Heavy Minerals as Indicators of the Source and Stratigraphic Position of the Loess-Like Deposits in the Orava Basin (Polish Western Carpathians)

Abstract

This study is focused on the loess-like deposits accumulated on glaciofluvial fans of the Czarny Dunajec River in the Orava Basin (Southern Poland). The deposition of these sediments took place during three cold intervals of the Pleistocene: Würm, Riss, and Günz/Mindel. So far, the provenance and age of the deposits has not been precisely defined, even though the development of each fan is believed to be related to the successive glacial periods in the Tatra Mountains. Heavy minerals were studied to determine the source of the deposits. Heavy mineral analyses revealed that zircon, tourmaline, rutile, garnet, amphibole, epidote, and apatite are the typical constituents of the heavy mineral fraction. Abundances of heavy minerals differ in each of the Pleistocene fans of the Czarny Dunajec River, especially the amphibole content. However, the chemical composition of garnet, amphibole, and tourmaline is rather uniform. This research showed that mainly medium-grade metamorphic rocks with a subordinate share of high-grade metamorphics, and granitic rocks are the dominant source rocks of the deposits studied. Such rocks are exposed in the Western Tatra Mountains, which most probably supplied the Orava Basin with clastic material. Change in abundances of heavy minerals in the succession may reflect the progressive erosion of the source area. Grain-size distribution and textural features of the sampled sediments suggest fluvial and aeolian modes of transportation. Additionally, this study indicated that heavy minerals may be used to correlate the loess covers in the Orava Basin.

Source areas of the Eastern Ebro Valley loess (NE Iberian Peninsula): Heavy mineral composition as a provenance indicator

“…This dynamic is due to a heavy mineral depletion by weight sorting and the contributions of aeolian material from other areas, such as Miocene substrate interfluves with a lower heavy mineral concentration. The Ebro Valley loess %HM is higher than for other European loess(Chmielowska & Salata, 2020;Wolf et al, 2019Wolf et al, , 2021, except in the case of Pannonian Basin, with which they were very similar(Tham o-Bozs o et al, 2014).There was an enrichment in zircon and inosilicates in the loess compared to the terraces, and a certain impoverishment in staurolite.Zircon enrichment in loess could be explained by the preference for lower diameters during wind transport and a possible contribution from Miocene sandstones. Zircon crystals (50-70 μm) are found in the smallest particle sizes of fluvial terraces (average size 180-200 μm), favouring wind entrainment.…”

“…The heavy mineral analyses compare the presence and frequency of representative mineral species in sources and deposits (Chmielowska & Salata, 2020;Römer et al, 2016;Song et al, 2014 The Miocene formations and the terraces are taken from the geological map of Spain 1:1 000 000 (Rodríguez et al, 2015) and the loess deposits from Plata et al (2019). Acronyms of sample locations are detailed in Supplementary Table S1.…”

“…In the case of grain size, the degree of particle size sorting and fractioning caused by the wind deflation and transport plays a major role (Bertran et al, 2021; Bosq et al, 2018; Crouvi et al, 2008). The heavy mineral analyses compare the presence and frequency of representative mineral species in sources and deposits (Chmielowska & Salata, 2020; Römer et al, 2016; Song et al, 2014; Thamó‐Bozsó et al, 2014; Wolf et al, 2019). Calcium carbonate and gypsum contents have also been selected as common chemical components.…”

“…To establish the loess source areas, various techniques have been developed based on the recognition of specific or tracing characteristics in both sediments and source areas. The techniques consisted of the identification of heavy minerals (Chmielowska & Salata, 2020; Muhs et al, 2018; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2019), geochemical composition (Bosq et al, 2020; Schatz et al, 2015; Waroszewski et al, 2021) and U–Pb isotope analysis of zircons (Fenn et al, 2022; Újvári et al, 2016; Wolf et al, 2021). One of the most useful and effective methods is the comparison of sets of heavy minerals present in the loess sand fraction and their potential source materials: fluvial terraces and regional lithological substrates (Chmielowska & Salata, 2020; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2021).…”

“…The techniques consisted of the identification of heavy minerals (Chmielowska & Salata, 2020; Muhs et al, 2018; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2019), geochemical composition (Bosq et al, 2020; Schatz et al, 2015; Waroszewski et al, 2021) and U–Pb isotope analysis of zircons (Fenn et al, 2022; Újvári et al, 2016; Wolf et al, 2021). One of the most useful and effective methods is the comparison of sets of heavy minerals present in the loess sand fraction and their potential source materials: fluvial terraces and regional lithological substrates (Chmielowska & Salata, 2020; Peng et al, 2016; Thamó‐Bozsó et al, 2014; Wolf et al, 2021). As ancillary techniques, particle grain size analysis of the loess and original materials, and analyses of the general chemical composition, are also used.…”