Cluster	Na2O t	MgO t	Al2O3 t	SiO2 t	P2O5 t	SO3 t	Cl t	K2O t	CaO t	TiO2 t	Cr2O3 t	MnO t	FeO t	Ni t	Zn t	Br t	max t	max chem	min t	min chem
	1	0.085	0.194	-0.173	-0.154	-0.295	-0.395	0.888	0.535	-0.110	-0.037	0.563	-0.024	0.791	-0.071	0.293	0.500	0.888	Cl	-0.395	SO3
	2	0.015	-1.307	-0.144	1.877	0.381	-0.435	-0.614	0.135	-0.669	0.732	0.024	-0.398	-1.154	-0.165	0.386	0.140	1.877	SiO2	-1.307	MgO
	3	2.580	-1.119	1.945	0.704	-0.296	-0.699	-0.113	1.983	-0.023	-0.546	-1.080	-0.356	-0.969	-0.983	-0.171	-0.440	2.580	Na2O	-1.119	MgO
	4	-0.693	-0.093	-0.736	-0.734	-0.053	1.336	0.076	-0.141	-0.213	-0.336	-0.523	-0.137	-0.114	-0.007	-0.199	-0.150	1.336	SO3	-0.736	Al2O3
+2σ	5	-0.598	0.531	-0.732	-0.665	-0.521	-0.446	-0.518	-0.548	-0.403	-0.796	0.438	-0.115	2.553	0.693	-0.375	-0.438	2.553	FeO	-0.796	TiO2
+1σ	6	0.043	-0.069	0.312	0.182	0.033	-0.280	0.083	-0.207	0.097	0.273	-0.273	-0.012	-0.044	-0.014	-0.172	-0.224	0.312	Al2O3	-0.280	SO3
	7	-0.266	0.897	-0.310	0.094	-0.207	-0.101	-0.462	-0.003	-0.675	-0.365	0.407	-0.099	0.120	5.656	0.938	-0.259	5.656	Ni	-0.675	CaO
-1σ	8	0.552	0.566	0.597	0.231	-0.382	-0.604	-0.837	-0.400	0.074	-0.527	0.348	-0.058	-0.020	-0.292	-0.436	-0.524	0.597	Al2O3	-0.837	Cl
-2σ	9	-1.164	0.671	-0.798	-0.511	0.262	-0.523	0.432	2.866	-0.322	0.483	0.342	0.547	1.570	-0.048	4.009	3.718	4.009	Zn	-1.164	Na2O
	10	1.591	-0.343	1.894	0.290	3.558	-0.633	-0.099	-0.105	0.227	3.609	-1.298	-0.389	-1.303	-0.746	-0.579	-0.096	3.609	TiO2	-1.303	FeO
	11	-1.666	3.692	-1.794	-1.420	-0.655	-0.607	5.111	3.472	-0.688	-0.112	0.081	9.587	1.000	1.082	8.691	6.465	9.587	MnO	-1.794	Al2O3
	12	0.039	1.180	-0.031	0.374	-0.147	-0.377	1.678	-0.495	-0.480	-0.359	-0.151	-0.261	-0.468	0.108	-0.259	0.909	1.678	Cl	-0.495	K2O
	13	-1.718	-0.092	-1.689	-2.097	0.455	3.063	-1.136	-0.852	-0.175	-1.334	0.262	1.364	0.132	0.272	-0.543	-0.202	3.063	SO3	-2.097	SiO2
	14	-1.090	-0.969	-1.661	-2.581	-0.512	2.414	0.497	-0.841	5.971	-1.805	-0.806	0.163	-1.600	-0.660	0.337	-0.230	5.971	CaO	-2.581	SiO2
	15	-0.078	0.135	0.191	-0.021	-0.334	-0.406	-0.542	-0.225	0.152	0.304	1.136	0.051	0.471	-0.113	-0.235	-0.343	1.136	Cr2O3	-0.542	Cl
Table of mean standardized relative abundances (t-scores) of oxides and elements measured by APXS on Mars rovers (Pathfinder/Sojourner, Spirit, Opportunity, and Curiosity) compared with averages for all 901 spectra
15 clusters created in PAST 3 using k-means clustering of oxide and element t-scores
C.M. Rodrigue, January 2017