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Summary: The ability to quantify and predict discharge and nutrient export patterns from agricultural catchments is confounded by the effects of antecedent hydrologic conditions (AHC) in upland areas. This paper examines the impacts of AHC on storm hydrologic response and nutrient export for 59 events measured over a 2-year period (year-round). Event-related discharge and nutrient (nitrate, phosphate) export were highly temporally variable. Runoff ratios ranged from 0 to 0.99 over the study period, with the lowest median runoff ratios being observed during the summer and early autumn period and the highest median runoff ratios being observed in March following snowmelt. Runoff ratios were positively correlated with AHC indices such as pre-event stream discharge (1-day) and antecedent (14-day) stream discharge although strong predictive relationships could not be generated (p >0.01). In general, runoff ratios increased throughout successive events as AHC became wetter; however trends observed among suites of events with having similar AHC did not produce similar patterns of hydrologic or nutrient export response, which clearly demonstrates the non-linear responses to variable AHC in the watershed. Basin nitrate (), total phosphorus (TP) and soluble reactive phosphorus (SRP) export varied with AHC in the basin, and flow-weighted mean nutrient concentrations (FWMC) ranged considerably (mean, range: 8, 1–18mgL−1 NO3–N; 18, 3–161μgL−1 SRP; 75, 15–274μgL−1 TP). Nutrient export increased with successive events when the basin was on a wetting trend, but decreased with successive events when the basin was on an overall drying trend. These patterns were linked to peak water table position during events and timing of fertilizer application. Overall, this work demonstrates that watershed hydrologic and nutrient export responses to precipitation and AHC are complex and cannot be predicted using simple linear relationships. This study also demonstrates the need to collect larger data sets when examining relationships between watershed hydrologic and nutrient export response. [Copyright &y& Elsevier]

Abstract: The geometry of a foreland basin is mainly a product of a complex dynamic balance between the orogenic loading, erosion and sedimentation, and lithospheric flexural response. To improve our understanding of the relationships between these processes and the foreland basin stratigraphy, a detailed stratigraphic and sedimentologic study of the Middle–Late Cenomanian Belle Fourche Formation in the subsurface of southern Alberta is presented in this paper. The Middle Cenomanian lower Belle Fourche Formation and the Late Cenomanian upper Belle Fourche Formation were deposited in underfilled conditions, showing prominent forebulge zones. It is demonstrated that during the Late Cenomanian with the cratonward migration of the uplifting forebulge zones, the axes of backbulge zones also migrated cratonwards and a wide uplifted forebulge zone was formed. During the last stage of the underfilled condition, the foreland basin had a relatively flat topography and fine sands were deposited along the flank of the uplifting forebulge. A qualitative model for the migration and stratigraphic fill of an underfilled foreland basin is proposed. This model provides a qualitative pattern of the cratonward migration of the forebulge zone and backbulge zone within a several-million-year tectonically-driven cycle. It is suggested that during the early underfilled period, the basin geometry is mainly controlled by the orogenic loading, and a prominent forebulge zone with an approximately fixed location is formed. During the late underfilled period, the basin geometry is mainly controlled by the sediment loading, and the forebulge zone move very fast along with the rapid cratonward shift of the sediment loading center. Over a longer time period and between different tectonically-driven cycles, along with the cratonward propagation of the thrusting wedge, the orogenic loading plays a more important role than the sediment loading for the migration of the forebulge zone. [Copyright &y& Elsevier]