• 论文 •

### 南京葫芦洞石笋生长速率及其气候意义讨论

1. 1. 南京师范大学地理科学学院, 江苏 南京 210097;
2. 南京大学地球科学系, 江苏 南京 210093
• 收稿日期:2002-03-06 修回日期:2002-07-20 出版日期:2003-05-20 发布日期:2003-05-20
• 基金资助:
国家自然基金资助项目(49972055)。

### Approach to the Growth Rate and the Climatic Significance of Stalagmites in Hulu Cave, Nanjing

SHAO Xiao-Hua1, WANG Yong-Jin1, KONG Xing-Gong1, WU Jiang-Ying2

1. 1. College of Geography Sciences, Nanjing Normal University, Nanjing, Jiangsu 210097;
2. Department of Earth Sciences, Nanjing University, Nanjing, Jiangsu 210093
• Received:2002-03-06 Revised:2002-07-20 Online:2003-05-20 Published:2003-05-20

Abstract: The timing of growth phase in 17 stalagmites from Hulu Cave, Nanjing, has been precisely dated by thermal ionization mass spectrometric 238U-234U-230Th dating with 69 samples. Based on the comparison between the high-resolution oxygen isotopic records and the thickness of annual layers, we obtained some interesting relationship between the two records. The stalagmite YT which continuously growth for 4000 years during the last glaciation shows the closely and complex relationship between the thickness of annual layers in different time scales and the temperature as well as the effective humidity of the earth's surface above the cave. The growth rate of stalagmite MSD shows the negative variability with the δ18O. That is, the variability of the growth rate abruptly changed in about 28 ka B.P. During 28-18 ka B.P., the average growth rate was 14.27 mm/ka, while it was 9.73 mm/ka during 53-28 ka B.P. So the growth rate of stalagmite MSD was higher during the dry cold marine isotopic stage 2 (MIS2) than during the wet warm marine isotopic stage 3 (MIS3). However, the other stalagmite named MSL during 72-31 ka B.P., which overlapped the marine isotopic stage 3 (MIS3) and stage 4 (MIS4), shows the reversed results. The average growth rate reached to 11.14 mm/ka in the wet warmer period MIS3, while 5.63 mm/ka during the dry colder MIS4. Although the MSD and MSL showed the reversed growth rate feature during the warmer and colder period, but the absolute average thickness of annual layers is comparatively.In progressively, we analyse growth frequency of 17 stalagmites with 5000 year-step in the same cave. The results show the highest accumulative growth frequency during the 25-5 ka B.P., being 52% of the whole growth quantity and the lower accumulative growth frequency during the period 60-30 ka B.P., the wet warmer MIS3, which takes up only 30% of the whole growth quantity. Generally, the growth rate and quantity of the Cave stalagmite could reflect the variability of the outer cave climate. In Hulu Cave, Nanjing, the continuously growth of the annual layer controlled the average growth rate. Difference temperature effects of outer and inner cave results in the continuous growth of stalagmite during 24-14 ka B.P.. So the higher average growth rate could not entirely represent the wet warmer climate.

• F534.63