Archaeointensity results spanning the past 6 kiloyears from eastern China and implications for extreme behaviors of the geomagnetic field

Abstract

Variations of the Earth’s geomagnetic field during the Holocene are important for understanding centennial to millennial-scale processes of the Earth’s deep interior and have enormous potential implications for chronological correlations (e.g., comparisons between different sedimentary recording sequences, archaeomagnetic dating). Here, we present 21 robust archaeointensity data points from eastern China spanning the past ∼6 kyr. These results add significantly to the published data both regionally and globally. Taking together, we establish an archaeointensity reference curve for Eastern Asia, which can be used for archaeomagnetic dating in this region. Virtual axial dipole moments (VADMs) of the data range from a Holocene-wide low of ∼27 to “spike” values of ∼166 ZAm2 (Z: 1021). The results, in conjunction with our recently published data, confirm the existence of a decrease in paleointensity (DIP) in China around ∼2200 BCE. These low intensities are the lowest ever found for the Holocene and have not been reported outside of China. We also report a spike intensity of 165.8 ± 6.0 ZAm2 at ∼1300 BCE (±300 y), which is either a prelude to or the same event (within age uncertainties) as spikes first reported in the Levant.

More Rapid 14C Excursions in the Tree-Ring Record: A Record of Different Kind of Solar Activity at About 800 BC?

“…Indeed, Cai et al (2017) have also reported on several apparent excursions as high as 165.8 10 21 Am 2 , compared to the average of about 100-110 10 21 Am 2 for~1000 BC (Cai et al 2017), which were suggested earlier by Hong et al (2015). Not only high VADM anomaly, Cai et al (2017) also report a low in VADM about 2200 BC. Sternberg and Damon (1992) indicate that the global production rate of 14 C correlates approximately with the square-root of the magnetic field intensity.…”

Recent Advances in Chinese Archeomagnetism

“…de) (Brown et al, 2015) with the exception of data published by Deng and Li (1965); IGCAS (1977); Wei et al (1980), and Yang et al (1993a,b) and the recent work of Cai et al (2014Cai et al ( , 2015Cai et al ( , 2016Cai et al ( , 2017. The former three are absent from the database probably because they were originally published in Chinese.…”

“…A few results were then published in the 1990s (Tang et al, 1991;Yang et al, 1993a,b;Shaw et al, 1995Shaw et al, , 1999Batt et al, 1998;Huang et al, 1998). After that, archeomagnetic studies in China ceased for ∼15 years before revival in the current decade (Cai et al, 2014(Cai et al, , 2015(Cai et al, , 2016(Cai et al, , 2017.…”

“…The archeointensity data published in recent years by Cai et al (2014Cai et al ( , 2015Cai et al ( , 2017 were selected with different criteria, making the data quality inconsistent. In this paper, we combined all the measurement data from each paper and reanalyzed the data with the "Thellier Auto Interpreter" function incorporated in the Thellier GUI software (Shaar and Tauxe, 2013) included in the PmagPy software package .…”

“…"GEOMAGIA_int" and "GEOMAGIA_dir" represent locations of published archeointensity and archeodirection data from the GEOMAGIA50.v3 database. "New_pub int" and "New_pub dir" represent locations of archeointensity and archeodirection data published in the recent years (Cai et al, 2014(Cai et al, , 2015(Cai et al, , 2016(Cai et al, , 2017. "old int not in GEOMAGIA" and "old dir not in GEOMAGIA" represent locations of archeointensity and archeodirection data published in the twentieth century but not included in the GEOMAGIA database (Deng and Li, 1965;IGCAS, 1977;Wei et al, 1980;Yang et al, 1993b).…”