The present state of the certification of the reference materials for thermal analysis is considered. Six sets of reference materials for temperature calibration, resulting from the research work of the ICTA Standardization Committee, are discussed.
Organic matter associated with rocks was examined by means of thermal analysis using a new methodology in oxidising conditions.
This procedure has been named “Oxyreactive Thermal Analysis” (OTA). The OTA results presented in this study characterise samples
from sedimentary rock complexes in terms of their age, and of variations in the associated organic matter arising from different
precursors and degree of severity of subsequent transformation processes to which it has been subjected.
The results of the OTA method make it possible to estimate the temperature of maturation, to describe the process of evolution
of the organic matter, and to distinguish genetic features of its carbonised and metamorphosed products.
The influence of certain experimental conditions on the courses of the thermal curves (DTA and DTG) of selected clay minerals
was studied. The thickness of the sample layer, the sample mass, the type of sample holder and the parameters of the air atmosphere
were varied in thermal analyses of 13 samples of clay minerals. Comparison of the results obtained on different clay samples
analysed under different experimental conditions may serve as the basis for the improvement of the thermal analysis methodology
applied for the study of clay minerals.
Authors:S. Cebulak, A. Gawęda, and A. Langier-Kużniarowa
This paper presents the results of oxyreactive thermal analyses of organic matter in rocks, heated naturally during diagenetic
to metamorphic processes. During the experiments we traced the reactions in the temperature range up to 900C, it means from
the very beginning of diagenetic transformations to the highest real temperatures acting in the Earth's crust as a solid phase.
The results showed that TA could be a tool for the reconstruction of thermal regime in natural coal-bearing systems.
Authors:S. Cebulak, A. Matuszewska, and A. Langier-Kuźniarowa
The paper presents the applicability of oxyreactive thermal analysis (OTA) for the investigation of different kinds of resins
both natural (recent and fossil) and synthetic. For comparative reasons and a more precise interpretation, along with OTA
infrared spectroscopy was used as a method commonly applied for the investigation of fossil resins. The results obtained prove
that the OTA method may be very useful for diversification of different kinds of resins. The parameter most valuable for the
preliminary characteristics of resins and the evaluation of their transformation was found to be the mass loss recorded on
TG curves in three definite temperature ranges.
Authors:S. Cebulak, A. Karczewska, A. Mazurek, and A. Langier-Kużniarowa
The study presents examples of the application of oxyreactive thermal analysis to the geological prospecting of bitumen deposits. Thermal analysis performed under properly chosen analytical conditions allows determination of characteristic features of organic matter and, at the same time, estimation of the thermal history of rocks. Thermal oxyreactivity curves document whether rocks were heated before or not. The results of the oxyreactive thermal analysis correlate well with the results of routine chemical analyses of organic matter (e.g. the composition of kerogen and bituminous fraction, Rock-Eval analysis and others). Our study clearly demonstrates that the composition of organic matter in facially, lithostratigraphically, and biogenetically identical rocks depends on their thermal history.
Authors:S. Cebulak, A. Langier-Kuźniarowa, G. Czapowski, and G. Bzowska
The paper discusses the influence of variable experimental conditions on the thermal decomposition of carbonate minerals.
This study was based on Ca-Mg carbonate minerals from Upper Permian dolomite and zuber rocks as well as on calcite and magnesite
samples from geological formations of various ages. X-ray diffraction was applied for comparative purposes. Experimental conditions
were chosen based on the authors' experience related to studies of both fossil and contemporary organic matters as well as
various materials of geological provenience. Since the main factor in thermal analysis of carbonates is the appropriate choice
of experimental conditions for outflow of gaseous reaction products, the thermal analyses were carried out with various sample
holders, various sample masses and varied thickness of sample layers in holders, using also a dynamic atmosphere. The results
obtained indicated that different experimental conditions produced extremely different TA data, e.g. the traditional analysis
in crucible sample holders with a thick sample layer (great sample mass) showed well expressed double thermal effects of dolomite.
For thin sample layer both peaks of thermal decomposition of carbonate components occurred in very close or almost identical
temperatures. The presented results enabled to devise a detailed procedure referring to the choice of experimental conditions
and interpretation possibilities as well as to recommend specific TA instruments design and sample holders types.