Alluvial sediments: a tool for lanthanide exploration and for improving forecasts of critical resources for high-tech applications.
Project code: PN 23 39 02 04
Project Manager: Dr. Adriana ION
The project proposes a detailed exploration (geochemical, mineralogical, and radiometric) of alluvial sediments within the river basins of the Carpathian region. The aim is to precisely delineate target areas that may serve as potential sources of lanthanides and associated radioactive elements, as well as to evaluate the exploitability of these alluvial sediments as a resource for critical raw materials. Through systematic sampling—conducted at high densities to ensure representativeness regarding the underlying geological formations and local topographic and hydrological conditions—and subsequent physicochemical, mineralogical, radiometric, and statistical analysis, the project seeks to create an accurate picture of the distribution of lanthanides and associated radioactive elements in alluvial sediments. This approach enables the identification and assessment of geogenic sources and the natural geochemical factors governing their fractionation, migration, and subsequent concentration.
This study focuses on the detailed investigation of alluvial sediments in areas with a geological setting favorable for the accumulation of lanthanides and associated radioactive elements—specifically, Carpathian zones featuring occurrences of alkaline rocks, pegmatites, granites, gneisses, and crystalline schists, as well as the Southern Carpathians’ piedmont zone, which is characterized by massive deposits of clastic material. Accordingly, the Carpathian study areas have been selected as zones of potential interest based on the likelihood of containing exploitable-quality reserves, as follows: (i) the Ditrău Alkaline Massif zone (Eastern Carpathians); (ii) the upper drainage basins of the Jiu, Olt, and Argeș rivers (Southern Carpathians zone); (iii) the central zone of the Getic Piedmont, in an east-west cross-section; and (iv) the zone of alkaline rock occurrences in the Banat Mountains.
Objectives
- Conducting systematic sampling, highly accurate specialized analyses, and appropriate cartographic representations. Geochemical maps will detect primary and secondary geochemical halos, thereby contributing to the delineation of potential new mineralization as well as the comprehensive utilization of alluvial material.
- Obtaining additional information on the geochemical characteristics of lanthanides and radioactive elements from the uranium and thorium series within the source area–riverbed deposit system, with the potential to identify the specific factors and geochemical processes governing their fractionation, migration, and accumulation during longitudinal fluvial transport.
- Complex interpretation of acquired radiometric data (total gamma-ray intensity distribution and radon emanation) to highlight and delineate geological and tectonic mapping features, revealed by radioactivity contrasts between the geological formations present in the study areas.
- Environmental risk assessment in the context of heightened interest in monitoring radiation levels—specifically radon—and their implications for human health.
