Abstract This study sought to understand the role of continental influence on ocean productivity along the late Quaternary based on the comparison between continental palynomorphs and paleoproductivity proxies from the marine sediment core SIS188. Retrieved from the slope of the Pelotas Basin at a depth of 1,514 m, the core documents the time interval between 47.8 and 7.4 cal ka BP, including the Marine Isotope Stages (MIS) 3, 2 and 1. The palynological content found in the core SIS188 indicates a typical flora of the southern Brazil highlands, which is at the same latitude as the core. Thus, continental input sources, such as wind-borne dust and discharges from the Mampituba and Araranguá rivers, would more likely account for the palynological content than the Brazilian Coastal Current (BCC). During the glacial intervals (MIS 3 and MIS 2), paleoproductivity (indicated by the proxies coccolith numbers, N Ratio, and TOC content) suggest the intensification of upwelling and transport of wind dust, the latter of which may have transported pollen grains to the core region. There is a concentration decrease of continental palynomorphs at the end of MIS 2, which is accentuated during MIS 1 when the sea level is higher. Paleoproductivity was high during MIS 1, especially from the Holocene onwards, although the concentration of continental-derived palynomorphs decreases sharply, showing that the rise in sea level interferes with the fertilization of marine waters far from the coast by continental input.

Abstract In this study, we describe morphometric analyses of Orbulina universa morphotypes presently found in the Western South Atlantic, and their relation to the upper water thermohaline indexes. We also investigate this relationship under glacial and interglacial conditions between 7.2 and 32 kyr BP. Ten plankton samples distributed between 32º55' and 26º20'S were selected for the analyses of modern O. universa specimens. Core SIS188 was retrieved at 29º22’S, 47º28’W enabling the analysis of 21 fossil samples. Shell diameter, pore diameter, pore density and porosity were measured using SEM images. Chronology of core SIS188 is based on four AMS 14C ages and the planktonic foraminifera oxygen isotope curve. Planktonic foraminifera relative abundances were converted into SST data using the Modern Analog Technique (MAT). Correlations between the morphometric parameters and temperature and salinity of surface Waters (modern samples) or paleotemperature (fossil samples) were calculated. Morphological characteristics of the analyzed shells allowed to differentiate two morphotypes of O. universa, namely Caribbean and Mediterranean in the studied region. For the Caribbean morphotype, the large pore density showed a negative correlation with both temperature and salinity. For the Mediterranean morphotype, no significant correlations were found. For fossil samples, no significant correlations were found between summer SST (0-50m) and morphometric parameters for the Caribbean or the Mediterranean morphotypes. Possibly, other genotypes do exist in the fossil record, so modern and fossil morphotypes would not have the same behavior. Another explanation for the absence of correlation in fossil samples are errors associated with the SST estimates. Furthermore, fossil samples could represent distinct and more complex oceanographic conditions compared to current configuration, with Plata Plume Water and Brazil Malvinas Confluence migration playing a most significant role in the past.

(Pólen de Magnoliopsida (Asteridae) e Liliopsida do perfil sedimentar de uma turfeira em São Francisco de Paula, Planalto Leste do Rio Grande do Sul, Sul do Brasil). O trabalho tem por finalidade fornecer material de referência para pesquisas paleopalinológicas no sul do Brasil através da análise do perfil sedimentar de uma turfeira do Planalto Leste do Rio Grande do Sul. São apresentados os grãos de pólen de Asteridae, Alismatidae, Commelinidae e Liliidae. O perfil possui 286 cm de comprimento correspondendo, aproximadamente, aos últimos 25.000 anos. O processamento químico das 22 amostras obtidas seguiu o método padrão e a análise foi feita em microscopia óptica. As descrições morfológicas, incluindo medidas dos eixos polar e equatorial, são acompanhadas de fotomicrografias e dados ecológicos do esporófito de origem. Foram identificados grãos correspondentes a 21 Asteridae, uma Alismatidae, quatro Commelinidae, três Liliidae e mais três grãos de pólen indeterminados de Angiospermas.

(Magnoliopsida (Asteridae) and Liliopsida pollen of the sedimentary profile of a bog, São Francisco de Paula, Eastern Plateau of Rio Grande do Sul, Southern Brazil). This paper aims to provide data for paleopalynological research progress in southern Brazil by increasing the knowledge about the Quaternary in the region. Therefore, the palynological analysis of a sedimentary profile of a bog of Rio Grande do Sul Eastern Plateau was made and the Angiospermae pollen (Asteridae, Alismatidae, Commelinidae and Liliidae) are presented. The profile is 286 cm long, corresponding approximately to the last 25,000 years. The chemical processing of the 22 samples obtained followed the standard methodology and the analysis was made by light microscopy. The photomicrographs are accompanied by concise morphological descriptions, including measurements of polar and equatorial axis and ecological data of the original sporophyte. Pollen corresponding to 21 Asteridae, one Alismatidae, four Commelinidae and three Liliidae were identified, beside three indeterminate pollens of Angiospermae.

Este catálogo polínico visa servir de base para o estudo de reconstituições paleoambientais através da palinologia de sedimentos no Planalto do Sul do Brasil. Para tanto, apresenta os grãos de pólen de gimnospermas e angiospermas encontrados no perfil sedimentar de uma turfeira do Planalto Leste do Rio Grande do Sul. O perfil possui 286 cm de comprimento, correspondendo aproximadamente aos últimos 25.000 anos. As 22 amostras foram retiradas do perfil em intervalos regulares, tratadas quimicamente seguindo o método padrão e analisadas em microscópio óptico. São apresentados grãos de pólen de duas gimnospermas e 43 angiospermas (uma Magnoliidae, cinco Hamamelidae, seis Caryophyllidae, seis Dillenidae e 25 Rosidae). O material polínico é descrito e ilustrado. As descrições são acompanhadas, sempre que possível, de dados ecológicos do esporófito de origem.

This pollen catalogue aims at helping the study of paleoenvironmental reconstructions by palynology of sediments in southern Brazil Plateau. It presents gymnosperms and angiosperms pollen found in a sedimentary profile from a bog of Rio Grande do Sul Eastern Plateau. The profile has 286 cm long, corresponding approximately to the last 25,000 years. The 22 samples were collected in regular intervals in the profile, chemically treated following the standard method and analyzed by light microscopy. Pollen grains from two gymnosperms and 43 angiosperms (one Magnoliidae, five Hamamelidae, six Caryophyllidae, six Dillenidae and 25 Rosidae) are presented. The pollen material is described and illustrated. The descriptions are accompanied, whenever possible, by ecological data of the original sporophyte.

O trabalho tem como objetivo fornecer material de referência básico para o estudo de sucessão vegetal no Quaternário do Planalto Sul-brasileiro. Para tanto, apresenta a palinologia de 22 amostras, retiradas ao longo de um perfil sedimentar de 286 cm, em uma turfeira do Planalto Leste do Rio Grande do Sul, correspondendo aproximadamente aos últimos 25.000 anos. O processamento químico das amostras seguiu o método convencional e a análise foi feita em microscopia fotônica. Foram examinados palinomorfos correspondentes a 10 fungos, 6 algas, 3 briófitos e 16 pteridófitos. O material, especialmente esporos, é descrito e ilustrado. As descrições são acompanhadas, sempre que possível, de dados ecológicos do organismo de origem.

This paper aims at giving basic reference material to the study of plant succession in the Quaternary Brazilian southern plateau. Therefore, it presents the palynological analysis of 22 samples, taken along one sedimentary profile of 286 cm, in a bog of Rio Grande do Sul Eastern Plateau, corresponding approximately to the last 25000 years. The chemical processing of the samples followed the conventional method and the analysis was made by light microscopy. Palynomorphs corresponding to 10 fungi, 6 algae, 3 bryophytes and 16 pteridophytes were examined. The material, especially spores, is described and illustrated. The descriptions are accompanied, whenever possible, by ecological data of the original organism.