The Lewis Camp Mound: An Example of a Petrocalcic Horizon in Jefferson County, Florida
0
Citation
0
Reference
17
Related Paper
Abstract:
Soil scientists have described petrocalcic soil horizons, commonly referred to as caliche, from the southwestern United States for quite some time. Caliche normally occurs in semi-arid climates where evapotranspiration exceeds rainfall. In more arid climates, the repeated process of illuviation and precipitation of CaCO3 forms subsurface accumulations of CaCO3 or other carbonates. To the authors’ knowledge, petrocalcic soil horizons have not been reported in the southeastern United States, quite probably because environmental conditions are not normally favorable for such development. While soil scientists may not have been aware of petrocalcic horizons in the southeastern United States, archaeologists have noted their presence for some time. They are usually found within specific sites called middens, which are generally refuse piles, deposited by Native Americans. Many of these middens contain large quantities of shells, in addition to bones of various mammals, birds, fish and turtles, ceramic vessel fragments and lithic tool-making byproducts. The Lewis Camp Mound (08 Je00182) is one such midden, composed primarily of apple snail (Pomacea paludosa) shell material, with lesser amounts of banded mystery snail (Viviparus georgianus), freshwater mussel (e.g., Elliptio spp.), and several saltwater species including oyster (Crassostrea virginica) and great ark (Dinocardum robustus). The site was initially investigated in the summer of 1999, at which time the petrocalcic horizon was thought to have been the underlying bedrock. Subsequent fieldwork, conducted in September 2003 and in June 2006, has added to our knowledge of the age of the site, and provided insights into the formational processes which have occurred. This paper will discuss several explanations archaeologists have suggested for the formation of petrocalcic layers in middens, as well as the age and cultural occupations relating to the Lewis Camp Mound.Keywords:
Midden
Bedrock
Cite
Paleosol
Early Pleistocene
Cite
Citations (5)
Abstract A visually prominent desert soil with a horizon of clay accumulation (Typic Natrargid) has formed under an arid climate in Panamint Valley, California, in sandy, very calcareous, saline fan alluvium in less than about 3500 yr, and probably less than 2000 yr. Such soils can be used as stratigraphic markers, but could be confused with other desert soils with clay-accumulation horizons (Haplargids) which occur much more commonly on desert alluvial fans, are mostly late Pleistocene or older, and do not form in parent materials that are still calcareous. This Natrargid formed in a playa-margin environment, where clay for translocation and sodium salts that engender rapid clay movement probably were provided by dust fall.
Alluvial fan
Paleosol
Desert (philosophy)
Alluvial plain
Cite
Citations (52)
Landform
Soil horizon
Cite
Citations (48)
A study area in an arid region of southern New Mexico is in basin-and-range topography and includes both a river valley and a closed basin. Holocene soils occur in valley fills and low terraces between Pleistocene fans, in and near drainageways on the fan-piedmont, on ridges, and in dunes. Holocene soils suggest the character of initial development in soils that are much older and more complex, and record the beginnings of various soil horizons. Noncalcareous brown or reddish brown B horizons have formed in low-carbonate parent materials of stable sites. Incipient development of the argillic horizon and the Haplargids occurs at stable sites in very gravelly materials that are about 1–2000 yr old. The cambic horizon and Camborthids occur in adjacent low-gravel materials of the same age. The argillic horizon occurs continuously in soils of earliest Holocene, particularly in very gravelly materials. Where soils have been truncated, as in areas affected by landscape dissection, argillic and cambic horizons are usually absent and the soils are Torripsamments, Torriorthents, or Torrifluvents depending on content of sand, gravel, and organic carbon. In high-carbonate parent materials, noncalcareous, reddish brown B horizons have not formed at any time in the Holocene. Most of these soils are Torriorthents or Torrifluvents although an incipient calcic horizon has formed in some of the oldest Holocene soils; the latter are Calciorthids. Horizons of carbonate accumulation are the best and most common pedogenic indicators of soil age. Stage I carbonate horizons are a major feature of pedogenesis in the Holocene. Because of additions of carbonate from the atmosphere, carbonate horizons are morphologically similar whether they have formed in high or low-carbonate alluvium. The carbonate accumulations are illuvial. Some Holocene deposits apparently resulted from changes in climate. Others, such as the youthful deposits of coppice dunes, apparently were caused by man's introduction of cattle and subsequent overgrazing and seed dispersal.
Paleosol
Soil horizon
Cite
Citations (97)
Biome
Paleosol
Cite
Citations (20)
Paleosol
Basement
Laterite
Cite
Citations (14)
Abstract Radiocarbon ages have been obtained from seven buried charcoal horizons in a desert area of southern New Mexico. Several deposits of highly calcareous alluvium range in age from less than 1,100 to somewhat greater than 5,000 years and are therefore of Recent age. Pleistocene deposits much older than 5,000 years also occur. Pleistocene soils of adjacent topographic highs were a major source of the Recent sediments. Evidence in this area indicates that the present climate is warmer and drier than the Pleistocene pluvial climates. This change to a drier and warmer climate could have decreased the vegetative cover in places and started strong erosion of Pleistocene soils in these areas. The dated charcoal also establishes a maximum, and in some instances a minimum age for several soils formed in the deposits. With increasing age of soil during Recent time, the progression of soil development appears to have been marked by development of an A horizon, destruction of thin sedimentary strata, slight accumulation of carbonate, development of structure in materials of sufficiently fine texture, and, with continued carbonate accumulation, development of a weak calcic horizon. In contrast, soils of Pleistocene age can have distinct argillic horizons and strong horizons of carbonate accumulation. It is postulated that the wetter climates of Pleistocene pluvials, associated with greater vegetative cover and landscape stability, were required for development of argillic horizons in these highly calcareous parent materials.
Pluvial
Charcoal
Early Pleistocene
Cite
Citations (30)
Abstract In a study area of southern New Mexico, horizons in the B position may be ordered in degrees of increasing development, and form an essentially continuous series closely related to age. No evidence of soil development is found in freshly deposited arroyo alluvium. Next in the developmental scale are horizons with some weak evidence of soil formation, but which are still too weakly developed to qualify as cambic horizons. With increasing age, cambic horizons and finally argillic horizons occur in the B position. The relationships of soil development to age are confounded in some older soils by such factors as soils truncation and soil mixing. Distinct cambic horizons have formed in soils that are less than about 5,000 years old. In various cambic horizons there has been sufficient alteration of the original parent material to destroy fine strata, form structure, develop redder color, redistribute carbonate, and accumulate slight amounts of silicate clay. Cambic horizons of old, polygenetic soils show evidence of profound change in the B position since deposition of the parent materials and the start of soil formation. Argillic horizons apparently formed in some soils and were later destroyed. Some soils once had much thicker B horizons than they now have. The present climate of this desert region is arid, but evidence of former glaciation and lakes indicates a climatic change. The present climate is apparently warmer and drier than the climates of Pleistocene pluvials. Soils formed mainly in the Pleistocene tend to have thicker, stronger horizons than do soils formed in the Recent; this is apparently caused in part by the Pleistocene pluvial climates.
Cite
Citations (22)
Archaeological sites within physically “active” soils, such as Vertisols, are considered suspect by archaeologists because of concern for possible disturbance of stratigraphic context. Pedology, micromorphology, and geochemistry are tools useful for assessing soil mixing. Clay‐rich floodplain soils (Typic Haplusterts) were examined at the Debra L. Friedkin archaeological site along Buttermilk Creek in southwestern Bell County, Texas, USA. The soil contains abundant lithic (mainly chert) artifacts and was assessed for disturbance by vertic soil processes affecting the stratigraphic integrity of the archaeological materials. Vertic features are only weakly to moderately expressed (slickensides and coarse angular blocky peds) in the field, and they are correspondingly weakly expressed in thin section, consisting mainly of stress cutans around detrital grains, microslickensides, and cross‐striated birefringence fabric. Although there is evidence for clay shrink–swell, there has not been significant upward vertical displacement of older materials and no mixing of cultural horizons. Vertical fractures with dark infilling in gilgai microhighs are deep and narrow, and largely preclude downward movement of even small artifacts. Microdebitage is abundant in all levels within the soil profile above culturally sterile layers dated as >15,500 cal. yr B.P. Based on previously published OSL ages and magnetic susceptibility, sedimentation at the site was nearly continuous except for increases during the Younger and Older Dryas, possibly triggered by climate change, and subsequent pedogenesis resulted in uniform element leaching and concentration depth profiles. Vertisols can preserve “undisturbed” Paleoindian archaeological sites and therefore should not be excluded from archaeological surveys and excavations.
Vertisol
USDA soil taxonomy
Colluvium
Cite
Citations (33)