巴西Paraná和Bahia地区滑石矿床的地质特征与成因模式(英文)

本文总结了巴西两个最重要的滑石产地,Parana和Bahia区中滑石矿床的地质特征,并探讨了这些矿床的可能成因。巴西的滑石在世界滑石储量与产量中占有十分重要的地位。巴西Parana和Bahia区的滑石矿主要产于前寒武纪地体中。尽管该区的滑石具有不同的地质产状,与变质火山岩和变质沉积岩共生的滑石最为重要。其他类型的滑石,如与镁铁质-超镁铁质岩共生的、在花岗岩与白云质大理岩接触带的、在花岗岩体中呈包体或顶垂体状的、则相对不重要。在巴西与岩浆活动有关的滑石矿化主要发生在前寒武纪(Bahia区)和白垩纪(Parana区)。滑石的成因模式主要有两类:一为与岩浆热液有关的热液交代成矿模式,另一是起源于盆地热卤水的变质流体交代成矿模式。其中后一种成因模式可用来解释巴西的大多数大型滑石矿床,同时也适用于其他地区,如中国辽宁和乌拉尔南部的滑石成矿。

Klabin公司位于巴西Paraná州的New Puma纸浆厂投产

Klabin公司近日宣布,其位于巴西Paraná州Ortigueira市的New Puma纸浆厂已顺利投产,并已于2016年3月初生产出第一包浆板。New Puma纸浆厂持有森林管理委员会产销监管链认证（FSCC129105）。该项目总投资为85亿雷亚尔,包括所有设施、税费和合同的修改所产生的费用。New Puma纸浆厂在24个月内按计划完成了施工。

Hydrocarbon indication in Rio Bonito Formation sandstone:Implication for CO_(2)storage in São Paulo,Brazil

São Paulo State has witnessed CO_(2)storage-based investigations considering the availability of suitable geologic structures and proximity to primary CO_(2)source sinks related to bioenergy and carbon capture and storage(BECCS)activities.The current study presents the hydrocarbon viability evaluations and CO_(2)storage prospects,focusing on the sandstone units of the Rio Bonito Formation.The objective is to apply petrophysical evaluations with geochemical inputs in predicting future hydrocarbon(gas)production to boost CO_(2)storage within the study location.The study used data from eleven wells with associated wireline logs(gamma ray,resistivity,density,neutron,and sonic)to predict potential hydrocarbon accumulation and fluid mobility in the investigated area.Rock samples(shale and carbonate)obtained from depths>200 m within the study location have shown bitumen presence.Organic geochemistry data of the Rio Bonito Formation shale beds suggest they are potential hydrocarbon source rocks and could have contributed to the gas accumulations within the sandstone units.Some drilled well data,e.g.,CB-1-SP and TI-1-SP,show hydrocarbon(gas)presence based on the typical resistivity and the combined neutron-density responses at depths up to 3400 m,indicating the possibility of other hydrocarbon members apart from the heavy oil(bitumen)observed from the near-surface rocks samples.From the three-dimensional(3-D)model,the free fluid indicator(FFI)is more significant towards the southwest and southeast of the area with deeper depths of occurrence,indicating portions with reasonable hydrocarbon recovery rates and good prospects for CO_(2)injection,circulation and permanent storage.However,future studies based on contemporary datasets are required to establish the hydrocarbon viability further,foster gas production events,and enhance CO_(2)storage possibilities within the region.

Distribution Pattern of Trees in a Hydrological Gradient below the Paraná-Paraguay River Confluence

Riparian and riverine aquatic plant species have evolved within the context of flowing water habitats for which the flooding and droughts are the forcing factors that shape the community features, either through a positive or negative effect on the ecosystem’s function, according to the timing, frequency and magnitude of such events. In the Paraná floodplain landscape, topographic position is a crude indicator of the position along the complex gradient, but it also includes information about flood/drought periods and trees’ resilience to extreme hydrological phases. We present the occurrence of major tree species in riparian forests of the Paraná River on islands of different topographies in a section of the Paraná River downstream from the confluence with the Paraguay River. Our results suggest that each tree species had a preferred position in the topographic gradient, sites where the observed counts were more frequent. This trees species were more frequent between 2 and 8 m in the topographic position and were affected by 5 and 202 hydrosedimentologic pulses between 1949 and 1999. We suggest that knowledge of the distribution curves of the vegetation species present can help draw possible future scenarios of the river landscape. Future engineering works to alter the hydrological dynamics of Paraná should pay more attention to the distribution of riparian forests because they are indicators of changes at the landscape level and they are the support for the wildlife of the river.

2D TEM Modeling for a Hydrogeological Study in the ParanáSedimentary Basin, Brazil

This work uses 2D TEM (Transient Electromagnetic) modeling for a hydrogeological study in the Paraná sedimentary basin. The study area is located at the northern region of the state of S?o Paulo, Brazil, where groundwater is exploited from two aquifer systems: one sedimentary, shallow, and the other crystalline, deep. The interest in applying the TEM method in this area owes to the high exploitation rates of groundwater from the crystalline aquifer system for irrigation, which is triggering considerable seismic activity locally. This aquifer system is composed of fractured basalt within the Serra Geral Formation and is about 120 m deep. Eighty-six TEM soundings were acquired at this location, but in nine cases the data did not fit the modelled curve for 1D geoelectrical models due to the geological complexity of the area. This paper shows 2D geoelectrical modeling results based on the FDTD (Finite Differences in Time Domain) method to explain the lateral resistivity variation within the geological setting. A 2D model was generated for each sounding and compared with 1D inversion models as well as with direct information from wells. The results show some vertical variations of about 10 to 30 meters on the upper interface of the basalt layer from Serra Geral Formation. They are located at approximately 60 meters from the center of the soundings. The existence of these 2D structures in the subsurface can be related to the drainage system in the study area. The presence of these structures may indicate a connection between the shallow and deep aquifer systems, acting like a conduit that may contribute to the seismic activity reported.

Curupira V1.0: Joint Inversion of VES and TEM for Environmental and Mass Movements Studies

An innovative inversion code, named “Curupira v1.0”, has been developed using Matlab to determine the vertical distribution of resistivity beneath the subsoil. The program integrates Vertical Electrical Sounding (VES), successful in shallow subsurface exploration and Time Domain Electromagnetic (TEM) techniques, better suited for deeper exploration, both of which are widely employed in geophysical exploration. These methodologies involve calculating subsurface resistivity through appropriate inversion processes. To address the ill-posed nature of inverse problems in geophysics, a joint inversion scheme combining VES and TEM data has been incorporated into Curupira v1.0. The software has been tested on both synthetic and real-world data, the latter of which was acquired from the Parana sedimentary basin which we summarise here. The results indicate that the joint inversion of VES and TEM techniques offers improved recovery of simulated models and demonstrates significant potential for hydrogeological studies.

Assessment of Indoor and Outdoor Noise Pollution at a University Hospital Based on Acoustic Measurements and Noise Mapping

This paper describes an analysis of the sound pressure levels at the exterior façade and inside the Hospital de Clínicas of the Federal University of Paraná. Measurements were taken at a total of 45 points, 24 at the exterior facade and 21 points inside the hospital on all the floors of the main building and in the maternity building. These 45 measurements were used to calculate the acoustic map of the hospital, which is located on General Carneiro Street, in the city of Curitiba, state of Paraná, Brazil. A comparison of the measured outdoor sound pressure levels against those established by Curitiba Municipal Law No. 10625 revealed that they all exceeded the daytime limit of 55 dB(A) permitted for areas around hospitals. The indoor sound pressure measurements and the noise levels for acoustic comfort established by the Brazilian technical standard ABNT NBR 10152 were compared, indicating that all the measured points, including those in the neonatal intensive care unit, exceeded the established limit of 35 dB(A) to 45 dB(A).

Pre Impoundment Studies in Monday River, Eastern Paraguay I: Soils and Submerged Soils

Monday River, at Eastern Paraguay is located south of the Itaipu Dam, and discharges into the Paraná River. At the point of discharge it has been projected to build a Hydroelectric power Plant and the reservoir will extend upstream the Monday. As a result of the impoundment of a river, the flooded soil can provide a certain amount of nutrients into the aqueous medium setting new conditions for aquatic life and affecting to a greater or lesser degree the ecosystems. The aim of this work is the assessment of the impact on the water quality of the incorporation of major nutrients into the water body after damming Monday River. Samples from soil profiles were taken at selected sites on both banks of the river;the amount of phosphorus, nitrogen, potassium, calcium and magnesium as well as other parameters as pH, organic matter, exchangeable bases were determined using standard procedures. Granulometric analysis was also performed. Phosphorus availability was determined by isotopic exchange. In addition the samples were submitted to submersion/incubation experiments along 60 days, and the concentration of elements incorporated into the water analyzed. Results show that flooded soils are low in phosphorus and nitrogen which is scarce in some cases;so does other nutrients. Submersion experiments also indicate generally limited incorporation of such nutrients into the water body. Significant negative impact of these soils on the water quality of the reservoir cannot be expected.

Correlations among large igneous provinces related to the West Gondwana breakup:A geochemical database reappraisal of Early Cretaceous plumbing systems

The opening and spreading of the Atlantic Ocean between Africa and South America evolved during the Early Cretaceous and were preceded by dramatic tholeiitic(mafic)magmatism and minor silicic and alkaline volcanism.These features are presently recognized from the equatorial regions of Brazil and Africa to the Falklands and South Africa.In southeastern South America,continental flood basalts and related plumbing systems constitute the ParanáMagmatic Province(PMP),whose African counterpart is the Etendeka Magmatic Province(EMP).In northeastern Brazil,dike swarms and sill complexes compose the Equatorial Atlantic Magmatic Province(EQUAMP).As a common feature,these provinces are chemically represented by two prevalent magma types:(1)tholeiitic basalts and basaltic andesites with lowTi(TiO_(2)<~2 wt.%),also including transitional Ti tholeiites with TiO_(2)~2.7-1.7 wt.%,and low incompatible element contents.This type is predominantly found in the southern PMP and EMP,with minor occurrences in the EQUAMP.(2)Tholeiitic basalts and basaltic andesites with high Ti(TiO_(2)>~2 wt.%)and incompatible element contents.High Ti tholeiites are relevant in the northern PMP and EMP,and dominant in EQUAMP.Evolved rocks(SiO_(2)=57-65 wt.%)interpreted as byproducts of assimilation and/or fractional crystallization(AFC)processes from high Ti tholeiitic magmas,are scarce(but present)in all three provinces.An accurate analysis of multivariable databases collected from the literature for dikes and sills,including major and trace element and radiogenic isotope data,reveals close similarities in their geochemical signatures.In a paleogeographic reconstruction of West Gondwana,the intrusive remnants of the PMP,EMP and EQUAMP are spread over an area of nearly 10×10^(6)km^(2).forming perhaps the most extensive set of plumbing systems on Earth,with a relatively consistent chronology based on a vast collection of K-Ar and^(40)Ar/^(39)Ar data available in the literature.This work provides the first comprehensive data comparison to support the existence of what may have been a single intercontinental-scale magmatic province of West Gondwana.