广西更新世早期么会洞遗址动物牙釉质的C、O稳定同位素分析——试析华南地区直立人的生存环境

CARBON AND OXYGEN STABLE ISOTOPE ANALYSES ON ANIMAL TOOTH ENAMEL FROM THE MOHUI CAVE SITE IN GUANGXI DURING THE EARLY PLEISTOCENE—A PRELIMINARY STUDY ON THE PALEOENVIRONMENT OF HOMO ERECTUS IN SOUTH CHINA

目前,中国区域更新世早期直立人形态特征、年代及演化分类等方面的研究已经取得丰硕成果,然而,其生存时期的古环境却缺乏相应的研究。基于华南地区么会洞遗址23颗与直立人同层位的哺乳动物牙釉质碳氧稳定同位素分析,为研究华南地区直立人的生存环境提供了直接证据。么会洞遗址哺乳动物牙釉质δ^(13)C值范围在-17.7‰~-13.4‰,表明么会洞遗址动物群主要食物以C_(3)类植物为主,古生态环境以森林环境为主;哺乳动物牙釉质δ^(18)O值范围在-10.8‰~-5.7‰,不同种属的动物δ^(18)O值存在不同,可能与不同种属动物的食性差别有关。对么会洞遗址和龙骨洞遗址哺乳动物牙釉质碳同位素进行研究,显示出两个遗址直立人生活时期的古生态环境是以森林环境为主。同时,对广西布兵盆地更新世不同时期古人类遗址哺乳动物牙釉质碳同位素进行研究,显示么会洞遗址直立人和陆那洞遗址早期现代人生活时期,古生态环境以森林环境为主,气候较为温和;更新世晚期中山遗址现代人时期,古生态环境是以草原环境和边缘森林环境为主,气候开始变得干冷。结合更新世不同时期古人类遗址数量的变化,显示在更新世阶段,随着古人类技术的更新和提高,古人类对古生态和古环境的适应性不断提高。

The Mohui Cave site(23°34.891'N,107°00.13'E),is located at southeastern of the Bubing Basin in west Guangxi,South China.It is 50 m in length,2~8 m in width and 5~10 m in height.This site is one of the most important Early Pleistocene sites is South China and Southeast Asia because of the presence of Homo erectus fossils.In contrast to fruitful studies on anatomic and morphological characteristics,chronology and evolutionary taxonomy of Homo erectus in different geographic regions of China during the Early Pleistocene,paleoenvironmental research is still lacking.This article is based on the carbon and oxygen stable isotopic records derived from 23 pieces of mammal tooth enamel sharing the same stratum with Homo erectus fossil at the Mohui Cave site,which provide direct evidence for reconstructing paleoenvironment of the hominid in South China.The range of δ^(13)C values of enamel at this cave site is from-17.7‰to-13.4‰,with an average value of-15.5‰,implying that the fauna's food was dominated by C_(3) plants and that the landscape was dominated by forest;while the range of δ^(18)O is from-10.8‰to-5.7‰with average value-7.7‰.Discrete values of δ^(18)O in different genera and species might suggest various feeding habits.Patterns of carbon stable isotopes at the Mohui and Longgu cave sites indicate that the two localities were covered by such a forest-dominated landscape.Moreover,carbon stable isotope evidence at several sites in the Bubing Basin dated to Pleistocene also provide robust data to reconstruct paleovegetation and paleoclimate-during the period of Homo erectus(Mohui Cave site)and early modern human(Luna Cave site),climate was relatively warm and the vegetation was dominated by forest;while during the Late Pleistocene,dry and cold climate conditions led to steppe-and/or marginal forest-dominated landscape.Combining with the evidence of increasing number of Paleolithic sites,this research project suggests that adaptability of hominid during the Pleistocene got increased in terms of surviving in various environmental conditions with the aid of technological innovation and perfection.