Groundwater dolocretes from the Upper Triassic of the Paris Basin, France: A case study of an arid, continental diagenetic facies
C. Spotl, V.P. Wright
1992, Sedimentology (39) 1119-1136
Thick dolomite-cemented horizons (dolocretes) occur within a fluvial sandstone-mudstone sequence of Late Triassic age in the western part of the Paris Basin, France. Two types of dolomites can be distinguished: (a) nodular dolomitic beds less than a few metres thick, which formed within mottled overbank siltstones and mudstones; and (b)...
Dolomitization of Quaternary reef limestones, Aitutaki, Cook Islands
James R. Hein, S.C. Gray, B. M. Richmond, L. D. White
1992, Sedimentology (39) 645-661
Six holes were drilled to depths of 30–69 m in the shallow lagoon of Aitutaki in the southern Cook Islands. One hole encountered pervasively dolomitized reef limestones at 36 m subbottom depth, which extended to the base of the drilled section at 69·3 m. This hole was drilled near the...
Controls on the accumulation of coal and on the development of anastomosed fluvial systems in the Cretaceous Dakota Formation of southern Utah
M.A. Kirschbaum, P.J. McCabe
1992, Sedimentology (39) 581-598
Alluvial strata of the Cretaceous Dakota Formation of southern Utah are part of a transgressive systems tract associated with a foreland basin developed adjacent to the Sevier orogenic belt. These strata contain valley fill deposits, anastomosed channel systems and widespread coals. The coals constitute a relatively minor part of the...
Theoretical and measured aeolian sand transport on a barrier island, Louisiana, USA
John R. Dingman, S.A. Hsu, Thomas E. Reiss
1992, Sedimentology (39) 1031-1043
Over the past 100 years, the Isles Dernieres, a low lying barrier island chain along the coast of central Louisiana, Usa, has undergone more than 1 km of northward beach face retreat with the loss of 70% of its surface area. The erosion results from a long term relative...
Allozyme evidence for crane systematics and polymorphisms within populations of Sandhill, Sarus, Siberian and whooping cranes
H.C. Dessauer, G.F. Gee, J.S. Rogers
1992, Molecular Phylogenetics and Evolution (1) 279-288
Electrophoretic analysis of proteins yielded evidence on the relationships of species of cranes and on genetic diversity within populations of some species. Diversity within the Greater Sandhill crane and a Florida population of the Florida Sandhill crane was similar to that of most other vertebrates, but diversity was low in...
Stratigraphic framework of Cambrian and Ordovician rocks in the central Appalachian Basin from Medina County, Ohio, through southwestern and south-central Pennsylvania to Hampshire County, West Virginia
Robert T. Ryder, Anita G. Harris, John E. Repetski
1992, Bulletin 1839-K
The extent of temporal smearing in surface-temperature histories derived from borehole temperature measurements
G.D. Clow
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (98) 81-86
The ability of borehole temperature data to resolve past climatic events is investigated using Backus-Gilbert inversion methods. Two experimental approaches are considered: (1) the data consist of a single borehole temperature profile, and (2) the data consist of climatically-induced temperature transients measured within a borehole during a monitoring experiment. The...
Transgressive channel filling in the Breathitt Formation (Upper Carboniferous), Eastern Kentucky Coal Field, USA
S.F. Greb, D.R. Chesnut Jr.
1992, Sedimentary Geology (75) 209-221
Carbonaceous shales of brackish or marine origin in the Breathitt Formation may exhibit sharp bases with local channel-form scours. Minor channels at the bases of these shales exhibit three general types of fill: (1) shale, (2) bioturbated, heterolithic strata, and (3) coal overlain by shale or bioturbated, heterolithic strata. Most...
Pre-Elsonian mafic magmatism in the Nain Igneous Complex, Labrador: The bridges layered intrusion
L.D. Ashwal, R.A. Wiebe, J. L. Wooden, M.J. Whitehouse, Diane Snyder
1992, Precambrian Research (56) 73-87
Decades of work on the pristine, unmetamorphosed, and well exposed anorthositic, mafic and granitic rocks of the Nain igneous complex, Labrador, have led to the conclusion that all plutonic rocks in that area were emplaced in a short time intercal at about 1300 ± 10 Ma). We report here new...
Palaeoecology and sedimentology of the dysaerobic Bedford fauna (late Devonian), Ohio and Kentucky (USA)
J.C. Pashin, F.R. Ettensohn
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (91) 21-34
Oxygen-deficient biofacies models rely on lithologic and paleontologic attributes to identify distinctive biofacies interpreted to reflect levels of oxygenation in anaerobic, dysaerobic, and aerobic parts of a stratified water column. This study of the Bedford fauna from the Bedford Shale of Ohio and Kentucky and from adjacent black-shale units reports...
Geochronology and subsurface stratigraphy of Pukapuka and Rakahanga atolls, Cook Islands: Late Quaternary reef growth and sea level history
S.C. Gray, J.R. Hein, R. Hausmann, U. Radtke
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (91) 377-394
Eustatic sea-level cycles superposed on thermal subsidence of an atoll produce layers of high sea-level reefs separated by erosional unconformities. Coral samples from these reefs from cores drilled to 50 m beneath the lagoons of Pukapuka and Rakahanga atolls, northern Cook Islands give electron spin resonance (ESR) and U-series ages...
Geochemical and detrital mode evidence for two sources of Early Proterozoic sedimentary rocks from the Tonto Basin Supergroup, central Arizona
K.C. Condie, P.D. Noll Jr., C. M. Conway
1992, Sedimentary Geology (77) 51-76
The Tonto Basin Supergroup includes up to 6.5 km of Early Proterozoic sedimentary and volcanic rocks that were deposited in a relatively short period of time at about 1.7 Ga in central Arizona. Moderate correlations of rare earth elements (REE) and Ti with Al2O3 and REE distributions in detrital sediments of...
Chronologic evidence for multiple periods of loess deposition during the Late Pleistocene in the Missouri and Mississippi River Valley, United States: Implications for the activity of the Laurentide ice sheet
S.L. Forman, E. Arthur Bettis III, T.J. Kemmis, B.B. Miller
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (93) 71-83
The loess stratigraphy of the mid-continental U.S. is an important proxy record for the activity of the Laurentide Ice Sheet in North America. One of the most outstanding problems is deciphering the age of loess deposits in this area during the late Pleistocene. Radiocarbon dating of snails and thermoluminescence dating...
Pliocene and Pleistocene geologic and climatic evolution in the San Luis Valley of south-central Colorado
K.L. Rogers, E.E. Larson, G. Smith, D. Katzman, G.R. Smith, T. Cerling, Y. Wang, R. G. Baker, K.C. Lohmann, C.A. Repenning, P. Patterson, G. Mackie
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (94) 55-86
Sediments of the Alamosa Formation spanning the upper part of the Gauss and most of the Matuyama Chrons were recovered by coring in the high (2300 m) San Luis Valley of south-central Colorado. The study site is located at the northern end of the Rio Grande rift. Lithologic changes in...
Lake-size variations in the Lahontan and Bonneville basins between 13,000 and 9000 14C yr B.P
L. Benson, D. Currey, Y. Lao, S. Hostetler
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (95) 19-32
Recessions of Lakes Lahontan and Bonneville that commenced ∼13,500 14C yr B.P. were interrupted at ⪖11,500 14C yr B.P. in the Lahontan basin and ∼12,200 14C yr B.P. in the Bonneville basin by relatively large perturbations in lake level that persisted for ∼ 2000 years. Minor glacial readvances in the Sierra Nevada and...
Setting and occurrence of Late Paleozoic radiolarians in the Sylvester allochthon, part of a proto-Pacific ocean floor terrane in the Canadian Cordillera
T.A. Harms, B.L. Murchey
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (96) 127-139
Late Paleozoic radiolarians have been used to establish th allochthon of the Slide Mountain terrane in British Columbia, and have thereby greatly clarified the geology and tectonic history of the terrane. As the Sylvester radiolarian fauna is limited, age assignments were based on a few distinctive and diagnostic robust forms....
The "terminal Triassic catastrophic extinction event" in perspective: A review of carboniferous through Early Jurassic terrestrial vertebrate extinction patterns
R.E. Weems
1992, Palaeogeography, Palaeoclimatology, Palaeoecology (94) 1-29
A catastrophic terminal Triassic extinction event among terrestrial vertebrates is not supported by available evidence. The current model for such an extinction is based on at least eight weak or untenable assumptions: (1) a terminal Triassic extinction-inducing asteroid impact occurred, (2) a terminal Triassic synchronous mass extinction of terrestrial vertebrates...
Geology of the d'Entrecasteaux-New Hebrides arc collision zone: Results from a deep submersible survey
J.-Y. Collot, S. Lallemand, B. Pelletier, J.-P. Bissen, G. Glacon, M. A. Fisher, H. Gary Greene, J. Boulin, J. Daniel, M. Monzier
1992, Tectonophysics (212) 213-241
During the SUBPSO1 cruise, seven submersible dives were conducted between water depths of 5350 and 900 m over the collision zone between the New Hebrides island arc and the d'Entrecasteaux Zone (DEZ). The DEZ, a topographic high on the Australian plate, encompasses...
A-type granite and the Red Sea opening
Robert G. Coleman, Susan DeBari, Zell E. Peterman
1992, Tectonophysics (204) 27-40
Miocene-Oligocene A-type granite intrudes the eastern side of the Red Sea margin within the zone of extension from Jiddah, Saudi Arabia south to Yemen. The intrusions developed in the early stages of continental extension as Arabia began to move slowly away from Africa (around 30–20 Ma). Within the narrow zone...
The international seismological observing period in Africa
E.R. Engdahl, Eric A. Bergman
1992, Tectonophysics (209) 1-16
The International Seismological Observing Period (ISOP) is a specific time interval designated for enhanced international cooperation in the collection and dissemination of observatory measurements from the global seismographic network. The primary purpose of the ISOP is to strengthen the international infrastructure that supports current seismological practice and increase the cooperation...
Charnockites and granites of the western Adirondacks, New York, USA: A differentiated A-type suite
P.R. Whitney
1992, Precambrian Research (57) 1-19
Granitic rocks in the west-central Adirondack Highlands of New York State include both relatively homogeneous charnockitic and hornblende granitic gneisses (CG), that occur in thick stratiform bodies and elliptical domes, and heterogeneous leucogneisses (LG), that commonly are interlayered with metasedimentary rocks. Major- and trace-element geochemical analyses were obtained for 115...
Distribution and characteristics of a Middle Ordovician oolitic ironstone in northeastern Kansas based on petrographic and petrophysical properties: A Laurasian ironstone case study
P. Berendsen, J.H. Doveton, S. Speczik
1992, Sedimentary Geology (76) 207-219
The margins of Gondwana are generally considered to be the major sites of oolitic ironstone production during the Ordovician, and appear to be linked with global eustatic sea-level rise. Occurrences of oolitic ironstones within the North American craton are less well documented, but provide important supplementary data. The low latitude...
The nature of Archean terrane boundaries: An example from the northern Wyoming Province
D.W. Mogk, P.A. Mueller, J. L. Wooden
1992, Precambrian Research (55) 155-168
The Archean northern Wyoming Province can be subdivided into two geologically distinct terranes, the Beartooth-Bighorn magmatic terrane (BBMT) and the Montana metasedimentary terrane (MMT). The BBMT is characterized by voluminous Late Archean (2.90-2.74 Ga) magmatic rocks (primarily tonalite, trondhjemite, and granite); metasedimentary rocks are preserved only as small, rare enclaves...
The Midcontinent rift in the Lake Superior region with emphasis on its geodynamic evolution
W.F. Cannon
1992, Tectonophysics (213) 41-48
The Midcontinent rift is a Middle Proterozoic continental rift which records about 15 m.y. of extension, subsidence, and voluminous volcanism in the period 1109–1094 Ma in the central part of North America. During that time the crust was nearly totally separated and as much as 25 km of subaerial basalts...
Speculations on the origin of the North American Midcontinent rift
W.F. Cannon, W. J. Hinze
1992, Tectonophysics (213) 49-55
The Midcontinent rift is an example of lithospheric extension and flood basalt volcanism induced when a new mantle plume arrived near the base of the lithosphere. Very large volumes of basaltic magma were generated and partly erupted before substantial lithospheric extension began. Volcanism continued, along with extension and deep rift...
