Between 13,000 and 11,000 years ago, Lake Erie was divided into two distinct basins by the Norfolk Moraine, which intercepted the north shore of the lake at the base of the present-day Long Point (Coakley 1985). With increasing water levels and isostatic lift, Lake Erie began draining eastward through the Niagara River about 4,000 years ago. Lake Erie lies on a WSW-ENE plain, and the prevailing wind direction and currents are along this axis. This resulted in the movement of glacial till eastward along the north shore of the lake, through littoral drift. It was at this time, 4,000 years ago, that the Long Point spit started to form, presumably as shallow waters created by the Norfolk moraine retarded littoral drift laden with suspended clay, sand, and gravel near the base of the present-day Long Point, thereby causing the material to be deposited (Wood 1951; Sly and Lewis 1972; Liard 1975). The formation and evolution of the spit has likely been a more or less continuous process ever since. Spit formation has also been influenced by the tendency of shore processes to straighten shorelines by forming spits and bars across bays, which gradually close them with a barrier beach of sediment (Laidler 1944). This can be attributed to the fact that, when a shoreline curves away from the direction of longshore energy or drift, longshore current is turned away from shore and into the lake, resulting in sediment deposition out into the water body across the irregularity.
The principal source of sedimentary material that continues to form Long Point today is a 60 km section of unvegetated erosion-prone lakeshore bluffs, catchment slopes and stream banks (primarily glacial sediments) extending west from the base of the spit (Francis et al. 1985) (Figure 2.1). At an average of 1.6 m/yr of shoreline, these glacial sediments have one of the highest erosion rates in the Great Lakes basin (Gelinas 1974). These glacial deposits extend from 10 m below to 40 m above lake level, and the bluffs west of Clear Creek have retreated up to 16 km in the past 10 000 years (Quigley and Tutt 1968; Bradstreet 1977). It has been estimated that 62,000 cubic meters of sediment is transported annually via littoral drift from west to east along the Long Point spit, while 46,000 cubic meters is transported from east to west past Turkey Point (Figure 2.1) (Philpott Ltd. 1989). However, an unknown proportion of that sediment is deposited into Long Point Bay as well as into deep water sediment sinks, and consequently, does not contribute to the formation of the Long Point spit (Stenson 1993). It was estimated in 1975 that Long Point was 85 kmē in area and consisted of 5.5 billion cubic metres of sand (Liard 1975).