Paleomagnetic dating is based on the fact that Mlf chat
The lacustrine deposits infilling the intramontane Guadix-Baza Basin, in the Betic Range of Southern Spain, have yielded abundant well-preserved lithic artifacts.
In addition, the lake beds contain a wide range of micromammals including .
The situation of BL may be stratigraphically slightly below that of FN3 (20).
Recent field work at both sites enlarged the artifact record to more than 100 pieces (21–23) (Table 1; Fig. The lithologic study at BL shows a marked difference between the pebbles (limestone, chert, dolomitic limestone, etc.), originating in relatively high-energy environments, and the material of the archaeological level (flint, which is clearly a lithic artifact), showing the anthropic nature of the objects.
Although initially dated as 1.6–1.8 Ma old, both of these sites are strongly contested and they could be as young as 1 Ma (3).
At the gates of Europe, excavations in Dmanissi (Georgia) have yielded Oldowan lithic industry associated with a jaw and crania of probably Ar date of 1.85 ± 0.01 Ma, whereas the sediments give reversed (Matuyama) polarity (4), constraining the date to lie between 0.78 and 1.77 Ma.
The Guadix Formation is the most important marginal domain and consists of fluviatile sediments, whereas the Baza Formation (containing the archaeological sites of this study) consists of lacustrine sediments and is the most prominent distal domain.Some attempts at dating the sediments have included biochronology, uranium series, amino acid racemization, and stratigraphic correlation with other well-dated sections in the basin, but so far have failed to yield unambiguous ages.Here we present paleomagnetic age dating at the relevant localities and thus provide useful age constraints for this critical paleoanthropological and mammal site.The GB Basin is an intramontane basin situated in the Betic Cordillera, a mountain belt formed during the latest stages of the Tethys ocean closure caused by the convergence of the African and European plates during the Tertiary.It covers some 3,000 km and is located in a depression controlled by a set of northwest-southeast and north-northeast-south-southwest trending normal faults (14).