IODP SEDIS - Thesaurus -

Downtonian
BT	Chronostratigraphic Units
	.Phanerozoic
	..Paleozoic
	...Downtonian
RT	Silurian
	Devonian
	Lower Devonian
	Upper Silurian
	Old Red Sandstone
SN	In Old Red Sandstone, England. Uppermost Silurian or lowermost Devonian; Schmidt, l960--lowermost Gedinnian (Lower Devonian).