Aureal T. Cross

Source and distribution of palynomorphs in bottom sediments, southern part of Gulf of California

Abstract Detailed analyses are given of bottom surface sediments from about 150 cores in the southern half of the Gulf of California and preliminary analyses are given of another 100 bottom sediment samples from throughout the Gulf. Additional background data from the study of several hundred stream and surface sediment samples from surrounding regions in Mexico are drawn upon to aid in the interpretation of the distribution of the pollen and spores found. Conditions and characteristics of environment, plant distribution, structure of the basin, geomorphology of the surrounding area, air and water circulation, sedimentation and biology of the Gulf and adjacent regions which affect the dispersal of palynomorphs in the Gulf are reviewed. Sources of samples and methods of sampling bottom sediments and terrestrial sediments are given and preparation and study procedures are reviewed. Quantitative as well as qualitative analyses are made of all samples. About 120 sample localities along 9 transects across the southern part of the Gulf have been plotted on map-graphs to show, diagrammatically, the depth of samples, bottom profiles and sand-silt-clay ratios along the transects. On the same cross-sections, the absolute or relative frequencies of total pollen and spores, pine pollen, pollen of Chenopodiaceae and Amaranthaceae (Cheno-Ams), grass pollen, cuticles, tracheids (> 50 μ ), fungal spores and dinoflagellates are plotted for direct comparison with bathymetrical, sedimentological and geographical features. Three maps show, by isopleths, generalized distribution of total pollen and spores, pine pollen and Cheno-Ams pollen for the entire Gulf; three similar maps show detailed areal distribution in the southern half of the Gulf of oak pollen, fungal spores, dinoflagellates, microforaminifera (those with acid-resistant inner membranes, only) and an unidentified palynomorph of wide distribution. Additional information given on maps includes bathymetry, wind and sedimentation patterns and regional distribution of pine forests (generally the same pattern defines oak distribution). A table lists the species or groups of entities, their agencies of pollination and the general abundance of the pollen and spores in the bottom sediments of the Gulf. Results of the present studies show different types or groups of palynomorphs per gram of dried bottom sediment vary from a few thousand to 80.000 for the pollen-spore sum; a few hundred to over 20,000 pine; a few to over 4,000 oak; a few to over 12,000 Cheno-Ams; up to 8,000 grass, 2,000 to 25,000 cuticle fragments, up to 100,000 tracheids larger than 50 μ and up to 3,000,000 tracheids between 5 and 50 μ; up to 22,500 fungal spores; up to 17,000 dinoflagellates and up to 6,250 microforams. Others less regular in their dispersal but significant in frequencies are Rhizophora , Buxaceae, Bursera , Fouquieriaceae, Yucca (up to 3,000 grains/g), Cyperaceae (abundant), Compositae (very abundant), Zea (up to 3,000 grains/g), juniper and alder. Comparisons made of several palynomorphs show high concentrations in silty clays, at delta mouths, and in some submarine channels. Low concentrations occur along some shores probably due to dilution by terrigenous sediment and winnowing from coarse sediments but high concentrations build-up immediately beyond zones of coarse sediments offshore. Some palynomorphs diminish in number with greater distance from shore (e.g., total spores and pollen, grass, Cheno-Ams, composites, Zea ) whereas others become selectively increased in relative frequencies offshore (e.g., pine, mangrove) or in absolute frequency (e.g., dinoflagellates, O sp-1, an unknown entity). Cuticles and tracheids delineate shorelines and deltas and a striking parallelism between absolute frequency of dinoflagellates and relative frequency of fungi deserves further study. Dispersal of pollen and spores by streams and water currents (and in areas of upwelling and through submarine canyons to offshore deeps as submarine fans) appears to be far more important than wind distribution for the Gulf of California area.

Coal-ball floras of Maritime Canada and palynology of the Foord seam: geologic, paleobotanical and paleoecological implications

Abstract Coal balls in the Canadian Carboniferous System are known from the Clifton Formation (late Bolsovian) of New Brunswick and from the Foord seam (Stellarton Formation, late Bolsovian) of the Stellarton Basin of Nova Scotia. Coal balls from these two units are dominated by arborescent lycopods but ferns, seed ferns, calamiteans, and cordaiteans also occur. Baxters list (Baxter, 1960) of coal-ball plants from New Brunswick is updated and these fossil plants are illustrated here for the first time on the basis of an examination of his peels. The palynomorphs and coal-ball plants of the Foord seam of the Stellarton Basin are illustrated and their paleoecology is discussed. Five genera of arborescent lycopods were present in the Foord swamp: Diaphorodendron, Paralycopodites, Lepidophloios, Sigillaria and Lepidodendron. The first three genera are represented in coal balls; the second two are also represented as compressions in the Foord seam; and all genera are represented in the spore assemblages from the Foord seam. The palynostratigraphy indicates that Sigillaria and Diaphorodendron were almost exclusively confined to the upper bench, whereas the other three genera were probably present in the Foord mire throughout its entire history. Palynomorphic changes in the Foord mire probably reflect gradual changes in wet and dry conditions.

Palynostratigraphy of Upper Cretaceous-Lower Tertiary strata, Price Canyon, Utah

Abstract Palynological analysis of the Price Canyon section in east-central Utah, USA, confirms a late Campanian to late Paleocene age for the interval of Castlegate Sandstone, Price River Formation, and North Horn Formation. This 1100 m thick section represents a series of transgressive-regressive cycles of intertonguing coastal plain, fluvial, coastal margin and nearshore marine sedimentary deposits. Forty-five palynologically productive samples were analyzed. Ranges of the species or generic groups of palynomorphs were compared with time equivalent palynofloras mainly from North America. Two hiatuses were recognized, the most important of which includes the K-T boundary interval. Four biostratigraphic zones, Ka, Kb, Ta and Tb, were defined, and their relative ages correlated with those of other sections in western North America.

Geology of Principal Australia Coals and Coal Basins: A Review: ABSTRACT

Bituminous or subbituminous coals are known from nearly all parts of Australia. Those of greatest economic importance today are found in the Permian and Triassic Bowen and Galilee basins of Queensland and the Sydney-Bowen basin of New South Wales, with some coalfields of lesser significance in the Clarence-Moreton basin in Queensland and New South Wales. The lesser known fields also include the Permian Collie coalfield and Perth (Permian-Cretaceous) and Canning (Permian-Triassic) basins of Western Australia; the Bonaparte basin (Permian), mostly offshore in the Darwin area of Northern Territory and Western Australia; the shallow Permian coals of the large Arckaringa basin, and the smaller Triassic-Jurassic Leigh Creek basin in South Australia; the Early Cretaceous of the ippsland basin, Victoria; and the Permian and Triassic coals of the Tasmania basin, particularly the Fingal area. Structural, sedimentary, and paleobiologic features of the coal-bearing strata and regional trends of various coal characteristics of some of the principal economic or geologically interesting basins and coals are reviewed and illustrated. These include the Hail Creek syncline, Goonyella, Peak Downs, German Creek, Blackwater, Baralaba, Tolmeis and Moura Mines of the Bowen basin of Queensland and the unique Blair Athol mine at the far western edge of Bowen basin. In New South Wales these include the Hunter Valley area Singleton Coal Measures represented by the Foyebrook-Liddell Seam and Ravensworth mines; the Newcastle area; the Ulan Seam of the Goulburn Valley area; the weste n shelf area and Sydney-Wollongong region represented by the Illawarra (Permian) Coal Measures which are overlain by the thick Triassic Narrabean Series, Hawksbury Sandstone, and Wianamatta Group. A paleobiologic analysis of the thick brown coal sequences in the Yallourn, Latrobe Valley, and Bacchus Marsh areas of Victoria, and the significance of tectonics in the development of these great coal swamps will be reviewed. End_of_Article - Last_Page 1454------------

Some Aspects of Paleoecology and Stratigraphy of Lower Mancos Shale (Upper Cretaceous) of Colorado and Utah, Based on Palynologic Analysis: ABSTRACT

Paleoecology of the deposits in the early Mancos Sea of western Colorado and eastern Utah is being studied by palynologic analysis. Seven sections, including 1 from the type area along the Mancos River, have been sampled at 15-20-ft intervals, from the top of the Dakota upward for 100-600 ft. These strata--the Graneros Shale, Greenhorn Limestone, lower Carlile, Juana Lopez, and upper Carlile Members--include most of the Cenomanian and Turonian stages. The terrestrial microfossil flora includes more than 45 species of spores, about 15 species of gymnospermous pollen and more than 59 species of angiosperms. The microplankton differentiated include more than 30 species of acritarchs and about 40 species of dinoflagellates. Much of the deposition took place relatively close to the shoreline but some sections were farther from the strand. Variations in the sections also indicate transgressive and regressive stages of the sea and some environmental control over the microplankton. Some stratigraphic zonation seems possible, principally on the terrestrial palynomorphs, and correlation and relative time of deposition of the several sections have been determined tentatively. End_of_Article - Last_Page 842------------