Table 1. Mn and Fe areal densities and Mn/Fe ratios from pXRF measurements on intact rock varnish and petroglyphs at the study sites [Avg.: Arithmetic average, S.D.: Standard deviation].

Site	N	DMn		DFe		Mn/Fe
		[µg cm-2]		[µg cm-2]
		Avg.	S.D.	Avg.	S.D.	Avg.	S.D.
Intact varnish
Celebration Park	69	430	190	---	---	---	---
Map Rock	27	200	160	---	---	---	---
Old flow surface at MR	5	420	100	580	240	0.81	0.32
Legend Rock	66	81	41	240	140	0.52a	0.29a
Petroglyph Canyon	35	76	49	410	370	0.41a	0.16a
Craters of the Moon	25	52	25	200	170	0.25	0.24
Petroglyphs
Celebration Park	73	135	97	---	---	---	---
Map Rock	29	25	22	---	---	---	---
Legend Rock	68	32	23	180	120	0.32a	0.29a
Petroglyph Canyon	34	13	10	140	60	0.14a	0.07a

^a) outliers with Mn/Fe<0.05 removed