oth higher temperatures <strong>and</strong> an intensified hydrological cycle existed, although the polar light regime was similar to that <strong>of</strong> the present. In the absence <strong>of</strong> evidence <strong>of</strong> cryogenic processes in paleosols, it would be very difficult to determine a high-latitude setting for paleosol formation without independent evidence for paleolatitude. Consequently, paleosols formed at high latitudes under greenhouse conditions, in the absence <strong>of</strong> ground ice, are not likely to have unique pedogenic signatures.
INTEGRATED PALEOPEDOLOGY AND PALYNOLOGY FROM ALLUVIAL PALEOSOLS OF THE CRETACEOUS (CENOMANIAN) DUNVEGAN FORMATION, ALBERTA AND BRITISH COLUMBIA, CANADA: PALEOENVIRONMENTAL AND STRATIGRAPHIC IMPLICATIONS JACOB R. MONGRAIN* AND PAUL J. MCCARTHY Department <strong>of</strong> Geology & Geophysics, <strong>and</strong> Geophysical Institute, University <strong>of</strong> Alaska, Fairbanks, Alaska 99775-5780, USA *Present address: Shell Exploration <strong>and</strong> Production Company, Houston, Texas 77079-1115, USA e-mail: Jacob.Mongrain@shell.com A. GUY PLINT Department <strong>of</strong> Earth Sciences, The University <strong>of</strong> Western Ontario, London, Ontario, N6A 5B7, Canada AND SARAH J. FOWELL Department <strong>of</strong> Geology & Geophysics, University <strong>of</strong> Alaska, Fairbanks, Alaska 99775-5780, USA ABSTRACT: The Dunvegan Formation is a mid-Cretaceous alluvial plain–deltaic deposit exposed along the Rocky Mountain Foothills <strong>and</strong> Peace River Valley <strong>of</strong> Alberta <strong>and</strong> British Columbia, Canada. A multiproxy approach, combining paleosol micromorphology, geochemistry, <strong>and</strong> mineralogy with palynology, is used to reconstruct the climatic, pedogenic, <strong>and</strong> depositional history <strong>of</strong> this high-latitude setting during a greenhouse climate regime. Intrinsic features <strong>of</strong> paleosols within the Dunvegan Formation suggest a warm to cool temperate paleoclimate. These paleosols experienced multiple depositional phases superimposed on pedogenic phases that resulted in complicated compound, complex, <strong>and</strong> welded paleosol pr<strong>of</strong>iles. Well-preserved palynomorph assemblages within the paleosols are composed primarily <strong>of</strong> fern spores, with small percentages <strong>of</strong> gymnosperm pollen. The palynomorphs suggest a humid paleoclimate ranging from cool temperate to subtropical. The abundance <strong>of</strong> fern spores in all <strong>of</strong> the paleosol pr<strong>of</strong>iles suggests early successional colonization <strong>of</strong> the floodplain. Better-developed interfluve paleosols contain greater percentages <strong>of</strong> tree pollen, indicating the presence <strong>of</strong> nearby forests. Within interfluve paleosols, intervals barren <strong>of</strong> pollen coincide with sequence boundaries identified on the basis <strong>of</strong> micromorphology <strong>and</strong> geochemistry. Our combined paleopedological <strong>and</strong> palynological data sets, together with macr<strong>of</strong>loral <strong>and</strong> geochemical paleoclimate indicators, suggest that the Dunvegan alluvial– coastal plain complex probably formed under a humid, warm to cool temperate paleoclimate with a mean annual temperature (MAT) between 12 <strong>and</strong> 14° C <strong>and</strong> mean annual precipitation (MAP) between 1200 <strong>and</strong> 1300 mm yr -1 . These integrated data sets also provide a better underst<strong>and</strong>ing <strong>of</strong> the stratigraphic development <strong>of</strong> the coastal plains.
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