Spits and their sequential development were studied by a series of 27 wavetank experiments.

Waves with known parameters were directed obliquely against a erodible headland, inducing shore drift. In all cases a spit and platform developed at the down-drift end of the headland. Similar features are present along modern coasts.

Slopes of the resultant beaches and length and width of the spit-platform structure were measured. Statistical methods were employed in finding the relationship between beach slope and wave parameters.

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A spit-platform concept was derived from experimental results and statistically substantiated:

1. The platform is an embankment elevated above the shelf, but below mean low-water level.

The spit is a ridge on the upper surface of the platform, partially emergent above mean high water.

The spit-platform structure is a large-scale primary sedimentary structure formed principally by beach drifting.

Development of a spit is dependent on the presence of a platform.

2. Growth of spit and platform is inversely related and occurs in alternating cycles.

Slope and headland beach is a function of grain size of beach material, wave steepness, mass transport, wave energy, wave height and wave length.

Slope of spit-platform beach is a function of grain size of beach material, wave energy, depth ratio, wave height and wave length.

3. With time, spit-platform beach slope increases until it equals headland beach slope. This change advances progressively along the spit-platform structure extending the headland beach.

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