【作者】 吉笃学；

【导师】 陈发虎；

【作者基本信息】 兰州大学 ， 自然地理学， 2007， 博士

【摘要】 环境考古学是通过环境和文化之间关系的研究来揭示人类如何适应环境变化，如何调整自己的状态以缓解各种压力，从而实现规避风险保全自己的目的，为人类未来的生存和发展提供有益的借鉴。人类对环境变化的反应一般采取两种策略：一是响应；二是适应。目前，现代人扩散和农业起源是了解和认识人类适应策略的最理想的案例。为此，本文以甘肃宁夏新旧石器时代的考古发现和环境研究为例对这两个问题展开讨论。一、关于现代人扩散问题本文在全面回顾世界范围内有关现代人起源的古人类化石、旧石器制品以及基因研究等相关证据后，发现中国北方的旧石器文化在大约40kyr BP前后发生了巨大的变化，并推测这可能与非洲现代人向中国北方地区的扩散有关。为了寻找现代人类化石，追踪他们向黄土高原腹地迁移和扩散过程，了解现代人类迁移的根本动因，作者等人自2002年以来以甘肃和宁夏为中心进行大范围的野外考察，并依据国外的相关理论建立了人类迁移的环境反应模式。结果发现：1．在22kyr BP和21kyr BP左右的末次盛冰期，宁夏彭阳和甘肃秦安相继出现了与现代人有关的细石器制品，说明现代人已扩散到陇西黄土高原的腹地。2．ZL005地点的黄土—古土壤剖面的年代和磁化率、粒度以及碳酸钙等环境代用指标的研究表明，24kyr BP之前这里气候湿润，24-19kyr BP之间气候迅速变干，19-16kyr BP之间湿度又略有回升，这与大地湾遗址黄土—古土壤剖面利用磁化率和碳酸钙指标恢复环境的取得结果基本一致，也与彭阳PY01-02、PY03和PY05地点沉积地层由灰色泥炭层迅速转变为马兰黄土层这一明显的相变特征吻合。3．文化与环境之间的关系较为复杂，人对环境变化可能迅速做出响应，也可能逐步适应环境变化。a．石制品反映出的人口流动性表明，MIS3时期的石英岩技术组合说明人口流动性较弱；LGM时期石英技术组合也同样说明人口流动性较弱，但这一时期以燧石等精细原料技术组合却说明人口流动性明显增加。因此，末次盛冰期的气候变化可能导致了人口流动性增强。b．根据气温、降水以及¹⁴C年代建立起来的生物资源与遗址数量间的关系表明，在整个旧石器时代晚期这样的较长时间尺度上，遗址数量与生物资源状况具有反相关关系；在冷干或暖湿两种截然不同的气候事件的响应上，两者也具有同样的关系：在MIS3、LGM以及PG等不同阶段的环境变化的响应上，由MIS3至LGM时期，随着环境的恶化，遗址数量反而增加，人口流动性加强，与前面两种模式得出的结论一致，说明气候在这一转变中扮演着重要角色，因此这里暂称之为气候模式；但从LGM到PG，随着环境的好转，遗址数量增加，人口流动性减弱，可能与农业社会的人口增长模式相同，因之暂将其称为农业模式。4．彭阳和秦安等地22-21kyr BP发现的细石器制品是MIS到LGM的气候模式的具体反映，并且得到山西南部和陕西地区等相关考古证据的支持。说明现代人在末次盛冰期向中国北方黄土高原腹地的迁移可能主要与气候有关。二、关于农业起源问题通过对世界农业起源和中国北方粟作农业起源研究的回顾发现，尽管中国北方是世界主要农业起源中心之一，但目前却是世界上唯一一个尚未证明农业起源于当地采集经济的地区；中国北方缺乏系统的农业考古调查，农业起源与发展过程并不清楚；农业起源的原因大多留于揣测。据此，作者收集和整理了中国北方大量已发表的¹⁴C年代和考古资料，结合在甘肃东部的农业考古调查和对大地湾遗址多次科学考古发掘，并初步得到了以下新认识：1．中国北方10-3kyr BP的¹⁴C年代累积概率统计表明，中国北方存在10-8kyr BP、7.4-6.6kyr BP、4.8-4.5kyr BP以及3.8-3.5kyr BP四个年代低值期，并且前两者分别于对应于中国北方新旧石器时代过渡和新石器时代中晚期过渡这两个中国北方考古学文化上较为明显的“文化断层”。因此，中国北方迄今尚未揭露出一个具有探索新旧石器时代过渡与农业起源问题的连续剖面。2．秦安和礼县为中心的农业考古调查表明，8-7.3kyr BP之间的大地湾一期栽培作物黍数量少，出现频率低，并且处在半驯化状态下。而6.4kyr BP之后的半坡期农作物出现频率空前提高，籽实饱满，驯化状态良好。说明在由大地湾一期文化向仰韶文化过渡过程中栽培作物黍成功实现了向农作物的过渡。3．这里的气候背景的研究主要由大地湾遗址黄土—古土壤剖面和粟和黍类植物碳同位素分析两部组成。a．大地湾遗址的发掘首次在中国北方揭露出研究新旧石器时代过渡和农业起源的连续剖面。通过AMS¹⁴C精确测年，结合磁化率和碳酸钙等环境指标测定初步建立起农业起源前后的环境背景。结果表明，大约60-25kyr BP（MIS3）气候整体湿润，25-12kyr BP，这里气候干旱。12-7kyr BP之间，环境又逐渐湿润。但是，7.2-6.4kyr BP之间气候又突然干旱，而后迅速变得湿润。b．根据农业考古调查发现的粟和黍类植物的碳同位素分析说明，从仰韶文化半坡期到常山下层文化时期，植物碳同位素值持续偏正，说明降水不断增加。此后，到桥村类型和东周时期，植物碳同位素一直朝偏负方向发展，表明降水持续减少，气候干旱。4．农业起源问题实质是探讨采集狩猎经济如何向农业经济过渡的问题，而并不只是追溯栽培作物最早何时出现的问题。采集狩猎经济向农业经济的过渡主要体现在由以下几个方面：a．栽培作物向农作物转变。b．石刀组合取代磨盘、磨棒和石镰等农业工具组合。c．相互独立的栽培作物中心向统一的农业发展中心转变。d．人类由居无定所的流动生活方式向定居生活的转化。5．关于农业起源地区、时间与原因等问题。a．中国北方旱地粟作农业的两个主要作物品种粟和黍的起源地可能略有不同。粟可能主要起源于中原，而黍的起源地可能在中国北方的森林—草原过渡地带。b．中国北方农业起源时间与原因也存在两种可能，一种是受8.2kyr BP的气候事件，农业起源于8 kyr BP前后。另一种可能受7.2-6.4之间气候干旱事件的影响，农业起源发生于7 kyr BP之后。c．中国北方农业起源可能并不是同一时期，发展阶段也略有不同，很难用一种模式来解释。更多还原

【Abstract】 Environmental archaeology is devoted to knowing modern human’s adaptation and response to environment change, helping human to avoid damage and protecting themselves, and making it as a reference for people’s subsistence and development in the future by studying on the relationship between human and climate change.Two functional reactions, response or adaptation, are available when people are subject to climate change. The dispersal of Anatomically Modern Human （AMH） and Origin of Agriculture （OA） are the best cases for detecting human’s reaction to climate change. Based on the Paleolithic and Neolithic archaeological findings and environmental record in Gansu and Ningxia, environmental archaeological perspectives on the two issues will show as follows:1. Dispersal of AMHA detailed review on Human fossils, Paleolithic archaeological assemblages and DNA research indicates that a great change had happened around 40 ¹⁴C kyr BP, which can’t be explained by multiregion model for modern human evolution but the dispersal of "out of Africa" of modern human. A large scale field survey was carried out for the AMH fossils, route of their dispersal of AMH, and forcing factor of the dispersal in Gansu and Ningxia Hui autonomous region since 2002. Here are some preliminary findings:（1） Microlithic assemblages are revealed at Locality PY03 and Dadiwan site dated to ca. 22-21 kyr BP during Last glacial maximum （LGM）. This implies that AMH ever dispersed into this region. （2） Climate record reconstructed by precise AMS radiocarbon dating, magnetic susceptibility, grain size and CaCO³at locality ZL005 shows that it is wetter before 24 kyr BP and 19-16 kyr BP, but much drier between 24 and 19 kyr BP. It is also recorded by the transition from sand marl layer to Malan Loess deposit in Pengyang localities and Paleo-soil to loess in Dadiwan site.（3） It is much complicated for Human’s reaction to climate change. People may give immediate response to or gradually adapt to the climate change.a. Hunter-gatherers mobility is related to a certain kind of stone artifacts. Both Quartzite assemblages during Marine Isotope Stage 3（MIS3） and quartz assemblages in LGM may represent low mobility, but flint ones during LGM high mobility. This indicates that drier and colder climate of LGM probably leads to the higher mobility for hunter-gatherers.b. Biomass is dominated by temperature and precipitation, and the number of archaeological sites is reflected by radiocarbon dates of northern China. The abundance of bio-resources and the number of archaeological sites are negative correlated in the long scale of 50-10 kyr BP; This correlation also testfied by defining exactly cold/dry event or warm/moist event according to high-resolution climate record as stalagmite; This correlation is still right from MIS 3 to LGM, but reverse from LGM to PG （Post glacial） when we divide the whole Upper Paleoltihc Age into MIS 3（50-25kyr BP）, LGM（25-15kyr BP） and PG（15-10kyr BP）. The transition from MIS 3 to LGM was driven by climate change, which leads to higher mobility for hunter-gatherers when environment turn dry and cold, so we call it climate model. However, when climate ameliorates from LGM to PG, archaeolgical sites increased but the mobility of hunter-gatherers reduced, which is the same as the model of agriculture development. So it was named as agriculture model.4. The microlithic assemblages found at PY03 and Dadiwan at ca. 22-21 kyr BP is accord to climate change model, which also supported by the local style artifact change to microlithic assemblage in Shannxi and southern Shanxi. It was concluded that the dispersal of AMH into internal Chinese Loess Plateau was induced by climate change during cold and dry LGM.2. The origin of agricultureOA research in the world and northern China shows that northern China is the only one where it does not seem to unfold, in situ, from local hunter-gatherers in ten instances known worldwide in which agriculture evolved independently; Agriculture evolution from domesticated seeds is not clear deviod of systematic agriculture survey; the cause of what ever drove the change from the hunter-gathering to agriculture also need to be detected based on the detailed environmental records. So published radiocarbon dates of archaeological sites and archaeological materials in northern China was collected, a large scale survey centered on Hulu River and Xihan River drainage was carried out, and Dadiwan site was excavated scientifically since 2004 in order to answer these questions. Here are some points.1. 10-8kyr BP, 7.4-6.6kyr BP, 4.8-4.5kyr BP and 3.8-3.5kyr BP are the low value zone based on the cumulative probability of 1364 radiocarbon dates in northern China. 10-8kyr BP and 7.4-6.6kyr BP are right on the transition Paleolithic Age to Neolithic Age and Early Neolithic to Late Neolithic Age, and they both witnessed a "culture gap" in northern China. So no continuous archaeological record for origin of agriculture was ever discovered in north China.2. Agriculture survey indicates that hunter-gathering was dominated by low ubiquity of half-domesticated Panicum miliaceum during 8-7.3 kyr BP, but developed agriculture quite higher ubiquity of domesticated Panicum miliaceum after 6.4kyr BP. The replacement of hunter-gathering by Agriculture may take place on the transition from Dadiwan 1 to Late Banpo, Yangshao Culture.3. Paleosol-loess section at Dadiwan andδ¹³C of charred Panicum miliaceum and Setaria italica combine together a continuous environmental record for the research on OA. a. The first continuous archaeological record exposed at Dadiwan site make it possible to detect the climate change for origin of early agriculture and the transition from Paleolithic to Neolithic age in northern China. Environment proxies reconstructed by magnetic susceptibility and CaCo3 suggest that 60-25kyr BP and 12-7kyr BP are moister, but 25-12kyr BP and 7.2-6.4kyr BP much drier. 7.2-6.4kyr BP is much important for OA.b.δ¹3c of charred Setaria italica goes up from Late Banpo to Changshan culture, and then it goes down until Qiaochun type and Dongzhou. It suggests that the precipitation increased continuously from Late Banpo to Changshan culture, then reduced since Changshan and reached the lowest point during Dongzhou.4. The origin of agriculture is, in essence, not to find the earliest domesticated plant seed, but to study on how, when, why the transition from hunter-gathering to agriculture happened. The following points may be related to this transition:a. Domesticated plant seed evolved into crop.b. Toolkit change from grindingstone, stone roller, sickle to stone knifec. Seperated centre for domesticated plant seed develops into agriculture centre.d. Moblie hunter-gatherering turns into sedentism.5. When, where and why did agriculture originate in northern China?a. Setaria italica and Panicum miliaceum may originate at different region, central China and transitional zone from grassland to forest, respectively.b. Agriculture may originate firstly around 8 kyr BP induced by 8.2 kyr BP event, or around 7 kyr BP triggered by 7.2-6.4 drought event.c. It has different time, different development stage and different model for the origin of agriculture in northern China.更多还原