Roca dels Bous (archaeological site) interesting archaeological site indeed. Furthermore, it is to be noted that the samples used for the 14C AMS dating were obtained from deep strata at the site. The oldest Neanderthal sites known in the nearby areas date back to around 40,000 BP. The first settlements attributed to “anatomically modern” Homo sapiens sapiens in Northern Spain are dated around 39,000-38,000 BP. All this would suggest that Neanderthals could have persisted in this particular area longer than previously believed, preceding the arrival of the first Homo sapiens to the area. Research work began in 1988. This wide period of time has contributed
Isotope 40 different species referred to as "radioelements" (i.e. radioactive elements) between uranium and lead, although the periodic table only allowed for 11 elements from uranium to lead. Several attempts to separate these new radioelements chemically had failed. For example, Soddy had shown in 1910 that mesothorium (later shown to be Ra), radium (Ra, the longest-lived isotope), and thorium X (Ra) are impossible to separate. Attempts to place the radioelements in the periodic table led Soddy and Kazimierz Fajans independently to propose their radioactive displacement law in 1913, to the effect that alpha decay produced an element two places to the