CATEGORY: geology DEFINITION: Roughly equal parts sand and clay; a fine-grained material that is plastic and cohesive when wet but makes hard clods when dry.
SYNONYMS OR RELATED TERMS: loehm, lehm CATEGORY: geology DEFINITION: A texture of soil used to describe a mixture of less than 52% sand, 28-50% silt, and 7-27% clay. Loams are agriculturally productive and have good drainage qualities. There are other loamy textures with different percentages of the materials.
CATEGORY: geology DEFINITION: Sandy sediment containing enough clay and silt to make it hold together rather than falling apart; consists of 50% sand, 30% silt, and 20% clay.
CATEGORY: geology DEFINITION: A mixture of at least 50% silt and sand and 12-25% clay that feels somewhat silky and forms clods when dried out (clods break into soft, flourlike powder).
CATEGORY: site; artifact DEFINITION: A small valley in southern England with an important series of loams and gravels spanning the last two glacial periods and intervening interglacial. Stone tools included Levallois flakes, but only a few hand axes and other tool types were found. The area has also given its name to a decorated potterystyle of the Neolithicperiod. The first Jutes, Hengist and Horsa, landed at Ebbsfleet in the Isle of Thanet in 449 AD.
Swanscombe, Barnfield Pit
CATEGORY: site DEFINITION: British Lower Palaeolithic site on a terrace of the lower Thames Valley, North Kent, England, with a skull of possibly an archaic Homo sapiens with strong Neanderthal features. The skull bones are considerably thicker than those of modern European or Neanderthal skulls; the skull pieces may be the oldest of Homo sapiens found in Europe. More recent opinion holds that the skull is non-sapiens and has closer affinities with those of Neanderthal type. There is a succession of artifact-bearing strata of the Mindel-Riss interglacialperiod (400,000-200,000 years ago), with the earliest tools of Clactoniantype. Middle Acheulian handaxes and a pointed bifaceassemblage were found in the Middle Gravel level and in the Upper Loam level, Middle Acheulian tools of a more evolved form and a refined ovateassemblage. The deposits contain useful environmental evidence, including abundant mollusk and mammal remains and large assemblages of stone tools.