Amber and certain similar substances are found to a limited extent at several localities in the United States, as in the greensand of New Jersey, but they have little or no economic value.
The Cambridgeshire coprolites are either amorphous or finger-shaped; the coprolites from the Greensand are of a black or dark-brown colour; while those from the Gault are greenish-white on the surface, brownish-black internally.
They are found in the Lower Greensand, or Upper Neocomian series, in the Atherfield Clay at Stopham, near Pulborough; occasionally at the junction of the Hythe and Sandgate beds; and in the Folkeston beds, at Farnham.
But in 1858 were discerned in the Upper Greensand of Cambridgeshire remains which are now known as Enaliornis.
The Maltese Islands consist largely of Tertiary Limestone, with somewhat variable beds of Crystalline Sandstone, Greensand and Marl or Blue Clay.