A High-resolution Study of Moisture Evolution in the Jianghan Plain Since 12.76 cal. ka B.P.
Received date: 2011-07-22
Request revised date: 2011-10-22
Online published: 2012-07-20
Copyright
Six AMS radiocarbon ages combined with the concentration and distribution of element Rb, Sr and Ti, Rb/Sr ratio and magnetic susceptibility are utilized to reconstruct the moisture evolution in the Jianghan Plain during the last 12.76 ka. The multi-proxy integrated indicators of the regional moisture conditions turned from dry to wet after the Late Glacial and progressively became better and reached its optimum period until the mid-Holocene, however, punctuated by several humidity decrease phases. Begin with the severe dry event around 4.42-4.00 cal.kaBP, the environment was dry again in the Jianghan Plain as a whole. It can be inferred that the evolution of moisture condition in the study area was dominated by the East Asian monsoon system which likely be driven by the solar insolation changes on the Northern Hemisphere. As the first time to apply the Rb/Sr ratio and Ti concentration in tracing moisture evolution in a region with typical subtropical humid climate, this study highlights the different effects and consequences of the proxies throughout the paleoenvironment process. Also the regional characteristics of continuously subsided since the Cretaceous period as well as the topography opening down to southeast. What’s more the variations of magnetic susceptibility are well coincided with the transition of Neolithic culture of the Jianghan Plain.
LI Feng , WU Li , ZHU Cheng , SUN Wei , WANG Xiao-cui , MENG Hua-ping , LIU Hui , GONG Qi-lan , ZHU Guang-yao , ZHOU Feng-qin , LI Su-yuan , OUYANG Jie . A High-resolution Study of Moisture Evolution in the Jianghan Plain Since 12.76 cal. ka B.P.[J]. SCIENTIA GEOGRAPHICA SINICA, 2012 , 32(7) : 878 -884 . DOI: 10.13249/j.cnki.sgs.2012.07.878
Fig.1 The site of JZ-2010 profile in Jianghan Plain图1 江汉平原JZ-2010剖面区位 |
Fig.2 Lithology of JZ-2010 Profile and the variation of Magnetic Susceptibility图2 JZ-2010剖面示意及磁化率 |
Table 1 AMS14C and calendar age of JZ-2010 profile表1 JZ-2010剖面AMS14C测年及校正数据 |
送样编号 | 样品性质 | 采样深度(cm) | 测试编号 | AMS14C年代 (a B.P.) | 2σ校正年代 | 日历年代 (cal a B.P.) |
---|---|---|---|---|---|---|
JJ AMS14C-9 | 泥 炭 | 231~232 | GZ4100 | 1270±20 | 678AD(100%)775AD | 1224 |
JJ AMS14C-8 | 泥 炭 | 262~264 | GZ4099 | 2405±20 | 539BC(98.1865%)401BC | 2420 |
JJ AMS14C-6 | 泥 炭 | 318~320 | GZ4098 | 3185±20 | 1497BC(100%)1422BC | 3410 |
JJ AMS14C-4 | 淤 泥 | 395~397 | GZ4096 | 4235±20 | 2903BC(85.9137%)2867BC | 4835 |
JJ AMS14C-2 | 淤 泥 | 435~437 | GZ4095 | 4815±25 | 3588BC(67.242%)3528BC | 5508 |
JJ AMS14C-1 | 淤 泥 | 635~637 | GZ4094 | 10870±35 | 10943BC(100%)10670BC | 12757 |
Table 2 Concentration and distribution of Ti, Rb, Sr and Rb/Sr ratio of JZ-2010 profile表2 JZ-2010剖面Ti、Rb、Sr含量和Rb/Sr值分析统计 |
剖面 层号 | 深度 (cm) | 样品数 | Ti(×10-6) | Rb(×10-6) | Sr(×10-6) | Rb/Sr | ||||
---|---|---|---|---|---|---|---|---|---|---|
范围 | 均值 | 范围 | 均值 | 范围 | 均值 | 范围 | 均值 | |||
1 | 0~17 | 1 | 5507.14 | 5507.14 | 137.79 | 137.79 | 134.86 | 134.86 | 1.02 | 1.02 |
2 | 17~48 | 7 | 3983.31~5542.61 | 4789.88 | 74.70~128.03 | 107.59 | 131.53~161.91 | 145.69 | 0.46~0.97 | 0.75 |
3 | 48~67 | 7 | 5410.70~5723.84 | 5529.43 | 122.57~141.22 | 135.85 | 139.08~153.72 | 145.68 | 0.81~1.00 | 0.93 |
4 | 67~231 | 38 | 4916.00~6679.17 | 5540.96 | 120.89~210.20 | 152.86 | 114.16~177.70 | 141.60 | 0.69~1.73 | 1.11 |
5 | 231~334 | 53 | 4111.02~5872.10 | 5144.86 | 127.67~178.10 | 160.58 | 98.72~113.82 | 108.79 | 1.15~1.62 | 1.48 |
6 | 334~470 | 69 | 5408.69~6722.68 | 5870.51 | 141.44~184.43 | 161.18 | 94.44~125.25 | 106.99 | 1.13~1.76 | 1.52 |
7 | 470~637 | 84 | 4856.58~7998.21 | 6468.43 | 98.78-~151.88 | 125.34 | 95.91~130.63 | 113.43 | 0.76~1.52 | 1.12 |
Fig. 3 Multi-proxy records and comparison of the JZ-2010 Profile图3 江汉平原JZ-2010剖面环境替代指标变化 |
The authors have declared that no competing interests exist.
[1] |
|
[2] |
|
[3] |
|
[4] |
|
[5] |
|
[6] |
|
[7] |
|
[8] |
|
[9] |
|
[10] |
|
[11] |
|
[12] |
|
[13] |
|
[14] |
|
[15] |
|
[16] |
|
[17] |
|
[18] |
|
[19] |
|
[20] |
|
[21] |
|
[22] |
|
[23] |
|
[24] |
|
[25] |
|
[26] |
|
[27] |
|
[28] |
|
[29] |
|
[30] |
|
[31] |
|
[32] |
|
[33] |
|
[34] |
|
[35] |
|
[36] |
|
[37] |
|
[38] |
|
[39] |
|
[40] |
|
[41] |
|
[42] |
|
[43] |
|
[44] |
|
/
〈 | 〉 |