Abstract The objective of this study was to determine the mineralogical composition of equine enteroliths from the Aburrá Valley in Antioquia, Colombia. Samples of eight enteroliths from eight horses were subjected to semi-quantitative X-ray diffraction (XRD) and transmission and scanning electron microscopy (TEM/SEM) analysis. The TEM/SEM of the analyzed enteroliths reported the presence of carbon, oxygen, phosphorus, magnesium, calcium, silicon, potassium, bromine, iron, sulfur, and aluminum. The XRD identified struvite, newberyte, kyanite, low quartz, actinolite, nitratine, cordierite, and vivianite. Both techniques used in the analysis of the enteroliths were correlated by matching the mineral compounds with the detected chemical elements. The main mineral components of the enteroliths were magnesium phosphates, struvite and newberyte being the most common.

Resumen El objetivo de este estudio fue determinar la composición mineralógica de enterolitos de equinos del Valle de Aburrá, Antioquia, Colombia. Muestras de ocho enterolitos de ocho caballos, fueron sometidas a análisis por Difracción de Rayos X Semicuantitativo (DRX) y microscopía electrónica de transmisión y barrido (METB). La METB de los enterolitos analizados reportó carbono, oxígeno, fósforo, magnesio, calcio, silicio, potasio, bromo, hierro, azufre y aluminio. A través de DRX se identificó estruvita, newberyta, kyanita, quartz low, actinolita, nitratina, cordierita, vivianita. Ambas técnicas empleadas en el análisis de los enterolitos se correlacionaron al coincidir los compuestos minerales, con los elementos químicos determinados. Los principales componentes minerales de los enterolitos fueron fosfatos de magnesio, siendo la estruvita y la newberyta los más comunes.

Abstract The potential reactivity against the alkali-silica reaction of gravels from a quarry located near Villalonga town, Patagones district (province of Buenos Aires) was evaluated. The petrographic analysis was carried out according to IRAM 1649 standard test method. Also the accelerated mortar bar test (IRAM 1674), and the conventional and accelerated concrete prism test method (IRAM 1700) were used, in accordance with the requirements for concrete coarse aggregates established in IRAM 1531 standard. Partially altered volcanic glass, varieties of cryptocrystalline silica and, minor microcrystalline quartz, were identified as potentially reactive components. The expansion measured in mortar bars and concrete prisms exceeded the maximum limit established in the standards, qualifying the aggregate as moderately reactive (R1) (IRAM 1531). Finally, a pessimum effect was observed when replacing 40% of the gravel with a non-reactive sand, registering 0.36% expansion in the accelerated mortar bar test after 16 days of testing.

Resumen Se evaluó la potencial reactividad frente a la reacción álcali-sílice de cantos rodados provenientes de una cantera ubicada en proximidades a la localidad de Villalonga, partido de Patagones (provincia de Buenos Aires). Se realizó el análisis petrográfico según la norma IRAM 1649, el ensayo acelerado de la barra de mortero (IRAM 1674) y el método del prisma de hormigón convencional y acelerado (IRAM 1700) de acuerdo con los requisitos establecidos para los agregados gruesos para hormigón (IRAM 1531). Se identificaron vidrio volcánico parcialmente alterado, variedades de sílice criptocristalina y, en menor proporción, cuarzo microcristalino, como componentes potencialmente reactivos. La expansión medida en las barras de mortero y en los prismas de hormigón superó el límite máximo establecido por norma, calificando al agregado como moderadamente reactivo (R1) (IRAM 1531). Por último, se observó un efecto pessimum al reemplazar 40% del canto rodado por una arena no reactiva, registrándose 0,36% de expansión en el ensayo acelerado de la barra de mortero a 16 días de ensayo.

The hydrogeological conditions in the Chambishi mine area in Zambia. were investigated. Chambishi is a very wet mine and groundwater discharge costs are high. The research goal was to identify methods to reduce the discharge costs without greatly affecting the mining process. Hydrogeological data was obtained from measurements in drill-holes and from drill cores. The differences in structural deformation in different areas determine whether a layer of rock is an aquifer. In the mine region, the Lower Roan Group ore shale and quartz-sandstone unconformably lie on the basal schist and granite aquifuge. The Upper Roan Group dolomite is continuously distributed over a large area around the orebody. This dolomite is the main target of groundwater control efforts, and its water yield is also influenced by the deformation intensity. Based on the observations, backfilling was gradually adopted to appropriately safeguard the integrity of the aquifuge above the orebody. The overlapping relationship between the aquifer and aquifuge has been utilized to increase mine drainage efficiency. This measure has not only greatly reduced the costs of mine drainage, but also improced protection of the groundwater environment. The old drill-holes that were not sealed after exploration drilling were grouted. Further, possible water-conducting fracture zones were investigated. Cover drilling towards the suspected zone was conducted to prevent the high-pressure groundwater from shallower aquifers from entering stopes in deep areas of the mine.

Abstract Oyola 51 is an archaeological site identified in the town of Oyola, El Alto department, Catamarca province. It was interpreted as a domestic space. Even so, it does not fully conform to the homes already studied in the area. Therefore, this work aspires to add information regarding the particular characteristics of this occupation and the practices that occured in it, which allow us to specify if it is indeed a domestic unit. This was carried out through the study of the knapped lithic technology recovered at the site. The techno-morphological and morpho-functional analysis of the lithic assemblage was carried out, evaluating specific variables and taking into account the different stages of the production sequence. The analysis of the lithic technology of a site of these characteristics allowed us to identify some practices carried out at the site and evaluate the differences observed with respect to other similar sites in the area. Likewise, the information obtained allowed us to add to the general knowledge of occupations at El Alto-Ancasti Mountain range, and the way in which the people who inhabited it related to their environment.

Resumen Oyola 51 es un sitio arqueológico ubicado en la localidad de Oyola, departamento El Alto, provincia de Catamarca. El mismo fue interpretado como un espacio doméstico. Aun así, no se amolda en su totalidad a las viviendas ya estudiadas en el área. Por esta razón este trabajo aspira a sumar información respecto a las características particulares de esta ocupación y de las prácticas acontecidas en la misma, que nos permita especificar si se trata de una unidad doméstica efectivamente. Esto se llevó a cabo a través del estudio de la tecnología lítica tallada recuperada en el sitio. Se realizó el análisis tecno morfológico y morfológico funcional del conjunto lítico, evaluando variables específicas y teniendo en cuenta las diferentes etapas de la secuencia de producción. El análisis de la tecnología lítica de un sitio de estas características permitió identificar algunas prácticas realizadas en el lugar y evaluar las diferencias observadas con respecto a otros sitios de vivienda del área. Asimismo, la información obtenida permitió sumar al conocimiento general de las ocupaciones en la Sierra de El Alto-Ancasti, y de la manera en que las personas que la habitaron se relacionaron con su entorno.

Abstract This article presents the results obtained from the techno-morphological and technological analysis of the lithic assemblage from surface collections in different sectors of the Laguna La Huinca site, located in the middle basin of the Tapalqué creek (Buenos Aires province). The main objective is to identify, from the reconstruction of the operational chains for each rock, the technological practices and trajectories of production used by hunter-gatherer groups that inhabited this sector of the basin, far from the sources of procurement. In general terms, a predominance of orthoquartzite was identified, followed by chert and, to a lesser extent, silicified dolomite, sandstone, diabase and quartz. Although this same trend in the representation of rocks is recorded at the Empalme Querandíes 1 and Laguna de Frías sites, this situation is not consistent with the rest of the sites for the upper and middle basin of the Tapalqué creek. Differences in the treatment of the rocks were identified, which is reflected in the diverse technological practices and modes of production of lithic artefacts. The scarce presence of cortex on flakes suggests that the initial stages of debarking were carried out off-site. The operational chains in orthoquartzite and chert are represented by stages ranging from lithic production, linked to the production of blanks, to the maintenance of the stone tools.

Resumen En este artículo se presentan los resultados obtenidos del análisis tecno-morfológico y tecnológico efectuado sobre el conjunto lítico proveniente de recolecciones superficiales en distintos sectores del sitio Laguna La Huinca, ubicado en la cuenca media del arroyo Tapalqué (provincia de Buenos Aires). El objetivo principal es identificar, a partir de la reconstrucción de las cadenas operativas para cada roca, las prácticas tecnológicas y las trayectorias de producción utilizadas por los grupos cazadores-recolectores que habitaron este sector de la cuenca, alejado de las fuentes de abastecimiento. En líneas generales, se identificó un predominio de la ortocuarcita, seguida por la ftanita y en proporciones ínfimas dolomía silicificada, arenisca, diabasa y cuarzo. Si bien se registra esta misma tendencia en la representación de las rocas en los sitios Empalme Querandíes 1 y Laguna de Frías, esta situación no se condice con el resto de los sitios para la cuenca superior y media del arroyo Tapalqué. Se identificaron diferencias en el tratamiento de las rocas, lo cual se ve reflejado en las diversas prácticas tecnológicas y en los modos de producción de los artefactos líticos. La escasa presencia de desechos de talla con corteza permite pensar que las etapas iniciales de descortezamiento se realizaron fuera del sitio. Las cadenas operativas en ortocuarcita y ftanita están representadas por las etapas que van desde la producción lítica, vinculada con la obtención de formas-base, hasta el mantenimiento de los artefactos formatizados.

Different concentration techniques were evaluated for preconcentration of a mineral ore at a coarser size to avoid energy and resource wastage. Specifically, the aim was to reduce milling costs and energy required in the beneficiation of tin. In this study, cassiterite (0.17% Sn) was the mineral of interest in a pegmatite ore body associated with quartz (SiO2 > 60%) and alumina (Al2O3 > 20%). Three concentration techniques, namely dense media, shaking table, and flotation, coupled with characterization analysis, were used to assess the concentration response. The results confirmed that particle size and mineral liberation impact the separation process. High recovery and grade were obtained with gravity concentration methods (dense media and shaking table) for coarser (+300 to +212 μm) and intermediate (+150 to +53 μm) particle sizes. Lower recovery and grade were identified for much finer sizes (-53 to -38 μm). Flotation produced a high-grade product at a relatively low recovery and appeared to be only applicable to finer grains. Separation efficiency based on Schulz's equation measured a segregation performance of 74.8% for dense medium separation and 60.7% for the shaking table for the coarse and intermediate particle sizes. Flotation only achieved a separation of 30%-40%. The results suggest that use of dense media separation as a rough preconcentration method prior to further grinding, and the utilization of a more advanced concentration technique for mineral recovery and upgrade, constitute a successful approach to improve process economics.

Tribo-electrostatic separation is a promising method for effectively utiliing low-grade magnesite resources by removing quartz and improving the grade of magnesite. To determine the charge-to-mass ratios of pure magnesite and quartz, a triboelectric measurement system was employed, and a laboratory tribo-electrostatic separation system was used to separate low-grade magnesite. The results showed that the maximum difference in charge-to-mass ratio between pure magnesite and quartz particles was observed after friction with polyvinyl chloride. The grade and recovery of magnesite increased with temperature and initially increased with increasing voltage, feed rate, and air flowrate before gradually decreasing. The optimal conditions resulted in a concentrate with 46.91% MgO content and 77.36% recovery, while the quartz content decreased from 7.02% to 1.95%. These experimental results demonstrate the effectiveness and potential of tribo-electrostatic separation in removing quartz and upgrading magnesite.

Abstract: Soil is the basic material for the manufacture of compressed earth bricks, which is worked without any type of stabilization to obtain the minimum physical and mechanical properties required according to Peruvian standard E.070. The objective of this research is to evaluate the physical and mechanical characteristics of compressed earth bricks stabilized with different dosages of 5, 8, 12, 12, 15 and 18% of cement in dry weight of soil. The tests performed were: absorption, compressive strength, flexural strength per unit of masonry, compressive strength in piles, diagonal compressive strength of walls and the X-ray diffraction test. The results obtained show that with 18% of cement the optimum resistance is obtained, in terms of compressive strength increased by 53.95%, flexural strength by 43%, pile compressive strength by 36.6%, and wall diagonal compressive strength by 41.24%, respectively. The X-ray diffraction test applied to the optimum stabilized compressed earth brick sample shows that its composition is dominated by certain components such as 32.4% calcium silicate, 23.8% aluminum silicate, 17.4% hydrated calcium, 14.2% illite, 6.86% calcium oxide, 3.34% quartz, 1.2% kaolinite and 0.8% goethite. It is concluded that cement-stabilized compressed earth bricks (LTCEC) are a sustainable construction alternative that improves the mechanical properties of earth bricks.

Resumen: El suelo es el material básico para la fabricación de ladrillos de tierra comprimida, el cual se trabaja sin ningún tipo de estabilización para obtener las propiedades físicas y mecánicas mínimas requeridas según la norma peruana E.070. El objetivo de esta investigación es evaluar las características físicas y mecánicas de ladrillos de tierra comprimida estabilizados con diferentes dosificaciones de 5, 8, 12, 15 y 18% de cemento en peso seco de suelo. Los ensayos realizados fueron: absorción, resistencia a la compresión, resistencia a la flexión por unidad de mampostería, resistencia a la compresión en pilas, resistencia a la compresión diagonal de muros y el ensayo de difracción de rayos X. Los resultados obtenidos muestran que con 18% de cemento se obtienen la resistencia óptima, en términos de resistencia a la compresión aumenta en un 53.95%, resistencia a la flexión en un 43%, resistencia a la compresión en pilas en un 36.6%, y resistencia a la compresión diagonal de muros en un 41.24%, respectivamente. La prueba de difracción de rayos X aplicada a la muestra óptima de ladrillo de tierra comprimida estabilizada muestra que en su composición predominan ciertos componentes como 32.4% de silicato de calcio, 23.8% de silicato de aluminio, 17.4% de calcio hidratado, 14.2% de illita, 6.86% de óxido de calcio, 3.34% de cuarzo, 1.2% de caolinita y 0.8% de goethita. Se concluye que los ladrillos de tierra comprimida estabilizados con cemento (LTCEC) son una alternativa de construcción sostenible que mejora las propiedades mecánicas de los ladrillos de tierra.

Abstract Recent events involving iron ore tailings dam collapses have emphasized the need for developing alternative ways of depositing tailings. This study aims to evaluate the effects of using three hydroxamates and a sulfosuccinamate as collectors in the direct flotation of iron ore tailings, using a bench flotation. The best result obtained on bench flotation was tested in a pneumatic cell. The sample used in this study (10.8% of Fe) consists of quartz and hematite. The Aero® 6494 Promoter hydroxamate showed the highest selectivity among the analyzed reagents, reaching 64.31% of Fe in the final product of the test with the < 150 µm sample. The possibility of using these reagents as constituents of a mixed collector with dodecylamine was also investigated. In this case, the Aero® 845 Promoter sulfosuccinamate yielded the best results, with 62.84% of Fe and 59.01% of metallurgical recovery of Fe. The synergistic effect between the two reagents might be explained by the stability of the monolayer formed by the intercalation of the ions from the dodecylamine and the Aero® 845 Promoter, which reduces the electrostatic repulsion between ions of the same species This mixed collector was tested in a pneumatic cell. However, it had a lower performance in terms of Fe metallurgical recovery than in a bench-scale cell test, mainly for the finest particles, due to the greater control of the process’s variables in the bench cell. 10.8% 108 10 8 (10.8 hematite Aero 649 6431 64 31 64.31 15 investigated case 84 results 6284 62 62.84 5901 59 01 59.01 However benchscale scale particles processs process s 10.8 1 (10. 643 6 3 64.3 628 62.8 590 5 0 59.0 10. (10 64. 62. 59. (1 (

Abstract In the county of Pedra Lavrada - PB, various mineral occurrences of pegmatite are observed with prominence at Alto Dois Irmãos - PB, where quartz, feldspar and mica are mined. The understanding of mineral constituents is fundamental to define their industrial employment and to implement improvements in the beneficiation process. The proposal of this research is the detailed characterization and proof of that part of the ore (quartz) considered waste, presenting low poisoning (Fe2O3) and high silica (SiO2) content, to enable its industrial use. Besides that, to minimize the environmental impact through the reuse of this waste, and to determine the correct utilization of the milling equipment. For the pegmatite characterization, done were density determination tests, mineralogical identification by X-ray diffraction (XRD), chemical analysis by fluorescents X-rays and morphological analysis by scanning electron microscopy (SEM/EDS). Then tests were done for the Work Index (WI) calculous and consequently the empirical determination of the dimensions (LxD) of the pebble mill. The sterile presented a medium density of 2.66g/cm³, majority chemical composition of silicon and oxygen and quartz as the main mineralogical stage, indicating that this material has high purity. The. The Work Index (WI) was 15.9 kwh/t showing that this material can be considered resistant to breaking in the grinding process. The necessary energy to the milling was defined in 11.52 kwh/st, that corresponds to 57.28 HP. This power allowed the mill selection with diammeter and length of 1.83m, that provides the production maximization and the energy saving. PB mined process (quartz waste Fe2O3 FeO Fe O (Fe2O3 SiO2 SiO (SiO2 content use equipment Xray X ray XRD, XRD , (XRD) Xrays rays SEM/EDS. SEMEDS SEM/EDS . SEM EDS (SEM/EDS) WI (WI LxD (LxD 266gcm³ gcm 2 66g cm³ g cm 2.66g/cm³ stage purity 159 15 9 15. kwht kwh t 1152 11 52 11.5 kwhst st kwh/st 5728 57 28 57.2 HP 183m m 1 83m 1.83m saving Fe2O (Fe2O (SiO (XRD (SEM/EDS 266gcm 2.66g/cm 115 5 11. 572 57.

ABSTRACT Ore from the Yarusyacán District was analyzed in this research study, revealing the presence of sphalerite type 2, with a particle size ranging from 35 to 150 microns. Other species found included quartz, pyrite, pyrrhotite, calcium and potassium silicates, calcium carbonates, galena, chalcopyrite, and iron hydroxides. Based on the mineralogical characterization, laboratory tests were conducted that showed that dosing a secondary collector known as cuprocyanide can control the recovery and quality of the zinc concentrates in the third cleaning feed. Results showed that a 35 g/t dosage of cuprocyanide recovered 73.80% of zinc, whereas a 50 g/t dosage recovered only 52.94%. This demonstrated that both zinc grade and recovery increase when cuprocyanide is dosed in greater quantities; however, the excess of this reagent tends to decrease said values.

RESUMEN En este trabajo de investigación, se analizó un mineral de la zona de Yarusyacán, cuya mineralogía reveló la presencia de esfalerita tipo 2 con una granulometría de 35 a 150 micras, además de especies como cuarzo, pirita, pirrotita, silicatos de calcio y potasio, carbonatos cálcicos, galena, calcopirita e hidróxidos y óxidos de hierro. Sobre la base de la caracterización mineralógica, se realizaron pruebas a nivel de laboratorio que demostraron que la recuperación y la calidad de los concentrados de zinc pueden ser controladas a partir de la dosificación de un colector secundario, cuprocianuro, en la alimentación de la tercera limpieza. Los resultados de las pruebas demostraron que la dosificación de 35 g/t recuperó el 73.80% de Zn; en cambio, la dosificación de 50 g/t recuperó solo el 52.94%. De esta manera, quedó demostrado que tanto la ley como la recuperación de zinc aumentan cuando se dosifica cuprocianuro en mayor cantidad; sin embargo, el exceso de este reactivo tiende a disminuir estos valores.

Abstract The Atuba Complex occurs in the eastern region of Paraná State, located in the Southern Ribeira Belt. It is comprised of the Curitiba Terrane, northward of the Luís Alves Terrane, and southward of the Apiaí Terrane. This research was carried out by means of detailed petrography, microtectonics, and brittle and ductile structural analysis. The Atuba Complex is composed of migmatites, felsic granulites, granitoids, quartzites, phyllonites, schists, amphibolites, and cataclasites. The lithotypes are cut by diabase or gabbro dikes, lamprophyre dikes, pseudotachylites, and quartz, epidote, carbonate, or chlorite veins. The migmatites are characterized by two migmatization phases, the first composed of tonalitic leucosomes and the second formed by granitic leucosomes. The stromatic and mylonitized migmatites suggest dislocation creep mechanisms and dynamic recrystallization processes, mainly in quartz and feldspars. During the initial phase, melting reactions took place through dehydration, while in the subsequent phase, melting was facilitated by the presence of water-fluxed. The Atuba Complex comprises two foliations, Sn-1 (Dn-1 phase) and Sn (Dn phase). The Sn-1 surface (compositional banding) presents a ductile and anastomosed aspect with an N45W/55NE attitude, whereas the Sn mylonitic foliation is defined by the presence of mineral flattening or stretching and by the orientation of amphibole and biotite shapes, with a maximum plane of N45E/85NW. The observed faults and fractures strike in the NE-SW and NW-SE main directions. The paleostress study provided the recognition of a NE-SW sigma 1 associated with a NW-SE-striking sigma 3 for the left-lateral strike-slip faults and an E-W compressive SHMAX and an N-S distensive SHMIN for the right-lateral strike-slip faults. State Belt Terrane petrography microtectonics analysis granulites granitoids quartzites phyllonites schists amphibolites cataclasites dikes pseudotachylites epidote carbonate veins phases processes feldspars phase dehydration waterfluxed. waterfluxed water fluxed. fluxed water-fluxed foliations Sn1 Sn- Dn1 Dn (Dn- phase. . compositional banding N45W55NE NWNE N45W 55NE N W NE attitude shapes N45E85NW NENW N45E 85NW E NW N45E/85NW NESW SW NWSE SE directions NWSEstriking striking leftlateral left lateral strikeslip slip EW NS S rightlateral right

ABSTRACT Serra da Saudade Formation corresponds to the upper part of the stratigraphic column of the Bambuí Group. Few studies have addressed the soil properties and pedogenesis of the pelitic rocks rich in potassium minerals of this formation. This study analyzed siltstone-derived soils, some of which are glauconitic (green siltstone; “verdete”), to understand the role of the main pedogenetic factors and processes in the landscape of the Central-West region of the Minas Gerais State, covered by Cerrado vegetation. Nine soil profiles were described, and their morphological, physical, chemical and mineralogical properties were analyzed. Soils were classified as Neossolos Litólicos (P1, P3, P6, P8 and P9), Cambissolos Háplicos (P2 and P5), Argissolo Vermelho-Amarelo (P4) and Argissolo Acinzentado (P7). The main active pedogenetic processes identified in the study area are melanization, goethization, argiluviation and elutriation. These are essentially controlled by the nature of the parent material and position of the soil in the relief. Soils are typically shallow, dystrophic, highly Al-saturated and contain essentially quartz and micas in the coarse fractions (sand and silt) and illite/glauconite and kaolinite in the clay fraction. In soil environments with siltstone and green siltstone under “dry forests”, the soil water pH was higher and high levels of exchangeable calcium and magnesium, a eutrophic character and high-activity clay were observed. Barium, chromium, lead and zinc contents were high in all studied soils. Green siltstone-derived soils have peculiar physical and chemical properties, divergent from those developed from other glauconitic rocks on the Earth surface. However, greenish tones in horizons are common in all these soils. Group formation siltstonederived derived verdete, verdete , “verdete”) CentralWest Central West State vegetation described morphological P1, P1 P (P1 P3 P6 P9, P9 P9) P2 (P P5, P5 P5) VermelhoAmarelo Vermelho Amarelo P4 (P4 P7. P7 . (P7) melanization goethization elutriation relief shallow dystrophic Alsaturated Al saturated sand silt illiteglauconite illite glauconite fraction dry forests, forests forests” magnesium highactivity activity observed Barium chromium surface However “verdete” (P7 “verdete

Various aniline sensing materials have excellent properties based on quartz crystal microbalance (QCM) transducer, but their synthesis processes are complex. Herein, commercial calcium silicate hydrate nanosheets (CSH-S) was utilized for facile fabrication of aniline sensor based on QCM platform. This sensor was capable of detecting 0.1 ppm aniline, and the response time (14 s) and recovery time (16 s) were short. Besides, the devices could restore sensitivity after 30 days, demonstrating excellent stability. In addition, variable temperature experiment combined with simulation calculation methods were carried out to study the adsorption of aniline on CSH-S surfaces, then the sensing mechanism was revealed. This work opens up a rapid and convenient method for detecting gaseous aniline. (QCM transducer complex Herein CSHS CSH S (CSH-S platform 01 0 1 0. 14 (1 s 16 short Besides 3 days stability addition surfaces revealed (

ABSTRACT Along the coast of the state of Pernambuco, NE Brazil, the presence of coastal outcrops aligned with the shoreline and distributed above and below the mean sea level is remarkable. These outcrops were sampled, and petrological, isotopic, and geochronological analyses were integrated to investigate the local effects of the Holocene sea-level fluctuations. The results indicate that the rocks are recent (< 8ka), formed by cementation of beach sands (magnesian calcite cement, predominance of quartz and presence of marine bioclasts, signs of compaction, fractures, and dissolution), in a tropical climate and warm waters, which allows to classify them as typical examples of beachrocks. The carbonate cement consisted of Mg-rich calcite with values ranging from −1.1‰ to 3.5‰ for δ13C and from −0.9‰ to 0.5‰ for δ18OVPDB. These isotopic values are typical of marine carbonate cemented deposits in shallow marine environments under freshwater influence (meteoric vadose environment). In these conditions, the cementing processes occurred in the intertidal zones, which reinforce the use of these data as indicators of ancient sea levels. The sea level fluctuations could be divided, in chronological order, into three different phases, starting with a rapid sea level rise followed by a relative stabilization at a maximum level and, finally, a decreasing phase. Recent sea level fluctuations in Pernambuco are represented by beachrocks with ages between 8 ka and 800 years and a maximum level of 2 to 3 meters above the present mean level. In scenarios of a near future with a general global sea level rise pattern, significant local geomorphological changes may occur, which means a great future challenge to society. Brazil remarkable sampled petrological sealevel < ( 8ka, 8ka , 8ka) magnesian bioclasts compaction fractures dissolution, dissolution dissolution) waters Mgrich Mg rich 11 1 −1.1 35 5 3.5 δC δ C 09 0 9 −0.9 05 0.5 δ18OVPDB δOVPDB OVPDB meteoric environment. environment . environment) conditions zones levels divided order phases finally phase 80 pattern occur society −1. 3. −0. 0. −1 −0 −