A late quaternary pollen record from Cedarburg Bog, Wisconsin

Late Quaternary (from the last glaciation to present) forest history is inferred from the Cedarburg Bog fossil pollen record. Analysis of fossil pollen samples extend over 4 meters of continuous core recovered from near the center of the bog. The deepest and oldest of the fossil pollen assemblages (ca. 12,000 years ago) suggest open spruce woodlands unlike any in the contemporary boreal ecosystem. Pollen from the Pleistocene-Holocene transition (11,000 years ago) is marked by a number of abrupt changes in forest composition related to rapid climate change, species immigration, and progressive soils and ecosystem maturation. By 9,000 years ago most of the modern forest plant species were established. These mixed deciduous forests persisted until the historical deforestation

Late Quaternary Pollen Record From Cheyenne Bottoms, Kansas

A sediment and pollen record from Cheyenne Bottoms, a large (166 km2) enclosed basin in central Kansas, provides evidence for local and regional vegetation and climate change during the late Quaternary (ca. 30,000 yr.). Although radiocarbon dating of the carbonate-rich lacustrine sediments remains problematic, a basic chronological framework for the section is established. Two major litho- and biostratigraphic units, a Farmdalian zone (ca. 30,000 to 24,000 yr B.P.) and a Holocene zone (ca. 11,000 yr B.P. to present), are separated by a major unconformity spanning the Woodfordian (ca. 24,000 to 11,000 yr B.P.). Pollen and sedimentary data indicate a period of basin-wide drying preceding this unconformity. The sustained absence of sediment accumulation within this playa-like basin suggests that early Woodfordian conditions were increasingly arid with strengthened surface winds. Before this, persistent shallow water marshland dominated the local basin-bottom vegetation. Regional upland vegetation was an open grassland-sage steppe throughout the Farmdalian with limited populations of spruce, juniper, aspen, birch, and boxelder in riparian settings and escarpments. Throughout the Holocene, water levels within the basin fluctuated. Changes in wetland vegetation resulting from water level fluctuation have increased during the last 3,000 yr indicating that periodic episodes of wetland loss and rebound are not unique to postsettlement conditions but are an ongoing phenomenon at Cheyenne Bottoms

Aeolian cliff-top deposits and buried soils in the White River Badlands, South Dakota, USA

Aeolian deposits in the North American Great Plains are important sources of Holocene palaeoenvironmental records. Although there are extensive studies on loess and dune records in the region, little is known about records in aeolian cliff-top deposits. These are common on table (mesa) edges in the White River Badlands. These sediments typically have loam and sandy-loam textures with dominantly very fine sand, 0.5–1% organic carbon and 0.5–5% CaCO3. Some of these aeolian deposits are atypically coarse and contain granules and fine pebbles. Buried soils within these deposits are weakly developed with A-C and A-AC-C profiles. Beneath these are buried soils with varying degrees of pedogenic development formed in fluvial, aeolian or colluvial deposits. Thickness and number of buried soils vary. However, late-Holocene soils from several localities have ages of approximately 1300, 2500 and 3700 14C yrs BP. The 1300 14C yr BP soil is cumulic, with a thicker and lighter A horizon. Soils beneath the cliff-top deposits are early-Holocene (typically 7900 but as old as 10000 14C yrs BP) at higher elevation (approx. 950 m) tables, and late-Holocene (2900 14C yrs BP) at lower (approx. 830 m) tables. These age estimates are based on total organic matter 14C ages from the top 5 cm of buried soils, and agreement is good between an infrared stimulated luminescence age and bracketing 14C ages. Our studies show that cliff-top aeolian deposits have a history similar to that of other aeolian deposits on the Great Plains, and they are another source of palaeoenvironmental data

Wilson-Leonard An 11,000-year Archeological Record of Hunter-Gatherers in Central Texas Volume V: Special Studies

Study of the archeology of the Wilson-Leonard site has opened broad new vistas for the reexamination and improved interpretation of regional prehistory. Beyond that, it is of national importance in terms of both data and interpretation (for example, on the Paleoindian era) and the concepts used in its excavation and analysis. It is unique in other ways. In most cases, deep, stratified, multicomponent sites of this integrity are rarely excavated (in Texas, at least) more than once and the potential for long-term research is not fully met. As the reader will learn, Wilson-Leonard was first excavated on a large scale by archeologists of the Texas Department of Trans-portation (TxDOT) from 1982-1984 but was not formally published. Much attention went, deservedly, to the discovery of a Paleoindian burial at the site. Beginning in 1991, the Texas Archeological Research Laboratory was contracted by TxDOT to evaluate the records from the excavations and to make recommendations on the preparation of a comprehensive report. Given the many changes that had occurred in the technology of archeological excavation and the rise of new theoretical and analytical approaches, the TxDOT data appeared to be insufficient for more than a descriptive study. Yet, it was clear that the rich body of information from Wilson-Leonard warranted more than that. Thus, Michael B. Collins and his staff recommended that a second major excavation be undertaken in order to provide a better context for the TxDOT materials. Further, the findings from both excavations would then be fully integrated into a final report. Thanks to the foresight of Kenneth Bohuslav and Ann Irwin at TxDOT, this proposal was accepted and excavations directed by Collins were carried out in 1992-1993