| 根据地质记录恢复渐新世和中新世不同时期环境空间特征及其意义 |
| |
| 引用本文： | 张仲石,郭正堂.根据地质记录恢复渐新世和中新世不同时期环境空间特征及其意义[J].第四纪研究,2005,25(4):523-530. |
| |
| 作者姓名： | 张仲石 郭正堂 |
| |
| 作者单位： | 中国科学院地质与地球物理研究所,北京,100029;中国科学院地球环境研究所黄土与第四纪国家重点实验室,西安,710075;中国科学院地质与地球物理研究所,北京,100029 |
| |
| 基金项目： | 国家自然科学基金;中国科学院知识创新工程项目 |
| |
| 摘 要： | 已有工作对地质环境指标空间分布特征的研究揭示出,我国的环境在新生代期间经历了从近于东西向的带状格局向与现今相似的非带状格局的转变,代表了东亚地区重大的环境变化,但对这一转变的时间、空间变化的详细过程还缺少深入的认识。越来越多的证据显示,渐新世/中新世之交和中新世可能是这一环境变化最为关键的时期,因而有必要对渐新世和中新世内部不同时期的环境格局进行更详细的研究。近十年来,大量新的研究工作积累了更多的资料和证据,为进一步研究上述问题提供了新的可能。文章根据已有文献资料,对有明确环境意义和较可靠年代控制的地质记录进行了重新整理和分类,对渐新世和中新世不同时期的环境格局进行了详细的考察。研究显示,以内陆干旱为基本特征的非带状环境格局至少出现于中新世早期,与我国北方风尘堆积出现的时代具有一致性。
|
| 关 键 词： | 渐新世 中新世 环境格局 季风环境 |
| 文章编号： | 1001-7410(2005)01-523-08 |
| 收稿时间： | 2005-03-07 |
| 修稿时间： | 2005年3月7日 |
SPATIAL CHARACTER RECONSTRUCTION OF DIFFERENT PERIODS IN OLIGOCENE AND MIOCENE |
| |
| ZHANG Zhongshi,GUO Zhengtang.SPATIAL CHARACTER RECONSTRUCTION OF DIFFERENT PERIODS IN OLIGOCENE AND MIOCENE[J].Quaternary Sciences,2005,25(4):523-530. |
| |
| Authors: | ZHANG Zhongshi GUO Zhengtang |
| |
| Institution: | 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029;
2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi′an 710075 |
| |
| Abstract: | Previous studies illustrated that the Tertiary paleoenvironmental pattern in China was dominated by roughly zonal climates resulted from the planetary wind systems. Conspicuous changes had occurred for the Neogene when the originally arid south-western and south-eastern part of the country became much more humid and the geographic location of arid region in the north China was further close to the present-day status, indicating the initiation of the East Asian monsoon and inland-type aridity. More geological evidences indicated that the boundary of Oligocene and Miocene was the key time of the change. It is necessary to reconstruct the environmental patterns of different periods in Oligocene and Miocene. Here, we attempt to compile a series of paleogeographical maps based on newly collected climate indicators from the literature and age-controllable evidence of geological maps in order to re-examine the temporal and spatial evolution of climate belts in China during the Oligocene and Miocene with special emphasis on the changes of the arid belt. These newly collected indicators include mammalian faunas, coal, carbonate concretions, jarosite, salt, gypsum deposits and pollen assemblages with reliable chronological controls and etc. Pollen assemblages and mammalian faunas have been classified into three categories, arid, semi-arid/sub-humid, humid, to reflect the intensity of aridity/humidity. And salt, jarosite, and gypsum deposits are classified into the arid category. Carbonate concretions and coal are classified into the semi-arid/sub-humid and humid one respectively. Paleogeographic maps of the arid belts corresponding to five time slices have been reconstructed. They are the Oligocene, Miocene, Early Miocene, Middle Miocene and Late Miocene. The obtained results essentially confirm the earlier conclusions about the change of the East Asian environmental patterns from planetary wind system dominating type to monsoon system dominating type. The environmental pattern of monsoon system dominating type has formed by the earliest Miocene, which is consistent with the onset of eolian deposits in China. |
| |
| Keywords: | Oligocene ) Miocene environmental patterns monsoon |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《第四纪研究》浏览原始摘要信息 |
| 点击此处可从《第四纪研究》下载免费的PDF全文 |
|
