2), possibly a result of aclimate considerably dryer and more seasonal thantoday.
Kealhofer (2003)notes that the burnt phytoliths(identiﬁed by the presence of black (charred) organicmaterial encased in the phytoliths) predominantly derivefrom grasses, suggesting the presence of a woodlandsavannah that was burned regularly.
Possible relationships between theenvironmental changes and cultural and/or climatic impacts are discussed. Its peninsular exposure to the southwestmonsoon traversing the Indian Ocean and northeastmonsoon traversing the Paciﬁc, as well as its inland andcoastal environs, argue that palaeoenvironmental se-quences from the region should have great potential tocontribute important insights into the climate history for Asia.
In the text that follows we employ, a priori, thefollowing conventions for the subdivision of the late Quaternary, which are based primarily on the climatephases described by Maxwell and Liu (2002).
Rockshelter siteswithin 75km to the northwest and southeast of the lakereveal a cultural sequence with: (1) an upper Palaeolithichabitation characterized by a ﬂake and core industrydating from ca. to younger than ca.26,000bp uncal.; followed by (2) a terminal Pleistocene/early Holocene Hoabinhian occupation characterized byﬂaked core tools; (3) an early to middle Holocene stoneage occupation here termed ‘‘late lithic’’ characterizedby ﬂaked stone tools, polished stone adzes, and potteryfragments; followed by (4) pottery-using and presum-ably agricultural groups by at least 4000 years ago(Anderson, 1990, 1997; Pookajorn, 1996; Bellwood, 1997, pp. The NTSH core, which comprises four core sections,has a date of 21,170 7 90bp uncal.
at 222–226cm depth(Beta-106538, see Table 1) preceding the beginning of the last glacial maximum.
The ‘‘strength’’ of each micro-fossil identiﬁcation, or the conﬁdence the analyst has inthat identiﬁcation, is indicated by the sufﬁxes ‘‘sim.’’(used when a microfossil type is similar , but notidentical, to known microfossil types), ‘‘comp.’’ (themicrofossil is comparable to known types, but there is agreater degree of uncertainty), or ‘‘id.’’ (only used herein binomial classiﬁcations where the analyst wishes toindicate that the identiﬁcation of the genus is certain butthe species is not; e.g., Podocarpus id. A chronology for the three sites is provided by a totalof 18 radiocarbon dates (Table 1).
In all cases excludingone (OZC-319), age determinations were based onundifferentiated organic material.