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Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2022-10-07T16:28:42Z No. of bitstreams: 1 2022 - Carlos Roberto Pinheiro Junior.pdf: 5459166 bytes, checksum: 145ed89d85e94622e70120734d3970d2 (MD5) Made available in DSpace on 2022-10-07T16:28:42Z (GMT). No. of bitstreams: 1 2022 - Carlos Roberto Pinheiro Junior.pdf: 5459166 bytes, checksum: 145ed89d85e94622e70120734d3970d2 (MD5) Previous issue date: 2022-04-28 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior CNPq - Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico FAPERJ - Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do Rio de Janeiro Despite several lithostratigraphic and paleontological studies, there are only few studies about the genesis of soils in the Araripe Sedimentary Basin and the main factors and processes at work, as well as the role of these soils in the storage of organic and inorganic carbon. In this study we evaluated (i) the action of pedogenesis and weathering of soils formed from shales and fine sandstones under Caatinga vegetation in the Vale do Cariri; (ii) the mechanisms of organic and inorganic carbon accumulation of black soils formed from limestone under Cerrado vegetation; and (iii) the main soil organic matter compartments of Umbric Ferralsols formed from coarse sandstones under Subcaducifolic Tropical Forest vegetation. The values of Ki index (SiO2/Al2O3) and Fed/Fet ratio indicate a low degree of weathering, conditioned mainly by a dry climate. From the mid-IR spectra, absorption features associated with calcite, Mg-silicate, illite, and smectite-illite interstratifications were identified. These minerals were interpreted to have originated authigenically, formed from evaporation processes in lacustrine environments. Despite the smaller influence of the relief and the low action of pedogenetic processes, incipient evidence of clay translocation is observed in the profile located in the upper third of the landscape. In black soils formed from limestone, the combination of high mineral-associated organic carbon (MAOC) content, high MAOC/soil organic C ratio, and low C/N ratio indicates a high degree of transformation and stabilization the organic matter in these soils. The high levels of 2:1 clays and exchangeable Ca2+ benefits the stabilization of organic C by means of organic?mineral interactions. Additionally, the dominance of carbonates of geogenic origin (limestone particles in the sand fraction) is indicative of the low dissolution of these carbonates. Through micromorphological evaluation, pedogenic carbonates were observed at the top of the B horizon of these soils, where the carbon dioxide (CO2) pressure is lower. The variation in relief influences only on inorganic carbon of soils in the lower third of the landscape. This favored high humidity and root activity at depth, increasing the CO2 pressure and hindering the re-precipitation of carbonates, despite the high pH and abundance of exchangeable Ca2+. In the soils classified as Umbric Ferralsols of the Chapada do Araripe, charcoal fragments were observed in the coarse fractions, representing an important carbon pool due to the high recalcitrance. The high carbon contents of the free light fraction (C-FLF) suggest high carbon inputs by native vegetation. The high contents of residual particulate organic carbon (POCres) may have underestimated the contents of the light intraggregate fraction (C-ILF), given the low contents of C-ILF, despite the fact that all horizons have a strongly developed granular structure. Due to the relevance of the light fractions, land use changes can drastically reduce the carbon content in the Umbric Ferralsols of the Chapada do Araripe. Apesar dos diversos estudos litoestratigr?ficos e paleontol?gicos, pouco se conhece sobre a g?nese dos solos na bacia sedimentar do Araripe e os principais fatores e processos atuantes, assim como o papel desses solos no armazenamento de carbono org?nico e inorg?nico. Neste estudo foram avaliados (i) a atua??o da pedog?nese e a intemperiza??o de solos formados a partir de folhelhos e arenitos finos sob vegeta??o de Caatinga no Vale do Cariri; (ii) os mecanismos de acumula??o de carbono org?nico e inorg?nico de black soils formados a partir de calc?rio sob vegeta??o de Cerrado e; (iii) os principais compartimentos da mat?ria org?nica de Umbric Ferralsols formados a partir de arenitos grossos sob vegeta??o de Mata Atl?ntica. No Vale do Cariri, os valores do ?ndice Ki (SiO2/Al2O3) e da raz?o Fed/Fet indicam um grau de intemperismo baixo, condicionado principalmente pelo clima seco. A partir dos espectros de mid-IR foi poss?vel identificar fei??es de absor??o associadas ? calcita, silicatos de Mg, ilita e interestratifica??es de ilita-esmectita. Esses minerais foram interpretados como de origem autig?nica, formados a partir de processos de evapora??o em ambientes lacustres. Apesar da menor influ?ncia do fator relevo e da baixa atua??o de processos pedogen?ticos, evid?ncias incipiente de transloca??o argila foi observada no perfil no ter?o superior da paisagem. Nos black soils formados a partir de calc?rios, os altos teores de carbono org?nico associada aos minerais (MAOC), alta raz?o MAOC/carbono org?nico do solo e baixa raz?o C/N indicam um elevado grau de transforma??o e estabiliza??o da mat?ria org?nica dos solos. Os altos teores de argilas 2:1 e Ca2+ troc?vel favorecem o mecanismo de estabiliza??o por intera??o organo-mineral. O predom?nio de carbonatos de origem geog?nica (fragmentos de calc?rio na fra??o areia) indica uma baixa dissolu??o dos mesmos. Entretanto, atrav?s da avalia??o micromorfol?gica, carbonatos pedogen?ticos podem ser observados no topo do horizonte B dos solos, onde a press?o de CO2 ? menor. A varia??o do relevo parece ter influ?ncia no carbono inorg?nico de solos apenas na parte mais baixa da paisagem, favorecendo uma maior umidade e maior atividade de ra?zes em profundidade, elevando a press?o de CO2 e dificultando a re-precipita??o dos carbonatos apesar dos altos valores de pH e Ca2+ troc?veis. Nos solos classificados como Umbric Ferralsols da Chapada do Araripe, fragmentos de carv?o foram observados nas fra??es grossas, representando um importante compartimento de carbono devido a elevada recalcitr?ncia. Os elevados teores do carbono da fra??o leve livre (C-FLF) sugerem elevados inputs de carbono pela vegeta??o nativa. Os altos teores de carbono org?nico particulado residual (POCres) podem ter subestimado os teores da fra??o leve intragregado (C-ILF), tendo em vista os baixos teores de C-ILF apesar de todos os horizontes possu?rem estrutura granular fortemente desenvolvida. Devido a relev?ncia das fra??es leves, mudan?as no uso da terra podem reduzir drasticamente o teor de carbono nos Umbric Ferralsols da Chapada do Araripe.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2021-05-13T21:58:50Z No. of bitstreams: 1 2018 - Carlos Roberto Pinheiro Junior.pdf: 4978373 bytes, checksum: 72e3dc068293e5c2679f387278164d55 (MD5) Made available in DSpace on 2021-05-13T21:58:53Z (GMT). No. of bitstreams: 1 2018 - Carlos Roberto Pinheiro Junior.pdf: 4978373 bytes, checksum: 72e3dc068293e5c2679f387278164d55 (MD5) Previous issue date: 2018-09-03 CNPq - Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico In Brazil, carbonate rocks occur in approximately 7% of the territory, distributed in the most diverse climatic and environmental conditions. Due to this wide range, studies of pedological characterization have great importance for the knowledge of the soils of these areas. The northwestern region of Rio de Janeiro geology is included in the Italva Group, where calcissilictic rocks and marbles occur. This material, which is associated with drier climates, favors the addition of calcium and magnesium, presence of carbonates and high activity clays, among other attributes. The objective of this work was to characterize the morphological, physical, chemical and mineralogical attributes of soils of a carbonate nature of the Italva Group, and to evaluate the influence of the main factors and processes in the pedogenesis. For the study, a toposequence was selected in the municipality of Italva, RJ, where 6 profiles were described and collected. The material of origin, climate and relief were the main factors responsible for the soil genesis influencing in several attributes such as high values of base saturation with predominance of Ca and Mg, high pH, presence of carbonates, high Ki ratio, low Fe2O3 contents, in addition to controlling the water flow, drainage condition and cations accumulation. The absence of effervescence of the soil samples with HCl solution and the high MgO / CaO ratio suggest the dolomitic nature of the carbonates. Despite the high carbonate content, these compounds were not detected in the mineralogical analysis. However, based on the literature it is suggested the presence of amorphous calcium carbonate and protodolomite, both of which were not detected by X-ray diffraction. The main minerals found in the sand fraction were quartz, feldspar, mica and pyroxene, in addition to sepiolite possibly precipitated on protodolomite grains; while in the clay fraction there was presence of ilite and kaolinite. The main active pedogenetic processes are melanization, calcification, eluviation / illuviation, vertization and gleization. The profiles were classified as Chernossolo R?ndzico L?tico t?pico (high plain); Chernossolo H?plico Carbon?tico saprol?tico (shoulder poistion); Argissolo Vermelho-Amarelo Eutr?fico chernoss?lico (backslope); Chernossolo Eb?nico Carbon?tico t?pico (footslope in a colluvium ramp); Cambissolo Fl?vico Carbon?tico t?pico (footslope in an alluvial dike) and; Vertissolo Hidrom?rfico Carbon?tico t?pico (low plain). The presence of compression surfaces associated to the microrelevo gilgai occurrence should be added as a diagnostic criterion for the Vertissolos soil order in the Brazilian Soil Classification System, since they indicate the occurrence of intense vertization. No Brasil as rochas carbon?ticas ocorrem em aproximadamente 7% do territ?rio, distribu?das nas mais diversas condi??es clim?ticas e ambientais. Devido a essa grande abrang?ncia, estudos de caracteriza??o pedol?gica s?o muito importantes para o conhecimento dos solos dessas ?reas. A regi?o noroeste fluminense est? inserida na geologia do Grupo Italva, onde ocorrem rochas calcissilic?ticas e m?rmores, material que associado ? condi??o de climas mais seco favorece a adi??o de c?lcio e magn?sio ao solo, presen?a de carbonatos e argilas de alta atividade, entre outros atributos. O objetivo desse trabalho foi caracterizar os atributos morfol?gicos, f?sicos, qu?micos e mineral?gicos de solos de natureza carbon?tica do Grupo Italva e interpretar a atua??o dos principais fatores e processos na pedog?nese. Para o estudo, foi selecionada uma topossequ?ncia no munic?pio de Italva, RJ, onde foram descritos e coletados 6 perfis. O material de origem, clima e relevo foram os principais fatores respons?vel pela g?nese dos solos influenciando em diversos atributos como elevados valores de satura??o por bases com predom?nio de Ca e Mg, pH elevado, presen?a de carbonatos, alta rela??o Ki, baixos teores de Fe2O3, al?m de controlarem o fluxo de ?gua, condi??o de drenagem e acumula??o c?tions. A aus?ncia de efervesc?ncia com solu??o de HCl das amostras de solo e a alta rela??o MgO/CaO sugerem natureza dolom?tica dos carbonatos. Apesar dos altos teores de carbonatos, esses compostos n?o foram detectados na an?lise mineral?gica, contudo, baseado na literatura sugere-se a presen?a de carbonato de c?lcio amorfo e protodolomita, ambos n?o detectados por difra??o de raios-X. Os principais minerais encontrados na fra??o areia foram quartzo, feldspatos, mica e pirox?nio, al?m de sepiolita possivelmente precipitada sobre gr?os de protodolomita; enquanto na fra??o argila verificou-se presen?a de ilita e caulinita. Os principais processos pedogen?ticos atuantes s?o melaniza??o, calcifica??o, eluvia??o/iluvia??o, vertiza??o e gleiza??o. Os perfis foram classificados como Chernossolo R?ndizo L?tico t?pico (topo); Chernossolo H?plico Carbon?tico saprol?tico (ter?o superior); Argissolo Vermelho-Amarelo Eutr?fico chernoss?lico (ter?o m?dio); Chernossolo Eb?nico Carbon?tico t?pico (ter?o inferior em rampa de col?vio); Cambissolo Fl?vico Carbon?tico t?pico (ter?o inferior em dique aluvial) e; Vertissolo Hidrom?rfico Carbon?tico t?pico (baixada). A presen?a de superf?cies de compress?o associada ? ocorr?ncia microrelevo gilgai devem ser adicionados como crit?rios diagn?sticos para a defini??o da ordem dos Vertissolos no Sistema Brasileiro de Classifica??o de Solos, tendo em vista que indicam a ocorr?ncia de intensa vertiza??o.