STRATIGRAHUC ANALYSIS OF ARARIPE BASIN, NORTHEASTERN BRAZIL. The Araripe Basin comprises four main stratigraphic sequences separated by unconformities: 1. a Paleozoic sequence composed of the Cariri Formation; 2. a Juro-Neocomian sequence composed of the Brejo Santo Formation, Missão Velha Formation (redefined) and Abaiara Formation; 3. an Aptian-Albian sequence composed of the Barbalna Formation and Santana Formation; and 4. an Albian-Cenomanian sequence composed of the Exu Formation. The Juro-Neocomian sequence is characterized by horsts and grabens displayed in two sub-basins: Cariri and Serrolândia subbasins. The Aptian-Cenomanian is characterized by sub-horizontal bedding and localized brittle deformation. The events of sedimentation, erosion, and deformation proposed for the sequences above, integrate the Phanerozoic evolution in Northeastern Brazil. The Paleozoic deposits which have, in attempt, been classified as Upper Ordovician/ Lower Silurian, have also been interpreted as an extension of the cratonic Parnaiba Basin. The Juro-Neoconian sequence is ú» sedimentary response to the mechanical subsidence brought about by the Gondwana rifting processes. The Barbalha and Santana formations comprise a transgressive-regressive cycle characterized by short-lived sea ingression which has deposited an exuberant fossiliferous carbonate concretions level and extensive gypsum beds. The presence of alluvial deposits of Exu Formation, deposited contemporaneously to a global eustatic sea level rising, suggests an epeirogenic uplift early in the Albian-Cenomanian time.

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PALEOCURRENTS AND PALEOGEOGRAPHY IN THE ARARIPE BASIN, NORTHEAST BRAZIL. The Araripe basin is composed of four unconformity-bounded sequences: 1) Lower sequence; 2) Jurassic-Neocomian sequence; 3) Aptian-Albian sequence, and 4) Albian-Cenomanian sequence. Each sequence shows different alluvial paleocurrent pattern and bears no relation to the geometry of their areas of occurrence, suggesting that these areas are fragments of distinct and originally larger basins. The main sedimentary flow direction N-NW in the Lower sequence (Cariri Formation) is similar to the flow directions in the Paleozoic units in the neighbouring Tucano-Jatobá and Parnaíba basins. The paleocurrent pattern in the Jurassic-Neocomian sequence (Missão Velha and Abaiara formations) indicates a southward paleoflow towards the Recôncavo-Tucano basin. In both sequences the paleocurrent pattern is constant regardless of the several faults, either cutting through them or running along their boundaries, suggesting that the horst-and-graben style is a basin-modifying tectonic product. The fluvial deposits present at the base of the Aptian-Albian sequence (Barbalha Formation) portray southeast paleoflows towards the Sergipe-Alagoas basin. An opposite direction is suggested for the Albian marine transgression in the Santana Formation. Although the sea level was in a global eustatic rising movement, the Albian-Cenomanian deposits of the Exu Formation record the return to continental conditions with rivers flowing westward in the direction of the Parnaíba basin. Such rearrangement in the continental paleodrainage was a consequence of the uplift of Northeast Brazil during the Albian time.

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PR-151. km 'l31 5 PR-151. km 137 Estreda Carembeí-cetanduvas. a 6.5km do trevo com a PR-151 Entrada do canvon do rio lapó, afloramento na margem esquerda 71 Rodovia Castro-T¡baoi. kml6 Rodovia Castro-Tibaqi, km19,5 Canvon do Rio laoó: acesso oela rodov¡a Castro-Tibaoi. km 35 Canvon do Rio laþó no Guartelá; acesso pela rodovia Castro-T¡bagi, km 42 Estreda Cestro/Tibaoi. na Donte sobre o rio Tibaoi Anoio Såo Oominoos. a cerca de skm a oeste de T¡baqi Estrede oere â cescâte Sente Rosa. a 5.5km de T¡baoi Estrada Þara a cascata Santa Rosa, a 12 km cle T¡þag¡ PR-090, entre Piraí do Sul e Ventania; afloramento contínuo na escarpa do 20 olenalto. com início a 8.4km a oeste da oonte sobre o rio Piraí PR-090, entre Piraí do Sul e Ventania, a 20,3km a oeste da ponte sobre o rio Piraí 81 PR-090, entre Piraí do Sul e Ventan¡a; afloramento nas proximidades do rio Fortaleze PR-151, km203,5 PR-151. km206 a4 PR-151, km217 PR-151. km219 PR-092, km 225,5 PR-092. km227.4 PR-092, km 233,8 Rua Mal. Deodoro no bairro Laooão. em Jaouariaíva Acêssô âô terminâl ferrôv¡áriô dâ indúslria PISA em Jeouar¡a¡va 91 PR-151. km237.5. a 500m da oonte sobre o rio das Mortes Grute da Sântâ: acêsso oela estrede de Jeouârieíve oara o Distrito de Janoai Cachoeira do Corisco. vale do rio ltararé. Senqés-PR Escama do 20 olânâlto na estrâde oere e indústria Luber. a leste de ltãraré lSPl Estrada ltararé-Bonsucesso. a 34km do centro de saúde ll em ltaraÍé Estrâda ltâbeve-Bonsucesso. e 16-skm do entroncamento com a SP-258 PR-092. km232.4 PR-092. km 234 6 PR-092. kÍt237.7 100 Estrada de ferro no cruzamento com a R. Mal. Deodoro, baino Lagoão, em Jaouariaíva 101 Corte em estrada de ferro no baino Santa Luzia em Ponta Grossa; acesso pela BR-376. km174.6 1o2 Final da Rua Paul Harr¡s. bairro Jardim Sabará em Ponta Grossa 103 Gruta da Baneira em ltararé (SP)

The Pantanal is the world's largest tropical wetland and a biodiversity hotspot, yet its response to Quaternary environmental change is unclear. To address this problem, sediment cores from shallow lakes connected to the Upper Paraguay River (PR) were analyzed and radiocarbon dated to track changes in sedimentary environments. Stratal relations, detrital particle size, multiple biogeochemical indicators, and sponge spicules suggest fluctuating lake-level lowstand conditions between ~ 11,000 and 5300 cal yr BP, punctuated by sporadic and in some cases erosive flood flows. A hiatus has been recorded from ~ 5300 to 2600 cal yr BP, spurred by confinement of the PR within its channel during an episode of profound regional drought. Sustained PR flooding caused a transgression after ~ 2600 cal yr BP, with lake-level highstand conditions appearing during the Little Ice Age. Holocene PR flood pulse dynamics are best explained by variability in effective precipitation, likely driven by insolation and tropical sea-surface temperature gradients. Our results provide novel support for hypotheses on: (1) stratigraphic discontinuity of floodplain sedimentary archives; (2) late Holocene methane flux from Southern Hemisphere wetlands; and (3) pre-colonial indigenous ceramics traditions in western Brazil.

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