[3] The cutting exposes rocks dating to the Middle Jurassic Bathonian stage, between 168.3 and 167.1 million years ago.

It is described by Natural England as important for reconstructing the environment of deposition during the period, and correlating the White Limestone Formation in Oxfordshire and the East Midlands.

The ground proved to be an unstable combination of limestone, clay, and shale and the construction work suffered problems with water ingress.

[5][6] The overbridges have all been rebuilt but the aqueduct, in cast iron and supported on stone piers, is original and is now a Grade II listed building.

[8] The railway initially bypassed Northampton, despite it being a large town, partly because reaching its location on the River Nene would require a steeper gradient than 1:330; Stephenson instead chose to take the line through Roade and Blisworth to Weedon Bec (via Stowe Hill Tunnel and Weedon Viaduct) and cross the Nene there.