Volcanogenic Sandstones as Areomagnetic Markers on Judge Daly Promontory and in Robeson Channel, Northern Nares Strait

摘要: Aeromagnetic data were collected over the Hall Basin and adjacentcoastal land areas of northern Nares Strait during 2001 Canadian-GermanNares Expedition to provide an improved onshore-offshore linkage ofgeological structures related Late Cretaceous Early PaleogeneEurekan Orogeny. The total field magnetic anomaly are characterized bybroad long-wavelength anomalies compatible with thick sequences nonmagneticSilurian Devonian carbonate facies. On Greenland side ofthe survey block, generally positive, possiblyreflecting characteristics deeply buried crystalline rocks thePaleozoic platform. Over Ellesmere Island, low inamplitude, suggesting a different basement composition from Greenland. Twolinear northeast oriented positive observed on JudgeDaly Promontory. One extends along south coast between Carl Ritter Bayand mouth Daly River. second occurs end thepeninsula offshore Cape Baird Robeson Channel. Fromfield samples, this has been correlated thrust fault-boundedTertiary sedimentary basins, which have increased susceptibility valuescaused by content basalt clasts. fault, bounding southernedge these basins mapped as continuous feature across Promontory, however, absence islikely result complete erosion wedge. amplitudeof decreases Bay, decreasedcontent A small at 81.3 °N, 66.8 °W alsocoincides isolated outcrop Tertiary rocks, associated differentfault. extension indicates continuity northeastward Channel LincolnSea. It does not follow simple line, but appears be broken insubsections slightly differing directions. Similar offsets in aparallel crosscutting NWSEtrending faults. onshore geological observationssuggest that Wegener Fault is strike-slip complexsystem faults chain blocks basins.