【摘要】 在综合研究南方 2 0多个大型石笋纵剖面的基础上 ,以董歌洞 4号石笋为代表 ,论述石笋沉积特征与气候演化的对应性。 4号石笋从距今 14 7.838± 2 .6ka开始沉积以来 ,形成了 5 3个沉积纹 (壳 )层组 ,组成 2 4个亚旋回 ,构成 9个旋回 ,呈现韵律式旋回性沉积特征。石笋纹 (壳 )层组分、结构、叠复构造呈多级次旋回性很突出 ,其中沉积间断具普遍性、沉积速率具多变性 ,间断和速率变化级次亦明显。以系统测试和测年引证沉积特征的同时揭示 :①～⑨旋回间沉积间断时间累积达 75 .80 4ka ,占石笋形成时间的 5 1.2 1% ,①～⑨旋回实际沉积时间仅 72 .2 2 2ka ,占形成时间的 4 8.79% ;④旋回之前 ,沉积速率很小 ,最小仅 0 .36mm/ 10 0a ,比最大速率小 2 2～ 2 4倍 ,自⑤旋回起 ,沉积速率很大 ,最大达 39.0 3mm/ 10 0a ,是最小速率的 3.8倍。石笋沉积特征与气候环境演化的成生关系表明 ,石笋沉积多旋回性的纹 (壳 )层组、亚旋回、旋回与气候演化的气候期、阶段和旋回彼此对应 ,石笋沉积的多级次旋回及其变化就是气候演化的级次及旋回性转 (跃 )变时间 ,彼此同时显示。论证了石笋沉积的多旋回性与气候演化的不稳定性 ,及其彼此协调的宏观、微观综合表现特征。更多还原

【Abstract】 The sedimentary characteristics of stalagmite parallel with the process of climate evolution are discussed according to a synthetic study of over 20 large stalagmite vertical profiles, with No.4 stalagmite in the Dongge cave as an example. The No.4 stalagmite formed at 147.838 ka B.P. consists of 9 sedimentary cycles comprising 24 sedimentary sub-cycles or 53 lamina groups, with the 9 sedimentary cycles assuming the deposition characteristics of rhythm cycles. The components, structure or fabric and fold combination of laminae or crust layers show obvious multi-class cyclicity. The sedimentation interruption of stalagmites is very common, and the growth rate of stalagmite is varied. The sequence order of sedimentation interruption and the variation of the deposition rate are very clear too. The above results can be proved by a lot of analytical data and age data. The accumulation time of sedimentation interruption from Cycle 1 to Cycle 9 is about 75.804 ka, which accounts for 51.21% of the total growing time of stalagmite. This means that the actual growth time of stalagmite from Cycle 1 to Cycle 9 is only 72.222 ka, which accounts for 48.79% of the total growing time of stalagmite. The growth rate of stalagmite before the fourth sedimentary cycle is very small, and the smallest growth rate is only 0.36 mm every 100 years, which is 22 or 24 times smaller than the largest one. The growth rate of stalagmite after the fifth se-dimentary cycle is very fast. The largest growth rate is 39.0 mm every 100 years, being 3.8 times that of the smallest one. The relationship between the sedimentary characteristics of stalagmite and the evolution of climate environment has revealed that the cycles, sub-cycles and multi-sequence lamina groups of stalagmite deposition are parallel with the climate period, stage and sedimentary cycles respectively and in accord with the time. The multi-class sequence cycles and changes of stalagmite deposition are actually the time span changed by the multi-class sequence cycles of climate evolution, and they are consistent with each other in time. The above stu-dies have proved the instability of the climate evolution, which has controlled the multi-sequence lamina groups of stalagmite deposition. The process of the climate evolution affects the instability of the sedimentary environment, the multi-sequence variation and the time span or interval, and also serves as the time limit of the multi-class sequence cyclicity and variation for the formation of stalagmite.更多还原