Sediment transport investigation in a karst aquifer hypothesizes controls on internal versus external sediment origin and saturation impact on hysteresis

•Internal sediment transport occurs when the karst aquifer is fully saturated a priori.•External sediment is common transport for karst for 80% of storm events studied.•Timing of sediment pulses and hysteresis depend on antecedent water in the aquifer.•Counter-clockwise patterns of sediment hysteresis are common results for karst.•Surface stream interpretations of hysteresis patterns are not valid for karst springs.