Bland and Altman plot showing the “line of equality”: the line on which the values would lie if Sr levels measured in premolar enamel (pm) exactly equaled the levels measured in the otic capsule of the petrous portion (pp).

<p>The values cluster around the line of equality, thus no systematic bias is indicated. The horizontal and vertical lines indicate the upper limit for strontium levels in Denmark (0.711; the lower level is 0.708). The two individuals in the upper right quadrant are thus non-Danish, while the individuals in the lower quadrant can be assumed to be Danish. The individual in the upper left quadrant could be either, depending on whether the enamel or the petrosal value is used. The cremated individual from Rishøjen (K442/RH U2) is indicated by an arrow.</p

Plot of Sr isotope ratios for the cremated individuals.

<p>Error bars correspond to +/−2SD of the premolar enamel-petrous portion difference (0.001076) derived from the data in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0101603#pone-0101603-g004" target="_blank">Figure 4</a>. The individuals from the cremation graves KH HF, KH JE and OB QE can therefore be assumed to be non-local.</p

The petrous portion of the human temporal bone (<i>pars petrosa</i>) retains its morphology after cremation or similar intensive heat exposure, being one of the last bones of the body to burn.

<p>Here, a typical cremated petrous portion as found in cremated human remains is shown.</p

Strontium isotope ratios (87Sr/86Sr) of petrous portions and dental enamel from Tjærby (non-cremated) and Rishøj (cremated) and of residues and leachates of petrous portions from crematin grave sites in the Fraugde region.

<p>Strontium isotope ratios (87Sr/86Sr) of petrous portions and dental enamel from Tjærby (non-cremated) and Rishøj (cremated) and of residues and leachates of petrous portions from crematin grave sites in the Fraugde region.</p

The otic capsule surrounding the vestibulo-cochlear organs of the inner ear is the one of the densest bone tissues in the human body and does not remodel after the age of 2.

<p>Here, the bone tissues in the inner ear are illustrated in a cross section of a petrous portion. The limit of the otic capsule is indicated by the arrow.</p

Bland and Altman plot showing the limits of agreement.

<p>The difference between the enamel and the petrosal values (var) are plotted against the mean value of the enamel and petrosal values (st mean). Again, no bias is seen. The mean difference is 0.00007 (indicated by solid horizontal line) and +/−2SD (+/−0.001076) is indicated by the horizontal dotted lines. No values lie outside these limits, indicating that measuring either the premolar enamel or the petrosal Sr isotopic ratios will give the other value within 0.001075 (2SD).</p

Sagittal CT view of the skull, showing the development state of the teeth.

<p>Sagittal CT view of the skull, showing the development state of the teeth.</p

Strontium isotope ratios of tooth enamel and hair from the Skrydstrup Woman.

<p>Strontium isotope ratios of tooth enamel and hair from the Skrydstrup Woman.</p

A close up image of the Skrydstrup Woman’s facial remains (Photo: Lennart Larsen, National Museum of Denmark).

<p>A close up image of the Skrydstrup Woman’s facial remains (Photo: Lennart Larsen, National Museum of Denmark).</p

Strontium isotope diagram depicting the results of the human remains of the Skrydtsrup Woman (hair segments and tooth enamel).

<p>The area between the horizontal green dotted lines indicate the bioavailable strontium isotopic range of the area of Skrydstrup calculated from the values in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178834#pone.0178834.t002" target="_blank">Table 2</a>. The area between the horizontal green solid lines indicate the bioavailable strontium isotopic range for territorial Denmark.</p