Photogrammetric mapping of fluvial channel sand-bodies in the Atane Formation at Paatuut, Nuussuaq, central West Greenland

Abstract

Upper Cretaceous deltaic sediments from the Atane Formation are well exposed in a series of steep-sided gullies at Paatuut on the south coast of Nuussuaq. The large exposures within the gullies allowed a large-scale sedimentological investigation of delta stratigraphy, sand-body geometry and fluvial style of the distributary channels. Multi-model photogrammetry was applied in several ways. Photogrammetric mapping of good exposures within the area produced accurate vertical sections up to 2 km long and 0.5 km high. A bed to bed stratigraphy of the delta cycles was established and the sand-bodies within each cycle correlated. The horizontal extent of the sand-bodies was subsequently mapped photogrammetrically using the already orientated stereomodels. This mapping allowed a three-dimensional interpretation of the sand-body geometry. Cross-sections of the sand-bodies and the sand-body geometry formed the basis for the interpretation of the fluvial style of the distributary channels. Using the three-dimensional photogrammetric data the width/thickness ratio, the sinuosity and the shape of sand-bodies as well as of palaeochannels are described. These data are useful when modelling the reservoir geometry in deltaic hydrocarbon fields.