Thermal maturity of the Palaeozoic Moravo-Silesian Basin: a digital image analysis approach to conodont colour alteration index (CAI)
Authors | |
---|---|
Year of publication | 2006 |
Type | Article in Periodical |
Magazine / Source | Geophysical Research Abstracts |
MU Faculty or unit | |
Citation | |
Field | Geology and mineralogy |
Keywords | conodont colour alteration index; Moravo-Silesian basin; image analysis; Variscan orogeny; Carboniferous |
Description | Colour composition of the representative CAI samples from the Moravo-Silesian basin (MSB) ranging from CAI3.5 to CAI6 was quantified by measurement of the intensities of the red, green and blue colour components of reflected light from unpolished conodont elements. Conodonts were photographed using digital camera attached to a stereomicroscope, under standard conditions of illumination and magnification. The images were imported into PC and, after white point adjustment, intensities of reflected light from the conodont surface were measured in the RGB mode. As the thermal maturity data show, the rocks in the western part of the MSB attained their maximum thermal maturation during the final stages of the Variscan deformation and just after it, within the Upper Carboniferous to Lower Permian period. This coincides with: late Carboniferous early Permian remagnetisation of the Moravian part of the MSB, intrusion of the Žulová intrusive body in northern Moravia and 300-310 Ma cooling ages of white micas in the Silesicum. Stretching lineations in the Silesicum and the sediments of the MSB document a Late Variscan orogen-parallel extension, which was associated with a huge thermal pulse. |
Related projects: |