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.
Understanding the development of Asia’s mon-soon climate, moreover, is fundamental to understand-ing its role as one controlling factor for the naturalresource base and agriculture for half the world’spopulation (Maxwell and Liu, 2002, p. Until recently, however, no sediment records frommainland Southeast Asia dating from the late Pleisto-cene had been extracted and analyzed for palaeovegeta-tion and other environmental changes.
It thus incorporatesthe ﬁrst of two ‘‘surges’’ in the strength of the southwestmonsoon (Maxwell and Lui, 2002, p.
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.Moreover, the environmental context for humanhabitation in mainland Southeast Asia and the natureand magnitude of human impact on the region’senvironments are poorly understood, despite havinglong been the subject of interest and debate amongprehistorians of the region. All rights reserved.doi:10.1016/j.quaint.20 change, primarily from lake sediment cores, in threeareas of Thailand with important prehistoric culturalsequences (Fig. These areas also represent environ-ments that contrast in latitude, altitude, rainfall, andother variables.Only recently have archae-ological data from mainland Southeast Asia, and Thailand speciﬁcally, become sufﬁciently robust thatthe relationship between cultural and environmentalchange can begin to be addressed from empirical bases. In each area, a primary criterion forchoosing a lake for coring was its potential to yield asequence of signiﬁcant, hopefully late Pleistocene-aged,time-depth. Methods Sediment cores were extracted from three lakes in thesouth, north, and northeast of the country (Fig. Coring was conducted by Kealhofer and White, and cores were analyzed forpollen by Penny and Maloney and for phytoliths by Kealhofer.