The Matrix of the first two components in the Principal Component’s Analysis.

<p>The Matrix of the first two components in the Principal Component’s Analysis.</p

Mean summed component 1 and 2 values for different core types.

<p>Note that unidirectional and multiplatform technologies tend to have positive values, while radial technologies tend to have negative values.</p

Levallois cores from Gibraltar.

<p>A: Gorham’s Cave Waechter’s Layer P, recurrent unidirectional Levallois on chert. B: Gorham’s Cave Sands and Stony Lenses member GOR98 925, recurrent bidirectional Levallois on chert. C: Gorham’s Cave Waechter Layer M, recurrent centripetal Levallois on chert. D: Ibex Cave 046, recurrent unidirectional Levallois on jasper.</p

Two Mousterian cores from Gibraltar.

<p>A: facetted centripetal disc core on rounded dark red chert from Gorham’s Cave Lower Bioturbated Sands member GOR95 200; B: quartzite unifacial cobble core from Gorham’s Cave Layer IV GOR00 72.</p

Lithic artefacts from Beefsteak Cave.

<p>Data from Giles et al., <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065185#pone.0065185-Giles1" target="_blank">[14]</a>.</p

Breakdown of raw materials in the Mousterian layers of Gorham’s Cave.

<p>Quartzite includes quartzitic sandstone and silcrete. Data from Barton & Jennings <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065185#pone.0065185-Barton4" target="_blank">[15]</a> and Pacheco et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0065185#pone.0065185-Giles1" target="_blank">[14]</a>.</p

Two Levallois cores in red chert from Ibex Cave.

<p>A: recurrent bidirectional Levallois IBE 046. B: recurrent centripetal Levallois, IBE 053.</p

The location of sites mentioned in the text.

<p>Inset: the location of Gibraltar on the Iberian Peninsula.</p

Breakdown of raw material type for formal and informal cores from Gibraltar.

<p>For the Chi-square test limestone and quartzite cores were lumped together and Yates’ continuity correction was applied.</p

Mean summed component 1 and 2 values for different raw materials.

<p>Note that coarser grained materials tend to have higher values and finer grained materials tend to lower negative values.</p