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Physical Sciences and Mathematics Commons

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1985

Environmental Sciences

United States Geological Survey: Staff Publications

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Full-Text Articles in Physical Sciences and Mathematics

Soils And The Location Of Cacao Orchards At A Maya Site In Western Belize, Daniel R. Muhs, Robert R. Kautz, J. Jefferson Mackinnon Jan 1985

Soils And The Location Of Cacao Orchards At A Maya Site In Western Belize, Daniel R. Muhs, Robert R. Kautz, J. Jefferson Mackinnon

United States Geological Survey: Staff Publications

Cacao was one of the most important crops of the lowland Maya. Ethnohistoric sources document that the Postclassic-Colonial Period Maya settlement of Tipu in western Belize was an important cacao-growing center, yet evidence of where the cacao was grown is not apparent. We analysed the suitability of floodplain, terrace, and bedrock soils for cacao cultivation. Our results indicate that the soils most likely to have been used for cacao growth were those on the modem floodplain of the Macal River, based on their suitable physical and chemical properties. In addition, buried stone walls of Late Classic or Postclassic age that …


An Evaluation Of Uranium-Series Dating Of Fossil Echinoids From Southern California Pleistocene Marine Terraces, Daniel R. Muhs, Los Angeles County Museum Of Natural History, Los Angeles, Ca Jan 1985

An Evaluation Of Uranium-Series Dating Of Fossil Echinoids From Southern California Pleistocene Marine Terraces, Daniel R. Muhs, Los Angeles County Museum Of Natural History, Los Angeles, Ca

United States Geological Survey: Staff Publications

Fossil sea urchins (Strongylocentrotus) from Pleistocene marine terraces on the southern California Channel Islands have been dated by the uranium-series method in order to test the suitability of echinoids for dating marine terraces. Results indicate that urchin plates and spines do not behave as closed systems with respect to both uranium and thorium. Calculated ages based on these data do not agree with uranium-series ages (120,000 and 127,000 yrs) obtained previously from corals from the same localities. Thus, fossil sea urchins (Strongylocentrotus) are not considered suitable for uranium-series dating of Pleistocene marine terrace deposits.