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Made available in DSpace on 2021-06-25T15:01:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Universidade Federal de Santa Catarina Micropaleontology is crucial branch of Earth Sciences, with a pivotal role in the success of the oil and gas industry over the decades. This sector of paleontology is based on the taxonomical description of microfossils, which encompass fossils with size variation from 0.001 mm to 1 m. Normally these microorganisms have a high rate on preservation, thus they are widely accepted as reliable evidence to infer about paleodepositional settings and paleoclimate change. Furthermore, microfossils are critical to understanding the evolution through time, being many of them recognized as index fossil and providing useful biozones to correlation. Since 1950, microfossils have been taxonomically described mainly by stereomicroscopes. However, as the technology progress, traditional ways to study these organisms are challenged and improved by nondestructive three-dimensional imaging techniques, as X-ray tomographic microscopy (SRXTM), three-dimensional X-ray microscopy (3DXRM), the X-ray computed microtomography (microCT) and X-ray computed nanotomography (nanoCT). Recently, one of the most compelling research areas in micropaleontology is the desire to automatize and enhance the details of systematic classification. Thereby, an increasing number of researches have applied the high-resolution X-ray analysis aiming to improve the morphological, taxonomic and taphonomic examination. Most of them have detailed the enhancement provided by the technique when compared with the standard microscopes, and raised questions about the traditional characters used on the microfossil systematic taxonomy. Nevertheless, even with the surpassing detail on microfossil characterization, the application of microCT has been hampered by the costs and sometimes by the needs of specific computer skill. Thus, this research has evaluated the use of microCT as the technique to classify a random bulk of microfossil (comprising foraminifers, ostracods, radiolarians, gastropods and echinoderms) with no further software treatment. No standard microscope analysis was performed. Despite chemical composition of microfossils, most of the specimens morphology, especially internal structures, have been easily acquired and analyzed. 96% of the microfossils of the dataset were identified at least on genus level. Irrespective of the deepness of detail, when considering the overall taxonomic identification, the microCT seems to be effective as the standard microscope. Nonetheless, when problematic specimens are evaluated, the microCT seems to be a more reliable and practical tool than other methods as Scanning Electron Microscopy. Thus, the technique can be used solo or as a complementary method to the stereomicroscope. Additionally, the high-resolution has the potential to lead to the expected automatized & nbsp;micropaleontology, since they can provide numerous images in several planes. This may create a strong database necessary to machine learning and computer identification. Univ Fed Santa Catarina, Dept Mech Engn, Lab Meios Porosos & Propriedades Termofis LMPT, BR-88040535 Florianopolis, SC, Brazil Univ Fed Pernambuco, Dept Geol, Lab Micropaleontol Aplicada LMA, BR-50740540 Recife, PE, Brazil Univ Vale Rio dos Sinos, Inst Tecnol Micropaleontol, Itt Fossil, Sao Leopoldo, RS, Brazil Univ Vale Rio dos Sinos, Geol Grad Program, BR-93022750 Sao Leopoldo, RS, Brazil Univ Estadual Paulista, Fac Ciencias Bauru, Dept Ciencias Biol, Ave Engenheiro Luiz Edmundo Carrijo Coube, BR-17033360 Bauru, SP, Brazil Univ Fed Santa Catarina, Dept Geol, Lab Geoquim LABGEOQ, Rua Engn Agron Andrei Cristian Ferreira S-N, BR-88040535 Florianopolis, SC, Brazil Univ Estadual Paulista, Fac Ciencias Bauru, Dept Ciencias Biol, Ave Engenheiro Luiz Edmundo Carrijo Coube, BR-17033360 Bauru, SP, Brazil

The porosity of volcanic rocks can be strongly affected by secondary processes such as the percolation of water and hydrothermal fluids, thus promoting crystallization of secondary minerals in the pores. With an aim to evaluate the impact of secondary mineral fillings, this paper shows the segmentation of secondary and filled pores based on the micro-CT technique. The mineralogy of the sample was analyzed with optical microscopy. Multiscale analysis was performed to determine the total porosity before and after the processes. The results show the influence on the permeability parameter caused by crystallization.