Programa de Pós-Graduação em Geologia e Geoquímica - PPGG/IG

URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2603

O Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) surgiu em 1976 como uma necessidade de desmembramento do então já em pleno desenvolvimento Curso de Pós-Graduação em Ciências Geofísicas e Geológicas (CPGG), instalado ainda em 1973 nesta mesma Universidade. Foi o primeiro programa stricto sensu de Pós-Graduação (mestrado e doutorado) em Geociências em toda Amazônia Legal. Ao longo de sua existência, o PPGG tem pautado sua atuação na formação na qualificação de profissionais nos níveis de Mestrado e Doutorado, a base para formação de pesquisadores e profissionais de alto nível. Neste seu curto período de existência promoveu a formação de 499 mestres e 124 doutores, no total de 623 dissertações e teses.

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Análises texturais de produtos derivados de LiDAR para discriminação de cangas lateríticas, Serra Sul de Carajás (PA)
(Universidade Federal do Pará, 2016-09-30) SANTOS, Jaqueline Alcântara dos; SILVA, Arnaldo de Queiroz da; http://lattes.cnpq.br/1682623730626187; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The characterization of geological features through products derived from remote sensing in humid tropical regions suffers severe restrictions due to the influence of vegetation on the radiometric measurements. This is the motivation to investigate new methodological approaches aimed at extracting remote sensing information data applied to geological mapping. This research aimed to develop a methodological approach to discriminate types of lateritic surfaces from textural parameters of the Haralick extracted shaded relief image generated Digital Model Land of high spatial resolution (1 m) derived from the last return signal (ground) of LiDAR data. The study area is located in body S11CD in Serra Sul of Carajás Mineral Province, including the city of Canãa dos Carajás (Pará State - Brazil). The body S11CD is characterized by a residual relief supported by ferruginous crust thick developed on Archean banded iron formations (Carajás Formation / Grão Pará Group) and is covered by savannah (campus rupestres) that contrast with the surroundings tropical rain forest. The lateritic crust in the study area is classified into (1) structural duricrust and (2) detrital duricrust. The difference between the types of lateritic crust was analyzed by microtopography relief metrics (Hrms), measured in the field and textural parameters of the Haralick extracted from the shaded relief image. Statistical tests of averages Hrms comparison (Student t test) showed that it is possible to identify the terrain microrugosidade kinds of lateritic duricrust present in S11CD. The object-oriented classification (GEOBIA) was used dissimilarity textural parameter of the Haralick to discriminate the types of lateritic duricrust. For this, it was used the standard deviation of the average dissimilarity threshold for separating the detrital duricrust (26.1 ↔ 33.234) and structure duricrust (20.573 ↔ 28.515). The result of this classification overlaid around 89.35% the study area, remaining ~ 11% of the image not classified, possibly as a result of noise in the LiDAR data. The validation of this classification attested that the overall accuracy of field data and the classification was 78.8%. Note also, that the structural duricrust occurs in the area as small "windows" through the detrital duricrust, which made it difficult to carry out field sampling at this site, so the errors of commission and of omission become high.
Acesso aberto (Open Access)
O aumento do nível do mar pós-glacial afetou a dinâmica das florestas de várzea da Amazônia durante os últimos 5000 anos?
(Universidade Federal do Pará, 2015-04-10) ARAUJO, Mayra Nina; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
Four sediment cores, between three and ten meters depth, were sampled from fluvial plains and abandoned channels along the Rio Branco-Roraima. The stratigraphic analyses were based on grain size, structures and pollen content. In addition, the age of events were determined by seven radiocarbon dating. The data show cycles of channel abandonment, resulting in formation of lakes and, latter, its reactivation. The lake phases permitted the accumulation of mud sediments in different time intervals, suitable for pollen preservation. Pollen analyze indicated a combination of at least seventy taxa, the most representative are: Moraceae, Euphorbiaceae, Caesalpiniaceae, Fabaceae, Rubiaceae, Melastomataceae, Combretaceae, Sapindaceae, Poaceae, Cyperaceae, Aizoaceae and Apiaceae. They characterize arboreal and herbaceous vegetation, similar to modern vegetation of the study, since the middle Holocene. Considering the dry period occurred in the Amazon region during the early and middle Holocene, followed by a wet period in the late Holocene, the data presented in this work do not suggest significant changes in vegetation as a consequence of that climatic changes. Therefore, climatic and hydrologic conditions have favored the stability of vegetation in the study site for at least the last 5500 years. Three hypotheses are presented to justify this stability: 1) the early and middle Holocene dry period did not affect vegetation pattern; 2) a dry climatic phase was never present; or 3) the stabilization of the relative sea level about 6000 cal yr BP along the northern Brazilian littoral may have influenced the water table, and favored the establishment and maintenance of Amazonian lowland forest during the mid and late Holocene. In addition, this process may have attenuated the impact of that dry period in areas under most fluvial influence.
Acesso aberto (Open Access)
Detecção de mudanças paleoambientais no litoral do Rio Grande do Norte (RN) durante o Holoceno médio e superior
(Universidade Federal do Pará, 2017-08-16) BATISTA, Edson José Louzada; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790
The vegetation dynamics during the Holocene on the coastal region of Rio Grande do Norte (RN) was characterized by mangrove establishment, expansion and contraction. The dynamics of this vegetation is mainly related to the sedimentary dynamics and to the relative sea level change (RSL) recorded for this period. During the last millennium, sedimentary process controlled the vegetation dynamics along stratigraphic profiles formed by sequences of active tidal channels, followed by abandonment. Therefore, based on grain size, sedimentary structures, pollen data, isotopic data (δ13C and δ15N), C/N ratio and 14C dating of the sedimentary organic matter of two cores (NAT 6 and NAT 8) sampled in the tidal plain, shows a paleoenvironmental model since mid- to late-Holocene (~7 k yr BP to modern), described by four facies associations: (A) estuary/channel, represented by massive sandy deposits (facies Sm) and mud deposition; (B) abandoned channel, represented by the wavy heterolithic bedding (facies Hw), lenticular heterolytic bedding (facies H1) and small intervals with massive sand (facies Sm); (C) active channel, corresponding to massive sandy deposits (facies Sm); and (D) low marsh (mangroves/herbaceous plain and palms), represented by clay deposits with lenticular heterolithic bedding (facies Hl). In this context, short-time (millennium/century) changes between mangroves and other associated vegetation in this region are not necessarily related to RSL or to the climatic changes (allocyclic process), but to the sedimentary dynamics (autocyclic process) must have controlled mainly the pollen assembly along the stratigraphic profiles studied.
Acesso aberto (Open Access)
Os efeitos da subida do nível do mar sobre os manguezais do litoral sul da Bahia durante o Holoceno
(Universidade Federal do Pará, 2015-03-25) FONTES, Neuza Araújo; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
This work integrates the palinological, sedimentological and geomorphological data with radiocarbon dating, as well as δ13C and C/N from the sedimentary organic matter to identify the impact of changes in sea level and climate during the Holocene in Jucuruçu River’s mangroves, near the city of Prado, South Bahia. A sediment core with 4.5 m depth was sampled from a fluvial valley, 23 km away from the modern coastline. The base of sediment core presents age of 7450 cal yrs BP. The data reveal two important phases characterized by 1) an estuarine system with tidal flats colonized by mangroves. Its sedimentary organic matter is mainly sourced from estuarine algae during the early and middle Holocene; and 2) in the second phase, the mangroves shrank and herbaceous vegetation expanded. The δ13C and C/N values show an increase in contribution of terrestrial C3 plants. These phases identified in this study are in agreement with the relative sea-level (RSL) rise during the early and middle Holocene, and its subsequent fall during the late Holocene. In addition, the influence of weather patterns proposed for Holocene may be identified throughout the studied sediment core. Probably, changes in depositional environment and dominant vegetation at the study site were caused by the combined action of changes in RSL and fluvial discharge. According to the model proposed in this work, during the early and middle Holocene occurred a RSL rise that caused a marine incursion along the studied fluvial valley. The dry period occurred during the early and middle Holocene produced a decrease in the fluvial discharge and contributed to this marine transgression. However, during the late Holocene occurred a RSL fall and a wet period. It favored the marine regression and consequently, the mangroves migrated to tidal flats attached to the edge of lagoons near the modern coastline. The geomorphologic and vegetation evolution is in agreement with the mid-Holocene RSL maximum above present RSL and subsequent fall to the present time. Keywords: climate; Holocene; relative sea-level; South of Bahia; vegetation.
Acesso aberto (Open Access)
Estudo da morfodinâmica sazonal e quantificação de transporte sedimentar costeiro nas praias de Fortalezinha e Princesa, Algodoal/Maiandeua (nordeste do estado do Pará)
(Universidade Federal do Pará, 2015-02-03) SILVA, Paulo Victor Magno; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
Understanding the processes responsible for the morphodynamics of the coastal environments and sediment transport is necessary considering that such processes play an important role in the formation and stabilization of the beach. The coastal zone is a complex, dynamic and unstable range in which is subject to continuous changes generated by coastal morphodynamic processes such as winds, waves, tides and tidal currents. This Master thesis shown the morphodynamics and transport measurement of sediment in macrotidal on the Princesa and Fortalezinha beaches (Pará coast). These beaches are part of the sandy plains, around the Algodoal/ Maiandeua island (Maracanã city), being inserted in the Salgado Atlantic Coast of Pará. Two data collection campaigns were conducted: (i) in the dry season (15 - 19/10/2012) and; (ii) in the rainy season (13 - 16/03/2013). To analyze the morphological variation of these beaches and its erosive trends and / or accretion, were executed 8 topographic profiles (4 in each beach). At the same time the survey of profiles, sediment samples and measurements of hydrodynamic parameters (waves and currents) were performed. To quantify the coastal sediment transport were used two methods: (1) “traps” for aeolian sediment transport in each profile, and (2) “portable traps” for longitudinal transport in the surf zone, over three different sectors of the beaches. These beaches are composed predominantly of fine and well selected sand. The beaches exhibited low slope (<2 °) for the two periods. In the dry period was observed on the Princesa beach one well developed bar-rip in the middle intertidal zone, characteristic of dissipative beaches, while in the rainy season occured loss of sediment in this area, allowing the exposure of a muddy terrace (paleomangrove) in the central sector. In general, the Princesa and Fortalezinha beaches are subject to a semidiurnal macrotidal regime. The active winds have preferred direction of E in less rain season and NE in the rainy season period, with sliding dominant waves of low period and NE direction. The coastal currents have preferred NW direction, with variations during the tidal cycle. The active winds have preferred direction E in less rainy period and NE in the rainy season. During the dry season the beaches have intermediate characteristics beaches, with Ω between 4.322 to 4.579 on the Princesa beach and 4.074 to 4.668 in the Fortalezinha beach. During the rainy season were characterized as dissipative, with Ω ranging from 5,088 to 6,763 values on the Princesa beach and 5.790 to 6.174 on the Fortalezinha beach, with only the NE sector of the Princesa beach with intermediate characteristics. The Princesa beach evolved from ultradissipative beach state (7 5)(rainy period). However, the Fortalezinha beach had its status as an intermediary with low-water channel-bar system (3 5), in the rainy season. On the beaches is bidirectional longitudinal transport however in the rainy season the beach was characterized as dissipative and no bars (3 5). On the beaches is bidirectional longitudinal transport, with resulting NW. The direction of the longitudinal current and longshore drift is influenced, respectively, by the direction and intensity of the trade winds from the NE (dry season) and tidal currents (rainy season). The aeolian transport is a function of the intensity and duration of winds and rains mainly, however, in the dry season this is high due to strong winds, and the lack of rain makes the sediments of less cohesive swash zone and easier to be transported. The coastal dynamics on the beaches is influenced by the adjacent drainages (rivers and tidal channels) especially during the ebb tide. During the rainy season, the Marapanim and Maracanã rivers flow is high, due to increased rainfall in the headwaters of rivers, increasing the export of continental sediments (silt and clay) for the coastal region, and are incorporated into coastal drift and deposited in beaches during times of low energy, along with sandy sediments mainly from adjacent continental shelf by tidal currents.
Acesso aberto (Open Access)
Impacto do último máximo glacial pleistocênico na vegetação de Humaitá, Amazonas
(Universidade Federal do Pará, 2016-09-27) LIMA JÚNIOR, Walmir de Jesus Sousa; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The amount of pollen data recovered from the sedimentary record of western Amazonia is still far from adequate to fully approach climate changes in this region over the Last Glacial period. In the present work, vegetation dynamics of western Amazonia during the past 42000 cal yr BP is analyzed in the context of previous and new pollen data. Two sediment cores were sampled from fluvial terraces of the Madeira River, a major southern Amazonian tributary. The study sites are covered by tropical rainforest vegetation. The sedimentary deposits consist mostly of massive sand, heterolithic bedded sand/mud as well as either laminated or massive mud. These deposits were formed under reducing and low energy conditions in an abandoned fluvial channel/lake environment. Such depositional setting favored the preservation of a pollen community suggestive of arboreous taxa common to the modern Amazonian rainforest mixed with herbaceous vegetation. Pollen analysis also recorded a significant proportion of cold-adapted Andean tree species, represented by Alnus (0-20%), Hedyosmum (1-15%), Podocarpus (0-5%), Illex (1-11%) and Weinmannia (0-1%) at least between > 42,000 cal yr BP and 10,300 cal yr BP. During the Holocene, only pollen representative of herbs and modern Amazon vegetation persisted. This new pollen record confirm previous multiple proxies analyzes of two sediment cores sampled also from Humaitá region, where a significant plant population, at present restricted to Andean areas located at altitudes higher than 2000 - 3000 m, in areas of the Amazonia lowland toward the onset, and probably, during the Last Glacial Maximum.
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Morfodinâmica da praia estuarina do Cajuúna, Soure, Marajó – Pará
(Universidade Federal do Pará, 2016-06-08) BITTENCOURT, Lorena Amaral; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The Cajuúna beach is located in the municipality of Soure (0 ° 37 '41,971 "S - 48 ° 28' 56,980" W and 0 ° 38 '54,888 "S - 48 ° 29' 6.867" W), on the eastern shore of the Marajó island (Pará state). This beach is cut by tidal channels (one in the middle and two at the ends), and is influenced by meteorological parameters (wind, rain, thunderstorms), hydrological (water and solid discharge of Pará estuary) and hydrodynamic (waves, tidal currents). The aim of this work is to identify the morphodynamics of estuarine Cajuúna beach through seasonal analysis, may clarify questions about which morphological features are characteristic during the rainy and less rainy periods; which the textural changes of the sediments; which most forcing this change in the transport and distribution of sediments and with what intensity and preferred direction they are transported. There were two field campaigns: during the rainy periods of equinoctial tide (04/01/2014) and less rainy (11/23/2014). The beach stretches for 4 km, your lenght reaches about 100-489m, was applied 7 topographic profiles with equidistance of 300 m. The beach was divided into three sectors: profiles A and B - Sector 1, profiles, C, D and E - sector 2, F and G profiles - sector 3. The sediment samples were collected from: (1) timely measurement longitudinal transport in the surf zone (traps) and (2) over topographical profiles, adopting morphological zonation (Souza Filho et al., 2003). Still, waves and currents data acquired in the surf zone. The sediment samples were subjected to analysis and classified according to Folk and Ward's method (1957), Shepard diagrams (1954) and Pejrup (1988). Besides these were produced morphometric parameters: Sedimentary volume variation (Vv), declivity of praial face (β), width of the beach (Yb), coefficient of shoreline change (CVYb), Speed decanting of sedimentary particles (Ws ) beach morphodynamic state (Ω) Dean (1973) and the relative variation of the tide (RTR – Relative Tide Range) Davies and Hayes (1984), suggested by Masselink and Short (1993). The results show that the Cajuúna beach is composed of sediments ranging from fine sand (< 2 to 3 Φ) to very thin (< 3 to 4 Φ) with a good degree of selection (0.35 to 0.50 Φ) very well selected (<0.35 Φ) to moderately selected (from 0.50 to 1.00 Φ) in less rainy season. The asymmetry remained approximately symmetrical tending to positive values (0.10 to 0.30 Φ), very positive (from 0.30 to 1.00 Φ) and negative (-0.30 to -0.10 Φ) and kurtosis predominant in both periods was leptokurtic (1.11 to 1.50 Φ), hooting for very leptokurtic (1.50 to 3.00 Φ), mesokurtic (0.90 to 1.11 Φ) and platykurtic (0.67 to 0.90 Φ). This beach had a positive balance of the sediment volume during the rainy season (lower volume 134 m³ / m higher volume 955 m³ / m) to the less rainy (lower volume 74 m³ / m higher volume 1,567 m³ / m), and growing, with the exception in sector 2 which is the decrease in sediment volume (136 m³ / m in the rainy season to 74 m³ / m in less rainy). The Cajuúna beach remains wider in the rainy season; the coefficient of variation of shoreline was also higher in this period; however the sectors 1 and 3 were larger in the less rainy season (sheltered areas). This beach had low slope (<2.0 °) in both periods, related to the presence of fine sediments. Prevailed morphodynamic state (Ω) intermediate in both periods; Terrace Low Sea (TLS) in the rainy season and variation between Terrace Low Sea and Bank Cusp Beach (BCB) in less rainy season. The RTR classified as intermediate beach in less rainy and wet seasons, with wave-tide interaction (RTR < 7), occurring variation in the least rainy season, a reflective classification, dominated by wave with RTR < 3. In the surf zone, the fine sand fraction (< 3 to 4 Ф) was dominant in rainy periods (up to 74.27g) and less rainy (maximum 562.61g) during ebb tides in the sector 2; the silt remained high fraction (100g), even surpassing the dominant fraction in the less rainy season; and the clay had the lowest amount in both periods (minimum of 0.27g and maximum 23,48g). The incidence angle of the waves varies from NW (rainy season) to NE (less rainy season). The largest wave height was recorded during the ebb tide in both periods (1,074 m - rainy season and 2.94 m - less rain). The wind speed was more intense during the flood in the rainy season (8.4 m/s), and the ebb in less rainy season (10.3 m/s). The intensity of tidal currents was higher during the flood in rainy seasons (0.73 m/s) and less rain (0.35 m/s). Various features such as ridges and troughs, paleomangrove soils, dunes, sand spit and canals occur in the Cajuúna beach are formed and / or seasonally modified by weather forcings, hydrological and hydrodynamic. Understanding the morphodynamics of the Cajuúna beach is important, due to his strategic location above the beaches of the eastern part of the Marajó island, suffers influence of the waters of Pará mouth, and is part of an Environmental Protection Area Despite the implementation of a Coastal Management Plan, in some parts of the Northeast region of Pará ; to date, the Marajó Island does not have a methodology and set to the prognosis and monitoring of coastal erosion . Given these shortcomings , it is necessary to determine how the rising sea level is affecting the eastern margin of Marajó Island . This study makes contribution the Organization of the Amazon Cooperation Treaty Organization, the project " Adaptation to Sea Level Rise in the Amazon Delta " which aims to assess the impact of rising sea level caused by global climate change on island environments Marajó (Eastern and Northern margins).
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Processos autocíclicos e alocíclicos afetando os registros da paleoflora da foz do rio Jucuruçu, litoral sul da Bahia, durante os últimos 1000 anos
(Universidade Federal do Pará, 2016-06-07) MORAES, Caio Alves de; COHEN, Marcelo Cancela Lisboa; http://lattes.cnpq.br/8809787145146228
The vegetation holocenic history along the southern Bahia littoral is characterized by establishment, expansion and contraction phases of mangroves. This vegetation dynamics is mainly associated to climate change and to relative sea level oscillations. However, punctually and in a smaller time scales, for example, during the last 1000 years, other processes inherent to the sedimentary dynamics of depositional environment, termed autocyclic processes, are controlling the pollen assembly along stratigraphic profiles formed by active channels followed by its abandonment. Based on sedimentary features, pollen grains, isotopes (δ13C, δ15N C/N) and radiocarbon dating of sedimentary organic matter from two cores (PR-11 and PR-12) sampled from an abandoned meander and a tidal flat in the mouth of the Jucuruçu river, is proposed a model for evolution of a tidal channel surrounded by wetlands. The core PR-11, with 1.48 meters depth, was sampled from a mangrove zone, with a maximum age of 678 cal yr BP. The PR-12 was collected from a várzea vegetation, approximately 2.7 km from the current shoreline with 1.92 meters depth and, maximum age of 680 cal yr BP. The data present two facies associations: (A) Tidal channel, represented by massive sand deposits (facies Sm); cross-stratified sand (Scs) and facies flaser heterolithic bedding (Hf) and (B) Tidal plain, represented by facies wavy heterolithic bedding (Hw), lenticular heterolithic bedding (Hl), massive mud (Mm) and massive sand (Sm). The pollen data reveals that the facies association (A) presents absence of pollen grains of mangroves. It may have been caused be an intense activity of sediments reworking of channel margins and sediment deposition with pollen grains sourced from vegetation units not necessarily from the study site. In the top of the studied succession, in association facies (B), is possible to identify the establishment and expansion of mangroves in the newly formed tidal flat (PR-11) or lake (PR-12). Regarding the core PR-12, it is marked by channel abandonment. The reduced interaction between fluvial discharge and tidal waves have caused the infilling of mud sediments, and a highest potential for organic matter preservation. It provided conditions for the mangrove development and pollen preservation. In the case of PR-11, the tidal channel migration have caused the development of a tidal flat, which have favored the mangrove expansion. These depositional environments, favorable to the formation of mangroves, can be partially or completely modified by the natural dynamics of tidal channels and estuarine channels, which are under the influence of changes of sedimentary fluvial contribution on the shore and littoral drift processes along the coast associated with tides, waves and currents. These results were compared with some data from one core sampled 23 km upstream of Jucuruçu River that also indicated the presence of mangroves on tidal flat with estuarine organic matter during the early and middle Holocene, followed by herbaceous vegetation on a fluvial plain with organic matter sourced from freshwater during the late Holocene (Fontes, 2015). In this case, the sea level fluctuations and climate change were the main driving forces controlling the wetlands dynamics at the mouth of this river during the Holocene, characterizing an allocyclic process. However, considering the stratigraphic sequences of the analyzed cores in this master's work (PR-11 and PR-12), such sedimentary sequences associated with changes in vegetation and sources of organic matter are related to the infilling processes of coastal depressions, mainly marked by active channels, abandoned channels and tidal flats. Therefore, in a small time scale of coastal vegetation changes are not necessarily directly associated with sea-level and climate change (allocyclic processes). On the other hand, processes associated to the sedimentary dynamics of the depositional environment (autocyclic processes) must have controlled pollen assembly along the studied stratigraphic profiles.

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