*Article* **Potential for Mineral Carbonation of CO2 in Pleistocene Basaltic Rocks in Volos Region (Central Greece)**

**Nikolaos Koukouzas 1,\*, Petros Koutsovitis 2, Pavlos Tyrologou 1, Christos Karkalis 1,3 and Apostolos Arvanitis <sup>4</sup>**


Received: 30 August 2019; Accepted: 8 October 2019; Published: 11 October 2019

**Abstract:** Pleistocene alkaline basaltic lavas crop out in the region of Volos at the localities of Microthives and Porphyrio. Results from detailed petrographic study show porphyritic textures with varying porosity between 15% and 23%. Data from deep and shallow water samples were analysed and belong to the Ca-Mg-Na-HCO3-Cl and the Ca-Mg-HCO3 hydrochemical types. Irrigation wells have provided groundwater temperatures reaching up to ~30 ◦C. Water samples obtained from depths ranging between 170 and 250 m. The enhanced temperature of the groundwater is provided by a recent-inactive magmatic heating source. Comparable temperatures are also recorded in adjacent regions in which basalts of similar composition and age crop out. Estimations based on our findings indicate that basaltic rocks from the region of Volos have the appropriate physicochemical properties for the implementation of a financially feasible CO2 capture and storage scenario. Their silica-undersaturated alkaline composition, the abundance of Ca-bearing minerals, low alteration grade, and high porosity provide significant advantages for CO2 mineral carbonation. Preliminary calculations suggest that potential pilot projects at the Microthives and Porphyrio basaltic formations can store 64,800 and 21,600 tons of CO2, respectively.

**Keywords:** basalts; carbonation; CO2 storage; hydrochemistry; regional heat flow
