San Quirce (Palencia,Spain): new chronologies for the Lower to Middle Palaeolithic transition of south-west Europe     

Marcos Terradillos-Bernal  Martina Demuro  Lee J. Arnold  Jesús F. Jordá-Pardo  Ignacio Clemente-Conte  Alfonso Benito-Calvo  J. Carlos Díez Fernández-Lomana 《第四纪科学杂志》2023,38(1):21-37

San Quirce is an open-air archaeological site situated on a fluvial terrace in the Duero basin (Palencia, northern Iberia). This paper presents new and consistent chronologies obtained for the sedimentary sequence using post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and single-grain thermally transferred optically stimulated luminescence (TT-OSL) dating of quartz. The new dating results indicate that the sequence is older than ~200 000 years and place San Quirce Level III within marine isotope stages (MIS) 8 and 7, between 274 ± 13 ka and 238 ± 13 ka. The main lithic assemblage at San Quirce comes from Level III. The predominant tool types found in this level are hammerstones, manuports and flakes, with a small proportion of cores and a significant presence of denticulates. Adaptation to local environmental conditions resulted in distinctive cultural habits, which were embedded in the cultural tradition of hominins occupying the site during the final third of the Middle Pleistocene. San Quirce preserves a simple cultural tradition that was employed by local hominins to engage in a diverse array of activities, and highlights the cultural diversity that appears to have been a characteristic feature of the Lower to Middle Palaeolithic transition 300–200 ka.  相似文献   

Estimates of Chandler's Component of Polar Motion as Derived from Various Data Sets     

C. R. Wilson  R. O. Vicente 《Astronomische Nachrichten》1981,302(5):227-232

Data sets consisting of several combinations of classical and modern techniques (Doppler and laser ranging to artificial sattellites) have been analysed by autoregressive (AR), sinusoidal and autoregressive moving averag (ARMA) methods in order to obtain estimates of the frequency and quality factor of the Chandler component of polar motion. The ARMA method shows advantages over the other methods and the results obtained do not furnish evidence of temporal variation in these polar motion parameters. The disadvantages associated with smoothing the data sets and the difficulties as sociated with short time intervals for the data are cleary demonstrated. There is a great need for regular and long observational series obtained by the modern techniques.  相似文献