The Homoródszentpál Kerek-tó (Round Lake) is a Holocene peat bog deposition in the western foothill area of the Eastern Carpathians in Romania. This paper presents the result of geochemical analysis of the peat bog at Homoródszentpál Kerek-tó (Round Lake) and compared previous sedimentological and pollen analytical data.. The elemental composition was examined by XRF and six elements (Fe, Mn, Ca, Mg, Na, K) were analysed in water extraction method using atomic absorption spectrometry AAS. The elemental distribution describes the paleoenvironmental and palaeohydrological changes and indicates the different evolution stages of the bog system. Through our results, water-soluble Fe and Mn could be linked to the mineral component of the sediment while the Ca shows biophilic origin. The Na, K and Mg show affinity both the organic and inorganic material. Total element content was determined by handheld XRF (X-ray fluorescence spectroscopy). We use major and trace elements (Fe, Mn, Ti, Si, Zr, P, S)to correlate the sediment matter and apply Fe/Ti, Mn/Ti and Mn/Fe ratios to interpret as indicators of changes in in situ redox conditions of the bog. Based on the sedimentation rate, we distinguished 3 sections from the Middle Neolithic to the Migration Period, in which the influence of human cultures gradually emerged around the lake
