【摘要】 孢粉通常被用作古气候的代用指标,长江三角洲地区已经进行了许多相关的饱粉-古气候的研究工作。通过对长江三角洲地区7个晚更新世钻孔的孢粉资料进行提取对比,发现冷杉和云杉两种花粉在地层中分布有一定的规律性。现代长江流域这两种耐寒植物集中分布在青藏高原区,长江中下游地区极少分布,但其花粉确出现在近河口区的晚更新世以来的暖期地层中(MIS 1,3和5期),并且达到了一定数量,这很可能是长江从其上游地区搬运至此沉积下来的。同时,我们也发现西部内陆平原区由于受长江物源影响较少,其晚更新世以来地层中的冷杉和云杉花粉分布与河口区差别很大,这也为河流携带冷杉和云杉花粉至河口地区提供了证据。这一发现如果成立,冷杉和云杉花粉即可作为长江物源的一个判别指标。更多还原

【Abstract】 Sediment samples from seven Quaternary sediment boreholes（ Zk04, SklO, FX, MFC, Pd, Chl, and Mz） on the Yangtze coast of the Eastern China were collected. These boreholes are of 100 ～ 350m depth. They are located respectively at 31°33′14″N and 119°54′38″E,31°16′58″N and 120°39′53″E,31°12′07″N and 121°14′52″E, 31° 11′02″N and 121 °27 ′04″E, 31 °08 ′31 ″N and 121 °47 ′38″E, 31 °21′12″N and 121 °37 ′01 ″E, 31 °47′ 12″N and 121°30′12″E. ¹⁴C,OSL,ESR,and paleomagnetism methods were applied for dating. 2 boreholes reached the Late Pleistocene and 5 ones reached Early Pleistocene. The bottoms of the Late Pleistocene of the 7 boreholes are 49m, 75m, 100m, ll0m, 130m, 123m, and 143m respectively. Samples were analyzed for examining pollen-climate changes in relation to glacial and interglacial oscillations. The data from boreholes FX and MFC display 6 pollen and spore zones in the Late Quaternary sediments, which coincides generally with glacial and interglacial periods. Particular attention has been paid to Abies and Picea （A & P） pollen species found from the boreholes as they are used as either high-latitude or high-elevation indicators for cold climate setting. A certain proportion （ca. 5%）of A & P pollen species are found in the interglacial Late Quaternary sediments in those boreholes located at the river mouth area,which is confirmed to he at a low elevation by marine sediments of Late Pleistocene and Holocene. It is proposed that the exclusive A & P in the interglacial marine sediments of Late Pleistocene would indicate sediment sources from the distal upper Yangtze plateau a signal of river channelization through the plateau at that time. In addition, no A & P appears in the Late Quaternary sediments in boreholes near the close by Taihu Lake area,which also suggests the remote source of A & P in Yangtze River delta sediments. This preliminary study would shed light on a new interpretation of pollen record on monsoon and provenance.更多还原