Full text
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| Author(s): |
Patrick Francisco Fuhr Dal Bo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Geociências |
| Defense date: | 2008-08-19 |
| Examining board members: |
Francisco Sérgio Bernardes Ladeira;
Fresia Ricardi Branco;
Kenitiro Suguio
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| Advisor: | Giorgio Basilici; Francisco Sérgio Bernardes Ladeira |
| Abstract | |
The Marília Formation (Maastrichtian), outcropping in the northwestern portion of the Bauru Basin (Goiás and Mato Grosso do Sul brazilian states), is interpreted here as an ancient Aeolian sand sheet. The vertical succession, c.150 m thick, is made up of very fine to medium-grained sandstone and, it is characterised by cyclic interbedding of sediments and palaeosols. Planar laminated sandstone (subcritically climbing translatent stratification), formed by aeolian sand with wind ripple, is the most common lithofacies. Palaeosols, mainly Aridisols, represent more than 65% of the geological record of the Marília Formation. Subhorizontal aeolian deflation surfaces divide Marília Formation in two distinct constructional phases of geological bodies linked to palaeoclimatic variations: i) phase of prevalent aeolian sand deposition; ii) phase of Aridisols development. The two phases they alternated in time and probably record periods of formation with difference of the order greater than 105 between aeolian sand deposition and development of the Bk Aridisols horizons. Palaeoclimate is the main forcing factor of the Aeolian sand deposition and soil development. Episodes of sedimentation and soil development likely result from cyclic decreases and increases in available moisture and vegetation cover. Aeolian deflation and sedimentation were predominant during drier phases of past climatic cycles, when vegetation cover was sparse in source areas and windier conditions have the capacity to remove and transport clastic materials. During wetter phases of climatic cycles, increased vegetative cover stabilised the landscape, reduced deflation, and intensified Entisols and Aridisols development (AU) | |
| FAPESP's process: | 07/02079-2 - Paleosols of semi-arid environment: an ancient analogue (Marília Formation, Bauru Basin, GO, MS and SP states) |
| Grantee: | Patrick Francisco Führ Dal' Bó |
| Support Opportunities: | Scholarships in Brazil - Master |