TUNG KWU ISLAND
79
or saucer, painted with an open flower in underglaze blue, crudely executed and very badly glazed; and the third, found at 78 cm. in the sandbank, was a bronze button wrapped in a fragment of coarse cloth, hollow and containing a small object which rattles. I interpret this as a fragment from a modern burial: its depth is noteworthy.
A group of late pottery fragments is recorded on my last visit but one to the site. Three of them were at 69, 71 and 76 cm. from the surface, and one, probably a piece of tile, at 61 cm. They were near the north end of the west beach, where rainwash from the hill has increased the depth recordings compared with those on the sand isthmus. Other pieces of tile, with textile impressions on their concave sides, and gray in colour, apparently old-fashioned, lay at 1 m. depth in rainwash 25 m. north of the group described. These tiles evidently mark an occupation level, most likely fishermen's huts of the Yuan or later period; some of the fishermen may even have been using pieces of porcelain left behind by the Sung court after its retreat from the Kowloon district to its final end on the Ngai Mun mouth of the West River. The accumulation of rainwash over this level points to the island's deforestation as having started about the Sung period, when Chinese immigration from the north had increased the population, and with it the demand for timber and firewood, as the log runways on the Lantau hills testify.
PUMICE
An interesting feature of the site is a layer, roughly 32 cm. thick, and from 75 to 107 cm. from the surface, containing fairly numerous rolled pebbles of pumice, stained yellow by the sand. It is confined to the east shore of the isthmus. This layer evidently points to an eruption that took place in Japan or the Philippines, possibly submarine, and coming from a magma of the acid type rather than the basic, from which the 'froth' was expelled by explosions, and was drifted by wind and currents on to the Tung Kwu beach. Similar beds of ancient pumice are found at eight other sites in the Colony, very likely more, and give a very useful datum line for correlation, like a zone fossil in geology.
This holds good also in some sites on the Tonkin (North Vietnam) coast visited by Dr. Andersson in 1938; his results were published in the Stockholm journal of the Museum of Far Eastern