Bulletin of Canadian Petroleum Geology, Vol.53, No.2, 189-199, 2005
Tectonic deformation and its sedimentary consequences during deposition of the Lower Cretaceous Chaswood Formation, Elmsvale basin, Nova Scotia
The Lower Cretaceous fluvial Chaswood Formation is the proximal onshore equivalent of deltaic deposits of the Missisauga and lower Logan Canyon formations of the offshore Scotian basin. Detailed description of boreholes and analysis of published seismic-reflection profiles from the Elmsvale basin show that syn-sedimentary deformation in the Chaswood Formation resulted in onlap and unconformities. Deformation was concentrated in a syncline bounded on its northwestern side by the Rutherford Road fault. The deformation was probably synchronous along the 15 km length of the fault and might thus provide a basis for stratigraphic correlation. Closely spaced boreholes show that lignite horizons are not widespread stratigraphic markers and that major sandstone units are of more value for correlation. A new correlation from the type section of the Chaswood Formation northeastward along the Elmsvale basin and northwestward to Shubenacadie is proposed. A landslide deposit up to 5 m thick consisting of tilted mudstone blocks can be correlated for 4 km along strike in boreholes along the northern flank of the syncline, providing further evidence for syn-sedimentary deformation, which is a local manifestation of widespread Cretaceous deformation in Atlantic Canada.