This thesis on organic matter composition of polygon-patterned tundra in the Thule are in Northwestern Greenland is based on analysis of a permafrost core obtained during an expedition of the Danish NOW project in August 2015. In the ice-sheet marginal coastal area in NW Greenland, Holocene ice-wedge polygons developed under permafrost conditions. The ice-wedge growth in accumulating peats linked to the presence of local sea bird colonies is the topic of this thesis. It was found that in the study area there is a high presence of nitrogen within the soil as well as very high ice content, linking to the syngenetic freezing and permafrost aggradation. The samples obtained from the core were processed in the laboratory and analyzed for ice content, age of the core, carbon and nitrogen content, threshold of organic carbon and isotopic abundance ratios of total organic carbon and total nitrogen. Analytical results show a quite steady content of all of these features with some exceptions at different depths for each parameter. It was also found that there had to be a change in permafrost aggradation and peat accumulation approx. 3000 years BP (before present, meaning before 1950) as the accumulation rate drops at this point in time. The great impact of the bird colonies on this specific permafrost formation is reflected as the high nitrogen values indicate that the birds’ droppings were the original source of organic matter to decompose, allowing for vegetation growth and permafrost soil development. Temporary changes found in isotopic ratios within soil carbon may give a hint on bird colony evolution in the Thule area and the development towards the current state of the little auks’ colony momentary inhabiting the study area of GL-3.