Publications by authors named "Richard A Mortlock"
Most paleoclimate studies of Mainland Southeast Asia hydroclimate focus on the summer monsoon, with few studies investigating rainfall in other seasons. Here, we present a multiproxy stalagmite record (45,000 to 4,000 years) from central Vietnam, a region that receives most of its annual rainfall in autumn (September-November). We find evidence of a prolonged dry period spanning the last glacial maximum that is punctuated by an abrupt shift to wetter conditions during the deglaciation at ~14 ka.
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- Recent findings in West Turkana, Kenya, challenge the assumption that the earliest stone tools were made by the genus Homo and linked to climate change and savannah grasslands.
- *The Lomekwi 3 site, dated at 3.3 million years old, reveals ancient hominin tools found alongside fossils in a wooded environment, indicating an earlier technological development.
- *The term 'Lomekwian' is proposed for this discovery, suggesting a new phase in archaeological history that predates the known Oldowan tools by 700,000 years.*
The origin and evolution of early Pleistocene hominin lithic technologies in Africa occurred within the context of savanna grassland ecosystems. The Nachukui Formation of the Turkana Basin in northern Kenya, containing Oldowan and Acheulean tool assemblages and fossil evidence for early members of Homo and Paranthropus, provides an extensive spatial and temporal paleosol record of early Pleistocene savanna flora. Here we present new carbon isotopic (δ(13)CVPDB) values of pedogenic carbonates (68 nodules, 193 analyses) from the Nachukui Formation in order to characterize past vegetation structure and change through time.
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