Spacialization and geocronology of surface coverings in fluvial, fluvial-marine and marine terraces in the mouth of the Itapocu and Araranguá (SC) rivers basins, arising out of the episodes of marine transgressions and regressions associated with climatic oscillations/pulsations

Author(s)

Felipe Gomes Rubira

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Geociências
• Defense date: 2019-06-07

Examining board members

Archimedes Perez Filho; Antônio Carlos de Barros Corrêa; Pedro Manuel Rodrigues Roque Proença Cunha; Fernando Nadal Junqueira Villela; Regina Célia de Oliveira

• Advisor: Archimedes Perez Filho

Abstract

This research aims to identify, spatialize and compartmentalize morphologically levels of Holocene and Pleistocene marine terraces, Holocene tidal plain terraces, Holocene fluvial-marine and fluvial terraces, dissected by the fluvial dynamics of the lower courses of the Araranguá and Itapocu rivers. At the same time, it aims to correlate them with the geochronology of the depositional events associated with the surface coverings that sustain / cover them, to transgressive and regressive marine episodes identified by national and international paleoclimatic literature, linked to the Pleistocene climatic changes and oscillations and Holocene climatic pulsations (genesis), comprising the dynamics of the formation and transformation of the coastal landscape through the establishment of a regional geochronological scenario based on evolutionary phases. The proposed methodology aimed at recovering temporal and genetic lapses regarding the evolution and deposition of the surface coverings that originated the terraces, based on the elaboration of digital elevation models, topographic profiles, fieldwork, stratigraphic comparisons, granulometric analysis and optically stimulated luminescence (LOE) by the procedures indicated by the SAR protocol (Single Aliquot Regenerative-dose) in 15 aliquots. In the coastal plain of the Araranguá river, two levels of Pleistocene marine terraces were identified (NI and NII ? >75.000 years B.P.); two levels of Holocene marine terraces (NIII ? 6.000 ± 820 / 5.000 ± 620 / 420 ± 65 years B.P.) / (NIV ? 180 ± 25 / 165 ± 35 years B.P.); a level of Holocene lagoon terrace covered by aeolian deposits (3.450 ± 440 years B.P.); a level of Holocene fluvial terrace (2.250 ± 300 years B.P.); Holocene fluvial-marine terraces (6.000 ± 820 / 5.000 ± 620 / 2.700 ± 420 / 950 ± 130 / 180 ± 25 years B.P.). The geochronological results of the depositional events linked to the surface coverings of these terraces showed that the evolutionary dynamics of the southern coast of Santa Catarina (Araranguá) was characterized by the development of barrier-lagoon III (Pleistocene) and barrier-lagoon IV (Holocene) systems, which would be linked to the evolutionary proposal of Villwock (1984) for the southern coastal strands of Rio Grande do Sul. They also showed that the coastal plain of southern Santa Catarina (Araranguá) is composed of different generations of aeolian activities, responsible for burial of level I marine materials (35.250 ± 4.400 / 32.000 ± 3.600 / 16.500 ± 2.050 / 10.700 ± 1.260 / 9.800 ± 1.230 years B.P.), developing a thick pedogenized fossil dune; remobilize marine materials from the level II terrace (14.300 ± 1.400 / 12.800 ± 1.500 years B.P.), which are interdigitated; cover level III marine materials by developing a thin layer of stratigraphic surface aeolian; develop frontal dunes in sectors of the IV level marine. In the coastal plain of the Itapocu river, two levels of Holocene tidal plain terraces were identified (NI and NII ? 4.000 ± 620 / 3.820 ± 520 / 3.000 ± 470 / 3.050 ± 380 / 2.900 ± 320 years B.P.); a level of Pleistocene marine terrace (NI? >49.700 ± 9.750 years B.P.); two levels of Holocene marine terraces (NII ? 1.220 ± 110 years B.P.) / (NIII? 880 ± 110 / 250 ± 70 / <100 years B.P.); two levels of Holocene fluvial terraces (NI and NII ? 2.950 ± 300 / 1.200 ± 110 years B.P.). The geochronological results of the depositional events linked to the surface coverings of these terraces showed that the evolutionary dynamics of the northern coast of Itapocu (Itapocu) was characterized by the expansion of the present complex estuarine system of the Bay of Babitonga along marine regression that succeeded the Holocene transgressive peak of Santos, providing formation of tidal plain environments in paleoestuarine conditions developed in great part of the coastal plain, inhibiting the formation of barrier-lagoon type systems observed in Araranguá. Through the dates, it was possible to define 13 evolutionary phases for the coastal plain of the Araranguá river basin and 11 for Itapocu, by means of the dates it was possible to define 13 evolutionary phases for the coastal plain of the Araranguá river basin and 11 for Itapocu, which were determined in light of transgressions and marine regressions caused by quaternary climatic changes / oscillations / pulsations. It is concluded that, although the evolutionary dynamics of the environmental systems of the southern and northern coasts of Santa Catarina are totally divergent, terraces are, independently of the characteristics and procedural intensities by which they were developed, as geomorphological records of the occurrence of changes, oscillations and climatic pulsations. In the same way, it can be concluded that cycles of climatic alternations showed a close relationship with the dynamics responsible for sediment production, remobilization and deposition in the coastal environments of Santa Catarina (AU)

• FAPESP's process: 16/08944-6 - SPATIAL DISTRIBUTION AND GEOCHRONOLOGY OF SURFACE COATINGS IN LOW MARINE, RIVER-MARINE AND RIVER TERRACES, AT THE MOUTH OF THE RIVER BASINS OF ITAPOCU AND ARARANGUÁ (SC), ARISING OUT MARINE TRANSGRESSIONS AND REGRESSIONS EPIDODES ASSOCIATED OF CLIMATE FLU
• Grantee: Felipe Gomes Rubira
• Support Opportunities: Scholarships in Brazil - Doctorate