Andrzej Domonik

Ultrasonic waves and strength reduction indexes for the assessment of the advancement of deterioration processes in travertines from Pamukkale and Hierapolis (Turkey)

Abstract In constructions, the usefulness of modern technical diagnostics of stone as a raw material requires predicting the effects of long-term environmental impact of its qualities and geomechanical properties. The paper presents geomechanical research enabling presentation of the factors for strength loss of the stone and forecasting the rate of development of destructive phenomena on the stone structure on a long-time basis. As research material Turkish travertines were selected from the Denizli-Kaklık Basin (Pamukkale and Hierapolis quarries), which have been commonly used for centuries in global architecture. The rock material was subjected to testing of the impact of various environmental factors, as well as European standards recommended by the author of the research program. Their resistance to the crystallization of salts from aqueous solutions and the effects of SO2, as well as the effect of frost and high temperatures are presented. The studies allowed establishing the following quantitative indicators: the ultrasonic waves index (IVp) and the strength reduction index (IRc). Reflections on the assessment of deterioration effects indicate that the most active factors decreasing travertine resistance in the aging process include frost and sulphur dioxide (SO2). Their negative influence is particularly intense when the stone material is already strongly weathered.

Self-Similar Pattern of Crystal Growth from Heterogeneous Magmas: 3D Depiction of LA-ICP-MS Data

Crystals grown from mixed magmas are characterized by extreme geochemical heterogeneity. The system is self-similar which is reflected in a complex pattern of element distribution in the crystal. New tools are required to show the complexity. 3D depiction (digital concentration-distribution models DC-DMs) combined with fractal statistics is an ideal tool for the identification and description of any subsequent change occurring due to the chaotic processes. LA-ICP-MS analysis gives simultaneous information on the concentration of many elements from the same analysed crystal volume. Thus the data collected are an ideal basis for the calculation of both DC-DMs and fractals. Simultaneous information retrieved by LA-ICP -MS on both compatible and incompatible elements and further data processing allow the determination of the process dynamics in terms of element behavior: antipersistent/persistent, being incorporated according to Henry’s Law or beyond it. The multi-method approach can be used for any system showing geochemical variability.

Protomylonite evolution potentially revealed by the 3D depiction and fractal analysis of chemical data from a feldspar

Abstract An alkali feldspar megacryst from a protomylonite has been studied using laser ablation-ICP-mass spectrometry combined with cathodoluminescence imaging, Raman spectroscopy, and electron probe microanalysis. The aim was to determine the original (magmatic) geochemical pattern of the crystal and the changes introduced by protomylonitization. Digital concentration-distribution models, derivative gradient models, and fractal statistics, e.g., Hurst-exponent values are used in a novel way to reveal subtle changes in the trace-element composition of the feldspar. Formation of the crystal is reflected in a slightly chaotic trace-element (Ba, Sr, and Rb) distribution pattern that is more or less characterized by continuous development from a fairly homogeneous environment. Derivative gradient models demonstrate a microdomain pattern. Fractal statistics show that element behavior was changeable, with Ba and Sr always more persistent (continuing) and Rb always less persistent, with the latter showing a tendency to migrate. The variations in the Hurst exponent are, however, too large to be explained by magmatic differentiation alone. The observed element behavior may be explained by structural changes revealed by Raman spectroscopy and CL. In high-strain domains, T–O–T modes become stronger for Si–O–Al than Al–O–Al linkages. Increasing amounts of Al–O−–Al defects are demonstrated by cathodoluminescence. Both may result from small-distance diffusion creep, making the crystal geochemical pattern slightly patchy. In turn, the marginal part of the megacryst has a mosaic of randomly orientated, newly crystallized K-feldspars. The re-growth is confirmed by trace-element distribution patterns and fractal statistics which identify an abrupt change in the transformation environment. The novel set of tools used in this study reveals a complicated history of megacryst formation and transformation that otherwise would be difficult to unravel and decipher.