Abstract
Extensive spatial and temporal distribution of high-quality data are essential for understanding regional and global behaviors of the geomagnetic field. We carried out chronological and archaeomagnetic studies at the Angkor-era iron-smelting site of Tonle Bak in Cambodia in Southeast Asia, an area with no data available to date. We recovered high-fidelity full-vector geomagnetic information from the 11th to 14th century for this region, which fill gaps in the global distribution of data and will significantly improve the global models. These results reveal a sharp directional change of the geomagnetic field between 1200 and 1300 CE, accompanied by an intensity dip between 1100 and 1300 CE. The fast geomagnetic variation recorded by our data provides evidence for the possible existence of low-latitude flux expulsion. Related discussions in this paper will inspire a new focus on detailed geomagnetic research in low-latitude areas around the equator, and exploration of related dynamic processes.
Highlights
Archaeological Background and SamplingArchaeological studies identified the Phnom Dek region in north-central Cambodia as an important source of iron during the development of the Angkorian Khmer Empire, and the major periods of expansion between the 11th and 13th centuries CE (Fig. 1A) [14,15,16]
Radiocarbon dating was conducted at the Australian Nuclear Science and Technology Organization (ANSTO)
Accelerator mass spectrometry radiocarbon analysis was carried out using the STAR facility at ANSTO [32] with a typical 1-sigma uncertainty of 0.25–0.3%
Summary
Archaeological studies identified the Phnom Dek region in north-central Cambodia as an important source of iron during the development of the Angkorian Khmer Empire, and the major periods of expansion between the 11th and 13th centuries CE (Fig. 1A) [14,15,16]. Located 135 km east of the Khmer capital of Angkor, this region contains over a dozen sites comprising up to 50 individual mounds consisting of stratigraphic layers with mixed technological debris from the smelting processes. A total of seven trenches were excavated by the Industries of Angkor Project in 2017, uncovering considerable volumes of technical ceramics in the form of tuyères (air-delivery pipes), furnace fragments, and smelting slags (Fig. 1B). We collected oriented samples from the base of F1 and F2 Unoriented samples (tuyères, slags, and furnace fragments) were collected from the south wall of Trench 1 (T1S, SI Appendix, Fig. S4A), the south and west wall of Trench 3 (T3S and T3W, SI Appendix, Fig. S5 A and B), and the west wall of Trench 4 (T4W, SI Appendix, Fig. S6A). Trench 5, located to ∼100 m southeast of Mound 5, was not sampled
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
