Surrounding Burnley, Nelson, Blackburn and Accrington, it is separated from the larger southern part by an area of Millstone Grit that forms the Rossendale anticline.
Occupying a syncline, it stretches from Blackburn past Colne to the Yorkshire border where its eastern flank is the Pennine anticline.
The Rossendale anticline, an area of Millstone Grit, separates it from the larger southern part of the coalfield.
[1] Occupying a syncline bounded by the Pendle monocline to the north, the coalfield stretches from Blackburn, eastwards past Colne to the Pennine anticline on the border with Yorkshire.
The intersecting Theiveley Lead Mine and nearby Hameldon Faults are some of a smaller number of easterly aligned structures which separate the coalfield from the horizontal strata of Rossendale.
[10] The arrival of the Leeds and Liverpool Canal was a catalyst for industrialisation as was the coming of the Lancashire and Yorkshire Railway line through Burnley to Colne in 1848.