4 Uni ver sity of Zagreb, Fac ulty of Min ing, Ge ol ogy and Pe tro leum En gi neer ing, Pierottijeva 6, Zagreb, CroatiaHusanoviae, E., Novak, K., Malviae, T., Novak Zelenika, K., Veliae., J., 2015. Pros pects for CO 2 car bon ation and stor age in Upper Mio cene sand stone of Sava De pres sion, Croatia. Geo log i cal Quar terly, 59 (1): 91-104, doi: 10.7306/gq.1215Up per Mio cene sand stones in the Sava De pres sion (North ern Croatia) are po ten tial tar gets for car bon di ox ide (CO 2 )-based en hanced oil re cov ery (EOR) pro cesses or min eral car bon ation with res er voir brine. In gen eral, sand stone li thol ogy, even rich with alu mi no sili cate min er als, is not the most fa vour able rock me dium for ef fi cient se ques tra tion of CO 2 in min er als. How ever, CO 2 is nat u rally se ques tered in min er als when CO 2 is in jected into sand stone res er voirs and sub dued to car bonation. The timescale of such se ques tra tion is on the or der of 10 4 -10 5 years. Up per Mio cene sand stones in the Sava De pression could in cor po rate up to 25% of alu mi no sili cate min er als (10% K-feld spars) and up to 20% dolomites and of ten lat er ally tran si tion be tween pelitic and psam mit ic lithofacies, rich in clay min er als (15% micas). To tal vol umes are ap prox i mately 107 and 62 mil lion m 3 (ap prox i mately 268 and 155 mil lion t of rocks), re spec tively for the po ten tial in jec tion res er voirs in the Ivaniae Field. Oil sat u ra tion in the in jec tion in ter vals is es ti mated to be ap prox i mately 14.8 and 4.1 mil lion m 3 re spec tively. Geo chemi cal anal o gies and min er al ogy can be used to sup port pre dic tions for the low per cent ages of in jected CO 2 that may be stored dur ing car bon ation and form sec ond ary min er als.