洞穴石笋沉积间断类型研究
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摘要
以广西桂林,贵州荔波、茂兰、都匀凯口及云南宣威、泸沽湖等地典型岩溶峰丛-峰林平原、岩溶斜坡和岩溶高原的大量大型石笋纵剖面研究为基础,依据石笋沉积旋回或纹层组的系统测年数据和碳氧同位素系统测试资料,确定石笋沉积间断面上、下的年龄,若以上、下纹层结构构造差异大、构造类型不同、结构构造突变或有间断沉积特征为前提,将上、下纹层的年龄差作为沉积间断时间:差值大,间断时间长,其间若有间歇性停、滴转变,则沉积纹层的测年值是此时段的正常年序;差值小,间断时间短;差值很小,又无宏观异常,为正常的连续沉积。本文从石笋沉积间断标志,间断面上、下的年代异常,间断类型和古气候环境意义,论述石笋沉积间断,阐明石笋纵剖面有丰富的古气候环境信息,是全球气候变化研究的重要领域之一。此外,根据石笋纹层的宏观、微观资料和测年统计,提出了年季和年际的短期性、10年际—万年际的长期性、瞬时性间断类型的分类方案,短期停滴,是常态气候条件下,年旱季或年际干旱停滴,形成年际和季节性沉积间断;长期停滴,是气候环境冷暖周期性变化,略呈小周期的干冷气候间歇性停、滴相间的演变,形成10年际—万年际沉积间断;瞬时性停滴,指地震、掉顶、坍塌等天然或人为事故,碰断石笋,引起瞬时或短暂停滴,形成灾害性沉积间断
The ages of the top and bottom laminae of a hiatus produced by sedimentary interruption are determined on the basis of synthecial dating of sedimentary cycle and lamina groups of stalagmite and synthecial determination of carbon and oxygen isotope of large stalagmite sections from the typical peak cluster and forest plain, the slope zone of karst and karst plateau in Xuanwei and Lugu lake of Yuannan, Libo and Duyuan of Guizhou and Guil-in. The age difference of the upper and lower laminae will be taked as the duration of the sedimentary inter-ruptin if there are more differences in the texture and structure the upper and lower laminae. The duration of sedimentatary interruption is long when the age difference is large and the dating values of the laminae (group) are in the normal order in this time period when there is intermittent water dropping. The duration is short when there are a little age difference. The sedimentation is continuous when there is little age difference and no visible anomaly. The sedimentary interruption of stalagmite contain rich information of paleoclimatic environ-ment and is one of the key field in the study of global climatic change.Based on the macroscopic, microscopic observation and dating of laminae, a classification scheme of sedi-mentary interruption on the seasonal, annual, 10 to 10 thousand-year and instant scales is put forward. The genetic and paleoclimatic implications of the sedimentation interruption are that, a short-time interruption of water dropping indicates a seasonal, annual or perennial dry condition under normal climate, a long-term inter-ruption of water dropping suggests periodical change of cold and warm climatic environment that result in sedi-mentary interruption of 10 years to 10 thousand years and an instant interruption of water dropping implies earthquake, falling top man-made events, etc.
The ages of the top and bottom laminae of a hiatus produced by sedimentary interruption are determined on the basis of synthecial dating of sedimentary cycle and lamina groups of stalagmite and synthecial determination of carbon and oxygen isotope of large stalagmite sections from the typical peak cluster and forest plain, the slope zone of karst and karst plateau in Xuanwei and Lugu lake of Yuannan, Libo and Duyuan of Guizhou and Guil-in. The age difference of the upper and lower laminae will be taked as the duration of the sedimentary inter-ruptin if there are more differences in the texture and structure the upper and lower laminae. The duration of sedimentatary interruption is long when the age difference is large and the dating values of the laminae (group) are in the normal order in this time period when there is intermittent water dropping. The duration is short when there are a little age difference. The sedimentation is continuous when there is little age difference and no visible anomaly. The sedimentary interruption of stalagmite contain rich information of paleoclimatic environ-ment and is one of the key field in the study of global climatic change.Based on the macroscopic, microscopic observation and dating of laminae, a classification scheme of sedi-mentary interruption on the seasonal, annual, 10 to 10 thousand-year and instant scales is put forward. The genetic and paleoclimatic implications of the sedimentation interruption are that, a short-time interruption of water dropping indicates a seasonal, annual or perennial dry condition under normal climate, a long-term inter-ruption of water dropping suggests periodical change of cold and warm climatic environment that result in sedi-mentary interruption of 10 years to 10 thousand years and an instant interruption of water dropping implies earthquake, falling top man-made events, etc.
引文
邓自强,林玉石,张美良,等.1994． 略论古岩溶不整合.广西地质,7(2) :61～70．
林玉石,张美良,覃嘉铭.2001a.洞穴石笋沉积速率研究.中国岩溶,20(2) :1～5．
林玉石,张美良,覃嘉铭.2001b.洞穴石笋纹(壳)层构造类型研究.中国岩溶,20(1) :5～10．
军建雄等译.1995． 碳酸盐岩地层不整合及孔隙发育.地质科学译丛,12(1) :49～57．
袁道先等.1993． 中国岩溶学.北京:地质出版社,118～128．
Deng Ziqiang, Lin Yushi, Zhang Melliang, et al. 1994． Preliminary discussion on paleokarst unconformity--Illustrated by Late Cretaceous karst in Baishabao, Yangshuo County, Guangxi. Geology of Guangxi,7 (2) : 61～70 (in Chinese).
Lin Yushi, Zhang Meiliang, Qin Jiaming. 2001a. Study on the sediment rate of stalagmite in cave. Carsologica Sinica ,20 (1) : 1～5(in Chinese with English abstract).
Lin Yushi, Zhang Meiliang, Qin Jiaming. 2001b. Study on the structure types of stalagmite lamina or lamella in cave. Carsologica Sinica, 20 (1) : 5～10 (in Chinese with English abstract).
Yuan Daoxian, et al. 1993． Karst of China. Beijing: Geological Publish House, 118～128 (in Chinese).
林玉石,张美良,覃嘉铭.2001a.洞穴石笋沉积速率研究.中国岩溶,20(2) :1～5．
林玉石,张美良,覃嘉铭.2001b.洞穴石笋纹(壳)层构造类型研究.中国岩溶,20(1) :5～10．
军建雄等译.1995． 碳酸盐岩地层不整合及孔隙发育.地质科学译丛,12(1) :49～57．
袁道先等.1993． 中国岩溶学.北京:地质出版社,118～128．
Deng Ziqiang, Lin Yushi, Zhang Melliang, et al. 1994． Preliminary discussion on paleokarst unconformity--Illustrated by Late Cretaceous karst in Baishabao, Yangshuo County, Guangxi. Geology of Guangxi,7 (2) : 61～70 (in Chinese).
Lin Yushi, Zhang Meiliang, Qin Jiaming. 2001a. Study on the sediment rate of stalagmite in cave. Carsologica Sinica ,20 (1) : 1～5(in Chinese with English abstract).
Lin Yushi, Zhang Meiliang, Qin Jiaming. 2001b. Study on the structure types of stalagmite lamina or lamella in cave. Carsologica Sinica, 20 (1) : 5～10 (in Chinese with English abstract).
Yuan Daoxian, et al. 1993． Karst of China. Beijing: Geological Publish House, 118～128 (in Chinese).
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