{'fraction_non_alphanumeric': 0.030583873957367932, 'fraction_numerical': 0.009731232622798888, 'mean_word_length': 4.997222222222222, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 1, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Volcanic ash-fall placers: a new type of REE deposit?

The Çanakli deposit, a part of the Aksu Diamas project in western Turkey, owned by AMR Mineral Metal Inc., has an inferred resource of 494 million tonnes at 0.07% TREO (total rare earth oxide) in unconsolidated sediments at surface. This deposit is a potentially important source of European rare earth element (REE) supply. Alternative supplies of critical minerals are being intensely investigated across the globe, with a focus on by-product or added-value minerals such as REE, for example from alumina processing (Deady et al. 2016) and phosphate production (Emsbo et al. 2015). The deposit is hosted in Quaternary sediments situated in a basin in Mesozoic limestone. REE-bearing heavy minerals occur in lenses and are disseminated in channelised debris flows. There is no obvious source of these minerals within the basin catchment. However, the alkaline Gölcük volcano is located approximately 20 km north-west of the deposit and repeatedly erupted during the Plio-Quaternary (Platevoet et al. 2014). The related ash falls represent a potential source for the REE-bearing minerals. The source of the REE is being investigated by the British Geological Survey through the EU-funded FP7 project EURARE (www. eurare.eu). Scanning electron microscopy (SEM) analysis of heavy mineral concentrates has confirmed the presence of REE-bearing minerals such as allanite and chevkinite. These minerals are also found in samples of pyroclastic material from the Gölcük alkaline volcano. Chemical fingerprinting of both major minerals, such as magnetite and pyroxene, and the minor REE-bearing minerals, using a combination of LA-ICP-MS and quantitative SEM, is used to investigate the potential for Gölcük as the source. If the Çanakli REE deposit resulted solely from the accumulation of air-fall tuff-borne minerals in a topographic depression, without additional concentration processes, then this is a new type of deposit. Improved understanding of the origin of this deposit type would aid identification of additional REE resources in similar settings globally, including those at Monte Vulture, Italy.