Geochemical and mineralogical characteristics of Fe–Ni- and bauxitic-laterite deposits of Greece

Geological, Mineralogical and Geochemical Aspects for Critical and Rare Metals in Greece

“…These Fe-Ni laterites, which also contain cobalt, are mainly allochthonous and are associated with Mesozoic ophiolites. They are intercalated in Mesozoic limestones and show multistage transportation and re-deposition, responsible for a post-sedimentary redistribution of metals, resulting in Mn, Co, Ni-rich zones [20,21]. Chemical composition of different laterite occurrences in Greece shows that cobalt is mainly concentrated in the Fe-Ni-rich zones, demonstrating elevated contents which reach 0.10% in Paleochori, Grevena, 0.14% in Vermio, 0.16% in Kastoria and 0.22% in Lokris [20][21][22].…”

On the Origin of Bastnaesite-(La,Nd,Y) in the Nissi (Patitira) Bauxite Laterite Deposit, Lokris, Greece

“…Geochemical characteristics of the Ni-laterite deposits in Lokris have been studied for major and trace elements, including rare earth elements and chemistry of minerals in those deposits [1,[3][4][5][6][7][8][9]. At the Nissi deposits, a strong enrichment of light rare-earth elements (LREE) relative to heavy rare-earth elements (HREE), due to the presence of the authigenic hydroxylbastnaesite-(Nd) minerals, has already been described [8,10].…”

“…A peculiarity of the Nissi (Patitira) deposit lying on Triassic-Jurassic limestone is the association of bauxite laterite ore towards its upper part, with Ni-rich bauxite laterite ore characterized by an epigenetic enrichment in Ni,Co,Mn (asbolane), Al-Ni-silicates and REE at the lowest part of the deposit, close to its contact with the basement limestone, and within limestone itself (Figures 2 and 3; [3,6,9,18]). In addition, the upper transition zone between Cretaceous limestone and the Nissi laterite deposit is characterized by an association of framboidal pyrite with organic matter; the zone below the laterite ore and the carbonate basement is characterized by the occurrence of bacteriomorphic goethite [16].…”

“…Besides, the XRD pattern shows reflections assigned to any of the following minerals: bastnaesite-La [La(CO 3 display commonly acicular or needle-shaped morphology, ranging in length from a few tens of nm to several microns. Intergrowths of takovite-Al-Ni-silicate are commonly found as successive thin (a few to tens of µm) layers, composed of fine fibrous crystals of nm to a few µm (Figure 7D,E F).…”

“…The laterite ores at Aghios Ioannis and Nissi area deposits have been eroded, transported, and deposited onto karstified Triassic-Jurassic limestones and are conformably overlain by Upper Cretaceous limestones ( Figure 1). The Nissi area deposits are comprised of a series of lenses, that may occur either as isolated typical Fe-Ni-laterite or bauxite laterite ores or as an association of Fe-Ni ore at the lowest part of the deposit, followed by bauxite laterite towards its upper part ( [3] and references therein)-such as the Patitira deposit (located at the eastern part of the Nissi area) (Figure 1). …”