Abstract
The mature transgressive Albian quartz sands in the Miechów Synclinorium contain a poor (<1%) heavy mineral suite consisting of tourmaline, rutile, garnet, staurolite, ilmenite, zircon, monazite, kyanite, and gahnite. The other minerals, especially those containing Fe and Ti (e.g., biotite), are subordinate. Over 512 tourmaline grains from seven outcrops in the Miechów Segment were analysed using electron probe microanalysis (EPMA). The majority of grains belong to the alkali tourmaline group in which the X-site is dominated by Na (0.4 to 0.9 apfu). Detrital tourmalines are mainly dravite with a prevalent schorl end-member with average XMg values over 0.6. Apart from Mg and Fe, the other Y-site cations rarely exceed 0.1 apfu. Fluorine content is usually below the detection limit. Their chemical composition suggests that most tourmaline grains were sourced from Al-rich and Al-poor metapelites/metapsammites. The main source rocks for the Albian sands were rocks from low- to medium-grade metamorphism, probably from Al-rich quartz-muscovite schist and/or muscovite rich gneisses. Additional minor source rocks were granites and pegmatites coexisting with them. A comparison of the examined tourmaline to tourmaline from possible source areas indicates that these areas were located in the eastern part of the Bohemian Massif and/or eastern Sudetes.
Highlights
In the history of the Earth, the Cretaceous (145–66 Ma) is considered to have been a very uneventful period in Europe
The composition of the heavy mineral assemblage in analysed Albian sediments samples is similar from all examined localities of the Miechów Segment
70% of all tourmaline grains studied here are classified as dravite
Summary
In the history of the Earth, the Cretaceous (145–66 Ma) is considered to have been a very uneventful period in Europe. 300 Ma) in the Late Palaeozoic, denudation and peneplanation processes of elevated areas took place in extra-Alpine Europe during the Permian, Triassic and Jurassic, and the land was flooded by relatively shallow epicontinental seas [1]. In the latest Early Cretaceous, in Albian times (earlier than 100.5 Ma), after the neo-Cimmerian tectonic movements phase 145 Ma), a widespread sea transgression took place in epicontinental extra-Alpine Europe. The area of the nowadays Miechów Synclinorium, in the literature commonly called the Miechów Segment of the Szczecin–Miechów Synclinorium [3], is located in southern Poland (Figure 1). That area, during the Middle and Late Albian (110.8–100.5 Ma), was the southern peripheral part of that epicontinental sea and was limited by land and/or islands to the south (Figure 2).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
