Norman D. Newell

Generation and Maintenance of Gradients in Taxonomic Diversity

Latitudinal gradients in diversity of organisms represent an equilibrium distribution for at least the last 270 x 106 years. Faunas endemic to tropical regions evolved significantly faster than extra-tropical faunas. The latitude-dependent difference in rates of evolution also represents an equilibrium condition for at least the last 270 x 106 years and has consequences for paleontological correlation of rocks because the attainable resolution depends on rate of evolution and will thus be greater in tropic regions than in extra-tropical ones.

Rostroconchia: A New Class of Bivalved Mollusks

Four Paleozoic bivalved genera are assigned to the new molluscan class Rostroconchia: Eopteria, Euchasma, Conocardium, and Pseudoconocardium. These mollusks have ani uncoiled univalved larval shell; an untorted bivalved adult shell; no hinge teeth, ligament, or adductor muscles; and a fused, almost inflexible. hinge. Rostroconchianis developed separately from the pelecypods through the ribeirioids, but are regarded as more closely related to the Pelecypoda and Scaphopoda than to other known classes of mollusks.

CORRELATION OF THE PERMIAN FORMATIONS OF NORTH AMERICA

The chart (PI. 1) indicates the present stratigraphic classification of the Permian rocks in each important area of outcrop in North America and the time relations of the deposits in the several areas as now understood. Annotations in the text suggest the evidence for many of the correlations and point out unsolved and controversial problems.

The Reef Flat and ‘Two-Meter Eustatic Terrace’ of Some Pacific Atolls

Characteristics of Indo-Pacific coral reefs long cited as evidence of a recent decline in sea level include: (1) the reef “flat” or pavement, (2) intertidal and supratidal flat erosion remnants of cemented coral rubble, and (3) erosion of the shores of reef islets. Our examination of 25 low islands and 8 high islands in the Caroline and Marshall Islands during the 1967 Scripps Institution of Oceanography Expedition CARMARSEL leads us to conclude that the reef flats in the western Pacific generally are not simply erosional platforms but represent an equilibrium surface between upward accretion by reef-building organisms and erosion at the mean level of low tides. Intertidal and supratidal coral rubble and calcareous sand accumulate above low-tide level during storms forming all of the visible land in the visited low islands. This rubble is currently being cemented and welded to the reef flats between tidal limits, and probably is also being cemented as beachrock and island conglomerate below the fluctuating water table of the cays. Topographically highest cemented carbonate rocks of the Caroline and Marshall Islands are uniformly less than 2 m above the adjacent reef flat, and entirely in the intertidal zone, hence, within the tidal range of present sea level. Flat horizontal surfaces of small extent occur on shore rocks, locally truncating inclined beds of beach rock. These surfaces roughly correspond to the upper limit of contemporary cementation somewhat modified by gravel scour. Comparison with rock platforms of a slightly elevated atoll of the Tuamotus, Raroia, indicates that the Marshall and Caroline Islands do not display expectable features of uplift or of subsiding sea level.

Lower Eo-Triassic stratigraphy, western Wyoming and southeast Idaho

A thickness of from 1000 to 2000 feet of strata in western Wyoming, southeastern Idaho, and southwestern Montana is shown to belong to the Otoceras , and probably to the Genodiscus , zones of the Scythian stage of the Lower Triassic. These strata, herein classified as the Dinwoody and Woodside formations, exhibit marked overlap relations on the underlying Phosphoria formation, indicative of a marked hiatus corresponding to the Permo-Triassic boundary. Unlike current usage in southeastern Idaho the term Woodside is herein employed for unfossiliferous red beds, which apparently grade northeastward into a nonred fossiliferous section similar to the underlying Dinwoody formation. Further work remains to be done in the areas in which the red-beds facies is lacking. The marine invertebrate fauna of the Dinwoody has a marked affinity with the Otoceras fauna from east Greenland, Seis (lower Werfen) fauna of the Alps, and early Triassic faunas from eastern Siberia.

Holocene Changes in Sea Level: Evidence in Micronesia

Investigation of 33 islands, scattered widely across the Caroline and Marshall Island groups in the Central Pacific revealed no emerged reefs in which corals had unquestionably formed in situ, or other direct evidence of postglacial high stands of sea level. Low unconsolidated rock terraces and ridges of reefflat islands, mostly lying between tide levels, were composed of rubble conglomerates; carbon-14 dating of 11 samples from the conglomerates so far may suggest a former slightly higher sea level (nine samples range between 1890 and 3450 and one approaches 4500 years ago). However, recent hurricanes have produced ridges of comparable height and material, and in the same areas relics from World War II have been found cemented in place. Thus these datings do not in themselves necessarily indicate formerly higher sea levels. Rubble tracts are produced by storms under present conditions without any change in datum, and there seems to be no compelling evidence that they were not so developed during various periods in the past.

Invertebrate fauna of the late Permian Whitehorse sandstone

The Whitehorse fauna occurs high in the red beds section of the Mid-continent region near the Paleozoic-Mesozoic boundary. Underlain and overlain by a great thickness of nearly unfossiliferous rocks this fauna occupies a key position for the correlation of a part of the red beds. Although composed dominantly of pelecypods and gastropods the fauna also contains bryozoans, serpulids, and brachiopods. The fossils occur as molds in very long, narrow sandstone and dolomite lenses interpreted here as marine offshore bars. There are 32 species recognized, of which 7 are described as new. They are distributed among 29 genera, of which 6 are presented as new. Pertinent stratigraphic and faunal evidence bearing on the age of the Whitehorse fauna is marshaled, resulting in the conclusion that it is late Permian in age, probably correlative with the Capitan fauna of the standard Permian section in western Texas. The possibility is recognized that the Whitehorse fauna may be slightly younger or older than the Capitan.

Carbon dioxide and people

The correlation between population growth and steady buildup of atmospheric carbon dioxide (CO2) is almost perfect (.9985). Both growth rates rise exponentially simultaneously. Human activities account for atmospheric CO2 growth not population growth itself. They include burning of fossil fuels and wood changes in agricultural methods and deforestation. They exceed changes in all natural sources including weathering of rocks ice melting warming of sea water decay of vegetation seasonal defoliation and volcanic activity. Demographers and environmentalists can use the rise in CO2 as a gross index of land development population growth climatic changes change of natural environments and industrialization. CO2 analyses can reinforce censuses and supply data from periods between census surveys. CO2 data collected at the US Mauna Loa weather station and the South Pole show that in 1958 atmospheric CO2 was 315.2/ppm and the world population was 2.9 billion. Ice core analyses in Greenland find that CO2 levels were 225/ppm 18000 years ago and rose somewhat to 271/ppm around 1300 A.D. when the continental glaciers melted. The extent of CO2 fluctuates sizably with the seasons. Changing patterns of climate energy use and deforestation correspond to irregularities in the rising trend of CO2. This rise in atmospheric CO2 provides us with a sensitive gauge of the rate of economic development and follows the expanding blows humans exert on the environment e.g. the 1973 OPEC price hike of petroleum. Population growth stymies all activities to lower the poverty level. Reduced energy use at present population levels would mean reduced productivity and increased hardship but most of the world is reluctant to confront it. International cooperation beyond what human behavior had ever done before and attrition are needed to avoid catastrophe.

KEY PERMIAN SECTION, CONFUSION RANGE, WESTERN UTAH

Approximately 10,000 feet of Permian strata, mainly of marine origin, and in some beds abundantly fossiliferous, is well exposed and readily accessible in the northern part of the Confusion Range, western Utah. Because of their strategic location between the better known sections of southern Nevada, southern Utah, and central Utah the exposures in the Confusion Range are of especial importance for the light they shed on Permian problems in the western United States. Pennsylvanian and Lower Permian limestones of undetermined total thickness are correlated with the similar Bird Spring formation of southern Nevada and with the Oquirrh formation of the Wasatch Mountains in central Utah. The Bird Spring limestone is overlain by 2500 feet of relatively unfossiliferous limy sandstones, impure limestones, and calcareous shales prevailingly of drab colors. Discontinuous lenses of red sandstone occur in the upper part. This unit tentatively is correlated with the Supai formation and associated elastics of the Grand Canyon region, although the lithologic facies is quite different. Approximately 2000 feet of massive limestone containing Dictyoclostus ivesi s.l. in the upper part is correlated with the Kaibab limestone of the Colorado Plateau. At the top of the Permian sequence is 4555 feet of richly fossiliferous interbedded cherty limestone and calcareous shale. The contained fauna is that of the Phosphoria formation of the middle and northern Rocky Mountains. There is no apparent intermingling of Kaibab and Phosphoria faunal types. The Permian succession is overlain with angular unconformity by red shales and interbedded limestones of the Lower Triassic. Silty red limestones some hundreds of feet above the base of the Triassic contain an abundance of Meekoceras . Interpretation of the succession in the Confusion Range confirms a discovery by Baker and Williams (1940) of Phosphoria strata directly above Kaibab equivalents in the Wasatch Mountains. It seems clear that the entire Phosphoria formation is younger than the Kaibab.

A Unique Pterioid Bivalve from the Early Triassic of Utah

Abstract The new species Bakevellia? silberlingi is described from a single locality in the upper Thaynes Formation (mid-Spathian) near Salt Lake City. The 133 specimens studied are natural casts of siltstone freed from limestone in the laboratory by acid dissolution. In external form, B? silberlingi resembles inequivalved and auriculate taxa of several pterioid families. However, its peculiar combination of hinge characters precludes unqualified assignment to either an established genus or family. The shallow, troughlike ligament scar extending backward from the beak resembles that of some pteriids, whereas the numerous teeth form a pattern typical of multivincular bakevelliids and their putative duplivincular ancestors. The new form is provisionally assigned to Bakevellia in recognition of the numerous characters it has in common with that familiar genus. The single-locality occurrence and unlikely mode of fossilization of this unusual taxon suggest that a significant amount of the diversity of early Triassic marine faunas may consist of short-lived, geographically isolated taxa awaiting discovery.