Calcic versus non-calcic paleosols as an indicator of Cretaceous paleoclimatic changes in the western interior of North America

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5808213

Buck, B J; Mack, G H ^[1]

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1. New Mexico State Univ., Las Cruces, NM (United States). Dept. Earth Sciences

Retention of calcium carbonate in a soil is an indicator of relatively dry climate, generally less than 75 cm of annual precipitation. Cretaceous calcic paleosols are widespread in the Western Interior of North America at two stratigraphic levels: upper Lower Cretaceous (Aptian and Albian)0 and Upper Cretaceous (upper Maastrichtian). Aptian and Albian calcic paleosols are characterized by stage 2 morphology calcic nodules and tubules (Bk horizon) or stage 3 morphology massive carbonate beds (K horizon) that are overlain by structural B (Bw) or argillic B (Bt) horizons, and have been documented in central Texas, southern New Mexico, central Utah, and southwestern Montana. However, Albian paleosols in British Columbia lack pedogenic carbonate and have features that more commonly form in subhumid or humid climates. Upper Maastrichtian calcite paleosols are similar in appearance to those of the Lower Cretaceous and have been described in west Texas, southern New Mexico, central Utah, and Alberta. In contrast, the majority of paleosols in Cenomanian through lower Maastrichtian rocks lack pedogenic carbonate and some are associated with coal, suggesting subhumid or humid paleoclimate. In southern New Mexico these paleosols are olive-gray, display A, E, Bt, and C horizon, and resemble modern Alfisols. The argillic B horizons (Bt) contain large vertical root traces, blocky peds, and grain and ped argillans. These features, plus the fact that some of the paleosols are associated with large (up to 1 m diameter) in situ petrified stumps, indicate a woodland setting. Future models of Cretaceous paleoclimate need to incorporate the type and distribution of paleosols in order to develop a more accurate picture of paleoclimatic changes through time.

• OSTI ID: 5808213
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CRETACEOUS PERIOD
PALEOCLIMATOLOGY
NORTH AMERICA
SOIL CHEMISTRY
ALBERTA
ATMOSPHERIC PRECIPITATIONS
BRITISH COLUMBIA
CALCIUM CARBONATES
CLIMATE MODELS
CLIMATIC CHANGE
ECOLOGICAL CONCENTRATION
NEW MEXICO
TEXAS
UTAH
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CANADA
CARBON COMPOUNDS
CARBONATES
CHEMISTRY
DEVELOPED COUNTRIES
GEOLOGIC AGES
MATHEMATICAL MODELS
MESOZOIC ERA
OXYGEN COMPOUNDS
PALEONTOLOGY
USA
580000* - Geosciences