambiental de estos sistemas, en caso de que la densidad y diversidad de estos grupos decrezca o incluso desaparezca; 2) la reconstrucción de paleoambientes en depósitos cuaternarios recientes costeros, si los taxones determinados están también presentes en el registro fósil; o 3) la identificación de niveles tsunamigénicos recientes a lo largo de este litoral costero, caracterizados por la presencia de especies infralitorales dentro de secuencias sedimentarias eólicas o en humedales costeros.},
organization = {This paper has been funded by the grants PID2021- 127268NB-100 (TRAMPA project, funded by MICIU/ AEI/10.13039/501100011033 and by “ERDF/EU”), ANID/ CONICYT/FONDECYT 11180015, and URJC M2616. In addition, RNM-238 research group of the Plan Andaluz de Investigación, Desarrollo e Innovación (P.A.I.D.I.) and the DYNAMICAL-URJC research group (URJC M3189) supported this research. This is a contribution to the Center for Research in Historical, Cultural and Natural Heritage of the University of Huelva. The authors thank Dr. Ángel Baltanás, Universidad Autónoma de Madrid (Spain) for his help in the identification of freshwater ostracods species. We sincerely thank the two anonymous reviewers for their insightful comments and constructive suggestions, which greatly enhanced the final version of this manuscript. We also extend our deepest gratitude to Dr. D. Bertin for his invaluable guidance and support as Editor throughout the review process.},
publisher = {Servicio Nacional de Geología y Minería},
title = {Foraminifera and ostracods from the semiarid Carrizal Bajo coastal wetland, southern Atacama Desert},
doi = {10.5027/andgeoV53n1-3810},
author = {Abad de los Santos, Manuel and Ruiz Muñoz, Francisco and Viso, Antonio and Gómez Martín, Cristina and Bonnail, Estefanía and González-Regalado Montero, María Luz and Forch, Maximiliano and Izquierdo, Tatiana},
}