陕西九仙洞石笋氧同位素数据集（过去19000年）

利用铀系测年法和稳定同位素分析法，对陕西省九仙洞采集的石笋(C996-1、C996-2)进行了研究。38个钍230年代测定结果表明，石笋C996-1是通过最近的8.5 ka BP(距今1000年，现在=1950年AD)连续沉积的，C996-2是通过最近的19 ka BP沉积的，在8.3 - 5.7 ka BP和15.4 - 11.9 ka BP之间有两次生长间断。在相对稳定的边界条件下，我们解释洞石笋的方解石δ18O主要反映夏季季风降水量，尽管温度和其他因素可能有一些轻微的影响。δ18O记录显示，在末次冰盛期(LGM)内发生了显著的变化，类似于葫芦洞和三宝洞等东亚季风记录，表明在末次冰盛期，东亚北至秦岭的季风气候均发生了明显变化。其他拥有比较精确的记录日期的洞穴堆积物记录也表明δ18O有不断增加的趋势，从全新世期开始，在低纬度季风区域，较早出现在7.5~ka BP，如霍蒂洞，在高纬度地区，这一转变发生稍晚，如董哥洞在7.0~ka BP，和尚洞在~5.3 ka BP，三宝洞在~4.7 ka BP，九仙洞在~4.5 ka BP。这些结果表明，全新世东亚夏季风降水发生了异步变化。这种不同步可能与热带和亚热带季风系统对日晒变化和热力强迫差异的响应有关，这是由复杂的地理结构造成的。热带太平洋西部海面温度(SST)的变化对中国中部和北部夏季季风降水的变化也有重要影响，因为它影响着西北太平洋副热带高压这一季风锋的调节因子。需要更可靠的测试来证实这一现象，并详细评估不同因素的影响。
数据实体包括：
1) 九仙洞230Th测年数据
2) 石笋C996-1与C996-2的氧同位素数据

We conducted research on two stalagmites (C996-1, C996-2) collected from Jiuxian Cave in Shaanxi Province using uranium-series dating and stable isotope analysis. Thirty-eight 230Th dating results indicate that stalagmite C996-1 was continuously deposited over the past 8.5 ka BP (where "present" refers to AD 1950), while stalagmite C996-2 was deposited over the past 19 ka BP, with two growth hiatuses occurring between 8.3–5.7 ka BP and 15.4–11.9 ka BP, respectively.

Under relatively stable depositional boundary conditions, we interpret that the calcite δ¹⁸O values of these stalagmites primarily reflect summer monsoon precipitation amounts, although temperature and other factors may exert minor influences. The δ¹⁸O records show significant variability during the Last Glacial Maximum (LGM), which is consistent with East Asian monsoon records from caves such as Hulu Cave and Sanbao Cave, indicating that the monsoon climate across East Asia north to the Qinling Mountains underwent prominent changes during the LGM.

Other precisely dated speleothem records also reveal an increasing trend in δ¹⁸O starting from the Holocene. This transition first emerged at ~7.5 ka BP in low-latitude monsoon regions, as exemplified by Hoti Cave; at higher latitudes, this shift occurred later: Dongge Cave at ~7.0 ka BP, Shangdong Cave at ~5.3 ka BP, Sanbao Cave at ~4.7 ka BP, and Jiuxian Cave at ~4.5 ka BP.

These results demonstrate asynchronous changes in East Asian summer monsoon precipitation during the Holocene. This asynchrony may be linked to the differential responses of tropical and subtropical monsoon systems to insolation variations and thermal forcing, which are shaped by complex geographic structures.

Variations in sea surface temperature (SST) in the western tropical Pacific also exert critical impacts on summer monsoon precipitation changes in central and northern China, as it modulates the Northwest Pacific Subtropical High (NPSH), a key regulator of monsoon fronts. More robust tests are required to validate this phenomenon and comprehensively evaluate the influences of various contributing factors.

The dataset comprises:
1) 230Th dating data from Jiuxian Cave
2) Oxygen isotope data for stalagmites C996-1 and C996-2