This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-06-03 Creation time: 09:00:28 --- Number of references 21 article CisnerosdeLeon2025 Article 2025 10.1029/2024GC011953 Geochemistry, Geophysics, Geosystems 26 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105000323705&doi=10.1029%2f2024GC011953&partnerID=40&md5=2e4541f1f7d6c8c56afcdb2b2b138702 Cited by: 0; All Open Access, Gold Open Access Alejandro León Martin Danisik Axel K. Schmitt Julie C. Schindlbeck-Belo Steffen Kutterolf Tushar Mittal Jennifer M. Garrison Kenneth W. W. Sims article RN96 2024 10.22498/pages.32.2.80 Past Global Changes Magazine 32 80-81 2 Rodrigo Martínez-Abarca Liseth Pérez Mark Brenner Frederik Schenk Jonathan Obrist-Farner Alex Correa-Metrio Thorsten Bauersachs Antje Schwalb article Martínez-Abarca2024 Article 2024 10.1016/j.quascirev.2024.108985 Quaternary Science Reviews 344 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85206321128&doi=10.1016%2fj.quascirev.2024.108985&partnerID=40&md5=ff7b25c6b15689d2d57e662497e0457a Cited by: 0; All Open Access, Hybrid Gold Open Access Rodrigo Martínez-Abarca Liseth Pérez Thorsten Bauersachs Frederik Schenk Steffen Kutterolf Mark Brenner Thomas Guilderson Alex Correa-Metrio Flavio S. Anselmetti Robert Brown Daniel Ariztegui Laura Macario-González Esmeralda Cruz-Silva Juan Carlos Beltran-Martinez Mark Bush Mona Stockhecke Jason Curtis Antje Schwalb article Martínez-Abarca20231409 Lake Petén Itzá (Guatemala) possesses one of the longest lacustrine sediment records in the northern Neotropics, which enabled study of paleoclimate variability in the region during the last ∼400000 years. We used geochemical (Ti, Ca/(Ti+Fe) and Mn/Fe) and mineralogical (carbonates, gypsum, quartz, clay) data from sediment core PI-2 to infer past changes in runoff, lake evaporation, organic matter sources and redox conditions in the water column, caused by hydrological changes in the northern Neotropics during Marine Isotope Stages (MISs) 3-2. From 59 to 39 cal ka BP climate conditions were relatively wet, and the lake was marked by higher primary productivity and anoxic bottom waters. This wet environment was interrupted for two periods of possible low water level at 52 and 46 cal ka BP, when our data suggest higher evaporation, high terrestrial organic matter input and persistent oxic conditions. Between 39 and 23 cal ka BP, evaporation and input of terrestrial organic matter increased considerably, lake level declined, and lake bottom waters generally became oxic. These conditions reversed during the Last Glacial Maximum (23.5-18.0 cal ka BP), when runoff and lake productivity increased, and rising lake level caused bottom waters to again become anoxic. Comparison of our hydrologic proxy data with sea surface temperature anomalies between the eastern Pacific and the Caribbean suggests that changes in the intensity of the Caribbean Low-Level Jet (CLLJ) may have influenced long-term changes in runoff during MISs 3-2. Higher intensity of the CLLJ during the onset of MIS 3 and the LGM might have led to greater runoff into the lake, whereas the MIS 3-2 transition experienced a weaker CLLJ and consequently less runoff. A refined, high-resolution age-depth model for the PI-2 sediment core enabled us to identify millennial-scale Greenland interstadials (GIs) 14-2, Greenland stadials (GSs) 14-2 and Heinrich stadials (HSs) 5-1. In general, HSs and GSs were characterized by drier conditions. In contrast to GSs and HSs, GIs were characterized by greater runoff and overall wetter conditions, with the most pronounced GI peaks between 40 and 30 cal ka BP. Whereas GSs 9, 8, 7 and 6 began with abrupt increases in evaporation and ended with gradual increases in humidity, GSs 11 and 10 showed reversed patterns. The Lake Petén Itzá paleohydrology record, along with other regional paleoclimate records, led us to conclude that shifts in the position of the Intertropical Convergence Zone (ITCZ) altered moisture delivery to the lake on millennial timescales. During GSs and HSs, high evaporation from Petén Itzá (dry climate conditions) was associated with a more southerly position of the ITCZ, whereas wetter GIs prevailed during a more northerly ITCZ position. Although abrupt millennial-scale shifts in ITCZ and hydroclimate between GSs/HSs and GIs can be linked to instabilities in the Atlantic Meridional Overturning Circulation (AMOC), longer-term changes were additionally influenced by changes in atmospheric convection linked to modulations of the CLLJ in response to ΔSST between the equatorial Pacific and tropical Atlantic. © 2023 Rodrigo Martínez-Abarca et al. Article 2023 10.5194/cp-19-1409-2023 Climate of the Past 19 Copernicus Publications 1409 – 1434 7 Atlantic Ocean; Atlantic Ocean (Tropical); Guatemala [Central America]; Lake Peten Itza; Pacific Ocean; Pacific Ocean (Equatorial); Peten; Atlantic Multidecadal Oscillation; atmospheric convection; climate conditions; climate variation; hydrological change; intertropical convergence zone; lacustrine deposit; marine isotope stage; Neotropical Region; overturn; paleoclimate; primary production; redox conditions; sediment core https://www.scopus.com/inward/record.uri?eid=2-s2.0-85169905724&doi=10.5194%2fcp-19-1409-2023&partnerID=40&md5=4cce60068015bdb1e83c4241b83a4565 Cited by: 0 Rodrigo Martínez-Abarca Michelle Abstein Frederik Schenk David Hodell Philipp Hoelzmann Mark Brenner Steffen Kutterolf Sergio Cohuo Laura Macario-González Mona Stockhecke Jason Curtis Flavio S. Anselmetti Daniel Ariztegui Thomas Guilderson Alexander Correa-Metrio Thorsten Bauersachs Liseth Pérez Antje Schwalb article WOS:000921452700001 2023 10.1016/j.quascirev.2022.107935 QUATERNARY SCIENCE REVIEWS 301 Quaternary geochronology; Zircon; (UeTh)/He; SIMS; Central America; 40Ar/39Ar A. Cisneros Leon M. Danisik J. C. Schindlbeck-Belo S. Kutterolf A. K. Schmitt A. Freundt J. Kling K. -L. Wang H. -Y. Lee article Macario-González201820 A three-step integrative taxonomy approach combining molecular, morphological and ecological methods was successfully used to delimit species boundaries within three freshwater ostracode taxa of the Yucatán Peninsula (Mexico): Darwinulidae, Cypretta and Cypridopsis. These species groups were selected because they are well-suited paleobioindicators for late Pleistocene-early Holocene climatic reconstructions in the region, but their high inter-population morphological variability in recent communities represents a challenge for accurate transfer of information to fossil assemblages. As a first step, we analyzed the congruence of two genes of different inheritance, the mitochondrial COI (cytochrome c-oxidase subunit 1), and the nuclear 18S rDNA (small-subunit rDNA). Second, we tested the lineages discriminated for concordant differentiation in morphology, using morphometry of the carapace and typological analysis of the appendages. The third step assessed the association of occurrences and abundances of lineages to environmental variables. The integration of these methods revealed six hidden species within clades previously considered as a single widely distributed nominal species. Of these, Cypretta elongata sp. nov. and Alicenula yucatanensis sp. nov. are herein formally named and described given their morphological distinctness. Three species of Cypridopsis: Cypridopsis sp. [Ca1 ECO-CH-Z-09396], Cypridopsis sp. [Ca2 ECO-CH-Z-09398], Cypridopsis sp. [Ca3 ECO-CH-Z-09401] and a species that may represent a new genus, Cyprididae sp. [Ca1 ECO-CH-Z-09402], are allocated to a confirmed candidate full species status. Cypretta maya and Cypretta sp., considered a priori as separate species, are recognized as a single species with phenotypic plasticity, attributed to its broad ecological tolerances. For paleoenvironmental reconstructions these results have relevance because the particular carapace morphology of the new species can be correlated with specific ecological traits, thus constituting a potential tool for refining interpretations of fossil assemblages. © 2018 Elsevier GmbH Article 2018 English 00445231 10.1016/j.jcz.2018.04.002 Zoologischer Anzeiger 275 Elsevier GmbH 20 – 36 Yucatan Peninsula; Alicenula; Crustacea; Cypretta; Cyprididae; Cypridopsis; Darwinulidae; Ostracoda; crustacean; DNA; fossil assemblage; gene expression; Neotropical Region; paleoecology; paleoenvironment; reconstruction; taxonomy https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049071632&doi=10.1016%2fj.jcz.2018.04.002&partnerID=40&md5=082d5b431ce8b0f1b66854ac03b72aa4 Cited by: 11 Laura Macario-González Sergio Cohuo Manuel Elías-Gutiérrez Miguel Vences Liseth Pérez Antje Schwalb article Cohuo20175 Freshwater ostracodes from the Neotropical-Caribbean region are potentially excellent tools for evolutionary and paleoenvironmental studies but their use is limited, because integrated data in taxonomy, environmental, and geographical preferences of the species at large scale remain unknown. A total of 118 species were recorded in the Neotropical-Caribbean region based on existing literature and results from fieldwork. About 74% of the species are restricted to the region and most of them show limited distributional areas as a consequence of environmental heterogeneity. Based on Parsimony Analysis of Endemicity, five areas of endemism were identified: (1) southern Florida, (2) southern Mexico-northern Central America, (3) Cuba, (4) Lesser Antilles, and (5) northern Venezuela-Aruba-Curacao-Trinidad. The conservation status of these areas was revised and lake ecosystems with endemic taxa were proposed to be included in environmental protection initiatives. Biogeographical analysis showed a strong differentiation between the ostracode faunas of the Neotropical-Caribbean region and the Neotropical-Neogen region. Few exchanges of species were attributed to ecological and geographical barriers such as volcanism and irregular orography. Faunal affinities within the Neotropical-Caribbean region indicated closer relationship between southern Mexico, southern Florida and the Antilles suggesting a common biogeographical history. Middle Central America and Chiapas-Guatemala highlands were discriminated as isolated regions. © 2016, Springer International Publishing Switzerland. Article 2017 English 00188158 10.1007/s10750-016-2747-1 Hydrobiologia 786 Springer International Publishing 5 – 21 1 Crustacea; Ostracoda https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962713883&doi=10.1007%2fs10750-016-2747-1&partnerID=40&md5=d9c193e6de29dcd661b533197058a25e Cited by: 17 Sergio Cohuo Laura Macario-González Liseth Pérez Antje Schwalb article Kutterolf2016200 Lake Petén Itzá, northern Guatemala, lies within a hydrologically closed basin in the south-central area of the Yucatán Peninsula, and was drilled under the auspices of the International Continental Scientific Drilling Program (ICDP) in 2006. At 16°55′N latitude, the lake is ideally located for study of past climate and environmental conditions in the Neotropical lowlands. Because of its great depth (>160 m), Lake Petén Itzá has a record of continuous sediment accumulation that extends well into the late Pleistocene. A key obstacle to obtaining long climate records from the region is the difficulty of establishing a robust chronology beyond ∼40 ka, the limit of 14C dating. Tephra layers within the Lake Petén Itzá sediments, however, enable development of age/depth relations beyond 40 ka. Ash beds from large-magnitude, Pleistocene-to-Holocene silicic eruptions of caldera volcanoes along the Central American Volcanic Arc (CAVA) were found throughout drill cores collected from Lake Petén Itzá. These ash beds were used to establish a robust chronology extending back 400 ka. We used major- and trace-element glass composition to establish 12 well-constrained correlations between the lacustrine tephra layers in Lake Petén Itzá sediments and dated deposits at the CAVA source volcanoes, and with their marine equivalents in eastern Pacific Ocean sediments. The data also enabled revision of eight previous determinations of erupted volumes and masses, and initial estimates for another four eruptions, as well as the designation of source areas for 14 previously unknown eruptions. The new and revised sedimentation rates for the older sediment successions identify the interglacial of MIS5a between 84 and 72 ka, followed by a stadial between 72 and 59 ka that corresponds to MIS4. We modified the age models for the Lake Petén Itzá sediment sequences, extended the paleoclimate and paleoecological record for this Neotropical region to ∼400 ka, and determined the magnitude and timing of CAVA eruptions. © 2016 Elsevier Ltd Article 2016 English 02773791 10.1016/j.quascirev.2016.08.023 Quaternary Science Reviews 150 Elsevier Ltd 200 – 220 GEOMAR Helmholtz Center for Ocean Research Kiel, Kiel, 24148, Germany; Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Switzerland; Department of Earth Sciences, University of Geneva, Rue des Maraichers 13, Geneva, 1205, Switzerland; Department of Geological Sciences and Land Use and Environmental Change Institute (LUECI), University of Florida, Gainesville, FL 32611, United States; Department of Earth Sciences, University of Cambridge, United Kingdom; Swiss Federal Institute of Technology, ETH, Zurich, 8092, Switzerland; Institute of Geology, Universidad Nacional Autónoma de México, Mexico; Institute of Geosystems and Bioindication (IGeo), Technische Universität Braunschweig, Germany; Institute of Earth Sciences, Academia Sinica, Taipei, 11529, Taiwan Guatemala [Central America]; Lake Peten Itza; Pacific Ocean; Pacific Ocean (East); Peten; Yucatan Peninsula; Sediments; Trace elements; Volcanoes; CAVA; Explosive volcanism; ICDP; Paleoclimates; Tephrochronology; caldera; drilling; explosive volcanism; island arc; lowland environment; Neotropical Region; paleoclimate; Pleistocene; sediment analysis; sedimentation; tephrochronology; volcanic eruption; Lakes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84984621696&doi=10.1016%2fj.quascirev.2016.08.023&partnerID=40&md5=fd7408c4491b6322e26e1c2dc71bdb49 Cited by: 36; All Open Access, Bronze Open Access S. Kutterolf J.C. Schindlbeck F.S. Anselmetti D. Ariztegui M. Brenner J. Curtis D. Schmid D.A. Hodell A. Mueller L. Pérez W. Pérez A. Schwalb M. Frische K.-L. Wang article Wojewódka2016151 Cladocera species composition was analyzed in surface sediments of 29 lakes in Central America (Guatemala, El Salvador and Honduras). The material studied was collected with an Ekman grab in autumn 2013 from lakes located in lowland, highland and mountain regions. The study revealed high variability in qualitative and quantitative composition of subfossil Cladocera. A total of 31 Cladocera species (5 planktonic and 26 littoral) were identified, as well as 4 morphotypes that could not be identified (NRR 1-4). Planktonic Bosminidae and Daphniidae were the most abundant families. Daphniidae were restricted to water bodies in mountain regions, whereas Bosminidae were widely distributed in lakes with different abiotic conditions. Moreover, Bosminidae species also occurred in highly mineralized waters (> 900 μS cm–1). The great majority of the identified Cladocera species belonged to the littoral family Chydoridae. Chydorus cf. sphaericus was the most common species (found in 20 lakes), which probably reflects its tolerance to a wide spectrum of habitat conditions. Cluster analysis discriminated 6 groups of Cladocera species with a high correlation level within groups (≥0.8), which showed different types of correlation with lake characteristics and environmental variables. Canonical correspondence analysis (CCA) showed that altitude and secondly water electrical conductivity were the most important drivers of Cladocera species composition in the region studied. Furthermore, CCA analysis indicated lowland lakes with low water transparency were also characterized by peculiar species assemblages. © 2016, Page Press Publications. All rights reserved. Article 2016 English 19475721 10.4081/aiol.2016.6266 Advances in Oceanography and Limnology 7 Page Press Publications 151 – 162 2 El Salvador [Central America]; Guatemala [Central America]; Honduras; Bosminidae; Chydoridae; Chydorus sphaericus; Cladocera; Daphniidae; cluster analysis; crustacean; fossil assemblage; lacustrine deposit; morphotype; paleoecology; paleontology; plankton https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054003587&doi=10.4081%2faiol.2016.6266&partnerID=40&md5=dae9834831d490ac9200cb46b4c5f7a5 Cited by: 11; All Open Access, Gold Open Access, Green Open Access Marta Wojewódka Edyta Zawisza Sergio Cohuo Laura Macario-González Antje Schwalb Izabela Zawiska Liseth Pérez article Pérez201396 Modern lake hydrodynamics, ostracode species autecology, stable isotopes (δ18O and δ13C) of multiple ostracode species, ostracode taphonomy and sediment geochemistry were studied to improve interpretation of the late Pleistoceneeearly Holocene (~24-10 ka) stable isotope record of ostracodes in sediment core PI-6 from Lago Petén Itzá, northern Guatemala. Oxygen and carbon stable isotopes in modern and fossil species assemblages of Lago Petén Itzá were used as indicators of changes in the balance between evaporation and precipitation, past lake level and carbon source. Ostracode taphonomy was used to detect past periods of strong currents, high-energy environments, and possible partial or full mixing of the lake. The modern lake water isotopic composition displays clear seasonal differences that are independent of lake level fluctuations. Modern benthic species displayed lower δ18O and δ13C values than nektobenthic species, with differences of 3.0‰ and 5.3‰, respectively. Valves of nektobenthic species display higher values of d13C because these ostracodes live in shallower environments among abundant algae and aquatic plants, where productivity is high. The benthic species Limnocythere opesta Brehm, 1939 displayed the smallest average offset from d18O water (0.3‰) and the largest offset from δ13CDIC values (4.1‰) among studied ostracode species. Nektobenthic species Heterocypris punctata Keyser, 1975 displayed the smallest difference relative to the δ13CDIC values (0.1‰). Late Pleistoceneeearly Holocene climate conditions and water levels in Lago Petén Itzá can be summarized as follows: 1) high lake levels and cold conditions (Last Glacial Maximum [LGM], ~24-19 ka), 2) fluctuating lake levels and cold conditions (Heinrich Stadial 1 [HS1], ~19-15 ka), 3) high lake levels and warm and wetter conditions (Bølling-Allerød [BA], ~15-13 ka), 4) low lake levels and dry conditions (Younger Dryas [YD], ~13-11.5 ka) and 5) high lake levels and warm and wetter conditions (early Holocene, ~11.5-10.0 ka). Average lake level fluctuation in Lago Petén Itzá during the late Pleistoceneeearly Holocene was as much as ~25 m. Ostracode analyses suggest that the LGM was characterized by relatively low d18O (4.7 to 6.0&), and d13C values (7.1 to 6.4‰) in ostracode valves, high inferred water depths and high percentages of broken adult and juvenile valves (>66%), suggesting a high-energy environment, strong currents, partial to full mixing, downslope transport, colder water temperatures and wetter conditions. An increase in the relative abundance of the benthic species L. opesta and higher numbers of broken valves suggest heavy precipitation events during the LGM (~23.7, 21.7, 20.8 and 20.1 ka). HS1 was predominantly dry, but we identified times when lake levels were slightly higher, at the onset of the deglacial and a brief period (~17-16 ka) between HS1b and HS1a. All studied climate proxies indicate wetter and warmer conditions and lake system stability during the BA. Lake levels dropped during the YD and gradually increased during the Preboreal and early Holocene. We demonstrate that modern and fossil ostracode isotopic signatures, species assemblages and taphonomy can be used together with physical and geochemical variables in Lago Petén Itzá sediments to make high-resolution inferences about late Pleistoceneeearly Holocene environmental changes in the lowland Neotropics. © 2012 Elsevier Ltd. Article 2013 English 02773791 10.1016/j.quascirev.2012.10.044 Quaternary Science Reviews 66 Elsevier Ltd 96 – 111 Guatemala [Central America]; Lake Peten Itza; Peten; algae; Heterocypris punctata; Limnocythere; Ostracoda; Climate change; Fluid dynamics; Geochemistry; Hydrodynamics; Isotopes; Mixing; Sediments; System stability; Water levels; Autecology; Environmental change; Holocenes; Lake level changes; Neotropics; Ostracoda; Stable isotopes; abundance; autecology; benthos; fossil assemblage; fossil record; hydrodynamics; isotopic composition; lake level; Neotropical Region; ostracod; oxygen isotope; paleoecology; paleohydrology; paleolimnology; Pleistocene-Holocene boundary; seasonal variation; sediment core; stable isotope; taphonomy; Younger Dryas; Lakes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84881377247&doi=10.1016%2fj.quascirev.2012.10.044&partnerID=40&md5=f1b2ebb469373e248f0aaaed0b143311 Cited by: 27 Liseth Pérez Jason Curtis Mark Brenner David Hodell Jaime Escobar Socorro Lozano Antje Schwal article Pérez2011407 This study presents limnological and morphological characteristics, physical and chemical properties of waters, and geochemistry of surface sediments for 63 aquatic ecosystems located on the karst Yucatán Peninsula and surrounding areas of Belize and the Guatemalan highlands and eastern lowlands. Our principal goal was to classify the aquatic systems based on their water variables. A principal component analysis (PCA) of the surface water chemistry data showed that a large fraction of the variance (29%) in water chemistry is explained by conductivity and major ion concentrations. The broad conductivity range, from 168 to 55,300 μS cm-1 reflects saline water intrusion affecting coastal aquatic environments, and the steep NW-S precipitation gradient, from ~450 to>3,200 mm year-1. Coastal waterbodies Celestún and Laguna Rosada displayed the highest conductivities. Minimum surface water temperatures of 21.6°C were measured in highland lakes, and warmest temperatures, up to 31.7°C, were recorded in the lowland waterbodies. Most lakes showed thermal stratification during the sampling period, with the exception of some shallow (<10 m) systems. Lakes Chichancanab, Milagros, and Bacalar displayed sulfate-rich waters. Waters of sinkholes had relatively high conductivities (<3,670 μS cm-1) and a broad range of δ18O values (-4.1 to +3.8%). Ca, HCO3, and SO4 dominated the waters of the lowland lakes, whereas Na was the dominant cation in highland lakes. Coastal aquatic ecosystems were dominated by Na and Cl. Cluster analysis based on surface water variables classified aquatic environments of the lowlands and highlands into three groups: (1) lowland lakes, ponds, wetlands, and coastal waterbodies (2) highland lakes, and (3) sinkholes and rivers. A broad trophic state gradient was recorded, ranging from the eutrophic Lake Amatitlán and the Timul sinkhole to oligotrophic Laguna Ayarza, with the highest water transparency (11.4 m). We used major and trace elements in surface sediments to assess pollution of waterbodies. Lakes Amatitlán, Atescatempa, El Rosario, Cayucón, Chacan-Lara, La Misteriosa, rivers Subín and Río Dulce, the wetland Jamolún, and the sinkhole Petén de Monos showed evidence of pollution and urban development. Their surface sediments displayed high concentrations of As, Cu, Fe, Ni, Pb, Se, Zn, and Zr, which suggest moderate to strong pollution. © Springer Science+Business Media B.V. 2010. Article 2011 English 00188158 10.1007/s10750-010-0552-9 Hydrobiologia 661 Kluwer Academic Publishers 407 – 433 1 Belize [Central America]; Guatemala [Central America]; Mexico [North America]; Yucatan Peninsula; hydraulic conductivity; karst; lake pollution; limnology; morphology; Neotropical Region; physicochemical property; pollution effect; principal component analysis; saline intrusion; surface water; trace element; urban development; water temperature https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957921074&doi=10.1007%2fs10750-010-0552-9&partnerID=40&md5=094e24633a5ab3db9ac3940a6beea82e Cited by: 59 Liseth Pérez Rita Bugja Julia Lorenschat Mark Brenner Jason Curtis Philipp Hoelzmann Gerald Islebe Burkhard Scharf Antje Schwalb article Pérez201159 We inferred late Pleistocene and early Holocene (24-10 ka BP) environmental conditions in and around Lago Petén Itzá,Guatemala from ostracode remains in the lake sediments. Multivariate statistics were run on autecological information for 29 extant ostracode species collected in 63 aquatic ecosystems on the Yucatán Peninsula along a steep, increasing NW-S precipitation gradient and across a large altitudinal range. Conductivity and water depth are the most important factors that shape ostracode communities. Transfer functions were developed and applied to fossil ostracode assemblages in a ~76-m sediment core (PI-6, ~85 ka) taken in 71 m of water from Lago Petén Itzá, to infer past shifts in conductivity and water level. Results suggest climate was cold and wet during the Last Glacial Maximum (LGM). Alternating dry and wet conditions characterized the deglacial. Early Holocene climate was warmer and wetter. The LGM was characterized by low ostracode species richness (4 spp.) and abundance (<940 valves g-1), dominance of benthic over nektobenthic taxa, abundant Physocypria globula, conductivity as low as 190 μS cm-1, and clay-rich sediments with relatively high total organic carbon and low C/N ratios (<14), suggesting relatively deeper water at the core site associated with abundant precipitation. Greatest water depth at the core site during the LGM occurred late in the period and was ~50 m. The deglacial was characterized by drier conditions, higher ostracode species richness (6 spp.) and abundances up to 18,115 valves g-1, dominance of nektobenthic species, and presence of shallow-water and littoral-zone indicators such as Heterocypris punctata and Strandesia intrepida, conductivity up to 550 μS cm-1, C/N ratios as high as 37, and gypsum deposition. Lowest inferred lake depth at the core site during the deglacial was ~20 m. The early Holocene was characterized by high numbers of ostracode remains, up to 25,500 valves g-1, and the presence of L. opesta and P. globula. Cytheridella ilosvayi was absent from late Pleistocene sediments, suggesting it colonized northern Central America during the Holocene. © 2011 Springer Science+Business Media B.V. Article 2011 English 09212728 10.1007/s10933-011-9514-0 Journal of Paleolimnology 46 59 – 74 1 Guatemala [Central America]; Lake Peten Itza; Peten; Heterocypris punctata; Ostracoda; Physocypria; abundance; aquatic ecosystem; benthos; carbon; community structure; crustacean; deglaciation; dominance; environmental change; environmental conditions; Holocene; intertidal environment; lacustrine deposit; Last Glacial Maximum; lowland environment; multivariate analysis; Neotropical Region; nitrogen; organic carbon; precipitation intensity; sediment analysis; shallow water; species richness; transfer function; water depth https://www.scopus.com/inward/record.uri?eid=2-s2.0-79957922065&doi=10.1007%2fs10933-011-9514-0&partnerID=40&md5=9445fc9e154af1fb35aaa1c62ad05e15 Cited by: 33 Liseth Pérez Peter Frenzel Mark Brenner Jaime Escobar Philipp Hoelzmann Burkhard Scharf Antje Schwalb article 2010 09 en 0034-7744 10.15517/rbt.v58i2.5252 Revista de Biologia Tropical 58 scielo 871 - 895 Liseth Pérez Julia Lorenschat Rita Bugja M. Brenner Burkhard Scharf Antje Schwalb article Pérez2010146 We analyzed modern ostracode species assemblages and water column physico-chemical characteristics in Lago Péten Itzá, Guatemala. Lake waters are dominated by sulfate, bicarbonate, calcium and magnesium and display a total ion concentration of ~11 meq L-1. Eleven extant ostracode species were identified. We found higher abundances of living ostracodes, as well as relatively higher species richness (eight species) and biodiversity (H of 1.6) between the littoral zone and a water depth of <20 m. At water depths >40 m, these variables all decreased. The thermocline is located at a water depth of ~20-40 m. Cluster analysis revealed three water depth ranges in the lake of importance to ostracode distribution: 1) littoral zone (0.1-3 m), 2) water depths from the base of the littoral zone to the base of the thermocline (3-40 m), and 3) water depths below the thermocline (40-160 m). The assemblage Darwinula-Heterocypris-Pseudocandona-Strandesia is characteristic of waters <15 m. The Cypridopsis-Cytheridella-Limnocythere assemblage characterizes waters <40 m and Physocypria indicates waters >40 m. Ostracode taxa from Lago Petén Itzá show specific ecological preferences related to water depth and associated physico-chemical characteristics, thus illustrating the potential of ostracodes as indicators of lake level changes and hydrodynamics. Article 2010 Feb. English 11295767 10.3274/JL10-69-1-14 Journal of Limnology 69 146 – 159 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-77956866062&doi=10.3274%2fJL10-69-1-14&partnerID=40&md5=55526e64bba06d9068c55d92858098e0 Cited by: 41 Liseth Pérez Julia Lorenschat Rita Bugja Mark Brenner Burkhard Scharf Antje Schwalb article Mueller20101220 Long sediment cores were collected in spring 2006 from Lake Petén Itzá, northern Guatemala, in water depths ranging from 30 to 150 m, as part of an International Continental Scientific Drilling Program project. The sediment records from deep water consist mainly of alternating clay, gypsum and carbonate units and, in at least two drill sites, extend back >200 kyr. Most of the lithostratigraphic units are traceable throughout the basin along seismic reflections that serve as seismic stratigraphic boundaries and suggest that the lithostratigraphy can be used to infer regional palaeoenvironmental changes. A revised seismic stratigraphy was established on the basis of integrated lithological and seismic reflection data from the basin. From ca 200 to ca 85 ka, sediments are dominated by carbonate-clay silt, often interbedded with sandy turbidites, indicating a sediment regime dominated by detrital sedimentation in a relatively humid climate. At ca 85 ka, an exposure horizon consisting of gravels, coarse sand and terrestrial gastropods marks a lake lowstand or partial basin desiccation, indicating dry climate conditions. From ca 85 to ca 48 ka, transgressive carbonate-clay sediments, overlain by deep-water clays, suggest a lake level rise and subsequent stabilization at high stage. From ca 48 ka to present, the lithology is characterized by alternating clay and gypsum units. Gypsum deposition correlates with Heinrich Events (i.e. dry climate), whereas clay units coincide with more humid interstadials. © 2010 The Authors. Journal compilation © 2010 International Association of Sedimentologists. Article 2010 English 13653091 10.1111/j.1365-3091.2009.01144.x Sedimentology 57 1220 – 1245 5 Guatemala [Central America]; Lake Peten Itza; Peten; Gastropoda; Anoxic sediments; Carbonation; Climatology; Core drilling; Deepwater drilling; Drills; Gypsum; Lakes; Lithology; Offshore oil wells; Sedimentology; Seismic waves; Seismology; Guatemala; Lake level changes; Lake sediments; Palaeoclimatology; Seismic stratigraphy; climate conditions; deep drilling; deposition; environmental change; Heinrich event; lacustrine deposit; lake level; lithostratigraphy; paleoclimate; paleoenvironment; Quaternary; sediment core; sedimentation; seismic reflection; seismic stratigraphy; Stratigraphy https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955244122&doi=10.1111%2fj.1365-3091.2009.01144.x&partnerID=40&md5=a8a71906e9f39b8c9df5e45ec5da9a39 Cited by: 34; All Open Access, Green Open Access Andreas D. Mueller Flavio S. Anselmetti Daniel Ariztegui Mark Brenner David A. Hodell Jason H. Curtis Jaime Escobar Adrian Gilli Dustin A. Grzesik Thomas P. Guilderson Steffen Kutterolf Michael Plötze article Pérez2010490 Two ~40-cm-long sediment cores, PI-SC-1-10m and PI-SC-2-40m, were recovered at 10 and 40 m water depth, respectively, from Lago Petén Itzá, in the Department of Petén, northern Guatemala. The cores span the last ~525 years of sediment accumulation in the basin. This study explores lake level and trophic state changes that Lago Petén Itzá has experienced since European contact in the early 1500s. We inferred past environmental variability using changes in sediment geochemistry and fluctuations in relative species abundances of ostracode and chironomid fossil assemblages. Changes in concentrations of organic matter (OM), carbonate, total carbon (TC), total nitrogen (TN), C/N ratios, bromine (Br), and faunal relative abundances were used to infer changes in the trophic status of the lake. Cultural eutrophication began in the 1930s, and anthropogenic impact increased significantly after ~1970. Higher linear sedimentation rates, up to 9.1 mm yr-1, began recently. They are attributed to increases in riparian settlement, deforestation and associated land use changes, which led to accelerated soil erosion. An ostracode-based transfer function was applied to assemblages in core PI-SC-1-10m, which enabled us to identify periods when lake level fluctuated. Such historical fluctuations in lake levels were driven primarily by changes in rainfall. Past lake levels can be summarized as follows: (1) fluctuating, high lake levels from ~1550s to the 1730s and from the early 1940s to 2005, and (2) stable, lower lake levels from about 1750 to the early 1900s. Higher relative abundance of the ostracode Physocypria globula and higher rubidium (Rb) concentrations indicate higher lake levels than today. Chironomids also show sharp fluctuations along the cores that could be related to water level changes. The presence of chironomid assemblages Chironomus, Procladius, and Einfeldia from 1960-2000 AD shows high productivity levels. The Lago Petén Itzá sediment record indicates a generally arid Little Ice Age (LIA), with exceptions around 1580 and 1650 when high lake levels similar to those of the 20th century, i.e. ~5 m higher than today, indicate more humid conditions. Article 2010 Spanish 10268774 Revista Mexicana de Ciencias Geologicas 27 490 – 507 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649702880&partnerID=40&md5=f2bc7c0b10e6c4748b2eb0fd71bb612f Cited by: 26 Liseth Pérez Rita Bugja Julieta Massaferro Philip Steeb Robert Geldern Peter Frenzel Mark Brenner Burkhard Scharf Antje Schwalb article Hodell20081152 Drill cores obtained from Lake Petén Itzá, Petén, Guatemala, contain a ∼85-kyr record of terrestrial climate from lowland Central America that was used to reconstruct hydrologic changes in the northern Neotropics during the last glaciation. Sediments are composed of alternating clay and gypsum reflecting relatively wet and dry climate conditions, respectively. From ∼85 to 48 ka, sediments were dominated by carbonate clay indicating moist conditions during Marine Isotope Stages (MIS) 5a, 4, and early 3. The first gypsum layer was deposited at ∼48 ka, signifying a shift toward drier hydrologic conditions and the onset of wet-dry oscillations. During the latter part of MIS 3, Petén climate varied between wetter conditions during interstadials and drier states during stadials. The pattern of clay-gypsum (wet-dry) oscillations during the latter part of MIS 3 (∼48-23 ka) closely resembles the temperature records from Greenland ice cores and North Atlantic marine sediment cores and precipitation proxies from the Cariaco Basin. The most arid periods coincided with Heinrich Events when cold sea surface temperatures prevailed in the North Atlantic, meridional overturning circulation was reduced, and the Intertropical Convergence Zone (ITCZ) was displaced southward. A thick clay unit was deposited from 23 to 18 ka suggesting deposition in a deep lake, and pollen accumulated during the same period indicates vegetation consisted of a temperate pine-oak forest. This finding contradicts previous inferences that climate was arid during the Last Glacial Maximum (LGM) chronozone (21±2 ka). At ∼18 ka, Petén climate switched from moist to arid conditions and remained dry from 18 to 14.7 ka during the early deglaciation. Moister conditions prevailed during the warmer Bolling-Allerod (14.7-12.8 ka) with the exception of a brief return to dry conditions at ∼13.8 ka that coincides with the Older Dryas and meltwater pulse 1A. The onset of the Younger Dryas at 12.8 ka marked the return of gypsum and hence dry conditions. The lake continued to precipitate gypsum until ∼10.3 ka when rainfall increased markedly in the early Holocene. © 2008 Elsevier Ltd. All rights reserved. Article 2008 English 02773791 10.1016/j.quascirev.2008.02.008 Quaternary Science Reviews 27 1152 – 1165 11-12 Arctic; Atlantic Ocean; Atlantic Ocean (North); Cariaco Basin; Caribbean Sea; Central America; Greenland; Guatemala [Central America]; Lake Peten Itza; Peten; Drilling; Glaciers; Gypsum; Isotopes; Sediments; Soil moisture; climate change; climate conditions; deglaciation; gypsum; Holocene; hydrodynamics; ice core; interstadial; intertropical convergence zone; Last Glacial Maximum; last glaciation; lowland environment; Neotropical region; oceanic circulation; precipitation (chemistry); precipitation intensity; proxy climate record; reconstruction; sediment core; stratigraphy; Younger Dryas; Central America; Drill cores; Terrestrial climate; Climate change https://www.scopus.com/inward/record.uri?eid=2-s2.0-44549085036&doi=10.1016%2fj.quascirev.2008.02.008&partnerID=40&md5=d80ca0680931a5de11cd65199326174c Cited by: 196; All Open Access, Green Open Access David A. Hodell Flavio S. Anselmetti Daniel Ariztegui Mark Brenner Jason H. Curtis Adrian Gilli Dustin A. Grzesik Thomas J. Guilderson Andreas D. Müller Mark B. Bush Alexander Correa-Metrio Jaime Escobar Steffen Kutterolf article Anselmetti2007915 We used seismic and sediment core data to quantify soil erosion rates for the past ∼6000 yr in the closed catchment of Lake Salpetén, in the tropical lowlands of northern Guatemala. The region was affected by ancient Maya land use from before ca. 1000 B.C. to A.D. 900. This period of human impact coincided with deposition in the lake of a detrital unit (Maya Clay) as much as 7 m thick that contrasts sharply with the relatively organic-rich gyttja deposited both before and after Maya occupation of the watershed. The greatest soil loss, with mean sustained values of ∼1000 t/kM2 yr-1, occurred in the Middle and Late Preclassic Periods (700 B.C. to A.D. 250), associated with relatively low Maya population densities. Soil erosion slowed during the period of maximum population density in the Late Classic Period (A.D. 550-830), indicating a decoupling between human population density and soil erosion rate. The most rapid soil loss occurred early during initial land clearance, suggesting that even low numbers of people can have profound impacts on lowland tropical karst landscapes. © 2007 The Geological Society of America. 2007 English 00917613 10.1130/G23834A.1 Geology 35 915-918 Geological Institute, Swiss Federal Institute of Technology, ETH, 8092 Zurich, Switzerland; Department of Geological Sciences, University of Florida, Gainesville, FL 32611, United States; Section of Earth Sciences, University of Geneva, 1205 Geneva, Switzerland; Department of Geology and Planetary Sciences, University of Pittsburgh, Pittsburgh, PA 15260, United States; Swiss Federal Institute of Aquatic Science and Technology (Eawag), Ueberlandstr. 133, CH-8600 Duebendorf, Switzerland 10 Lake sediments; Seismic stratigraphy; Soil erosion rate, Erosion; Lakes; Sediments; Seismology; Stratigraphy, Structural geology, anthropogenic effect; Classic period; core analysis; deforestation; deposition; erosion rate; gyttja; lacustrine deposit; land use; seismic data; seismic stratigraphy; soil erosion, Central America; Guatemala [Central America] https://www.scopus.com/inward/record.uri?eid=2-s2.0-35448988374&doi=10.1130%2fG23834A.1&partnerID=40&md5=ed23aaf6f8862ef9839e0b70c30e503f cited By 153 F.S. Anselmetti D.A. Hodell D. Ariztequi M. Brenner M.F. Rosenmeier article Anselmetti200652 We used seismic images and sedimentary data from piston cores to conduct a sequence stratigraphic analysis of sediments in Lake Petén Itzá, northern Guatemala. Our results document lake level fluctuations in this lowland Neotropical region that were related to glacial-to-interglacial climate change during the Late Pleistocene. A bathymetric survey of Lake Petén Itzá (area = 100 km2) revealed a maximum water depth of ∼160 m and the existence of a deep cryptodepression that extends 50 m below modern sea level. The great depth suggests that the basin held water even during arid conditions associated with full glacial periods. Lake Petén Itzá may thus possess the only long continuous lacustrine sediment record of Late Pleistocene environmental and climate change in the lowland Neotropics. Two seismic reflection campaigns imaged the subsurface basin sediments that overlie basement. The sediment package was divided into four major seismic sequences (T, G, R, and B). Sequences are separated by unconformities that represent depositional cycles related to lake level fluctuations. Sediments of the uppermost sequence (T) were recovered and radiocarbon-dated in Kullenberg piston cores taken along a water depth transect. Seismic profiles reveal a basin-wide paleoshoreline just below sequence T at ∼56 m below present lake level. This constructional feature formed during a lowstand of the last glacial period when the lake was reduced to only ∼13% of its present volume. In cores taken landward of the paleoshoreline, Late Glacial-age deposits consist of paleosols, indicating subaerial exposure. Basinward of the shoreline, sediments are composed of dense gypsum sands and interbedded silty clays, reflecting authigenic gypsum formation under arid climate conditions. The top of the soil horizon and cessation of gypsum precipitation are represented by a strong seismic reflection (t). It marks the base of the uppermost seismic sequence T and is dated in several cores between ∼11.1 and 10.2 cal kyr BP. Lake level rose quickly at this time in response to a shift from arid-to-humid climate conditions at the Late Glacial/Early Holocene transition. We infer a similar sediment response to climate variations in the older stratigraphic sequences (G, R, and B), related to earlier glacial-to-interglacial and stadial-to- interstadial cycles. Older sequences are also distinguished from one another by erosional unconformities that probably represent major lake level falls. Future recovery of the older stratigraphic record by drilling in Lake Petén Itzá will provide ages for these older units and enable us to test the depositional model inferred from seismic stratigraphy. © 2005 Elsevier B.V. All rights reserved. Article 2006 English 00310182 10.1016/j.palaeo.2005.06.037 Palaeogeography, Palaeoclimatology, Palaeoecology 230 52 – 69 1-2 Central America; Guatemala [Central America]; climate variation; lacustrine deposit; paleoclimate; Quaternary; seismic stratigraphy https://www.scopus.com/inward/record.uri?eid=2-s2.0-29744467735&doi=10.1016%2fj.palaeo.2005.06.037&partnerID=40&md5=a9b299ba54b9d245bc7442693db63f78 Cited by: 71 F.S. Anselmetti D. Ariztegui D.A. Hodell M.B. Hillesheim M. Brenner A. Gilli J.A. McKenzie A.D. Mueller article Hodell200625 2006 English 18168957 10.2204/iodp.sd.3.02.2006 Scientific Drilling 1 25-29 Department of Geological Sciences, Land Use and Environmental Change Institute (LUECI), University of Florida, 441 Williamson Hall, Gainesville, FL 32611, United States; Geological Institute, Swiss Federal Institute of Technology, ETH, Zurich Universtätsstrasse 16, CH-8092 Zurich, Switzerland; Department of Geological Sciences, Land Use and Environmental Change Institute (LUECI), University of Florida, 441 Williamson Hall, Gainesville, FL 32611, United States; Institut Forel, Department of Geology and Paleontology, University of Geneva, Geneva, Switzerland 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884525372&doi=10.2204%2fiodp.sd.3.02.2006&partnerID=40&md5=3e5fdc811aad31789ba62861eeea668d cited By 23 D. Hodell F. Anselmetti M. Brenner D. Ariztegui G. Alfaro J. Blijdenstein C. Bronnimann K. Brady M. Bush E. Chapron J. Curtis E. Endsley J. Escobar C. Gallup V. Gamble A. Gilli S. Girardclos D. Grzesik R. Hofmann G. Islebe A. Mueller A. Noren L. Pérez F. Thevenon article Peterson2005322 During its Classic period (250-950 A.D.), Maya civilization reached a zenith. At its peak, around 750 A.D., the population may have topped 13 million. Then, between about 750 and 950 A.D., their society imploded. The Maya abandoned what had been densely populated urban centers, leaving their impressive stone edifices to fall into ruin. The demise of Maya civilization (which archaeologists call "the terminal Classic collapse") has been one of the great anthropological mysteries of modern times. What could have happened? Scholars have advanced a variety of theories over the years, pinning the fault on everything from internal warfare to foreign intrusion, from widespread outbreaks of disease to a dangerous dependence on monocropping, from environmental degradation to climate change. Some combination of these and other factors may well be where the truth lies. However, in recent years, evidence has mounted that unusual shifts in atmospheric patterns took place near the end of the Classic Maya period, lending credence to the notion that climate, and specifically drought, indeed played a hand in the decline of this ancient civilization. Article 2005 English 00030996 10.1511/2005.54.968 American Scientist 93 Sigma Xi, Scientific Research Society 322 – 329 4 Social aspects; Collapse; Maya civilization; archaeological evidence; demography; Climatology https://www.scopus.com/inward/record.uri?eid=2-s2.0-23144456862&doi=10.1511%2f2005.54.968&partnerID=40&md5=3f1a5f9ad7f799671f4bbc9e1c311e73 Cited by: 52 Larry C. Peterson Gerald H. Haug