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Pleistocene to Holocene benthic foraminiferal assemblages from the Peruvian continental margin

Zeynep Erdem and Joachim Schönfeld

Plain Language Abstract

The majority of modern foraminifera pursue a benthic lifestyle, and they constitute an important group of organisms in benthic ecosystems with high levels of environmental adaptation, contributing significantly to biogeochemical cycling. Foraminiferal tests are readily preserved in the near-surface sediments after reproduction, thus providing a fossil record of environmental changes, such as bottom-water temperature, surface ocean productivity, or bottom and pore water ventilation. Foraminifera are therefore important tools for reconstructions of oceanographic conditions in the past. This study presents the benthic foraminiferal species inventory and assemblage composition observed in sediment cores that were recovered from offshore Peru. The sediment samples cover the last 22 thousand years including the transition from the last ice-age to the present warm period, thus, a major climatic event. Additionally, a documentation with incident light and scanning electron microscopic images of common species from the samples is presented, a timely contribution to our knowledge of Peruvian benthic foraminifera.

Resumen en Español

Asociaciones de foraminíferos bentónicos pleistocenos a holocenos del margen continental peruano

El inventario de foraminíferos bentónicos y la composición de sus asociaciones fueron documentados a lo largo de cinco testigos sedimentarios del margen peruano entre 3°S y 18°S a profundidades de agua de 500 a 1250 m, cubriendo el límite inferior de la Zona Mínima de Oxígeno (ZMO). El énfasis fue puesto en determinados intervalos temporales de los últimos 22 mil años cuando prevalecieron condiciones climáticas y oceanográficas distintas a las actuales. En total, tres especies aglutinadas y 186 calcáreas fueron reconocidas. Bolivina costata, Bolivinita minuta, Cassidulina delicata y Epistominella exigua fueron las más abundantes. Las distribuciones de foraminíferos revelaron un cambio marcado en la composición de las asociaciones particularmente en los testigos más profundos durante y luego de la deglaciación. La diversidad declinó y las especies de Bolivina se volvieron dominantes. Estos cambios tuvieron lugar gradualmente a lo largo de milenios y no se registraron fluctuaciones de alta frecuencia. Este patrón provee evidencia de condiciones ecológicas relativamente estables y cambios lentos en la circulación de las aguas de fondo durante la última deglaciación.

Resumen en lenguaje sencillo
La mayoría de los foraminíferos modernos tienen un estilo de vida bentónico y constituyen un grupo importante de organismos en los ecosistemas bentónicos, con altos niveles de adaptación ambiental, contribuyendo significativamente al ciclo biogeoquímico. Las tecas de los foraminíferos se preservan en la superficie o cerca de la superficie sedimentaria luego de la reproducción, proveyendo así un registro fósil de los cambios ambientales, tales como temperatura de agua, productividad oceánica superficial, o ventilación de aguas de fondo o porales. Los foraminíferos son, por ende, herramientas importantes para las reconstrucciones de condiciones oceanográficas del pasado. Este estudio presenta el inventario de especies de foraminíferos bentónicos y composición de asociaciones observado en testigos de sedimentos que fueron obtenidos en el offshore de Perú. Las muestras sedimentarias cubren los últimos 22 mil años, incluyendo la transición desde la última edad de hielo al presente período cálido, por ende, un importante evento climático. Adicionalmente, se presenta la documentación de imágenes con luz incidente y microscopio electrónico de barrido de especies comunes, una contribución oportuna a nuestro conocimiento de los foraminíferos bentónicos peruanos.

Palabras clave: foraminíferos bentónicos; taxonomía; Perú; Zona Mínima de Oxígeno; Holoceno; Deglaciación

Traducción: Diana Elizabeth Fernández

Résumé en Français

text

Translator: Antoine Souron

Deutsche Zusammenfassung

Der Artbestand und die Zusammensetzung benthischer

Foraminiferengemeinschaften wurde an fünf Sedimentkernen vom peruanischen Kontinentalhang dokumentiert, die aus Wassertiefen von 500 bis 1250 m zwischen 3°S und 18°S entlang der unteren Grenze der heutigen Sauerstoffminimumzone genommen worden sind. Der Schwerpunkt dieser Untersuchung wurde auf bestimmte Zeitintervalle während der letzten 22.000 Jahr gelegt, in denen andere klimatische und ozeanografische Bedingungen als heute vorgeherrscht haben. Insgesamt wurden drei agglutinierende und 186 kalkschalige Arten festgestellt. Bolivina costata, Bolivinita minuta, Cassidulina delicata und Epistominella exigua waren am häufigsten. Die Foraminiferenverteilungen entlang der Kerne zeigten einen markanten Wechsel in der Artenzusammensetzung während oder nach der letzten Abschmelzphase, was sich besonders in den tieferen Kernen zeigt. Die Diversität nahm ab und Arten der Gattung Bolivina dominierten. Diese Veränderungen erfolgten allmählich über einen Zeitraum von mehreren tausend Jahren. Kurzzeitige Fluktuationen wurden nicht registriert. Dieses Muster weist auf vergleichsweise stabile ökologische Bedingungen während des letzten Abschmelzphase und sehr langsame Änderungen in der Tiefwasserzirkulation nahe am Meeresboden hin.

Schlagwörter: benthische Foraminiferen; Taxonomie; Peru; Sauerstoffminimumzone; Holozän; Abschmelzphase

Translator: Authors

Arabic

Translator: Ashraf M.T. Elewa

 

 

TABLE 1. The metadata of the sediment cores used in this study.

Cruise

Core name

Year

Lat
(S)

Long
(W)

Water depth
(m)

Reference;
Age model

M77/2 059-PC1 2008 03°57.01' 81°19.23' 997 Mollier-Vogel et al., 2013
M77/2 052-PC2 2008 05°29.01' 81°27.00' 1249 Erdem et al., 2016
M77/2 047-PC2 2008 07°52.01' 80°31.36' 626 Erdem et al., 2016
M77/2 050-PC4 2008 08°01.01' 80°30.10' 1013 Erdem et al., 2016
M77/1 416-GC4 2008 17°28,13' 71°52,62' 505 Erdem et al., 2016

 

TABLE 2. List of the most abundant species with >5 % relative abundance observed in each sediment core. The most abundant and common species are indicated bold. * species without image.

Species name

Occurrence

59-1

52-2

50-4

47-2

416

Alabaminella weddellensis 0-6     absent absent
Anomalinoides minimus 0-5   absent   absent
Bolivina costata   1-43 5-45 16-26  
Bolivina interjuncta var. bicostata 0-7       0-5
Bolivina pacifica 0-6 0-5 0-6    
Bolivina plicata   absent     0-6
Bolivina quadrata* 0-7   absent   absent
Bolivina seminuda var. humilis     1-7 0-6 1-23
Bolivina spissa 0-5 0-7     absent
Bolivinita minuta 0-30 0-20 0-10 0-6  
cf Buccella peruviana     0-5 2-9  
Bulimina exilis     0-6    
Bulimina pagoda   0-7     absent
Buliminella elegantissima         0-22
Cassidulina auka absent 0-6 0-6   2-38
Cassidulina carinata 0-9 0-24 0-11    
Cassidulina delicata 3-14 5-21 3-14 6-16  
Cassidulina laevigata*   0-14     absent
Cassidulina minuta 0-9     0-9 absent
Cibicides mckannai   0-7   absent absent
Epistominella afueraensis     0-7   0-27
Epistominella exigua 5-23 0-33 0-13   0-6
Epistominella obesa* 0-5   0-15 2-16  
Epistominella pacifica 0-6 0-8 0-8   0-34
Epistominella smithi 0-6 0-12 0-7 absent absent
Fursenkoina fusiformis   0-5 0-5    
Gyroidina rothwelli 0-5       2-14
Nonionella auris*         0-15
Planulina limbata         0-7
Pseudoparella sp.     0-18 4-14 absent
Pseudoparella subperuviana*     0-15 3-14 0-18
Uvigerina auberiana 0-8 0-11     absent
Uvigerina bifurcata absent 0-9   absent absent
Uvigerina peregrina   0-10     0-6
Uvigerina semiornata 0-5 3-17 0-7    
Uvigerina striata         0-5
Virgulina cornuta*     0-6    
Virgulina spinosa 0-21 absent   absent absent
 

FIGURE 1. A) Map of the research area showing the core locations. The dashed line shows the approximate position of the section in B) depth vs latitude section showing the dissolved oxygen concentrations and the core locations. Oxygen data were taken from a CTD compilation after Schönfeld et al. (2015). Contour lines indicate the dissolved oxygen concentration interval. Prepared by ODV Software (Schlitzer, 2010)

figure1

FIGURE 2. Schematic description of the focused time intervals and samples considered regarding to the benthic foraminifera study at each core.

figure2

FIGURE 3. Dominance and Fisher α diversity indices calculated for each sample and core. Note that the scale bars are different.

figure3

FIGURE 4. Downcore distributions of the most abundant species (>5% relative abundance) observed in the sediment cores. N.A.: in case of absence of the species. Note that the scale bars are different.

figure4

FIGURE 5. Downcore distributions of A. minimum, A. weddellensis, B. minuta, C. delicata, E. exigua and U. auberiana observed in core M77/1-59-1. Note that the scale bars are different.

figure5

FIGURE 6. Visual description of core M77/1-416 with magnetic susceptibility (SI) measurements and < 63 μm (weight %) information. Relative abundances of given species are potentially in relation with the downslope transported material.

figure6

FIGURE 7. Optical microscope images; scale bar equals 100 μm. 1. Epistominella pacifica umbilical view 47-2; 128 cm, 2. Epistominella exigua spiral view 52-2; 450 cm, 3. Epistominella exigua umbilical view 52-2; 450 cm, 4. Anomalinoides minimus spiral view 59-1; 523 cm, 5. Anomalinoides minimus umbilical view 59-1; 523 cm, 6. Epistominella obesa spiral view 50-4; 100 cm, 7. Epistominella obesa spiral view 50-4; 100 cm, 8. Epistominella obesa umbilical view 50-4; 100 cm, 9. cf. Buccella peruviana spiral view 50-4; 230 cm, 10. cf. Buccella peruviana umbilical view 47-2; 113 cm, 11. Cassidulina auka 416; 100 cm, 12. Alabaminella weddellensis spiral view 52-2; 270 cm, 13. Gyroidina subtenera spiral view 52-2; 270 cm, 14. Gyroidina subtenera umbilical view 52-2; 230 cm, 15. Cassidulina minuta 52-2; 120 cm, 16. Cassidulina carinata 50-4; 210 cm, 17. Cassidulina delicata 47-2; 128 cm.

figure7

FIGURE 8. SEM images; scale bar equals 100 μm. 1. Bolivina seminuda 416; 200 cm, 2. Bolivina cf. seminuda var. humilis 416; 200 cm, 3. Bolivina seminuda var. humilis 47-2; 113 cm, 4. Bolivina pacifica 52-2; 270 cm, 5. Bolivina interjuncta var. bicostata 52-2; 520 cm, 6. Bolivinita minuta 52-2; 270 cm, 7. Bolivina aff. tortuosa 59-1; 523 cm, 8. Bolivina costata 52-2; 270 cm, 9. Bolivina ordinaria 47-2; 128 cm, 10. Bulimina pagoda 52-2; 520 cm, 11. Fursenkoina fusiformis 50-4; 230 cm, 12. Virgulina spinosa 59-1; 963 cm, 13. Fursenkoina glabra 50-4; 230 cm, 14. Anomalinoides minimus spiral view 59-1; 523 cm, 15. cf. Buccella peruviana umbilical view 47-2; 113 cm, 16. cf. Buccella peruviana peripheral view 47-2; 113 cm, 17. cf. Buccella peruviana spiral view 50-4; 230 cm, 18. Epistominella exigua spiral view 52-2; 450 cm, 19. Epistominella exigua umbilical view 52-2; 450 cm, 20. Anomalinoides minimus umbilical view 59-1; 523 cm, 21. Epistominella afueraensis umbilical view 416; 200 cm, 22. Epistominella afueraensis peripheral view 416; 200 cm, 23. Epistominella afueraensis spiral view 416; 200 cm, 24. Alabaminella weddellensis spiral view 52-2; 270 cm.

figure8

FIGURE 9. Optical microscope images; scale bar equals 200 μm. 1. Planulina limbata umbilical view 416; 100 cm, 2. Epistominella pacifica 416; 200 cm, 3. Epistominella pacifica umbilical view 416; 200 cm, 4. Angulogerina angulosa 50-4; 100 cm, 5. Epistominella smithi spiral view 50-4; 210 cm, 6. Uvigerina striata 416; 200 cm, 7. Uvigerina hispida 52-2; 120 cm, 8. Epistominella afueraensis spiral view 416; 200 cm, 9. Epistominella afueraensis umbilical view 416; 200 cm, 10. Gyroidina rothwelli umbilical view 416; 100 cm, 11. Gyroidina rothwelli spiral view 416; 100 cm.

figure9

FIGURE 10. Optical microscope images; scale bar equals 200 μm. 1. Bolivina interjuncta 47-2; 168 cm, 2. Bolivina subadvena 47-2; 113 cm, 3. Bolivina plicata microspheric form 416; 200 cm, 4. Bolivina plicata macrospheric form 416; 100 cm, 5. Bolivina argentea 50-4; 350 cm, 6. Praeglobobulimina spinescens 47-2; 168 cm, 7. Bolivina spissa macrospheric form 52-2; 520 cm, 8. Bolivina spissa microspheric form 47-2; 128 cm, 9. Stainforthia complanata 50-4; 210 cm, 10. Bolivina alata 50-4; 110 cm, 11. Buliminella tenuata 50-4; 100 cm, 12. Globobulimina pacifica 52-2; 230 cm, 13. Uvigerina peregrina 416; 200 cm, 14 - 15. Bulimina exilis 50-4; 100 cm & 350 cm, 16. Buliminella curta var. basispinata 50-4; 350 cm, 17. Uvigerina auberiana 50-4; 350 cm, 18. Cassidulina crassa 52-2; 520 cm.

figure10

FIGURE 11. SEM images; scale bar equals 200 μm. 1. Bolivina interjuncta 47-2; 168 cm, 2. Bolivina plicata microspheric form 416; 200 cm, 3. Bolivina plicata macrospheric form 416; 100 cm, 4. Bolivina spissa 52-2; 520 cm, 5. Uvigerina peregrina 416; 200 cm (different specimen depicted in optical microscope and SEM image), 6. Praeglobobulimina spinescens 47-2; 168 cm, 7. Stainforthia complanata 50-4; 210 cm, 8. Uvigerina auberiana 50-4; 350 cm, 9. Uvigerina semiornata 52-2; 230 cm, 10. Bolivina alata 50-4; 110 cm, 11. Buliminella cf. curta 50-4; 100 cm, 12.-13 Bulimina exilis 50-4; 100 cm & 350 cm, 14. Uvigerina striata 416; 200 cm, 15. Hoeglundina elegans 52-2; 500 cm, 16. Globobulimina pacifica 52-2; 230 cm, 17. Cassidulina delicata 47-2; 128 cm, 18. Cassidulina crassa 52-2; 520 cm, 19. Cassidulina auka 416; 100 cm

figure11

FIGURE 12. Optical microscope images; scale bar equals 100 μm. 1. Bolivina costata 52-2; 270 cm 2. Bolivina ordinaria 47-2; 128 cm, 3. Bolivina cf. seminuda var. humilis 416; 200 cm, 4. Bolivina seminuda 416; 200 cm, 5-6. Bolivina interjuncta var. bicostata 52-2; 520 cm and 450 cm, 7. Bolivinita minuta 52-2; 270 cm, 8. Bolivina aff. tortuosa 59-1; 523 cm, 9. Bolivina seminuda var. humilis 47-2; 113 cm, 10. Bolivina pacifica 52-2; 270 cm, 11. Bolivina tongi var. filacostata 59-1; 523 cm, 12. Buliminella cf. curta 50-4; 100 cm, 13. S uggrunda eckisi 50-4; 110 cm, 14. Suggrunda porosa 47-2; 128 cm, 15. Fursenkoina fusiformis 50-4; 230 cm, 16. Fursenkoina glabra 50-4; 230 cm, 17. Buliminella elegantissima 416; 180 cm, 18. Bulimina mexicana 52-2; 520 cm, Bulimina pagoda 52-2; 520 cm.

figure12

FIGURE 13. SEM images; scale bar equals 200 μm. 1. Cibicidoides wuellerstorfi spiral view 52-2; 500 cm, 2. Cibicides mckannai umbilical view 52-2; 230 cm, 3. Epistominella smithi umbilical view 50-4; 210 cm, 4. Epistominella smithi spiral view 50-4; 210 cm, 5. Planulina limbata umbilical view 416; 100 cm, 6. Epistominella pacifica umbilical view 416; 200 cm, 7. Epistominella pacifica spiral view 416; 200 cm, 8. Epistominella pacifica peripheral view 416; 200 cm, 9. Gyroidina rothwelli spiral view 416; 100 cm, 10. Oridorsalis umbonatus umbilical view 52-2; 230 cm, 11. Gyroidina subtenera umbilical view 52-2; 230 cm, 12. Gyroidina subtenera spiral view 52-2; 270 cm, 13. Epistominella pacifica umbilical view 47-2; 128 cm, 14. Gyroidina rothwelli umbilical view 416; 100 cm, 15. Cassidulina carinata 50-4; 210 cm.

figure13

 

 

author1Zeynep Erdem NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands. This email address is being protected from spambots. You need JavaScript enabled to view it.
previously GEOMAR Helmholtz Centre of Ocean Research, Kiel, Germany

Dr. Zeynep Erdem received her B.Sc. and M.Sc. from the Istanbul Technical University (ITU), Istanbul, Turkey and Dr. rer. nat. from the University of Kiel in 2016. As a part of her PhD project, she worked in the Research Unit Paleoceanography of GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany as part of a multidisciplinary project focusing on oxygen limited marine environments. Currently, she is working in Marine Microbiology and Biogeochemistry Department at NIOZ Royal Netherlands Institute for Sea Research, Texel, The Netherlands as a postdoc researcher. Her research interests are paleoceanography, multi proxy (biogeochemical) applications on marine sediments and micropaleontology, specificly benthic foraminifera.

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author2Joachim Schönfeld. GEOMAR Helmholtz Centre of Ocean Research, Kiel, Germany. This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr. Joachim Schönfeld obtained his Dr. rer. nat. from the University of Kiel in 1989 and continued research at the Federal Bureau of Geosciences and Natural Resources, Hannover, GEOMAR Research Centre for Marine Geosciences, Kiel at Department 5 – Geowissenschaften, Bremen University and with Tethys Geoconsulting, Ltd., Kiel, Germany. Doctor Schönfeld is currently a staff scientist from the Research Unit Paleoceanography of GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany. His scientific interests are benthic foraminifera, their taxonomy, ecology, Mesozoic and Cenozoic paleoceanography, stratigraphy and climate history. 

 

Relative abundances calculated for each sample and core.

Part 1.

M77/2-59-1 late Holocene early Holocene BA/ACR Heinrich Stadial-1
Species / Age
(cal yr BP)
3024 3413 3801 4178 4531 4877 8098 8596 9095 9594 10093 13112 13504 13867 14230 14569 15080 15643 16330 17065
Alabaminella weddellensis 4.85 5.96 5.45 4.50 5.77 4.17 3.03 4.35 2.64 3.10 2.67 0.00 0.00 0.38 0.00 0.00 0.44 0.00 0.00 0.00
Anomalinoides minimus 3.00 3.34 3.50 5.03 2.54 3.79 4.33 4.35 4.70 3.53 5.08 3.11 0.23 0.57 0.69 0.63 0.29 0.00 0.00 0.00
Bolivina interjuncta var. bicostata 0.57 0.73 0.00 0.53 0.46 0.19 0.43 1.16 1.17 1.21 1.60 6.99 3.97 4.39 3.45 2.83 5.84 4.05 4.84 3.93
Bolivina pacifica 0.00 0.00 0.39 0.00 0.23 0.19 0.43 0.00 0.15 0.52 0.40 0.78 2.10 4.77 5.86 5.03 1.61 2.02 3.96 5.36
Bolivina quadrata 0.14 0.00 0.00 0.00 0.00 0.00 0.87 0.87 1.03 1.03 1.60 4.50 3.50 6.87 1.38 2.83 1.75 0.00 3.96 3.39
Bolivinita minuta 21.83 21.80 29.57 22.49 20.09 13.64 12.12 16.81 16.74 19.83 20.32 18.94 9.11 5.92 2.76 0.63 10.80 3.85 1.32 0.36
Cassidulina carinata 2.71 3.78 5.06 6.08 8.31 5.11 5.19 8.70 6.75 6.21 6.42 5.28 5.37 7.63 0.00 1.89 4.38 7.29 8.79 4.82
Cassidulina delicata 9.70 11.92 11.28 12.17 9.93 12.88 13.42 8.41 11.89 12.33 8.16 2.80 7.01 3.63 4.14 3.77 7.74 15.59 7.69 10.00
Cassidulina minuta 8.27 4.22 0.00 1.59 4.85 2.27 0.00 4.06 1.17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.44 0.00 0.00 0.00
Epistominella afueraensis 0.00 0.00 1.56 0.00 0.00 4.36 1.30 5.80 2.94 1.47 1.07 2.95 1.87 0.19 0.00 0.63 0.00 0.00 0.66 0.00
Epistominella exigua 5.56 5.67 5.45 8.20 5.77 6.63 7.79 7.54 8.66 10.17 8.02 11.96 10.75 15.08 21.38 16.35 17.08 9.11 13.19 22.68
Epistominella obesa 2.57 3.05 1.56 3.70 5.08 0.95 0.00 0.00 0.00 1.81 0.94 0.78 3.74 2.10 4.48 3.14 2.77 3.24 1.76 1.61
Epistominella pacifica 0.71 1.45 0.39 0.00 0.00 0.00 0.00 0.00 1.17 0.95 2.67 0.00 2.57 6.30 5.52 0.00 2.19 2.02 1.76 0.89
Epistominella smithi 0.00 0.00 0.00 0.00 0.23 0.19 0.00 0.29 0.00 0.00 0.00 4.97 5.84 0.00 0.00 4.40 3.50 2.83 5.71 5.00
Gyroidina rothwelli 1.14 1.16 1.95 1.06 0.69 0.95 0.87 3.19 1.47 2.41 2.81 4.97 5.37 5.15 4.14 3.14 3.21 4.66 0.88 1.61
Uvigerina auberiana 6.56 7.27 5.06 6.35 6.24 7.77 6.93 5.51 6.31 5.26 5.08 3.26 3.27 2.10 1.03 1.26 0.00 0.00 0.00 0.00
Uvigerina semiornata 2.85 1.60 1.56 3.97 5.08 4.73 3.90 2.61 3.08 1.12 3.21 2.64 1.64 0.76 0.00 1.57 1.90 0.81 2.86 1.25
Virgulina spinosa 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.09 0.00 0.47 1.87 7.06 6.21 20.44 1.17 0.61 0.88 0.00
Miliolids 0.14 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.15 0.09 0.27 0.16 0.00 0.00 0.00 0.00 0.29 0.00 0.66 0.18
Other calcareous 29.24 28.05 27.24 24.34 24.48 32.20 39.39 26.38 29.96 28.88 29.68 25.47 31.78 27.10 38.97 31.45 34.60 43.93 41.10 38.93
Agglutinated 0.14 0.00 0.00 0.00 0.23 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
                                         
Total number specimens 701 688 257 378 433 528 231 345 681 1160 748 644 428 524 290 318 685 494 455 560
Total number species 57 71 40 48 51 56 45 50 67 70 63 52 51 54 43 49 56 49 52 53

Part 2.

M77/2-52-2 late Holocene early Holocene BA/ACR Heinrich Stadial-1 Last Glacial Max
Species / Age (cal yr BP) 3130 3845 4202 4559 4917 8097 8486 8839 9192 9546 9899 12714 13177 13641 14143 14465 15147 15469 16151 16653 17155 17657 20168 20670 21172 21674 22176
Bolivina costata 27.12 33.88 25.50 33.81 23.13 42.46 22.96 20.85 18.98 23.13 17.32 4.35 1.15 1.00 5.23 2.34 0.88 1.35 0.90 2.24 0.74 1.38 4.15 4.60 4.56 3.66 6.04
Bolivina spissa 4.24 4.47 6.19 3.57 3.06 6.36 4.14 3.64 4.92 6.22 5.08 4.35 3.93 2.99 3.35 2.05 4.84 2.12 4.30 2.52 1.98 2.75 0.98 1.02 1.45 0.37 0.15
Bolivinita minuta 1.69 1.88 2.23 1.67 3.40 2.21 5.80 3.24 4.92 3.84 5.77 11.84 19.86 4.23 6.90 1.46 3.96 1.54 4.52 1.12 0.74 0.79 0.37 0.26 0.00 0.18 0.15
Bulimina pagoda 0.00 0.71 0.99 1.43 0.68 0.41 0.59 0.81 0.00 0.00 0.00 1.21 0.69 1.00 1.05 0.88 1.10 0.19 0.00 0.84 0.50 0.79 5.73 3.32 6.01 3.84 6.50
Cassidulina carinata 0.00 1.65 1.73 0.95 4.08 0.00 1.78 0.00 0.51 0.73 1.39 2.42 2.08 6.97 4.60 4.39 4.84 3.08 0.45 3.36 4.95 2.75 8.29 23.27 9.12 10.42 7.28
Cassidulina delicata 7.63 5.88 7.18 7.38 8.84 8.44 15.50 10.53 12.03 11.83 20.55 12.80 8.78 15.17 12.13 9.94 7.47 6.92 6.33 9.52 6.93 13.75 8.41 5.63 8.29 5.67 14.86
Cassidulina laevigata 0.85 0.00 0.00 0.48 0.00 0.28 0.00 0.81 0.00 0.00 0.00 0.00 0.00 0.25 0.00 0.00 0.00 0.38 1.36 0.00 0.00 2.36 0.98 0.00 3.11 6.95 14.09
Cibicides mckannai 0.42 3.29 2.72 2.38 1.02 4.43 1.54 3.64 4.24 3.22 2.54 4.59 6.70 6.72 3.56 1.46 3.30 1.15 2.26 1.12 0.99 1.96 1.95 0.26 1.66 0.18 1.24
Epistominella exigua 7.63 3.06 2.97 6.67 9.86 0.00 2.25 1.62 1.69 1.76 3.70 3.38 2.77 1.99 4.18 9.36 13.19 23.27 22.17 25.49 31.19 33.01 0.98 10.23 0.62 5.12 3.56
Epistominella pacifica 1.69 4.47 0.00 0.00 3.40 1.38 6.51 6.28 7.29 6.95 2.54 4.11 5.08 8.21 2.51 0.88 3.52 6.35 3.62 2.24 1.98 1.96 0.00 0.00 0.21 1.10 2.17
Epistominella smithi 3.39 4.24 7.43 6.67 3.06 2.35 0.00 0.00 0.00 0.93 2.77 6.28 8.08 1.74 8.58 11.40 6.81 4.62 3.85 4.48 6.44 1.77 10.12 5.88 4.97 4.02 2.32
Uvigerina auberiana 7.63 9.88 10.64 8.57 9.18 5.67 5.44 5.87 4.58 4.67 5.77 6.04 5.54 5.47 4.81 6.14 2.42 2.69 2.71 3.08 0.50 2.75 7.68 5.63 7.25 5.85 5.88
Uvigerina bifurcata 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.62 0.00 0.00 1.15 0.00 1.26 0.00 0.00 0.00 0.00 0.00 0.00 0.00 4.63 3.07 8.91 0.00 0.00
Uvigerina peregrina 0.00 0.94 0.00 0.00 0.00 0.00 1.18 1.21 1.19 0.83 0.00 0.00 0.92 0.00 1.26 0.88 0.66 0.58 2.04 0.28 0.00 0.00 2.32 4.09 5.60 10.05 5.73
Uvigerina semiornata 8.05 6.82 8.42 8.10 6.12 5.39 5.56 8.91 10.85 4.67 3.46 7.00 5.54 11.44 4.60 7.60 10.55 4.23 6.11 8.68 5.69 6.29 17.20 5.88 6.53 3.66 6.04
Miliolids 0.00 0.00 0.00 0.00 0.00 0.14 0.00 0.00 0.34 0.00 0.23 0.00 0.46 0.00 0.42 0.29 0.22 0.00 0.23 0.00 0.00 0.00 0.00 0.00 0.31 0.37 0.00
Other calcareous 28.39 16.94 21.78 16.19 22.11 19.92 25.80 31.78 27.80 30.08 28.41 30.92 25.87 32.84 35.15 40.35 35.82 40.96 38.69 34.17 37.38 26.92 26.10 26.85 31.40 38.57 23.84
Agglutinated species 1.27 1.88 2.23 2.14 2.04 0.55 0.95 0.81 0.68 0.52 0.46 0.72 1.39 0.00 0.42 0.58 0.44 0.58 0.45 0.84 0.00 0.79 0.12 0.00 0.00 0.00 0.15
                                                       
Total number specimens 236 425 404 420 294 723 845 494 590 964 433 414 433 402 478 342 455 520 442 357 404 509 820 391 965 547 646
Total number species 45 48 50 41 48 53 62 67 60 77 46 60 50 53 69 67 59 63 50 51 45 50 76 50 75 73 70

 

Part 3.

                     

M77/2-50-4 BA/ACR Heinrich Stadial-1 Last Glacial Max
Species / Age
(cal yr BP)
12873 13502 14131 14377 14622 14868 15359 15850 16341 16832 17215 17598 20095 20359 20623 20900 21178 21455 21733 22010
Bolivina costata 39.30 28.85 43.63 44.31 32.44 25.06 30.97 26.58 12.08 5.85 11.38 6.52 17.22 7.60 11.18 9.43 9.13 8.30 10.14 10.71
Bolivina pacifica 0.00 0.00 0.00 0.00 0.00 0.76 0.00 0.21 0.67 0.00 5.33 4.67 0.37 0.58 0.63 2.20 0.48 0.53 0.62 0.74
Bolivina seminuda var. humilis 1.08 3.13 4.54 4.19 2.89 4.79 5.51 5.91 6.26 4.68 5.57 3.12 3.30 5.85 3.80 6.72 5.77 3.36 2.96 2.98
Bolivinita minuta 10.03 6.73 3.32 1.20 4.44 3.02 1.31 1.69 3.80 4.68 3.39 2.83 0.73 2.34 1.27 1.55 1.44 1.77 3.28 3.87
cf. Buccella peruviana 0.00 0.00 2.09 1.80 0.00 0.50 0.52 1.05 0.00 0.00 0.00 2.69 0.37 0.00 2.11 3.88 1.92 1.59 1.56 5.36
Buliminella tenuata 0.54 2.88 1.57 2.40 2.44 5.16 2.62 0.63 2.24 2.34 1.45 0.57 2.20 0.00 1.05 0.00 0.00 1.06 0.00 0.89
Cassidulina auka 0.00 0.00 0.00 0.00 0.00 0.76 0.00 0.00 0.00 0.00 0.00 0.00 5.13 1.75 2.32 3.23 5.77 4.59 1.40 1.04
Cassidulina carinata 0.00 0.00 0.00 0.00 0.89 1.51 0.00 2.11 0.89 0.58 2.42 2.97 7.33 5.85 6.96 5.68 1.92 10.78 7.49 4.02
Cassidulina delicata 8.40 8.65 4.01 2.99 5.11 4.66 6.82 3.59 11.19 8.77 7.02 6.09 6.59 5.26 9.49 7.75 13.94 8.30 7.49 7.74
Epistominella afueraensis 7.05 1.20 2.09 2.40 0.00 6.30 0.79 1.48 4.25 4.09 2.91 1.42 2.20 1.17 0.63 1.03 1.44 2.47 0.16 0.45
Epistominella exigua 2.44 2.64 1.75 4.19 3.78 2.52 0.00 3.16 5.59 7.02 6.78 14.16 1.83 8.77 4.43 9.82 1.44 7.77 12.17 8.18
Epistominella obesa 0.00 1.92 3.14 6.59 6.44 6.17 7.35 6.96 18.34 7.02 12.11 8.50 12.45 14.62 10.13 10.59 10.58 8.13 2.50 9.08
Epistominella pacifica 0.27 7.21 5.76 6.59 4.89 2.77 1.57 4.64 2.91 1.17 1.21 0.85 3.30 0.00 0.00 0.13 0.00 1.24 0.47 0.00
Epistominella smithi 6.78 2.40 0.00 0.00 2.22 2.90 2.89 3.80 0.22 1.75 2.42 0.14 0.00 0.00 0.63 0.00 0.00 0.18 0.00 0.30
Fursenkoina fusiformis 0.81 1.92 0.87 1.20 2.44 2.02 2.10 1.05 1.12 1.17 5.08 3.97 0.00 0.00 0.21 0.78 0.48 0.71 0.16 0.30
Pseudoparella subperuviana 6.78 6.25 6.11 0.00 6.00 4.91 7.09 7.81 2.24 14.04 9.93 5.81 7.33 2.34 2.53 2.84 8.65 4.95 15.60 9.08
Pseudoparella sp. 0.54 2.64 4.36 0.00 5.11 1.13 4.99 4.64 8.28 7.02 0.00 7.37 0.73 17.54 5.70 1.03 4.33 4.95 4.21 9.52
Uvigerina semiornata 0.00 3.13 1.40 2.40 2.44 1.76 2.62 2.32 1.79 0.58 0.48 1.27 2.56 4.68 6.12 3.88 3.37 6.71 2.03 1.64
Virgulina cornuta 0.00 0.00 0.70 2.40 1.11 1.89 1.84 0.84 0.89 1.75 5.57 5.38 2.20 1.17 1.69 0.39 0.48 1.24 0.62 0.74
Miliolids 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.17 0.24 0.14 1.10 1.17 0.63 0.78 0.96 0.53 0.31 0.30
Other calcareous 15.99 20.43 14.66 17.37 17.33 21.41 21.00 21.52 17.23 26.32 16.71 21.39 22.71 19.30 28.48 28.16 27.88 20.85 26.83 22.92
Agglutinated species 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.14 0.37 0.00 0.00 0.13 0.00 0.00 0.00 0.15
                                         
Total number specimens 236 425 404 420 294 723 845 494 590 964 433 414 433 402 478 342 455 520 442 357
Total number species 45 48 50 41 48 53 62 67 60 77 46 60 50 53 69 67 59 63 50 51

 

Part 4.

M77/2-47-2 BA/ACR Heinrich Stadial-1 Last Glacial Max
Species / Age
(cal yr BP)
13282 13717 14692 15388 16085 16782 17478 19568 20265 20961 21658 22354
Bolivina costata 19.71 15.90 25.24 23.28 24.87 19.92 22.61 21.39 13.92 26.03 25.76 30.50
Bolivina seminuda var. humilis 5.53 3.77 0.00 1.90 2.09 1.17 3.45 3.18 1.62 1.91 2.62 0.71
Bolivinita minuta 2.88 3.35 4.11 5.94 3.14 2.73 1.53 2.60 1.94 2.50 0.87 2.13
Buccella peruviana 4.81 8.37 4.50 3.80 2.88 4.69 1.92 4.62 3.88 5.00 3.49 4.61
Cassidulina delicata 7.21 11.30 13.50 15.44 13.87 10.94 12.26 7.80 6.15 11.32 11.79 7.09
Cassidulina minuta 3.13 0.00 4.11 0.00 2.62 3.13 5.36 8.96 2.91 2.21 6.11 0.00
Epistominella obesa 9.86 14.85 3.52 2.38 11.26 14.84 15.33 15.90 15.53 9.12 6.55 7.45
Pseudoparella subperuviana 8.65 11.51 9.98 13.54 7.85 8.20 7.28 3.18 13.59 10.74 4.37 3.90
Pseudoparella sp. 9.13 5.02 4.31 6.18 8.90 7.81 4.21 11.85 10.36 6.76 5.24 13.83
Miliolids (Quinqueloculina sp.) 0.00 0.00 0.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Other calcareous 29.09 25.94 30.72 27.55 22.51 26.56 26.05 20.52 30.10 24.41 33.19 29.79
Agglutinated species 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
                         
Total number specimens 416 478 511 421 382 256 261 346 309 680 229 282
Total number species 40 37 39 36 33 34 32 33 38 45 33 37

 

Part 5.

M77/1-416 Last Glacial Max
Species / Age
(cal yr BP)
20176 20395 20505 20615 21073 21531 21983
Bolivina plicata 0.90 0.39 0.93 2.99 5.19 5.59 3.44
Bolivina seminuda var. humilis 3.62 6.25 6.48 12.69 1.48 13.13 22.14
Buliminella elegantissima 0.00 0.78 21.30 0.75 20.74 0.28 0.00
Cassidulina auka 38.01 16.80 21.30 14.93 6.67 5.03 1.91
Epistominella afueraensis 0.90 27.34 0.00 9.70 0.00 6.70 9.54
Epistominella exigua 6.33 2.34 0.00 0.00 0.00 0.00 0.00
Epistominella obesa 0.00 0.00 1.85 0.00 8.89 0.84 5.73
Epistominella pacifica 9.95 12.11 9.26 10.45 0.74 33.52 12.98
Gyroidina rothwelli 13.12 10.94 2.78 14.93 1.48 2.23 7.63
Nonionella auris 0.00 0.78 9.26 0.00 14.81 0.00 0.00
Planulina limbata 7.24 2.34 3.70 2.24 0.74 1.40 3.44
Pseudoparella subperuviana 0.00 0.00 4.63 0.00 17.04 0.84 2.29
Uvigerina peregrina 0.00 1.95 0.00 1.49 0.00 5.59 5.73
Uvigerina striata 0.90 0.78 0.00 0.00 0.74 2.23 5.34
Miliolids (Quinqueloculina sp.) 0.45 0.00 0.00 0.00 0.00 0.00 0.00
Other calcareous 19.00 17.19 18.52 29.85 21.48 22.63 19.85
Agglutinated species 0.00 0.00 0.00 0.00 0.00 0.00 0.00
               
Total number specimens 221 256 108 134 135 358 262
Total number species 26 28 21 28 22 33 26