Sunday 18 February 2024

Understanding the orientation of graves in the Bronze Age Gumugou Cemetery of Xinjiang Province, China.

Many cultures bury their dead with a preferred orientation, and understanding how this is chosen can tell us a great deal about the beliefs of a culture. The orientation of graves has been extensively studied for ancient European and Mediterranean cultures, demonstrating that burials were often aligned with both terrestrial and celestial objects of importance by ancient peoples, but has been less well studied in other parts of the world.

In a paper published in the Journal of Archaeological Science: Reports on 17 February 2024, Jingjing Li of the Xinjiang Astronomical Observatory, Jarken Esimbek, also of the Xinjiang Astronomical Observatory, and of the University of the Chinese Academy of Sciences, and Yingxiu Ma, again of the Xinjiang Astronomical Observatory, examine the orientation of graves in the Bronze Age Gumugou Cemetery of Xinjiang Province, China.

The Gumugou Cemetery is located on the eastern fringe of the Taklimakan Desert, in the Tarim Basin, to the north of the now dry Kongque (Peacock) River and about 70 km to the west of the Lop Nor Salt Lake. The cemetery has been dated to between 3800 and 3400 years before the present, and along with a series of related sites within the region between Lop Nor and the Taklimakan Desert, is considered representative of one of the oldest known Bronze Age cultures within Xinjiang Province.

Location of the Gumugou Cemetery and other archaeology sites in the Tarim Basin, Xinjiang. Li et al. (2024).

The Gumugou Cemetery site was excavated in the winter of 1979 by an expedition from the Xinjiang Institute of Archaeology under the leadership of Binghua Wang. A total of 42 burials were discovered and excavated, all within an area of 1600 m³. The burials could be divided into two types, with six Type I burials forming an upper layer, and 36 Type II burials forming a lower layer. 

The Type I burials are quite often placed above Type II burials, and are surrounded by seven rounds of timber posts. These Type I burials apparently contained wooded coffins, which have long decayed away, leaving the (well preserved) Human remains exposed. A small amount of grave goods were present. 

Surface of Type I burials of the Gumugou site. Li et al. (2024).

Type II burials form a lower layer and each contain a single body placed within a boat-shaped coffin between two posts, one at the head of the coffin and one at the feet. These contained more numerous grave goods, including pointed felt hats, leather, woollen capes, grass woven baskets, bone and stone artifacts, wheat grains, and Ephedra twigs. While grave goods were more numerous in the Type II burials than the Type I burials, there was otherwise little to differentiate them, and they are presumed to have come from the same culture.

Part of Type II burials of Gumugou Cemetery. Binghua Wang in Li et al. (2024).

The tombs are aligned roughly along an east-west axis, with their heads to the east, which, combined with the posts surrounding the Type I burials, which resemble solar rays, was taken as evidence of sun-worship by the people who used the cemetery.

However, Wang took care to record every detail about the graves, including the azimuth of each burial (the azimuth is an orientation relative to true north, where north is 0°, east is 90°, south is 180°, etc.). Li et al. collated this data, and compared it to a calculated solar arc for sunrises at the site. A solar arc of sunrises is made up of the azimuth of the sunrise throughout the year, giving an arc (in the Northern Hemisphere) with the Summer Solstice to the north and the Winter Solstice to the south. At the Gumugou Cemetery the sunrise azimuth is 57.7° on the summer solstice and 120.8° on the winter solstice, while the graves have azimuths of between 102° and 58°.

Orientations of the grave in Gumugou cemetery. Li et al. (2024).

The region where the Gumugou Cemetery is located has an arid desert climate with temperatures reaching as high as 40°C in the summer and falling as low as -20°C in the winter, and strong winds in spring and autumn leading to dust storms which can cause potentially lethal respiratory illnesses. The graves in the cemetery contain men and women, adults and children, with no apparent connection between age and/or gender of the occupant and the type of burial, the amount of grave goods, or the orientation of the grave. 

The graves vary in orientation, but are clustered around azimuth directions of 90° and slightly north of this. If the graves were orientated in line with the orientation of the sun at the time of burial, as Li et al. suspect, then the overwhelming majority of the dead would have been buried at or around the Spring and/or Autumn Equinoxes. Since it is unlikely that people were only dying at these times of year, Li et al. instead suggest that the graves represent secondary burials, with the dead being stored elsewhere until the favoured season of funerals.

Histogram of aligned skeletons. Li et al. (2024).

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