Paleogeographic implications of a multi-parameter Paleogene provenance dataset (Transylvanian Basin, Romania)

Abstract

Recent developments in geoanalytics have led to the rapidly increasing potential of sedimentary provenance analysis in paleogeographic reconstructions. Here we combine standard methods (petrography, zircon U-Pb geochronology, optical heavy-mineral identification) with modern techniques such as automated Raman-spectroscopic identification of heavy minerals and detrital apatite and titanite U-Pb geochronology. The resulting multi-parameter dataset enables the reconstruction of tectonic and paleogeographic environments to an as-yet unprecedented accuracy in space and time. The Paleogene siliciclastic formations of our study area, the Transylvanian Basin, represent an intensely changing sedimentary environment comprising three transgressive–regressive cycles on a simultaneously moving and rotating tectonic plate. We identified six major source components of the Paleogene sediments and outlined the paleo-drainage patterns for the three cycles, respectively. According to our data these components include: 1) pre-Variscan basement units of the nappes, 2) Variscan granitoids, 3) Permo-Triassic felsic volcanic rocks, 4) Jurassic ophiolites, 5) Upper Cretaceous granodiorites, and 6) Priabonian to Rupelian (37–30 Ma) intermediate magmatites, the latter representing newly recognized formations in the region. Abrupt paleographic changes can be directly deduced from the obtained dataset. The first phase of the Paleogene siliciclastic sequence is composed of mostly Southern Carpathian–derived sediments, to which Jurassic ophiolite detritus of the Apuseni Mts. was added during the second phase, while the siliciclastic material of the third phase represents mainly recycled material from the second phase. According to the detected diagnostic heavy-mineral associations, U-Pb age components and the positions of the potential source areas a set of provenance maps are presented.

Zircon U‐Pb‐He Double Dating of Modern Sands From the Inn River Catchment: Assessing Resolution and Potential in a Complex Orogenic Setting

“…DZ geochronology has a high throughput at relatively low costs, allowing for the analysis of a statistically relevant number of detrital crystals per sample. The application of U‐Pb dating of detrital rutile, titanite, monazite, and apatite, often in combination with zircon, are also currently emerging techniques (e.g., D. M. Chew et al., 2011; McAteer et al., 2010; Moecher et al., 2011; Obbágy et al., 2021; O’Sullivan et al., 2018; Small et al., 2013). In this way, the cooling in mid‐crustal levels can be dated that is especially relevant in case of orogenic belts having no or subordinate syn‐collisional magmatic activity like the Alps (e.g., Mark et al., 2016).…”

Heavy mineral catalogue for the characterization and provenance of red sandstone macrolithic tools from Hódmezővásárhely-Gorzsa

“…Árgyelán & Császár 1998;B. Árgyelán & Horváth 2002;Thamó-Bozsó et al 2006Obbágy 2017;Pozsgai et al 2017, Józsa et al 2020.…”