排序方式： 共有4条查询结果，搜索用时 125 毫秒
1
1.
早第三纪古新世本区构造长期稳定,气候炎热潮湿,地表风化剥蚀形成准平原化夷平面,其表面发育了红色风化壳,矿物颗粒没有经过搬运与分选,属原生残积风化壳类型.特征与目前南亚热带类似,生长热带、亚热带常绿林. 始新世初EW向断裂活跃,北部上升为丘陵山地,中部稳定,南部下沉为渤海盆地.中新世渤海盆地尚有火山喷发.达时北部某些河段下切与地壳抬升速度大致平衡,开始形成嵌入曲流,气候由始新世 的南亚热带演化至中、上新世为北亚热带.早更新世初NE向断裂活动,东西分异,柳江盆地形成.石河水系沿断裂袭夺扬河上游.山间河谷有棕灰色泥砾堆积.古生物资源反映当时已演化为温带气候. 相似文献
2.
本区属于华北平原向东平平原的过渡地带——山海关走廊的西部,新生代古地理演化具有一定的典型性。本区早第三纪古新世构造长期稳定,气候炎热潮湿,地表风化剝蚀形成准平原化夷平面,发育了红色风化壳,但被喜马拉雅运动的断裂活动解体。矿物颗粒没有经过搬运与分选,属原生残积风化壳类型。其特征与目前亚热带类似,生长热带、亚热带常绿林。始新世初EW向断裂活跃,北部上升为丘陵山地,中部稳定,南部下沉为渤海盆地。中新世渤海盆地尚有火山喷发。这时北部某些河段下切与地壳抬升速度大致平衡,开始形成嵌入曲流。气候由始新世的中南亚热带演化至中新世上新世为北亚热带。 相似文献
3.
THE DESTRUCTION OF ANCIENT ECOLOGICAL ENVIRONMENT AND THE MOVEMENT OF CIVILIZATION CENTER IN CHINA 总被引：1，自引：0，他引：1
孔繁德 《中国地理科学(英文版)》1992,2(4):382-388
China is one of the ancient civilization countries. Owing to the blind reclamation, the vegetation had been destroyed, causing soil erosion and desertification, and making the civilization center move to the Changjiang (Yangtze) River valley from the Huanghe (Yellow) River. This movement began in the Qin and Han dynasties (221 B.C-220 A.D.) because at that time the large-scale reclamation was felled, the grassland was reclaimed into farmland, the vegetation was seriously destroyed in the loess and north of the Huanghe River, and the climate was getting colder; and the turn from north to south occurred in the Sui and Tang dynasties (581-907 A.D.) and completed in the Song Dynasty (960-1279 A.D.). However, at present the vegetation damage of the Changjiang River valley is very serious too and the silt carrying capacity of the Changjiang River is increasing sharply; thus the Changjiang River is in danger of becoming a second Huanghe River, so we must pay attention to the protection of ecological environmen 相似文献
4.
1