Complex sentence: Collieries at Ellistown, Nailstone, Ibstock, Moira, Gresley, Swadlincote, Woodville, Netherseal and Bardon provided mainly coal initially but more recently roadstone, gravel and granite have become the norm.
Split into simpler sentences: Collieries at Ellistown, Nailstone, Ibstock, Moira, Gresley, Swadlincote, Woodville, Netherseal and Bardon provided mainly coal. More recently roadstone, gravel and granite have become the norm.