A New Approach for Provenance Studies of Archaeological Finds: Inferences from Trace Elements in Carbonate Minerals of Alpine White Marbles by a Bench-to-Top μ-XRF Spectrometer

Table 5

Eigenvalues (in descending order) and extracted eigenvectors (PC1 and PC2 coefficients referring to the first 2 eigenvalues are reported in bold) belonging to the correlation matrix: PCA performed on 5 variables (𝛿¹⁸O, CaO, Fe, Sr, and Mn).

(a)  

Correlation Matrix
	𝛿^18O	CaO	Fe	Sr	Mn
𝛿^18O	1.000	−0.292	−0.122	−0.235	−0.665
CaO	−0.292	1.000	0.335	−0.098	0.384
Fe	−0.122	0.335	1.000	−0.418	0.224
Sr	−0.235	−0.098	−0.418	1.000	−0.236
Mn	−0.665	0.384	0.224	−0.236	1.000

(b)  

	Eigenvalue
	Eigenvalue	Variance%	Cumulative
1	2.098	41.95%	41.95%
2	1.408	28.16%	70.11%
3	0.747	14.94%	85.05%
4	0.570	11.41%	96.46%
5	0.177	3.54%	100.00%

(c)  

Eigenvector
Coef.	𝛿^18O	CaO	Fe	Sr	Mn
PC1	−0.477	0.473	0.400	−0.218	0.584
PC2	0.521	0.019	0.473	−0.69	−0.172