洛阳北窑遗址年代再研究

RE-EXAMINATION OF THE AGE OF BEIYAO SITE, LUOYANG CITY

文章重新研究了洛阳北窑遗址的地层序列,并测定了黄土-古土壤序列的磁化率曲线,认为洛阳北窑遗址的年代从MIS 7延续到MIS 2,光释光法测年和^(14)C测年得出的数据也与这一结果吻合。其中1998年发掘的层位的年龄从MIS 7延续到MIS 4的早期,而不是先前所认为的从MIS 5延续到MIS 3。

Beiyao Site is situated in the third sequence of Chanhe river, one branch of Luohe river. There are more than 20 meters loess-paleosol formation which contains a large number of stone artifacts pile up along the southern bank of Chanhe river. Based on field observations,the well-developed loess formation in the site is described top-down as follows ： 1. Tillage soil and disturbance of soil, with thickness of 0. 3 = 0.4m. 2. Brown-red paleosol layers, faded from top to bottom, it is obvious that the upper half was destroyed, with thickness of 0. 55 -0. 65m. 3. Pale yellow loess, with thickness of 6.4 - 7. 0m. According to two weakly developed soils, the layer can be divided into five smaller layers,contain a few stone artifacts. 3-1. Loess layer,the soil contains more calcium silk and calcium nodules,thickness is 1.2 - 1.6m; 3-2. paleosoil, the upper part contain more calcium nodules, the lower part is reddish-brown, dense soil structure, but clearly weaker than the first two layers. 0. 8m in thickness; 3-3. Loess, porous structure, contain calcium silk and calcium tuberculosis,with thickness of 0.9 -1.2m; 3-a. paleosoil,soil structure is dense block, there is 20cm of clear developed soil in the middle, thickness is 0.8 - 1. 0m; 3-5. Loess,loose structure,light yellow, and containing calcareous silk and calcium nodules in the lower part, 2.4m thick ; 4. The red-brown paleosol, Fe-Mn film developed, calcium tuberculosis is rare, unearthed a large number of stone artifacts,with thickness of 2.2m. 5. Pale yellow loess, there are calcium tuberculosis in the bottom, few stone artifacts were unearthed, with thickness of 2.4m. 6. Dark greyish yellow loess, unearthed stone artifacts,with thickness of 2.2m. 7. Dark brown red paleosoil, the best-developed soils, scaly structure, black Fe-Mn film developed,unearthed a large number of stone artifacts,a thickness of 2. 0m. In the course of archaeological excavations,we collected a set of loess samples with 10cm spacing, measured magnetic susceptibility and grain size data in the Sedimentary Laboratory of Institute of Geology and Geophysics, Chinese Academy of Sciences. Fig. 2 is the spliced magnetic susceptibility data of Beiyao section compared with Duanjiapo section and deep-sea oxygen isotope curves. From Fig. 2 we can see that loess magnetic susceptibility curve of Beiyao section corresponds to Duanjiapo section and deep-sea oxygen isotope curve. First of all,the magnetic susceptibility of Beiyao section has 3 peaks, which is respectively 169.8×10^-8 m^3/kg, 158×10^-8 m^3/kg and 224.5×10^-8 m^3/kg, There are also three peaks in Duanjiapo section and deep-sea oxygen isotope curve. Secondly, the morphology of Beiyao curve has two-peaksthree-valleys structure between the first and second peaks, second and third peaks. The same pattern is also present in Duanjipo section and marine isotope curve,so we can correspond three peaks respectively to S1 ,S2 ,S3 or Layer 2,4, and 7 in field section. In addition to collecting loess samples, we also collected seven thermoluminescence samples and two 14C samples （see Tables 1,2 and 3） , all data support the conclusions of the above （see Fig. 2）. Overall,the loess section in Beiyao site can be correlated with the other representative section in the Loess Plateau and contains So ,L1 ,S1 ,L2 and S2.