This is anopenaccess article undertheCCBY-NC-SAThis Universidad NacionalAutónoma de México. Peer Reviewing under the responsibility of 14,2020 Manuscript September accepted: Corrected manuscript received: August 25,2020 Manuscript received: March 16,2020 BSGM2021v73n1a171220 http://dx.doi.org/10.18268/A171220. de la Sociedad Geológica Mexicana, 73 (1), central Mexico: Boletín the rain shadowsof M., variability during the last three millennia in Wojewódka-Przybył, Blaauw, M.,Romero, E., F., 2021,Environmental Zawisza, Olivares-Casillas, G., Correa-Metrio, A., How tocitethisarticle: [email protected] * Corresponding author:(A.Correa-Metrio) Belfast, UnitedKingdom. Queen’s University Belfast,BT71NN, 4 00818, Twarda 51/55,Poland. Sciences, Research Centre inWarzaw,emy of 3 04510, Coyoacán, CDMX,Mexico. Autónoma deMéxico, Ciudad Universitaria, 2 MX, Mexico. Ciudad Universitaria, 04510,Coyoacán,CD Universidad NacionalAutónoma deMéxico, 1 Maarten Gustavo central Variabilidad ambientaldurantelosúltimostresmileniosenlassombrasdelluviaMéxico central Mexico Environmental variabilityduringthelastthreemillenniainrainshadowsof license(https://creativecommons.org/licenses/by-nc-sa/4.0/) colo Natural andBuiltEnvironment, School of GeologicalSciences, Polish Acad Institute of Posgrado en Ciencias del Mar y Limnología, Instituto de Geología, Universidad Nacional Olivares-Casillas Blaauw 4 , Francisco 1 Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín , Alex Romero - - Correa-Metrio nhg-rqec ek fdetrital material. The in high-frequencyof peaks the precipitation reflected torrentialitya high of the MWP was associated with low lake levels and and regional climatic variability.Metztitlán, In dynamiclacustrine systems, coupled with global passed by the record. Our record pointsto highly trine dynamicsthrough the time period encom chemical analyses were used to reconstruct lacus Madrethe Sierra Oriental. Cladoceran and geo in a Biosphere Reserve under the rain shadow of recordsedimentary from Lake Metztitlán, located change. Here we present a 3,000-year modern the lightof on conservation purposes environmental variability, aparamount tool for alies wouldresponseecosystem light on shed to regionalUnderstanding responses to these anom and their interaction with continental . regionalsuch seasurfacetemperaturesfactors as variabilityglobal modes have been modulated by Niño anomaliesinthe Equatorial Pacific. These variabilityassociatedbeen mostly has with El average temperatures, respectively. Precipitation (LIA), characterized by higher and lower than Warm Period (MWP) and the Little have been reported worldwide, the Medieval precipitation. Two maintemperature anomalies Celsius degree, andhigh frequency variability on aroundone by temperatureglobal oscillationsof last threeThe millennia have been characterized ABSTRACT Reserve. shadow, Barranca de Metztitlán Biosphere Ice Age, Cladocera, late , rain Keywords: Medieval WarmPeriod, Little pressure ontheregional . anthropogenican additional activitiesassource of controlling results emphasize the importance of climate changethe region in are inescapable, our global ElNiñoevents. of Although the effects of Mexico, andto changes inthe frequency of Gulf the area to changes in sea surface temperature of the Our record highlightsthe vulnerability of and depth. with changes inlakemorphometry associated the Metztitlán input in region,turn in regional precipitation anddetrital variability of Overall, climatic global variability resulted in high lower evapotranspiration. probablya result as of associatedLIA was with anenlarged water body, 2 2,* , Edyta Zawisza 3 , Marta - - - - /73(1)A1712202021 Medieval (PCM) y la PequeñaMedieval Edad de Hielo (PEH), mundialmente,han sido reportadas el Periodo Cálido precipitación. Dos principales anomalías de temperatura Celsius, yunavariabilidad de alta frecuencia dela laciones en la temperatura global alrededor de ungrado Los últimos tres milenios se han caracterizado por osci RESUMEN Metztitlán. de de la BiósferaReserva Barranca Holoceno tardío, sombra delluvia, val, , pequeñaedad de hielo, cladóceros, Palabras clave: Periodocálido medie presión sobre losecosistemasregionales. actividades antropogénicas como una fuente adicional de resultados enfatizan la importancia de controlar las del cambio climático el áreaen soninevitables, nuestros ElNiño.la frecuencia delos eventos los Aunqueefectos superficial de mar en elGolfo de México, y a cambios en vulnerabilidad del área acambios la temperaturaen profundidad del lago. Ennuestro resalta registro la a suvez asociada con cambios la morfometríaen y la deMetztitlán, de detríticos (detrital la input) enregión una alta en variabilidad delaprecipitación y entrada efectos de la variabilidad climática global se reflejaron tado de unamenorevapotranspiración. En general, los con un cuerpo lacustre más extenso, probablemente resul indicadores detrítico. de aporte asociada La PEH estuvo de la lluvia, reflejada en picos de alta frecuencia en los lacustrescon bajos niveles yunaalta torrencialidad asociado En Metztitlán, el PCM estuvo y regional. lacustres, asociados con la variabilidad climática global a sistemas dinámicos Nuestro apunta registro informe. dinámicas lacustre enel período de tiempo que abarca el análisis un geoquímico y cladócero para reconstruir Madrede la Biosfera Oriental. Se empleo en la Sierra Metztitlán, ubicado en la Reserva 3000 años del lago En este trabajo se presenta sedimentario de un registro vista en del cambio climático moderno. la conservación temas a la variabilidad global, un elementocrítico para anomalías ayuda a comprender la respuesta de los ecosis les. a estas El entendimiento delas respuestas regionales de los océanos y su interacción con las masas continenta modulados por factores comola temperatura superficial estos modos de variabilidad han sido regional, A nivel las anomalías el Pacíficode ElNiñoen Ecuatorial. precipitación ha estado estrechamente relacionada con que elpromedio, respectivamente. La variabilidad de la caracterizadas por temperaturas más cálidas y más frías Wojewódka-Przybył 3 , 1 - - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico ABSTRACT Environmental variability during the last three millennia in the rain shadows of central Mexico INTRODUCTION 1. Introduction 2 2 and Delcourt, 1991; Bradley, 2015). Through the at diverse spatial and temporal scales (Delcourt regional climatic variability with local processes strongly influenced by the interactionglobal of and Environmental and ecosystemdynamicsare process that, in the long term, transforms aquatic transforms process that, in the long term, lakedevelopment thesedimentationis property of al al Rodríguez-Ramírez regional climatic variability (e.g. Cuna ronments andtheir relationship and with global lacustrine envi the developmentsuccessional of mental studies have focused on understanding tions (DelcourtandDelcourt,1991;Bush,2003). with constantly changing environmental condi biological communitiespass andtheir interactions scale, represent ecosystems envelopes that encom redistributionenergy (Bradley, 2015).Atalocal that couple regional mechanisms and global of on regional environments on mechanisms depend (Cane, 2005). The effects these of variability modes regional hydrologic anomaliesacross the globe climatic variability that manifests in source of additional an been have Pacific equatorial the in ElNiñoanomalies the temporal distribution of (Richey tures andtherefore byregional hydrological cycles al two mainchanges temperatures inglobal (Mann Warm Period and the Little Ice Age represent the Bradley, 2015). precipitation (Haug or decreases of progressive increases of millennial-scale patterns precessional changes ininsolation, generating precipitation have been mostly associated with 2015). Throughout the Holocene, changes in temperatures (Mayewski regimes, but also through variability in regional mainly through changes inregional precipitation Holocene, climatic variabilitybeen expressed has / / ., 2009) that are reflected by sea surface tempera ., 2020; Franco‐Gaviria 2020; ., ., 2016;Vázquez-Molina Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín In recent decades, numerouspaleoenviron Within thelasttwo millennia,theMedieval et al ., 2007). The sub-decadal changes., 2007).The in et al ., 2015;Correa-Metrio et al et al et al ., 2020). A general ., 2020).A ., 2016;Escobar ., 2004;Bradley, http://dx.doi.org/10.18268/BSGM2021v73n1a171220 et al et al ., 2001; ., 2014; et et et /73(1)A1712202021 - - - - - /73(1)A1712202021 2000; Wetzel,process 2001). This can be driven by in autotrophic productivity (Wetzel and Likens, exogenic materials producing anincrease input of the lacustrine environments asa result of status of Eutrophication impliesachange on lake trophic process. this on dependent is highly consumption water for ecosystemfunctioning andhuman of interest, asthe availability been a majortopic of is closelyassociated andhas with these factors modulated by climatic andbiologicalfactors. between the lithosphere and the atmosphere, the interaction process 2001). This is the result of basin (Wetzel, the lacustrine of infilling gradual environments into terrestrial realms through the guez climateongoing global change (Esperon-Rodri most vulnerable biosphere reserves inthe light of conservations as it has been the classified as one of theregioncrucial for is its ronmental dynamicsof the samename. thetemporal envi Understanding Metztitlán, located in theBiosphere Reserve of Lake we present the environmentalof history variability (Caballero‐Rodríguez occupationhuman andnatural environmental plex landscape, marked byan intricateof history lake anditsdevelopment to formation study inahighlycom opportunity the offering Mexico, historic observations. lake development through time scales beyond the processesto understand involved and factors in opportunity an offers evidence sedimentary this opment through study time of (Cohen, 2003).The lakedevel cal, chemical, andphysicalevidence of tions inlacustrine environments containbiologi Franco‐Gaviria activities (e.g.human Carpenter nutrients derived from intensive and extensive of been acceleratedhas cess byanthropogenic input cover (Carpenter the catchment basinsuch assize and vegetation phometry, regional ,characteristics and of natural causes andvariesonlakemor depending h urpiaino freshwater ecosystems eutrophicationThe of Numerous lakesare distributed across Central However, duringthelate Holocene,pro this et al ., 2019). et al et al ., 2020).Sediment accumula ., 1998;Wetzel, 2001). et al ., 2017).Here et al ., 1998; ------2. Studyarea turbidites overlaid by clasticandbasaltic materials rocks,sedimentary particularly limestones and Mesozoic marine iscomposedof regional MadreSierra Oriental, Mexico(Figure 1).The the of flank western the on Hidalgo, of State asl), N, 98°53’- 98°49’ W, 1,253m at an elevation of de Metztitlán Biosphere Reserve (20°42’-20°39’ Lake Metztitlánlocatedis within the Barranca locallacustrine conditions. on the development of climatic variability regional of effects evaluatethe acterized by anarid climate. Also, we wanted to last three millennia on regions that are today char the climatic of variability investigate of effects the through the late Holocene. Overall, we intendto environmentalcoupling withglobal variability environmental variability through time, andtheir regionalOur aim was to understand and local geochemicaland cladoceran remains. composition We retrieved asediment core andanalyzed it for that hinders the formation of either a thermocline either a thermocline of thatthe formation hinders low transparency, witha polymictic mixingregime 2.5 km approximately slumped material covers anarea of between 500 and1,100years BP. Currently, the the river occurred to Suter (2004), the damming of (Suter,with thedammingslump 2004).According the lake which seemassociated margin of eastern mal faultsfeatureat pronounced thenorth scarps natural dam(Suter, 2004). the of flanks the Metztitlán River that resulted in a the valley of of one of slump massive a by and shallow ( et al multiple slumps and detrital flows (García Arizaga dissected landscapewithevidenceing ahighly of ranges andplateaus delimited by faults, constitut (Carrasco-Velázquez deposits ternary Neogene igneous origin,aswell as alluvial Qua of h aei netohcfehae oyo lake is aneutrophicThe freshwater body of Two regional, E-W striking, south-dippingnor parallel composed of is regionalThe relief ., 1996). Lake Metztitlán is a large (~2,949 ha) 2 (Figure 1). z mean = 11 m)water body originated Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín http://dx.doi.org/10.18268/BSGM2021v73n1a171220 et al ., 2008). - - - - - 3. Methods aesao fthe Atlantic, moisture from tropical cane season of (CONANP, 2003).Additionally, during the hurri ical Convergence Zone duringthe boreal summer theIntertrop fromthe northerly displacement of hand, the seasonal precipitation regime derives other the On Oriental. Madre Sierra the of effect conditions are associateddry with therain-shadow pronouncedtorrential rains.summer Generally thelakewater (Suter,level 2004). of the lake, around 250 m below the northeast side of water by the the slumping witharesurgence of of debris the through infiltration by occurs water byMetztitlán River, whereas the main drainage of or anoxycline (Sigala stored at the Instituto de Geología at a temperature piston corer (Colinvaux from Lake Metztitlán using a modified Livingstone In May 2017,a5.32-m-long core was retrieved asl) (CONANP, 2003;Rzedowski, 2006). 1800 masl), and coniferous forests (1800-2500 m (1500-1800 m asl),xerophytic shrublands (1000- (1100-1500 m asl),lower montane shrublands vegetation typesare tropical deciduousforests arboreal vegetation and shrublands. mean The created the conditions for a complex mosaicof and the highly dissected landscape havegradient orológico altitudinal steep Nacional,2020).The and May, respectively (Figure 1;ServicioMete 16.5and23.5°CinJanuary and maximum of perature is 20.7°C,withmonthlymeanminimum the catchment basin.Meanannual tem areas of water input fromthe higher permanent because of 2020). mm (Figure 1; Servicio Meteorológico Nacional, 1,788 406 mm,andameanevapotranspiration of out the entire year with anannual precipitation of Around the lake, moisture deficit through persists Madre Oriental, bringing additional precipitation. storms ascends along the eastern flank the of Sierra The regional climate is warm and dry with and dry regionalThe climatewarm is The lake maintains waterThe throughout the year /73(1)A1712202021 / 73(1)A1712202021 et al et al ., 2017). The lake is fed ., 2017).The ., 1999). The core., 1999). The was 3 3 - - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico INTRODUCTION/ STUDY AREA Environmental variability during the last three millennia in the rain shadows of central Mexico STUDY AREA / METHODS Nacional, 2020). meteorological station,showing monthlyevapotranspiration,precipitation,and meantemperature (datafrom ServicioMeteorológico Metztitlán region from the of Regional C) polygon). (yellow dammingslumpandthe star),(red coring showing site the et al Figure 1 4 4 ., 2002);4.PigmyBasin(Richey constructed using bacon(Blaauw and Christen, et al were calibrated using the IntCal20 curve (Reimer ator spectrometrymass (AMS). Radiocarbon ages dated by analyzingradiocarbon through acceler sequence. Organic matter from each sample was the sedimentary core for chronological control of the along depths different at extracted were ples texture, andsedimentreaction toHCl. Seven sam sediment sediment color, qualitative description of logical descriptionthat includeddescriptionof coreThe was longitudinally sectioned for litho 2°Cfor preserving evidence. the sedimentary of / / Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín

Study area.A)Continentalcontext:1.Lake Metztitlán;2.LakeAljojuca(Bhattacharya and Byrne,2016);3.Lake Pallcacocha(Moy ., 2020), and a Bayesian model was age-depth et al ., 2007).;5.CariacoBasin(Haug http://dx.doi.org/10.18268/BSGM2021v73n1a171220 /73(1)A1712202021 - - - /73(1)A1712202021 et al by the XRF (Löwemark variability associated with elements undetected ratios using Ca, accounting for dilution effects and to Ti and Zrwere transformed concentrations of repeated measurements per sample. Elemental three making XL3t, Niton Scientific Thermo a with fluorescence X-Ray using determined were a mortar and pestle. Elemental concentrations were freeze-dried and ground to silt texture using was extracted for geochemical analyses. Samples before 1950CE(calBP, hereafter). 2011). Allageswere expressedcalibrated in years ., 2001).B)Regionaltopographiccontextof Lake Metztitlán, Every two cmalong the core, a one-cm et al ., 2011).Elemental 3 sample were were counted until 200individuals reached cladoceranremains. For eachsample, of remains with safraninetobetter observe the morphology a 35- remainingHCl. The material was sieved through samples wasremoved by washingthem with 10% carbonates in culating the samples, excessof Sarmaja-Korjonen, defloc for used was KOH 10% and Whereas 2007). Szeroczyńska 1986; and treated according to standard protocols (Frey, aone-cm selected depth, cladocerans. From each for10 cm of analysis ical weathering (Kylander chem dominanceof calculated as anindicator of size,sediment grain whereas the Sr/Rb ratio was dominant calculated, aiming toanindicator of Algeo and Liu,2020). Also, the ratio Rb/Ti was the mud-water interface (Tribovillard are sensitive to changes inoxygen availability in theseelements,they as ositional alterationsof ratios usingTi,aimingto detect possible post-dep Fe to and Mn were transformed concentrations of especially the vegan package(Oksanen using R (R Corewere Team, performed 2020), environmental changes through time. All analyses Sample scores along PCA axes were usedtoinfer vector representing association among attributes. the original attribute among and angles ability of space, with vector magnitude representing vari represented byvectors in the newlyordinated the original attributes. Attributes are binations of new orthogonal thatcomponents are linear com the dataset through redistributes the variability of technique This 1986). (Jolliffe, ratios and trations mine the relationshipsamong elemental concen thedataset and deter summarize the variability of principal component analysis (PCA), aiming to 2008; Wojewódka illustrated taxonomic guides (Elías-Gutiérrez cm to concentrationswere (individuals/ transformed cladocerans and postabdominal claws. Countsof by assembling headshields, shells, postabdomens, The sedimentary sequence was sampled every sedimentary The The geochemicalThe dataset was submitted to a 3 ). Taxa were identified at species level using level species at identified were Taxa ). µ m mesh,takentoa5mlvolume andtainted et al ., 2020a,2020b). Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín 3 et al sample was extracted samplewas . , 2011). http://dx.doi.org/10.18268/BSGM2021v73n1a171220 et al et al ., 2019). ., 2006; et al ., ------MODEL 4.1. LITHOLOGICAL PROFILE AND AGE-DEPTH 4. Results 9 mbf otetpo tercr,cmoe f the record, composedof to the topof 398 cmblf blf,by composed darkcoarse and U3,fromsands; hereafter), (blf, characterized bydark silt; U2,from 441to398cm floor lake below cm 441 to 532 divided inthreethe sequence was U1, fromunits: sediments, sediment. According to the texture of carbonates in the a relatively high content of ized by a moderate reaction to HCl, indicating lime (Figure sediments were 2).The character and sand claysoverlying two thinnerlayersof of a massive layer coreThe was mainlycomposedof euto ilvaino organic matter through illuviation of a result of age, the other was younger (Figure 2), probably as U1 was statistically undifferentiable from the basal sedimentation. more thanlacustrine progressive energy of cesses these sediments weresuggest by deposited pro sedimentsthatcoarser characterized U1 andU2 the lake. Furthermore, the from the bottom of sediments older with flows detritus mixing lake, creatingmovements subsequent mass insidethe theremoved , and of the hillsides bility of (Figure 1;Suter, 2004). that extended for moreacross than2km the valley and created the remotionlake was amass process landslidethat U3.The dammedthe river ments of temporal reconstruction exclusivelythe sedi on aninstantaneous event. Thus, we based our of climate, it is likely that units 1 and 2 were product the regional 2004), as well as the torrentiality of the hillsides (Suter, and the high instabilityof from theanalyses(Figure 2andTable 1). 2 showed reversalsand were therefore excluded cm. Calibrated radiocarbon dates on units1and the last ~3000 years through the upper 398 of to the top ,the sequence comprises a record cm blf lightclays. homogeneous bandsof hra n fthe radiocarbon dates within Whereas one of landslide was probablyThis followed by insta the sediments Given the contrasting nature of According model, from to the age-depth 398 /73(1)A1712202021 / 73(1)A1712202021 5 5 - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico METHODS/ RESULTS Environmental variability during the last three millennia in the rain shadows of central Mexico RESULTS 4.2. GEOCHEMISTRY 1. Radiocarbon dates for thesedimentsofTable 1.Radiocarbondates LakeMetztitlán. 6 6 aineo the geochemical dataset, respectively,variance of record (last ~2000years). the tothe top of ative stability fromblf 283cm ~3000 to2000calBP), whereas theyshowed rel (from the record to 283 cm blf from the bottom of Pb and Zn concentrations were highly variable the record (last~250years). tothetopof blf cm the latter showinga substantialincrease from46 showed little variability through the record, with (from ~1620to1350calBP). blf showing anabrupt decrease from 236to 209 cm and Zrconcentrations were also highlyvariable, increasing trend towards present (Figure 3). Ti variable through therecord, showinga general Ca, Sr, K,andRbwere highly Concentrations of time. through variability significant showed and Rb, Sr, Ti, and Zn, Zr were statistically consistent Ca, Fe,Repeated K,Mn,Pb, measurement of will baseourresults anddiscussiononlyonU3. tion forU1 andU2,from units wepoint on, this with our results we cannot offer a reliable explana U1andU2.Given that materialsthe coarser of / / Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín C n C xlie 10ad2.%o the PC1 and PC2 explained 41.0 and 20.8% of the otherFeOn hand, concentrations andMn

Depth (cm) 500 501 345 251 152 0

http://dx.doi.org/10.18268/BSGM2021v73n1a171220 Laboratory ID Laboratory UBA UBA UBA UBA UBA Surface - - - - - 36487 34349 34348 34347 34346

bulk sediment bulk sediment bulk sediment bulk sediment bulk sediment bulk sediment bulk /73(1)A1712202021 - - /73(1)A1712202021 Material

increase through thelast~900 years. throughout the record, yet showing a progressive Fe/Ti and Mn/Ti ratios showed low variability ratio was inantiphase with Ti/Ca and Zr/Ca. and through the last ~900 years. Rb/Ti The ~3000 and 2800cal BP, ~1620 and 1350cal BP, cal BP, whereas they showed low values between 1620 calBP,~2800 and andfrom~1350 and900 2011). in their original concentrations(Löwemark elements these of concentrations high by effects Ca andZr/Caratios (Figure 4),impliesdiluting ciated withFe, Pb, Ti,Zr, andZn. between negatively them, andwere asso inturn Sr concentration showed a positively association associated and Fe/Tiwith K,Mn, ratio. Caand Fe/Ti ratio, Rbconcentrations were positively positively correlated from and independent the variance (Figure 4). as theywere associated to verylow amountsof we significant, decided to exclude them from the interpretation statistically also were PC4 and broken-stick model (Figure 4). Althrough PC3 the under significant statistically were both and

( Ti/Ca and Zr/Ca ratios were high from negativeThe association between Ca withTi/ Fe, Pb,Concentrations Ti,Zr,of andZnwere 14 C years) 2002 2365 2364 1928 Age 864 - 67

Error 31 31 29 40 32 ( 5 ± )

et al ., - 4.3. CLADOCERAREMAINS instant deposit afterinstant deposit thedamming of thelake. Figure 2 (Figure 5). therecord (last~800years) tothetopof blf cm viduals per cm reaching concentrations higher than 2,000 indi were the most abundant taxa through the record, bottom dwellers. L. cf. 1776), glabra sp. (Baird, 1843), (Baird, 1845), the littoral was composedof Liederobosmina group wascomposedof and sixplanktonic littoral species, respectively.and Whereas the plankton three in classified were analyzed through the entire record. taxa These Nine Cladocera taxa where found in54samples Stratigraphyand age-depth modelof the sediment core.Thegrayrectangle highlightsthesediment thatrepresents aprobable cf. striata (Sars, 1901), louisi louisi Leydigia Depth blf (cm) (Birabén, 1939). Two of 500 400 300 200 100 0 A. ossiani sp. (Brtek, 1997), and C cf. 3 o , withanabrupt increase from 150 lo Liederobosmina and louisi louisi r A. ossiani and Chydorus L. Daphnia cf. Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín Daphnia (Sinev, 1998), (Jenkin, 1934), and cf. 2500 striata sp. and http://dx.doi.org/10.18268/BSGM2021v73n1a171220 sp. (Müller, 1785), sphaericus sp. were present are benthonic Leydigia 2000 Bosmina Bosmina (Müller, species, Ovalona A Alona g sp. sp. e (c 1500 L. -

a l y e 5.1. DETRITAL ANDAUTHIGENIC INPUT 5. Discussion a r B 1000 P) et al processes (Rothwell and Rack,2006;Kylander detrital materials,associated mainly to erosive of are associateddeposits usually with theinput tary K,Rb, Ti,andZrinsedimen Concentrations of 1350 calBP)were barren for Cladocera. (~1550 to tively). Samples from 236to 209 cmblf (~2750 to 2500and~750650calBP, respec only from 381to 347 andfrom 145to 120 cmblf 2020). Inourrecord, whereas TiandZrwere pos 2006; Boës and Rack, respondsto detritus from parental rocks(Rothwell their abundance cor the provenance, asmostof ments that, maintainasignalof after deposited, ., 2011).Rb, Ti,andZrare conservative ele 500 /73(1)A1712202021 / 73(1)A1712202021 0 D o et al min Silt Sa C ., 2011;AlgeoandLiu, a l n a U1 U2 U3 n y d t ext

ur 500 400 300 200 100 0 e 7 7 - - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico RESULTS / DISCUSSION Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION Figure 3 8 8 2700 2500 2300 2100 1900 1700 1500 1300 1100 2900 Age (BP) 900 700 500 300 100 2006; Calvert and Pedersen, 2007;Kylander and lighter sediment fractions(Rothwell and Rack, finer with associates mainly Rb heavygrains, and and Zrare usually associated with relative coarse thetransported materials. Whereas Ti sorting of the transporting a sizeagents causing of energy our record could have been associated with the these elements in thatsuggests concentrations of dardized to Rb/Ti (Figure observation 4). This elements, even when concentrations were stan itively associated, Rb was decoupled from these reach saturation concentrations, andphysical, tation when dissolvedoccurs minerals in water 2006; Algeo and Liu,2020). Carbonate precipi carbonates (Rothwell and Rack, precipitation of parental materials and authigenic the erosion of bothclasticinput from iments are the result of material deposit. into thesedimentary fine of input the with associated were Lake Metztitlán (Figure these elements 4) suggests correlation between K andRbinthe sediments of 2007; Kylander (Rothwell2006; Calvert and Rack, and Pedersen, variable size grain of also replaces K infeldspars low mobility,minerals, but Rbisanelement of it in clay sorption 2011). Given its highcapacityof / / 1.0 Elementalconcentrations and elementalratiosof thesedimentary recordofLake Metztitlán. Ca (%) Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Ca and Sr concentrations inlacustrine sed 2.0 3.5 100 Sr (ppm) 150 200 0.5 0.6 K (%) 0.9 et al 1.0 60 Rb (ppm) ., 2011).Thus, the positive 70 80 90 100 3500 3500 Ti (ppm) 6500 6500 http://dx.doi.org/10.18268/BSGM2021v73n1a171220 Zr (ppm) 350 400 450 3.0 Fe (%) 6.0 8.0 600 et al Mn (ppm) 1000 1400 ., - - - 1800 /73(1)A1712202021 /73(1)A1712202021 Pb (ppm) 40 60 100 120 100 Zn (ppm) 150 a ueybe soitdwt ag mut fsurelyhas been associated with large amounts of ogy, whereas the torrential precipitation regime probably diminishedby the regional geomorphol roleMetztitlán, in aeolian erosionthe areain was Holocene, both erosive agents might have played a 1985; Ahnert, 1998). Although, through the late agents in humidand arid areas, respectively (Rose, 2003). Rainfall and wind represent the main erosive precipitation(Sageman andLyons,and wind of the latter associatedmainly with theerosive action detrital transport, weathering and mechanismsof sive processes. Overall, erosionis controlled by PCA ero reflects the directly PC1 that suggests in 4), (Figure flows detrital and authigenic with bly low lakelevels. increased regional evapotranspiration, and proba the authigenic flux is represented by Ca, reflecting detrital input, incorporating the Ca diluting effect, Thus, whereas Ti/Ca and Zr/Ca ratios reflect the carbonates. authigenic precipitation of result of indicate that these latter elements are mainly elements Zr) andCaSr(Figure(Ti and 4), our record, negative correlations among detrital often conditions associate with low lake levels. In These 2003). (Cohen, floor lake the in deposition chemical and biological processes facilitate their 200 250 h vdn eaaino elements, associated evidentThe separation of 0.1 Ti/Ca 0.3 0.4 0.6 0.010 0.020 Zr/Ca 0.030 0.040 0.010 0.014 Rb/Ti 0.016 0.020 8 Fe/Ti 9 11 12 0.10 Mn/Ti 0.20 0.25 IV III V II I 950 750 550 350 150 50 250 450 650 850 1050 1250 1450 1650 1850

- - - Age (BCE/CE) 5.2. REDOX CONDITIONS variance associatedwitheachcomponent(greybars),and thenullvarianceassociatedwithbroken-stickmodel. Figure 4 Thus, detrital input intoourrecordmost likely is pluvial laminarandlinear erosion(Ahnert, 1998). nesium and ferric iron.nesium andferric Onthe other hand, under mag cipitate in the sediments as oxyhydroxides of availability in the water column, MnandFe pre (Boës tion andoxidation that take place after deposition reduc of processes affected by be Fecan Mn and finer with materials. associated probably was it although detrital input, also anindicatorgesting itwas of with Fe, Fe/Ti,Rb, Mn, Rb/Ti(Figure 4),sug PC2, on the other hand, wasnegatively correlated thewater body. of impeding thedeepening basin, lacustrine the of infilling faster a in result would sediments load of ahigh of port anddeposition be associated with more regional erosion.Trans climate (Rzedowski,2006), wetter periods would vegetationthe sparse associated with the regional and/or amore torrential regional climate. Given awetter of phases PC1 are aresult of scores of associated with regional precipitation, andpositive Correlation biplot of the principal component analysis of the geochemical record of Lake Metztitlán. The inset showsthe The inset Metztitlán. Lakeofrecord geochemical the of component analysis the principal of Correlation biplot et al ,21) ne odtoso oxygen of ., 2011).Underconditions

-2 -1 PC2 (20.8 %) Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín 0 1 2 S http://dx.doi.org/10.18268/BSGM2021v73n1a171220 C -2 r/Rb a M S r Rb/T n/T i i K F -1 e/T M i Rb n - - - - - PC1 (41%) Explained variance

0.000 0.125 (%)0.250 0.375 0 wind mixing. water by would improve in turn oxygenation of tion usually takes place under low lake levels, which processes are closely related as carbonate precipita carbonates. These changes in the precipitation of the mud-water interface, or as oxygen content of Fe/Ti as changes ratios inthe canbe interpreted ates (Cohen,2003).Overall, changes inMn/Tiand carbon and Fe through authigenicprecipitation of Mn of fixation and enrichment suggesting Ca, of Fe/Ti ratios werephase withhighconcentrations in Mn/Tiand LakeMetztitlán, peaks of the record of (Algeo andLiu,2020).Additionally,conditions in theseelements caused byanoxic redissolution of ositional processes, withlow values pointing to post-dep Ti ratiosof couldbeusedasindicators by diagenetic processes. Thus, the Fe/Ti and Mn/ variance caused tions,a large implying amount of areand Mn decoupled from TiandZrconcentra processes.post-depositional Inourrecord, bothFe ciations with detrital elements that are not prone to these elements would imply positive asso signal of Liu, 2020).Given their detrital origin, anunaltered are liberatedto thewater back (Algeo and column anoxic conditions, these elements redissolve and PC1 PC3 PC5 Z threshold Broken Sticksigni cance Associated variance 1 Pb n F PC7 e /73(1)A1712202021 / 73(1)A1712202021 PC9 Z r T Z i T 2 r/C i/C a a 9 9 - - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION LAKE PRODUCTIVITY 5.3. LAKESURFACE, LITTORAL DEVELOPMENT, AND 10 10 rpi tts pce ru fBosminidaecan trophic status, species group of et al monly found under eutrophic conditions (Beaver trophic state, whereas huaronensis bosmina hagmanni ( the region may inhabit,both,environment poor However, species of lakes (Korhola and Rautio, 2001). phic status of changes inthe tro associated as anindicator of taxa usually bosminid is while theturnover of nutrients (Baysand Crisman,1983) increase of thelake. open water area of the the lake, but more likely anenlargement of of taxa are probably not associated with a deepening planktonic Metztitlán, abundance increases of Lake of 1987). Given(Hofmann, the morphology cladocerans, such aslake morphology habitat of changes that infactors the modify informative of littoral vs. planktonictaxa are ative abundant of rel Korhola and Rautio, 2001).Thus, changes of and Daphniidae(Whiteside Swindoll, 1988; and that mostlybelong tothe families Bosminidae open waters are colonized by planktonicspecies Rautio,2014). Contrastingly, 2001;Adamczuk, rocks, mud, and aquatic vegetation (Korhola and preferences for particular microhabitats such as distributed acrossshallow littoral areas with the Chydoridae familyare mainly of Members through the time period spanned byour record. the lake reconstruct environmental dynamicsof to elements offers record our in taxa of turnover Thus, the 2001). Rautio, and (Korhola affinities acrossthese areas isdriven by their ecological Cladocera species 2000), and the distribution of limnetic oropenwater zones (Wetzel and Likens, environment can be divided inthe littoral and Korhola and Rautio, 2001).Overall, the lake environments (Whiteside and Swindoll, 1988; group, systematically distributed acrosslacustrine Cladocerans are a highlyspecialized biological / / Liederobosmina tubicen Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín The higher Bosminidae biomass often reflects often biomass Bosminidae higher The ,21) nteohrhn,idpnetyo of ., 2018).Onthe other hand, independently ) didnotshow prominent relation with ); andsomespecies( ) andrichnutrients in ( Liederobosmina Bosmina sp. is more com http://dx.doi.org/10.18268/BSGM2021v73n1a171220 appearing in Liederobosmina Liedero /73(1)A1712202021 - - - - /73(1)A1712202021 5.4. THELAST3,000YEARS AT LAKEMETZTITLÁN etation (Korhola and Rautio, 2001).Onthe other glabra Cladocera genusBorum, 1991).The nutrients, favoring clear waters (Sand-Jensen and lakesastheyretain can regulate the trophic state of ronments2014). Littoral (Adamczuk, macrophytes envi littoral to adapted taxa for shelter offer they cladoceransas vegetation increases the diversityof the lake. Aquatic changes inthe trophic status of the open water zone thanwith the expansionof sp. through the record were more associated with gests abundancesof speciesturnovertaxa sug among bosminid lack of aforementioned The 2002). Szeroczyńska, 1987; coexist inopen water environments (Hofmann, conditions and wereconditions apparently dominated by were characterized by relatively homogeneous the lake. stages These stages in the evolution of main five identified we ratios, geochemical of ity the variabil Accordinginspection of toavisual together withthedetritalinput. promoted byin turn nutrients brought by the river with a highly productive environment, which was In ourrecord, these taxa were probably associated 2004; Wojewódka (Kotov for turbid environments withhighnutrient input cf. Lake Metztitlán, species found inthe record of C. populations of the growth of aquatic vegetation that promoted mats of ment of by a shallow water layer that allowed the establish the lake, the alluvial plain was probably covered Metztitlán valley. expansionof of Duringtimes of the water alluvial plain surface acrossthe southern littoral areas, probably resulting from advances of glabra species ( (Korhola, 1999). Thus, inourrecord, littoral centration andalsoassociated with macrophytes lownutrient con be foundof under conditions hand, cf. striata areassociated commonly with aquatic veg r niaigtedvlpeto mature ) are indicating the development of sphaericus C. et al Alona and cf. sphaericus ., 2003;Kotov and Elías-Gutiérrez, sp., L , and . cf. A. ossiani et al louisi louisi isadualistic species, asit can Liederobosmina O. glabra ., 2016; Sigala ., 2016;Sigala , C. , have been reported . Lastly, the benthic cf. Alona sphaericus sp. and sp., Alona et al A. ossiani, ., 2017). , and , and Bosmina O. O. O. L. ------

5.4.1. ZONEI(398-256CMBLF;~3000-1800CALBP) from littoral to benthic and planktonic species. cladoceran assemblages with the of succession materials were into the lake, deposited coinciding ratios (Figure that 3) suggest progressively coarser fresh material recently eroded. Decreasing Rb/Ti nutrients derived from the bringing ahighloadof lake the of bottom the filled event instantaneous the core (Figure 2). Such acterizes the bottom of material coarse that char of instantaneous deposit transparencyzone (Figure overlays 6).This the submerged vegetation andprobably low water llow environment with rather weakly developed of Through this time interval, higher abundances and biologicalsignals(Figure 6). which showbetween consistency the geochemical the record wassupported by PCA scores, zation of the record.discreti This stage towardsthe end of time allowed for an additional the identification of Cladocera assemblages through high variability of changes inthe regional moisture availability. The amn fthe river bythe massive landslide in damming of the lacustrine whichbasin, couldhave been associated with the of infilling progressive and ment time. aslightincreaselake extension in suggest at that concentrations of and littoral taxa increased (Figure 6). Increasing Cladocera as benthonic taxapelagic diminished, landslide damming. From~2550 to1800calBP, would have allowed the infilling the of lake after the for the region (Bhattacharya wet conditions. Ca ratios (Figures relatively 3and6),suggesting Zr/ and Ti/Ca of progressive increase the reflect the Fe/Ti ratio (Figure 6). Increasing PC1 scores of decrease the in reflecting interface,mud-water lake level probably caused anoxic conditionsinthe size inthe sediments, whereas the slight increase in grain ratio indicates progressively increasing of theRb/Ti Indeed, theprogressive decrease of Overall, this stage showsthe initial develop Relatively wet haveconditions been reported L. cf. louisi louisi Liederobosmina and L. Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín cf. striata et al http://dx.doi.org/10.18268/BSGM2021v73n1a171220 sp. and ., 2015),which suggest a sha- suggest Bosmina sp. - - - 5.4.2. ZONEII(256-209CMBLF, ~1800-1350CALBP) a paetylwtruhms f oe1o our zone 1of was apparently low through mostof Pallcacocha (Moy (CONANP, Lake 2003). According to the record of ing pronounced droughts tothe Metztitlán region variabilityMexico in (Magaña events are a major contributor to precipitation (Moy Pacific torial ElNiñoeventsthe equa in a low frequencyof relatively wetcould beassociated conditions with time spanned byrecord. our sedimentary The possible that the lake was much older than the associate U1 andU2to the landslide, it is also in theregion (Bhattacharya relativelymoisture high availability the context of ated with the uncertainty of our age-depth model. our age-depth ated with the uncertainty of El Niñofrequency, the mismatch couldbe associ Although ourPC1 peak predated the increase of recorded in lake Pallcacocha (Moy the El Niñofrequencies with reinvigoration of climate. Such torrentiality could beassociated erosivegiven capacity regional the generally dry probablyto torrentialcorresponds events withhigh BP cal 1620 and ~1750 between identified input terrigenic PC1 (Figure peakof 6). The scores of accompanied by low detrital input, reflected in low Cladocera remains, showed an abrupt decrease of thiszone (~1800-1620 calBP) bottomof The (Haug Zone revealed by the Cariaco basinTi record theIntertropical Convergence variability mode of were probably associated with the high frequency lake level and extension. erosive These peaks of highvariability of support our interpretation Cladocera assemblages further High variability of torrential events. even wetter conditions or of lived intermissions that could have been associated with either short detrital material, a high variability in the input of Ti/Ca and Zr/Ca suggest ter conditions, peaks of the lake. Superimposed on the trend towards wet droughts that facilitated the progressive infilling of record, probably producing a low frequency of Nevertheless, aswe do not have elements to et al ., 2001). /73(1)A1712202021 / 73(1)A1712202021 et al et al ., 2002),ElNiñofrequency ., 2002). Today, El Niño et al et al ., 2015). ., 2003),bring et al ., 2002). 11 11 - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION 5.4.3. ZONEIII(209-164CMBLF, ~1350-900CALBP) along axes1and 2areshown. Figure 5 12 12 enrpre o h ai fSerdán Oriental been reported for the basin of that conditions have dry with anabrupt onset of the water body.iccationperiod coincides of This to the lake, andprobably analmostcomplete des decreased (Figure 6), indicating low detrital input cladocerans andTi/Ca, Zr/Ca, and PC1 of From ~1700 to 1400 cal BP, sampleswere barren f niaoso detrital input, Ti/Ca, Zr/Ca, and indicators of of cladocerans and the increase the recolonization of the water bodywas evidenced by A recovery of drought. 2010; Park elevationsabove asl (e.g. 1000m Metcalfe hasbeen reported for other sites atsame pattern at ~1600 cal BP (Bhattacharya / / Cladoceraconcentrations inthesedimentary record ofLakeMetztitlán.Samplescores oftheprincipalcomponent analysis Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín 2700 2500 2300 2100 1900 1700 1500 1300 1100 2900 Age( cal BP) 900 700 500 300 100 0

D et al a 20 20 p ., 2019),thus, indicating aregional Pla h Li n ed ia s nktonic species er p obosm. 5000 5000 ina B s os p m . in http://dx.doi.org/10.18268/BSGM2021v73n1a171220 a s et al 3000 3000 p. Benthic species L ., 2015). This e yd 200 200 ig L ia ey cf d . l et al 50 50 i g ou A ia i

cf s ., /73(1)A1712202021 - l i l /73(1)A1712202021 on . o 100

100 s a t u s ri is

L A p i . at itto

8 l

8 a on O a o

r v a a s 200 200 l species l s bec f itrltx nms fthe samples littoral taxa in mostof absence of conditions. generally dry Indeed, in a matrix of also have been associated with torrential rains detrital materials (Ti/Ca and Zr/Ca) could of driver.solar activityasacommon implying Peaks Yucatan Peninsula (Hodell foralso beenreportedtime period has this for the successive centennial droughts variability of of the regional hydrological cycle. Asimilarmode variability of a high-frequencysuggest mode of detrital input indicators of evenly spacedpeaksof open water area. Three consecutive and relatively of a relatively shallow lake, moderate concentrations PC1 (Figure 6). Whereas o i littoral environment, impedingthe establishment frequentsediments causing disturbances tothe could have been caused by the massive input of n an Ch a gl i Liederobosmina 25 25 yd a o br -0.5 ru a s

PC1 cf

0 . s ph 0.5 aer i sp. and

1.0 cu

-0.8 s -0.4 PC2 -0.2 Bosmina 0 L 2 . cf. 0.4 et al I III V I louisi louisi V I sp. a large suggest I ., 2001),possibly 950 750 550 350 150 50 250 450 650 850 1050 1250 1450 1650 1850

Age(BCE/CE ) suggests 5.4.4. ZONEIV(164-47CMBLF, ~900-200CALBP) higher regional convective activity, andthus (Richeythan modern Mexico wasaround 2 °C higher of in the Gulf 1993). Duringthe MWP, seasurfacetemperature Mexico (Douglas of humid air from the Gulf the Metztitlán region are the easterlies that bring seasonality. Today, moisture for the main source of precipitation rains and therefore an accentuation of summer the regional of intensification an Such higherosion wasprobably associated with record shows conditionsthat seem more erosive. al Rodríguez-Ramírez the regional droughts (Metcalfe tion of intensifica an by characterized was period time (Mann tury higher than those that characterized the 20th cen when temperatures global were around one degree coincides withthe Medieval Warm Period, a time these areas. a community associated with establishment of littoral vegetation and,thus, preventing the of 3 and6). Increasing Rb/Ti ratios a pro suggest moisture availability was low but constant (Figures Ti/Ca, Zr/Ca and PC1 scoresthat suggest of (Acuña, 2017). Relative flat and diminishing ratios are todayoccupied by towns andextensive crops areas that the southern lake occupied much of species.report Indeed, historicaccounts that the both benthic and littoral Cladocera presence of mature littoral areasevidenced is bypermanent of lake (Bhattacharya the thisstage of ity that coincides withthe onset of regional moisture availabil an increasesuggest of the lake surface. Regional records as awideningof the lake environment, as well relative of deepening derobosmina habitats. Substantial increases of diversityof higher water levelsthe lakewith ahigher in all Cladocera species suggests increaseThe of Lake Metztitlán. recordsedimentary of explaining the high erosive activity reflected in the ., 2015;Park The time period comprised byThe thiszone roughly sp. and et al et al ., 2009).InCentral Mexico, this ., 2019),however, theMetztitlán Bosmina et al et al ., 2015). The development., 2015).The et al Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín ., 2015;Bhattacharya sp. (Figure a 5) suggest ., 2007),producing http://dx.doi.org/10.18268/BSGM2021v73n1a171220 et al ., 2010; et al Lie et ., - - - - - YEARS). 5.4.5. ZONEV(47CMBLFTO THE TOP, THE LAST~200 this zone (Metcalfe variability throughby thetimeperiodcomprised littoral areas.regional Most recordsshow high a large lakesize that allowed thedevelopment of moisture availabilityenough for was maintaining bysuggested conditions carbonate precipitation, Mn (Cohen, 2003). Overall, under generally dry Fe/ Ca ratios together with increasing ratios of the Ti/Ca and Zr/ bysuggested low values of carbonates is input. Authigenic precipitation of detrital the in material finer of increase gressive time intervalassociatedclosely was with anthro Regional environmental variability during this al Rodríguez-Ramírez (Figure 6)indicate a relatively andopen deep planktonic species toral taxa and rebounding of almost all benthic and lit disappearance of The acting onamore erodible landscape. rain, that strengthened the erosive capacityof the hydrological cycle temporal invigoration of conditions were once dry overcome, therea was LakeMetztitlán. Thus, in thecatchmentof basin probably associated with a low vegetation vigor 2011; Rodríguez-Ramírez (Bhattacharyaconditions associated with dry imum (Bard 1550 CE,Figure 6). detrital input between ~450and400 calBP(1500- terrigenic indicatorsof markedwas bya peakof Themost important event that took place through thisstage climate. drier the relatively of effects piration probably decreased, ameliorating the thewater body.enlargement of the regionin anomaly this associated was with the the LIA (~600 cal BP, Figure that 6), suggesting community wasestablished by the beginning of (Mann ture availability causedbythe Little Ice Age(LIA) pogenic activity, aswell as withchanges inmois ., 2015; Park This peak ispreceded This by the Spörer solar min Under regional colderconditions, evapotrans et al /73(1)A1712202021 ., 2009). In Metztitlán, the littoral / 73(1)A1712202021 et al et al ., 2000),which in the region was et al ., 2019; Wogau et al ., 2010;Cuna ., 2015;Bhattacharya et al ., 2015) that were et al et al ., 2019). ., 2014; et al 13 13 et ., - - - - -

Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION Environmental variability during the last three millennia in the rain shadows of central Mexico DISCUSSION / CONCLUSION and Byrne,2016). I. Rb/Ti ratiosinthe sediments of Lake Metztitlán. sediments ofPigmy Basin(Richey scores (black)of thesedimentary recordofLake Metztitlán. G.Seasurface temperatures of theGulf ofMexico reconstructed from the (Moy frequencyNiño El of proxy a Ecuadorianas Andes,Pallcacocha, Lake of sediments the of intensity Red D. diamonds.gray representedby planktonic, benthicand inthesedimentsofLake Metztitlán;samplesbarren littoralCladocerataxa,respectively, ofcladoceransare Figure 6 14 14 et al moistureavailability reflectedis low and in Ti/Ca plain previouslycovered by water. General low thewater bodyfrom the alluvial retraction of piration rates probably increased, the implying rebounded and asaconsequence, evapotrans littoral zone. temperatures After global the LIA, lacustrine environment, withaweakly developed water level (Suter, 2004), man-made infrastructure by the landslide continued to be the main control created of obstruction the through infiltration by hydraulic infrastructure (Waitz, modified 1947). Although highly was regional the site wasprobably progressively lower. coring the on river the of mouth the of influence ing site. As the valley was infilled by sediments, the fine materialspreferential in deposition theof cor Zr/Ca ratios, with high Rb/Ti ratios a suggesting 2700 2500 2300 2100 1900 1700 1500 1300 1100 2900

Age (cal BP) / / 900 700 500 300 100 The paleoenvironmental record of Lake Metztitlán in the regional and continental context. A, B, and C, concentrations of concentrations andC, B, A, context. andcontinental regional Lake Metztitláninthe ofThe paleoenvironmentalrecord Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín Boletín de la Sociedad Geológica Mexicana Geológica Sociedad la de Boletín However, during the 19th and 20th centuries, 0 ., 2002).E.Ticoncentration inthesediments of Cariaco Basin(Haug Planktonic A (ind/cm3) Cladocera concentration 6000 6000 Benthic B 150 150 et al Littoral ., 2007).H.d18O inthesedimentary record ofLake Aljojuca, Serdán OrientalBasin(Bhattacharya 250 250 C (color intensity) Red 50 http://dx.doi.org/10.18268/BSGM2021v73n1a171220 More frequent 100 El Niño 150 200 D 250 0.05 E Northerly 0.15 0.15 ITCZ (%) Ti /73(1)A1712202021 - - /73(1)A1712202021 0.25 0.25 6. Conclusion 0.2 Precipitation Ti/Ca Regional that LakeMetztitlán been in place has for at least last 3,000 years. chronological The model suggests highenvironmental variability through the of tory Lake Metztitlán shows a his recordimentary of Our multiproxyreconstruction the sed basedon by productive activities. the alluvial plain promoted by the occupation of littoral communities was probably also ance of process that tookplacethrough thistimeperiod. probably played a major control on the deposition and 500calBP (Suter, 2004).Within thistime locatedthe , formerly at between ~1100 three millennia, sheddingnewlight on the age of 0 PC1 0.5 Indeed, besides natural process, the disappear F 23.1 et al 1.0 (°C) SST Gulf ofMexico ., 2001).F.Ti/Ca ratios(red) and PC1sample Warmer 25.4 G 0.0

H -5.0 (‰) d -5.0 conditions 18 Wetter O -10.0 -10.0 0.010 I 0.014 Rb/Ti sediments Finer 0.016 0.020 IV III V II I 950 750 550 350 150 50 250 450 650 850 1050 1250 1450 1650 1850

Age (BCE/CE) - - - References Acknowledgements and Spörer. Overall, our record demonstrates the Maunder betweenmission the solar minimaof surface, witha very wet period during the inter the lake relatively wet climate and anexpansionof Contrastingly,characterizedwas theLIA bya drought andwet conditions. successiveof peaks whereas the regional climate was characterized by littoralareas. development of and infilling lake with associated erosion high of the water body, of producing cyclesmorphology itation regime conditioned the productivity and hydrological cycle. Changesinthe regional precip conditioned byhighly was changes inthe regional assemblages cladoceran the reflected evolutionby centennial drivers are evident. decadal-to of effects the pattern, specific a follow scale trend inthe regional climate does notseemto a highlydynamicWhereassystem. themillennial subjected to multiple forcings that have resulted in regional climate has alwaysbeen arid, it has been frame, ourresults demonstrate that, although the Adamczuk, M., 2014, NicheAdamczuk, separation by Acuña, R., 2017, Relaciones Geográficas del Siglo usaccesstothestudyfor area. granting Áreas Naturales Protegidas (CONANP, Mexico) analyses. We are to Comisión Nacional de grateful forVázquez Salgado their assistance withXRF thank LuisGerardo Martínez Jardines andAstrid de Ciencia y Tecnología No. (grant 256406). We research This wasfundedby ConsejoNacional environmental variability. Biosphere Reserve has been submitted to a high deMetztitlán theBarranca lennia, theregion of ronmental conditions. Through the last three mil close associationbetween localandregional envi During the MWP, the lake wasshallow, Our results that suggest the local environmental de Investigaciones Antropológicas, 632p. XVI: Antequera tomo 2: México, Instituto Boletín de la Sociedad Geológica Mexicana Mexicana Mexicana Geológica Geológica Sociedad Sociedad la la de de Boletín Boletín http://dx.doi.org/10.18268/BSGM2021v73n1a171220 - - - - Bard,G., E.,Raisbeck, Yiou, F., Jouzel, J., 2000, Algeo, T.J., Liu,J., 2020,Are-assessment of Ahnert, F., 1998,Introduction toGeomorphology: Bhattacharya, T., Byrne, R.,2016,Late Holocene Bhattacharya, T., Beach, T., Wahl, D., 2011, Birabén, M., 1939,LosCladóceros de la familia Beaver, J.R., Renicker, T.R., Tausz,C.E., Vitanye Bays, J.S., Crisman,T.L., 1983,Zooplanktonand 985 nuclides:based oncosmogenic Tellus B, 52, during the last 1200 yearsSolar irradiance doi.org/10.1016/j.chemgeo.2020.119549 Chemical Geology, 540,119549.https:// elemental proxies for paleoredox analysis: 352p.London, Arnold, https://doi.org/10.4081/jlimnol.2014.884 , 73,490-501. coupling: Journal of their distribution androle in littoral-pelagic lake - potential driversCrustacea) in adeep of littoral-benthic Chydoridae (Cladocera, gloplacha.2015.12.005 138, 56-69. http://dx.doi.org/10.1016/j. Change, Oriental: Global andPlanetary on Mexico’sCuenca the regional vegetation of influences climatic and anthropogenic revpalbo.2010.11.010 164, 109-120. https://doi.org/10.1016/j. Palaeobotany andPalynology,Review of Belize: northern the Maya lowlands of pollen rain from modern of An analysis 651-671. Argentina de CienciasNaturales, 17, “Chydoridae”: https://doi.org/10.11646/zootaxa.4407.4.3 coregoni the invasive cladoceran United States, includingexpanded range of lakesandreservoirswithin thecontinental of Branchiopoda: Anomopoda)inthe plankton the family Bosminidae Baird (Crustacea: B.T.,taxa sixin 2018,Distribution of org/10.1139/f83-210 Sciences, 40,1813–1819.https://doi. FisheriesandAquatic Canadian Journal of trophicsta v52i3.17080 - 99 Baird: Zootaxa, 4407(4), 506-520. /73(1)A1712202021 2. https://doi.org/10.3402/tellusb. / 73(1)A1712202021 te relationships in Florida lakes: te relationshipsFlorida in Revista de la Sociedad Bosmina ( Eubosmina 15 15 )

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