NC Greenland NG1: Three-dimensional stratigraphic Horizon in the Northern Central Greenland ice sheet (13.8 ka)@en

The NG1 3D horizon is located in northern central Greenland and covers an area of approximately 690 x 55 km and reaches almost from the eastern to the western outlet systems. The age of NG1 is 13.8 ± 1.0 ka (thousand years). NG1 extends in the east into the NEGIS trunk and shows in this area similar short-wavelength folds, which are observed in the NEGIS shear margins. Furthermore, NG1 resembles several cylindrical upright folds in the eastern and western edges of the horizons. The fold axes of the cylindrical folds in the west trend approximately west, whereas the trend of the cylindrical folds in the east trend north. In the central-eastern area, we find a large bump in the bed topography due to the paleofluvial mega-canyon, which is imprinted in the 3D horizons mimicking this bed depression. In the central-west, we find cylindrical upright folds trending in two different directions (north and north-west).NG1 3D层位（3D horizon）位于格陵兰中北部，面积约690×55千米，几乎贯通东西两侧的冰流出口系统。其形成年代为13.8±1.0 ka（千年）。NG1向东延伸至NEGIS主干（Northeast Greenland Ice Stream, NEGIS），该区域可见与NEGIS剪切边际（shear margins）中观测到的同类短波褶皱。此外，NG1层位的东西边缘发育若干直立圆柱状褶皱：西部的圆柱状褶皱轴迹（fold axes）大致呈西向，而东部的圆柱状褶皱轴迹则呈北向。在中东部区域，冰床地形（bed topography）因古河流巨型峡谷（paleofluvial mega-canyon）存在一处大型隆起，该3D层位中亦复刻了对应这一冰床凹陷的构造印记。中西部区域则发育两组走向分别为北向与北西向的直立圆柱状褶皱。