Les travaux réalisés ont pour but de répondre à deux questions : comment le collagène s'organise-t-il dans l'os mature ? Comment la phase minérale de l'os se forme-t-elle et quel est l'effet de son environnement sur sa formation ? Nous avons étudié d'un point de vue structural des coupes d'os en nous concentrant sur l'interface tissu ostéoïde/os mature, impliquant le front de minéralisation. Nous avons conclu qu'un domaine acide fait de collagène non fibrillaire existe à cette interface. Nous proposons ainsi un nouveau mécanisme pour la formation osseuse lors du remodelage osseux impliquant une mésophase acide de collagène au sein de laquelle l'apatite se forme. Nous avons donc étudié l'effet de cet environnement acide sur la formation d'apatite in vitro par Raman in situ et RMN du solide. Nous avons observé que la séquence de précipitation de l'apatite seule en solution passe par la formation d'une phase amorphe (ACP) qui se transforme en OCP puis en apatite. En présence de pAsp, la nucléation est ralentie et de l'OCP est stabilisé. Une grande concentration en citrate inhibe la formation de toute autre phase que l'ACP tandis qu'une plus faible concentration entraine la formation d'apatite directement depuis l'ACP. Cette séquence ACP/apatite est également observée lorsque la minéralisation est réalisée en présence de collagène quelle que soit sa concentration. Le collagène entraine la formation d'une apatite beaucoup plus désorganisée de cristallinité proche de celle de l'apatite osseuse. Enfin, une concentration en collagène supérieure à 80 mg/mL mène à la stabilisation d'une phase ionique stable à pH basique expliquant le co-alignement apatite/collagène. / This work aims to understand: How is reached the plywood architecture in bone? How is bone apatite formed and what is the effect of the environment on apatite formation? Thus, histological bone thin sections were investigated focusing on the interface between the osteoid and mature bone tissues. Our results show that this interface is acidic and collagenic but not in the form of fibrils. Thus, we propose a new mechanism for bone formation in bone remodelling where osteoclasts dissolution and new fibrils formation from osteoblasts lead to the formation of an acidic collagen mesophase in which apatite is then formed. In such mechanism, apatite forms from an acidic solution in interaction with an organic matrix (collagen molecules, citrate and non-collagenous proteins). Acidic biomimetic models have been set and the apatite formation has been followed in vitro using in situ Raman and ssNMR spectroscopies. Without organic molecules, biomimetic apatite is formed through the precipitation of an amorphous phase (ACP) that transforms into OCP which then turns into apatite. With pAsp, the same scenario is observed but the nucleation is delayed and residual OCP is stabilized. With a high concentration of citrate, only ACP is observed whereas with a lower concentration formation of OCP is inhibited. The same sequence is also observed with collagen but the final product is a more disorganized apatite. Apatite formation in dense and organized collagen solutions leads to the formation of a liquid ionic solution stable at basic pH during the first 72 hours explaining the resulting apatite/collagen co-alignement.

On appelle biominéraux l’ensemble des minéraux fabriqués par le vivant. Ce sont des matériaux essentiels, présents dans la quasi-totalitédes espèces vivantes. Néanmoins les caractéristiques structurales, chimiques ainsi que les mécanismes de formation, et l’évolution de cesmatériaux sont encore fortement débattus. Cela s’explique notamment par les difficultés à étudier expérimentalement des espèces chimiquesévoluant en milieux biologiques.Bien que tout aussi complexe, une approche théorique, à l’échelle moléculaire, peut aider à la caractérisation de ces matériaux biologiqueset notamment la caractérisation de leurs interfaces formées avec les milieux biologiques environnants. Cela étant essentiel pour une meilleurecompréhension de la formation et de l’évolution de ces minéraux.Les oxalates de calcium constituent une famille de biominéraux très importante dans le monde du vivant. Ils constituent notamment les principales espèces cristallinesrencontrées dans les calculs rénaux où ils peuvent exister sous trois phases possédant différents degrés d'hydratation. Au cours de cette thèse, nous avons effectuéles simulations des propriétés spectroscopique IR et RMN des ces trois phases, ce qui permet d'obtenir une signature propre à chacune d'entre elle, aidant ainsi àl'identification de ces phases à partir des spectres obtenus expérimentalement.Les phosphates de calcium font aussi partie des biominéraux. Ils composent la majeure partie du minéral osseux des mammifères. Ce minéral se trouvesous la forme de nanoparticules décrites comme possédant un cœur cristallin d’hydroxyapatite substituées entourée d'une couche hydratée et désordonnée en surface.Durant ce travail de thèse, nous nous sommes intéressés à ces deux composantes. Concernant le cœur cristallin des particules, nous avons étudié en particulierle cas des substitutions par des carbonates car il s'agit de la substitution prédominante dans les apatites biologiques. En couplant ce travail à des expériencesde RMN solide nous pouvons proposé une localisation précise de ces substituants au sein de la maille d’hydroxyapatite.La couche désordonnée de surface est encore très mal comprise à l'heure actuelle et de nombreux modèles structuraux sont proposés dans la littérature pour la décrire. Nous avonsconsidéré un certain nombre d'entre eux pour lesquels nous avons modélisé les propriétés RMN, qui confrontées à celle issues de l'expérience nous ontpermis d'identifier les points forts et faibles des différentes hypothèses. / Biominerals are all the minerals produced by living organisms. They are essential materials, present in almost all living species. Nevertheless,the structural, chemical properties and, formation mechanisms and the evolution of these materials are still heavily debated. This is due in particular to thedifficulties of experimentally studying chemical species evolving in biologicalenvironments. Although, equally complex, a theoretical approach at the molecular level can help in the characterization of these biological materialsand in particular the characterization of their interfaces formed with the surrounding biological media. This is essential for a better understandingof the formation and evolution of these minerals.Calcium oxalates are essential biominerals that are very common in the living world. They constitute the main crystalline speciesencountered in kidney stones where they can exist in three phases possessing different degrees of hydration. In this, thesis we carried outsimulations to predict the IR and NMR spectroscopic properties of these three phases. Thsi enabled us to obtain specificsignature of each polyhydrate, and thus makes it possible to obtain a signature specific to each of them, thus helpingthe identification of these phases from the experimentally spectra obtained.Calcium phosphates are part of the bio/biological minerals. They make up the major part of the bone mineral of mammals. This mineral is in the form of nanoparticles havinga crystalline core of hydroxyapatite and a hydrated and disordered surface layer.During this thesis we were interested in these two components. Concerning the crystalline core of the particles, we studied in particularthe case of carbonate substitutions because of its predominant substitution in biological apatites. By combining this work with solid state NMR experimentswe can propose a precise localization of these substituents within the hydroxyapatite crystalline cell.The disordered surface layer is still very poorly understood and many structural models are proposed in the literature to describe it. We haveconsidered a number of them for which we have modeled the NMR properties which were then confronted with experimental results. The comparaisonmade it possible to identify the strengths and weaknesses of the various hypotheses.

Le ranélate de strontium, prescrit dans le traitement de l'ostéoporose ménopausique, possède 2 atomes de strontium stable pouvant se fixer au minéral osseux. Le strontium a un effet dissociant sur le remodelage osseux, diminuant la résorption tout en augmentant la formation. Cependant, ses effets osseux ne sont pas complètement élucidés, en particulier ses interactions avec le minéral. Chez le singe, le strontium maintient à un niveau physiologique les propriétés intrinsèques majeures du tissu osseux, que ce soit aux niveaux tissulaire global ou des unités de remodelage. Chez la femme ostéoporotique ménopausée traitée par le ranélate de strontium, les caractéristiques du cristal d'apatite sont maintenues à un niveau physiologique. Par ailleurs, quelle que soit la durée du traitement (2 à 96 mois), le strontium est toujours distribué de façon hétérogène, présent principalement dans l'os récent formé pendant le traitement, les aires osseuses contenant du strontium augmentent progressivement mais de moins en moins avec la durée du traitement. Le contenu osseux focal en strontium est stable de 2 à 60 mois puis augmente de 60 à 96 mois, et la minéralisation secondaire est maintenue à un niveau physiologique. Enfin, après 6 et 12 mois de traitement, le ranélate de strontium maintient normaux les principaux paramètres reflétant la minéralisation secondaire, et ses effets sont similaires à ceux de l’alendronate. En conclusion, le ranélate de strontium maintient une qualité normale de la minéralisation secondaire, que ce soit à court ou à long terme, et quel que soit le modèle étudié. Le ranélate de strontium maintient également la microdureté osseuse, les caractéristiques minérales et organique tissulaires, ainsi que la structure du cristal d'apatite / Strontium ranelate, a treatment of postmenopausal osteoporosis, contains 2 atoms of stable strontium which interact with bone mineral. Strontium have a dissociating effect on bone remodeling, decreasing resorption while increasing formation. However, its bone effects are not fully clarified, in particular its interactions with mineral. In monkeys, strontium maintains the major intrinsic properties of bone at a physiological level, either at the global tissue or the bone structural units levels. In postmenopausal women treated with strontium ranelate, the characteristics of apatite crystals are maintained at a physiological level. Moreover, whatever the duration of treatment (2 to 96 months), strontium is always heterogeneously distributed, mainly present in recent bone formed during treatment, bone areas containing strontium progressively increase but less and less with the duration of the treatment. Focal bone strontium content remains stable from 2 to 60 months and then increase from 60 to 96 months, and secondary mineralization is maintained at a physiological level. Finally, after 6 and 12 months of treatment, strontium ranelate maintains normal the main parameters reflecting secondary mineralization, and its effects are similar to those of alendronate. To conclude, strontium ranelate maintains a normal quality of secondary mineralization, either after a shortterm or a long-term treatment, and whatever the model studied. Strontium ranelate also maintains bone microhardness, tissular mineral and organic characteristics, as well as the structure of apatite crystals

Les infections nosocomiales post-opératoires en sites osseux posent un problème majeur de santé publique. L'utilisation de biocéramiques bioactives et résorbables qui présenteraient des propriétés antibactériennes apparaît comme une des solutions les plus prometteuses pour lutter contre l'invasion de micro-organismes au niveau du site opératoire. Les apatites nanocristallines biomimétiques se révèlent être des candidats de choix pour ces applications en raison de leur similitude avec le minéral osseux et de leur forte réactivité de surface. Cependant, elles ne possèdent pas de propriétés antibactériennes intrinsèques, ce qui peut potentiellement être amené par un dopage ionique approprié. Dans ce contexte, ce travail traite de la synthèse et de la caractérisation physico-chimique d'apatites biomimétiques enrichies avec des cations zinc (Zn2+), cuivre (Cu2+) ou argent (Ag+) ou avec des anions oxygénés de type peroxydes qui présenteraient ces facultés antimicrobiennes ; puis sur l'évaluation préliminaire de leurs propriétés (micro)biologiques. Dans un premier temps, l'étude de systèmes apatitiques non dopés a indiqué qu'à l'instar du minéral osseux les apatites nanocristallines présentaient des cristaux de dimensions nanométriques dont la composition chimique s'éloignait de la stoechiométrie et exposant des environnements ioniques non-apatitiques hydratés en surface des nanocristaux. L'influence des paramètres de synthèse a été évaluée et révèle que le temps de maturation, la température, le pH et la nature des sels de phosphate impactent significativement les caractéristiques physico-chimiques de ces composés. Nous montrons également que les conditions de post-traitement (ré-immersion, traitement thermique, mise en forme) peuvent aussi modifier significativement les caractéristiques finales des biocéramiques. Dans un second temps, ce travail a révélé que l'enrichissement d'apatites nanocristallines avec des ions Zn2+, Cu2+, Ag+ ou des espèces oxygénées était possible – avec des taux de dopage limites qui ont été évalués – mais générait des modifications physico-chimiques notables en particulier en termes d'état de cristallinité et de teneur en environnements chimiques non-apatitiques. Le zinc et le cuivre engendrent des effets similaires et semblent agir en tant qu'inhibiteur de croissance cristalline. L'argent, bien que monovalent, ne modifie pas significativement les processus de formation et de croissance des nanocristaux d'apatites. En revanche, la présence de peroxyde d'hydrogène dans le milieu réactionnel conduit à la formation d'apatite dont l'état de cristallinité est augmenté. Le choix de paramètres de synthèse adéquats, influençant notablement les mécanismes d'incorporation des ions, s'est avéré déterminant pour l'obtention d'apatites nanocristallines monophasées et dopées. Des tests biologiques préliminaires ont été réalisés pour évaluer la cytotoxicité de ces composés et le comportement de cellules ostéogéniques (de types ostéoblastes et ostéoclastes). L'évaluation d'éventuelles propriétés antibactériennes a également fait l'objet de ce travail, dans le cadre d'une collaboration internationale. Parmi les formulations présentant des propriétés antibactériennes mesurées, les apatites biomimétiques enrichies en argent apparaissent au vu de ce travail comme les candidats les plus prometteurs pour conférer l'effet antibactérien nécessaire aux applications visées. / Hospital acquired infections in osseous sites are a major issue of public health. The use of bioactive and resorbable bioceramics that present antibacterial properties appears as one of the most promising solution against microorganisms invasion of the surgical site. Biomimetic nanocrystalline apatites belong to the choice candidates for those applications thanks to their similarities with the bone mineral and their high surface reactivity. Nevertheless, they don't possess intrinsic antibacterial capacity, property that can be reached by a suitable ionic enrichment. In this context, this work deals with the synthesis and the physico-chemical characterization of such biomimetic nanocrystalline apatites doped with zinc (Zn2+), copper (Cu2+) or silver (Ag+) cations or with oxygenated anions like peroxides that would present antibacterial activity; then their (micro-)biological properties have also been studied. As a first part, study of apatitic non-doped systems shows that, as well as bone mineral, nanocrystalline apatites exhibit nano-sized crystals which chemical composition depart from stoichiometry and possess hydrated non-apatitic environments on their surface. The influence of synthesis parameters has been studied and reveals that maturation time in solution, temperature, pH or the nature of starting phosphate salts impact significantly the physico-chemical characteristics of those compounds. We also point out that post-treatment conditions (re-immersion, thermal treatment, forming) can significantly modify final characteristics of those bioceramics. As a second part, this work reveals that nanocrystalline apatites enrichment with Zn2+, Cu2+, Ag+ or oxygenated species seem to be possible – with maximal doping rates that were evaluated – but generate significant physico-chemical modifications, especially in terms of crystallinity state or non-apatitic chemical environments content. Zinc and copper act on a similar way on apatite compound and exhibit a crystal growth inhibitory role. Silver, even with a single positive charge, don't modify significantly the formation and the growth mechanisms of apatites nanocrystals. On the opposite, hydrogen peroxide presence in the synthesis media generates the formation of apatites which crystallinity state is improved. All of those results suggest that synthesis parameters are determining to obtain doped nanocrystalline apatites and that they influence notably the incorporation mechanisms of ions. Finally, preliminary biological tests have been realized in order to evaluate the cytotoxicity and the behavior of osteogenic cells (osteoblast and osteoclast type) in contact with those compounds. The evaluation of potential antibacterial properties is also discussed in this work as part of an international collaboration. Among formulations that exhibit measured antibacterial activity, silver doped biomimetic apatites appear as the most promising candidates to confer antibacterialness necessary for the envisaged applications.

Une première partie de cette thèse est méthodologique: elle vise à améliorer la thermochronométrie (U-Th-Sm)/He sur apatite et les modèles de diffusion actuels. Nous avons étudié le cas du Massif Armoricain (France), et celui des Alpes Suisses. Nos travaux montrent que la rétentivité en hélium des apatites est plus élevée que prévu par les modèles traditionnellement utilisés. Une approche statistique comprenant des algorithmes d'apprentissage montre que la composition chimique des grains ne semble pas jouer sur la rétentivité des apatites en hélium. Le principal paramètre contrôlant la dispersion des âges hélium est l'état d'endommagement des cristaux. Nous proposons une approche de physique/minéralogie expérimentale pour le caractériser à l'échelle nanométrique. Dans la dernière partie de la thèse, nous avons appliqué la méthode (U-Th-Sm)/He sur apatite au cas de la marge algérienne. Nous mettons en évidence une phase majeure de dénudation dans la région des Petites Kabylies au cours du Tortonien. Cette phase marque probablement le début de l'inversion de la marge, bien plus précocement que suggéré jusqu'alors. / The first part of the thesis aims at improving the methodology and the models involved in apatite (U-Th-Sm)/He thermochronology. For this purpose, we studied two geological cases: the Armorican Massif (France) and the Swiss Alps. Our work suggests that apatite helium retentivity is higher than predicted in traditional models. A statistical approach using machine learning algorithms evidences that the apatite chemical composition of grains does not influence helium retentivity. The key parameter is the parent radionuclide and the crystal damage contents. We suggest an experimental procedure in order to characterize damage in apatite at the sub-micrometer scale. In the last part of the thesis, we applied the (U-Th-Sm)/He method to the Algerian Margin. We evidenced a major denudation phase in Petite Kabylie ("Lesser Kabylia") during the Tortonian times. This phase likely corresponds to the initiation of the margin inversion, earlier than previously suggested.

The main objective of this work was to study the structural stabilization of calcium apatites where the Ca2+ ions were substituted for Sr2+ in increasing concentrations (0%, 20%, 40%, 60%, 80% e 100%) via ionic co-substitutions. Two distinct syntheses were proposed for comparative purposes: a standard synthesis using counter ions which were not easily incorporated into the apatite structure (NH4+/NO3-) and another one, in which counter ions that can be easily incorporated into the structure (Na+/Cl-) were used. It was observed that Sr2+ ions linearly replaced Ca2+ in the apatite structure, leading to a linear growth of the lattice parameters as well as the unit cell volume for both syntheses. The coexistence of the two phases (calcium apatite and strontium apatite) was suggested only for the samples before calcination at intermediate concentrations (40% and 60%). After calcination, only the samples synthesized in the presence of NH4+/NO3- presented phase transformation, generating calcium and/or strontium phosphates. In contrast, the samples synthesized in the presence of Na+/Cl- formed a solid solution after calcination, having Ca2+ and Sr2+ shared the same apatite lattice. It was shown that the insertion of Sr2+ into the calcium apatite induced the introduction of Cl- ions into the structure. At the same time, Na+ ions were also observed in the structure. Thus, it was evidenced that such elements played an important role in the thermal stabilization of the apatite synthesized in this work. / O objetivo principal deste trabalho foi estudar a estabilização estrutural de apatitas de cálcio substituídas por estrôncio em concentrações crescentes de estrôncio (0%, 20%, 40,%, 60%, 80% e 100%) via co-substituições iônicas. Para isso, duas sínteses distintas foram propostas em termos comparativos: uma síntese padrão usando contra-íons que não são incorporados facilmente a rede de uma apatita (NH4+/NO3-) e outra, usando contra-íons facilmente incorporados à estrutura (Na+/Cl-). Foi possível observar que o Sr2+ substituiu linearmente o Ca2+ levando a um aumento linear dos parâmetros de rede e volumes da célula unitária para as duas sínteses propostas. A coexistência de duas fases distintas (apatita de cálcio e apatita de estrôncio) foi sugerida apenas para as amostras verdes em concentrações intermediárias (40% e 60%). Após calcinação, apenas as amostras sintetizadas na presença de NH4+/NO3- apresentaram segregação de fase, gerando fosfatos de Ca2+ e/ou Sr2+. Contrariamente, as amostras sintetizadas em presença de Na+/Cl- formaram uma solução sólida após calcinação, onde Ca2+ e Sr2+ compartilharam a mesma rede apatítica. Ficou evidenciado que a entrada do Sr2+ na rede das apatitas facilitou a entrada do íon Cl- na estrutura. Ao mesmo tempo, o íon Na+ foi igualmente inserido na estrutura. Assim, foi possível demonstrar que esses elementos desempenharam um papel importante na estabilização térmica das apatitas.

The interplay between geology and biology has shaped the Earth during billions of years. Microbe-mineral interactions are prime examples of this interplay and underscore the importance of microorganisms in making Earth a suitable environment for all forms of life. The present thesis takes an interdisciplinary approach to obtain an integrated understanding of microbe-mineral interactions. More specifically it addresses how the composition and distribution of biogenic weathering agents (siderophores) differ with regard to soil horizon and mineral type in situ, what siderophore type soil microorganisms produces under laboratory conditions, what role microbial surface attachment plays in mineral weathering reactions and what central roles and applications siderophores have in the environment. Podzol, the third most abundant soil in Europe, and most abundant in Scandinavia, was chosen for a field experiment, where three minerals (apatite, biotite and oligoclase) were inserted in the organic, eluvial and upper illuvial soil horizons. The study started with an investigation of the siderophore composition in the bulk soil profile and on the mineral surfaces (paper I), which was followed by a study of the siderophore producing capabilities of microorganisms isolated from the soil profile under laboratory conditions (paper II). Subsequently, a study was done on the impact of microbial surface attachment on biotite dissolution (paper III). Finally, the roles of siderophores in nature and their potential applications were reviewed (paper IV). The major findings were that the concentration of hydroxamate siderophores in the soil attached to the mineral surfaces was greater than those in the surrounding bulk soil, indicating that the minerals stimulate the microbial communities attached to their surfaces to produce more siderophores than the microorganisms in the bulk soil. Each mineral had a unique assemblage of hydroxamate siderophores, that makes the mineral type one of the main factors affecting siderophore composition in the natural environment. Siderophore production varied between the microbial species originating from different soil horizons, suggesting that the metabolic properties of microbes in deep soil horizons function differently from those at upper soil horizons. Microbial surface attachment enhanced the biotite dissolution, showing that attached microbes has a greater influence on weathering reactions in soil than planktonic populations. In conclusion, our findings reflected that the complicated relationship between microorganisms and mineral surfaces reinforces the central theme of biogeochemistry that the mineral controls the biological activity in the natural environments. However, the importance of these relationships to the biogeochemical systems requires further investigation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: In press. Paper 3: In press.</p><p> </p>

published_or_final_version / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy

The Malmberget apatite iron ore deposit is one of the most important iron producers within Europe located within an area of world-renowned mines and mining companies. It is becoming increasingly accepted that in order to increase our resources it is essential to gain a better understanding of the formation and evolution of our known mineral deposits. This thesis is part of an ongoing multi-scale 4-dimensional geological modeling project as part of a collaboration between Vinnova, LKAB, Boliden &amp; LTU. The aim of the which is to piece together the series of geological events that are responsible for the entire Gällivare mining district as seen today. This project looks at three smaller old open pits on the outer limbs of the synform fold structure that forms the Malmberget deposit. This thesis aims to gain a better understanding of the structures that have defined this current shape, and relating them to the regional-scale structural evolution. The results show two distinct deformation events, D1and D2, with each event leaving their own signature on the region. D1 deformation resulted in the formation of high strain zones and a gneissic cleavage within the volcanic rocks. D2 deformation subsequently folded the S1 gneissic cleavage and high strain zones but without developing its own fabric. / Multi-scale 4-dimensional geological modeling of the Gällivare area

As recentes descobertas de corpos carbonatíticos no estado geram interesse sobre o potencial econômico destas rochas. Associada ao Complexo Granulítico Santa Maria Chico, o carbonatito Três Estradas apresenta um elevado teor de apatita torna-o um alvo para a implantação de um empreendimento de produção de fosfato, importante para a produção de insumos na indústria agrícola. Neste projeto procurou-se examinar este mineral associado ao carbonatito Três Estradas no estado do Rio Grande do Sul, bem como no perfil de alteração intempérica gerado sobre estas rochas. Foi realizado um estudo detalhado das ocorrências deste mineral associado a este corpo carbonatítico que mostrou a presença de diferentes gerações de apatita ao longo do perfil de alteração intempérica, evidenciando processos de dissolução parcial, substituições químicas e precipitação. Confirmada a existência de apatitas de diferentes gerações, o estudo foi direcionado para caracterizar as populações de apatitas e o ambiente geoquímico associado. Dentre os métodos que foram utilizados cita-se a análise química das amostras por espectrometria de fluorescência de raios-X, microssonda eletrônica, espectroscopia de infravermelho por transformada de Fourier e espectroscopia micro Raman, análise mineralógica através da difratometria de raios X e análise petrográfica e dos elementos texturais por microscopia ótica complementada pela microscopia eletrônica de varredura. Com os resultados obtidos foi possível compreender as variações na composição química das apatitas proveniente do carbonatito e no perfil de alteração destas rochas, identificando distintos tipos de ocorrência deste mineral e caracterizando-os quimicamente, além de especular sobre as condições supergênicas que propiciaram a formação de gerações tardias do mineral elevando consideravelmente as concentrações de fosfato. / Recent discoveries of carbonatite bodies in the state of Rio Grande do Sul created interest about the economic potential of these rocks. Associated with the granulitic complex Santa Maria Chico, the Três Estradas carbonatite presents a high content of apatite, making it a target to the implementation of an adventure for the production of phosphate, an important mineral for the production of inputs for the agricultural industry. In this project, this mineral was examined, as well as the weathering profile occurring in these rocks. A detailed study of the occurrence of this mineral associated with this carbonatite body was elaborated and revealed the presence of different generations of apatite along the weathering profile, evidencing processes of partial dissolution, chemical substitutions and precipitation. Once confirmed the existence of apatite of different generations, the study was directed to characterizing the populations and the geochemical environment associated with each one. Among the methods applied were the chemical analysis of the samples by x-ray fluorescence spectroscopy, electronic microprobe, Fourier-Transform infrared spectroscopy and micro Raman spectroscopy, the mineralogic analysis by x-ray diffraction, and the petrographic and textural analysis by optic microscopy complemented by scanning electron microscope. With the results obtained it was possible to comprehend the variations in the chemical composition of the apatite from the carbonatite and in the weathering profile of these rocks, allowing the identification of different types of occurrence and its chemical characteristics, as well as speculate about the supergenic condition that favored the formation of late generations of the mineral, what elevates considerably the phosphate concentration.