Many thin sandstone units are graded, and locally display starved ripples with shapes and internal cross-laminations indicating the sense of current transport.

Scattered through the section are rounded pebbles up to 6 cm in diameter...which occur within thicker mudstone layers as well as on bedding planes demarcated by graded sandstones".

The probable depositional environment of the quarry strata, as envisaged by Rattigan (1967) and other workers, was a shallow periglacial lake which received sediment influxes via turbidity currents.

Low velocity traction currents modified the surface of these lake bed deposits, and ice-rafted pebbles (derived from moraines) were dropped into them at intervals from melting floes and icebergs.

Crowell and Frakes (1971) consider that this glaciation was of alpine type and took place at a (late Carboniferous) latitude of 45-50 degree S.[1] Perhaps the most spectacular features exposed in the quarry are localised contorted beds interstratified between apparently undisturbed layers and laterally continuous with undeformed planar strata.

However Fairbridge (1947), who reviewed in detail seven possible explanations of the origin of the contortions, concluded that gravitational slumping – probably due to release of water from impounded glacial lakes, or over loading, was the most likely cause.

[1] Rattigan (1967) described a variety of other deformational phenomena from these strata, including lode and flow structures, intraformational fracturing, penecontemporaneous sand intrusions, and non-hydrodynamic ripple forms.

The explanation on the signboard reflects the view of early workers in the area that the alternation of coarse and fine bands was attributable to seasonal deposition, and that the approximate time taken for accumulation could be established by counting pairs of layers.

The exceptional preservation of the Seaham varves (considering their age) prompted the Swedish scientist Carl Caldenius to investigate their potential use in geochronology (a section was actually measured for this purpose at Paterson nearby.

1971) have been more cautious about use of the term varves in reference to the Seaham strata, as the rhythmic bedding exhibited has not been proven to follow an annual cycle.