Estudo integrado geológico/tecnológico de rochas ornamentais: os granitos flores e jacarandá, RN

The main purpose of the present study is to integrate a geological and technological investigation of ornamental rocks of the Flores and Jacarandá granites, which are located near the Afonso Bezerra city, in the north central part of the Rio Grande do Norte State. The study area encompasses four litho-stratigrafic units: a Gneiss-Migmatitic Complex(cristalline basement), which is mainly composed of banded gneisses, usually deformed as mylonitic rocks and with several migmatic features, an Augen Gneiss, which occurs as an elongated body that constitutes the Jacarandá granite, a small granite stock, which presents a semi-circular form, named Flores granite, composed of pink, fine to medium coarse rocks, and fine to coarse alluvial sediments, which form extensive areas of large fluvial deposits. The technological characterization of the Flores and Jacarandá granites, carried out through several tests, has as the main purpose the determination of petrographic, physical, and mechanic parameters that allowed the characterization of these rocks. The test followed procedures recommended by Brazilian (ABNT Associação Brasileira de Normas Técnicas) and foreigner institutions (ASTM American Society for Testing and Materials). The petrografhic analysis indicated that the rocks investigated are granite sensu estrictu, summing an average 85-90% modal. The Flores granite is the more felsic rock, which presents mafic content ∼ 10% and monzonitic composition. The Jacarandá granite is an Augen Gneiss rock that presents sienogranitic composition and mafic modal content ∼ 15%. Several technological tests carried out (alterability, physical indices, velocity of ultrasonic wave propagation, uniaxial compression, flection resistence, Amsler desgaste, and resistence to freezing and heating) indicated that parameters and values were identical for both granites investigated. These parameters and values are consistent with the Brazilian and international standards for siliciclastic rocks of ornamental use, as well as other Brazilian ornamental granites. The analysis of all results indicates that both the Flores and Jacarandá granites present good quality, and that they are indicated for ornamental use of revetment interior and exterior of buildings

A releitura de um documento: o processo de tombamento do centro histórico de Natal (RN)

During over seven decades of institutionalizing the national heritage protection legal instrument it can be noticed the many ways of the instrument application, according to the approaches that were assigned to the spaces with heritage values and the dynamic of the elaborated thoughts within this theme. For the application of the instrument effectively, there is a long process that is carried out. This process begins with the study elaboration that aims to subsidize and justify the motivation of property protection, as well as the proposal of buffer zones and national protection areas delimitations, completing the process with the denial of the request or with the publication of the definitive national protection area at the Official Gazette. Starting with the relation between the existing heritage values identification into the historical centres and the definition of its protection areas that the area management will be done, based as well into the management intervention norms established for the protection area perimeter. From this context, the present essay has as porpoise to discuss the approach used for the identification and selection of a historical centre liable for national protection and the repercussion of this identification into the national protection area the was established, using a case study of the national protection of the historical centre of the city of Natal. Starting from the assumption that there are inconsistences and distortions about the text speech of the written document and the spatial delimitation of this document, motivated by an area that privileges the edifications rather than the urban space. Beginning with the urban history methodology, we are based on the precepts of Rossi (2011), Lamas (2010) and Cullen (2009) for that space reading, along with what Sant’Anna (2004) defines as “city-document” to make a new reading of this “heritage value space” verifying if the proposed protection area reflects what is defined as motivation for the national protection area process during the recognizing process. Therefore, it is concluded that it is essential that the buffer zones and the national protection areas are aligned with the text presented at the national protection area instruction, so the norms and criteria definition management process are established. We highlight that a site management and the identified values protection become very difficult without a specific law that beacon the decisions that should be taken.