Earth Sciences Commons^™

Chronostratigraphic Significance Of Cathodoluminescence Zoning In Syntaxial Cement: Mississippian Lake Valley Formation, New Mexico, Tracy D. Frank, Kuger C. Lohmann, William J. Meyers

Department of Earth and Atmospheric Sciences: Faculty Publications

Echinoderm-syntaxial cement crystals have been collected at several stratigraphic levels within the Lake Valley Formation, which is overlain by a major pre-Pennsylvanian subaerial exposure surface. The crystals were microsampled along growth bands, and yielded high-resolution elemental and isotopic information that record fluid evolution during their growth. Although cement crystals show little variation in cathodoluminescence character and bulk chemistry throughout the regional extent of the formation, intracrystalline patterns in minor element and stable isotope chemistry allow for the identification of several settings of cementation, including the marine phreatic, marine-meteoric mixing, and meteoric phreatic zones. When placed in a regional-stratigraphic context, crystal …

Dissociation Quotient Of Benzoic Acid In Aqueous Sodium Chloride Media To 250°C, Richard Kettler, David J. Wesolowski, Donald A. Palmer

Department of Earth and Atmospheric Sciences: Faculty Publications

The dissociation quotient of benzoic acid was determined potentiometrically in a concentration cell fitted with hydrogen electrodes. The hydrogen ion molality of benzoic acid/benzoate solutions was measured relative to a standard aqueous IiCI solution at seven temperatures from 5 to 250°C and at seven ionic strengths ranging from 0.1 to 5.0 molal (NaCI). The molal dissociation quotients and selected literature data were fitted in the isocoulombic (all anionic) form by a six-term equation. This treatment yielded the following thermodynamic quantities for the acid dissociation equilibrium at 25°C and 1 bar: log K_a = -4.206±0.006, ΔH_å=0.3±0.3 kJ-mol^{-1 …}

Impact Of Erosion, Mass Wasting, And Sedimentation On Human Activities In The Río Grande Basin, Jujuy Province, Argentina, Waldo Chayle, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Nearly all dry mountainous regions are affected by severe erosion, floods, and debris flows during times of intense precipitation. The lithology, geologic structure, and climate in Jujuy Province, Argentina combine to place at serious risk the people who live along the Río Grande, the major river that drains the east side of the Cordillera Oriental and the west side of the Sierras Subandinas. Nearly all precipitation falls during summer (January–March) with little during the remainder of the year; most of the basin is semiarid to arid, although the southern end has a humid subtropical climate. Relief is great, as much …

Initial Transgressive Phase Of Leg 144 Guyots: Evidence Of Extreme Sulfate Reduction, Bjørn Buchardt, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

The initial transgressive phase at the Leg 144 Guyots is characterized by a typical association of sedimentary facies (from bottom to top): in situ weathered volcanic rocks; variegated clays, partly pyritic; gray clay, pyritic, homogeneous, or mottled; black clay, peaty, laminated, or bioturbated; and marine argillaceous limestone. Site 877 at Wodejebato Guyot represents the typical development of the initial transgressive phase. The black clay is rich in organic carbon (up to 40%) and sulfur (up to 25%). The organic matter is dominantly of terrestrial origin, but it has a significant marine, algal input. The variegated clays consist of a red, …

Stratigraphy And Sediment Accumulation Patterns Of The Upper Cenozoic Pelagic Carbonate Caps Of Guyots In The Northwestern Pacific Ocean, David K. Watkins, Paul N. Pearson, Elisabetta Erba, Frank R. Rack, Isabella Premoli Silva, Horst W. Bohrmann, Julianna Fenner, Peter R.N. Hobbs

Department of Earth and Atmospheric Sciences: Faculty Publications

Many of the guyots of the Northwestern Pacific Ocean are capped by sequences of uncemented pelagic carbonate. Examination of three of these pelagic caps from Limalok, Lo-En, and Wodejebato guyots in the Marshall Islands indicates that sediment accumulation throughout the late Paleogene and late Cenozoic was characterized by episodes of deposition during the earliest Miocene, late early to early middle Miocene, late middle Miocene, mid-Pliocene, and Quaternary, separated by periods of little or no accumulation. The Miocene record consists of extensively winnowed foraminifer oozes, which suggest relatively energetic currents in the intermediate waters. The Pliocene and Quaternary sequences contain finer …

Oldest Cretaceous Sequence, Giralia Anticline, Carnarvon Basin, Western Australia: Late Hauterivian-Barremian, S. Mcloughlin, D. W. Haig, J. Backhouse, Mary Anne Holmes, G. Ellis, J. A. Long, K. J. Mcnamara

Department of Earth and Atmospheric Sciences: Faculty Publications

Outcrop of the oldest Cretaceous sequence in the Giralia Anticline and the Giralia No. 1 well, penetrating the same sequence, are described and biostratigraphically assessed in detail. The Cretaceous rocks lie on an erosion surface cut into Permian strata. A 10 m thick basal sand unit, the Birdrong Sandstone, is overlain by 56 m of carbonaceous siltstone-mudstone (Muderong Shale). The Birdrong Sandstone in the anticline belongs to the Muderongia australis Zone of late Hauterivian-Barremian age, as does the lower part of the Muderong Shale. The age of the upper Muderong Shale is uncertain, as is the age of a 10 …

Dissociation Quotients Of Succinic Acid In Aqueous Sodium Chloride Media To 225°C, Richard Kettler, Donald A. Palmer, David J. Wesolowski

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotients of succinic acid were measured potentiometrically with a hydrogen-electrode, concentration cell. These measurements were carried out from 0 to 225"C over 25 ° intervals at five ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The dissociation quotients from this and two other studies were combined and treated with empirical equations to yield the following thermodynamic quantities for the first acid dissociation equilibrium at 25°C: logK_1a = -4.210±0.003; Δ H_1̊a = 2.9±0.2 kJ-mol ^{- 1} ; ΔS_1̊a = -71±1 J-mol ^{- 1} -K ^-1; and ΔC_p̊,1a = -98±3 …

Cretaceous Calcareous Plankton Biostratigraphy Of Sites 872 Through 879, Elisabetta Erba, Isabella Premoli Silva, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper documents the distribution of calcareous nannofossils and planktonic foraminifers in Cretaceous sequences recovered at Sites 872 through 879 drilled on guyots in the central and western Pacific Ocean during Leg 144. Calcareous plankton biostratigraphy allows us to obtain important biostratigraphic age constraints for the onset, development, and demise of shallow-water sedimentation on these guyots.

Site 872 on Lo-En Guyot is the only site at which shallow-water limestones were not recovered during Leg 144. Here, the oldest sediment consists of pelagic limestone infilling fractures within the volcanic substrate. Calcareous plankton biostratigraphy constrains the age of these sediments to Coniacian …

Campanian Dwarf Calcareous Nannofossils From Wodejebato Guyot, Elisabetta Erba, David K. Watkins, Jörg Mutterlose

Department of Earth and Atmospheric Sciences: Faculty Publications

Calcareous nannofossils occur in lagoonal sediments recovered from Sites 873, 874, and 877 drilled on Wodejebato Guyot in the central Pacific Ocean. Nannofloras are present only in a few layers, from which several smear slides were prepared. All the specimens were counted, and the relative abundance of taxa was computed as percentages. Assemblages are characterized by excellent preservation, very high diversity (= number of taxa), but extremely low abundance. Both diversity and abundance decrease from the inner perimeter ridge along the northern edge of the atoll (Sites 877 and 874) to the inner lagoon (Site 873), but the assemblage composition …

Cretaceous And Paleogene Manganese-Encrusted Hardgrounds From Central Pacific Guyots, David K. Watkins, Isabella Premoli Silva, Elisabetta Erba

Department of Earth and Atmospheric Sciences: Faculty Publications

Manganese-encrusted hardgrounds and associated sediments from four guyots in the western Pacific Ocean were investigated using lithostratigraphic and biostratigraphic examination of thin sections. Biostratigraphic data from manganese-encrusted hardgrounds constrain the age of platform drowning to early middle Eocene for Limalok Guyot, latest Maastrichtian to early Paleocene for Wodejebato Guyot, and middle late Albian for MIT Guyot. Microstratigraphic examination of the hardgrounds reveals a complex Cretaceous and Paleogene history of bioerosion, pelagic sediment accumulation, manganese encrustation, and phosphatization. Fourteen distinct episodes of pelagic sediment accumulation occurred, with five in the Cretaceous, three in the Paleocene, and seven in the Eocene. These …

19. Pedogenic Alteration Of Basalts Recovered During Leg 144, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Basalts erupted to form the atolls and guyots of the Western Pacific have been altered in various ways, ranging from hydrothermal alteration to subaerial weathering by meteoric waters in a tropical environment. Subaerial weathering has been moderate to extreme. Moderate subaerial weathering is expressed by dissolution or replacement of primary minerals (olivine, pyroxenes, plagioclase feldspar) and alteration of glassy or aphanitic matrix to clay minerals, goethite, and hematite. The clay minerals are kaolinite or a brown smectite. Kaolinite concentrations decrease downhole and smectite concentrations increase. Although primary minerals are generally not preserved, primary structures, such as vesicles (generally filled by …

Springtime Microwave Emissivity Changes In The Southern Kara Sea, Robert G. Crane, Mark R. Anderson

Department of Earth and Atmospheric Sciences: Faculty Publications

Springtime microwave brightness temperatures over first-year ice are examined for the southern Kara Sea. Snow emissivity changes are revealed by episodic drops in the 37- to 18-GHz brightness temperature gradient ratio measured by the Nimbus 7 scanning multichannel microwave radiometer. We suggest that the negative gradient ratios in spring 1982 result from increased scatter at 37 GHz due to the formation of a near-surface hoar layer. This interpretation is supported by the results of a surface radiation balance model that shows the melt signature occurring at below freezing temperatures but under clear-sky conditions with increased solar input to the surface. …

Seven Million Years Of Glaciation In Greenland, H. C. Larsen, A. D. Saunders, P. D. Clift, J. Beget, W. Wei, S. Spezzaferri, J. Ali, H. Cambray, A. Demant, G. Fitton, M. S. Fram, K. Fukuma, J. Gieskes, Mary Anne Holmes, J. Hunt, C. Lacasse, L. M. Larsen, H. Lykke-Andersen, A. Meltser, M. L. Morrison, N. Nemoto, N. Okay, S. Saito, C. Sinton, R. Stax, T. L. Vallier, D. Vandamme, R. Werner

Department of Earth and Atmospheric Sciences: Faculty Publications

Glacial till, glaciomarine diamictites, and ice-rafted detritus found in marine cores collected off the shore of southeast Greenland record multiple Late Cenozoic glaciations beginning in the Late Miocene. Distinct rock assemblages and seismic stratigraphic control correlate the diamictites with glaciation of the southeast Greenland margin. Glaciers advanced to the sea during several intervals in the Pliocene and Pleistocene. North Atlantic glaciation may have nucleated in southern Greenland rather than further north because of the high mountains and the high levels of precipitation in this region.

Geologic Framework Of The Niobrara River Drainage Basin And Adjacent Areas In South Dakota Generally East Of The 100th Meridian West Longitude And West Of The Missouri River, Robert F. Diffendal Jr., Michael R. Voorhies

Department of Earth and Atmospheric Sciences: Faculty Publications

General geology and stratigraphy of the Niobrara River drainage basin in Nebraska and adjacent parts of South Dakota generally west of the Missouri River is reviewed. Of particular importance are the correlation of the Long Pine Formation of Pliocene age in Nebraska with the Herrick Gravels in South Dakota, the recognition of the members of the Ogallala Group named by Skinnner, Skinner and Gooris (1968) and by Skinner and Johnson (1984) in the basin, the acceptance of the relationships of the Miocene and older Tertiary units in the basin to those in the part of the study area in South …

Cleat-Filling Calcite In Illinois Basin Coals: Trace-Element Evidence For Meteoric Fluid Migration In A Coal Basin, Allan Kolker, Chen-Lin Chou

Department of Earth and Atmospheric Sciences: Faculty Publications

The microdistribution of Mn (786 to 9480 ppm), Sr (<5 to 461 ppm), and Fe (52 to 16,700 ppm) was determined for cleat-filling calcites in the Herrin, Springfield, and Colchester Coals, using focussed synchrotron radiation. Compositional zonation in the calcites reflects a multistage history of precipitation from fluids with differing trace-element characteristics. In nearly all of the samples, a high Fe (≥~5000 ppm) calcite is the latest composition to form, replacing earlier stages with varying, but generally lower Fe contents. Partitioning data for Sr suggest that a typical calcite with 200 ppm Sr formed from a fluid with a Sr/Ca of about 0.005. This Sr/Ca is ~4 times lower than seawater, and ~12 times lower than the average for present day Illinois Basin saline formation waters. Formation of cleat-filling calcite is best explained by precipitation from fluids similar to present day dilute (shallow) formation waters having a meteoric source.

Further Evidence Of Lead Contamination Of Omaha Skeletons, A. Mohamad Ghazi, Karl J. Reinhard, Mary Anne Holmes, Eric M. Durrance

Department of Earth and Atmospheric Sciences: Faculty Publications

A previous analysis of Omaha skeletons dating between A.D. 1780 and 1820 revealed the presence of lead in all skeletons with high concentrations in children and adult males (Reinhard and Ghazi [1992] Am. J. Phys. Anthropol. 89: 183-195). Two likely explanations for the high lead levels were presented: 1) metabolic absorption of lead and 2) diagenetic uptake of lead by the bones from postmortem application of pigments to the corpse. Two types of lead were available to the Omaha tribe: 1) Mississippi Valley type, and 2) non-Mississippi Valley type. It has been suggested that red-lead pigment mixed with mercury sulfide …

Groundwater Velocity In An Unconfined Aquifer With Rectangular Areal Recharge, Vitaly A. Zlotnik, Glenn Ledder

Department of Earth and Atmospheric Sciences: Faculty Publications

Three-dimensionsal solutions for the hydraulic head and velocity components for transient groundwater flow in an unconfined compressible aquifer of finite thickness with a rectangular areal recharge source are analyzed using a linearized mathematical model. The solution generalizes Dagan's (1967) results, which were obtained for an idealized aquifer of infinite thickness, and Hantush's (1967) results, which were derived using the Dupuit assumptions. Hydraulic head and velocity components are estimated by asymptotic methods for large times, which are most appropriate for contaminant transport problems. Numerical analysis of the solution demonstrates spatial features of the velocity components in general and a transient effect …

Groundwater Flow In A Compressible Unconfined Aquifer With Uniform Circular Recharge, Vitaly A. Zlotnik, Glenn Ledder

Department of Earth and Atmospheric Sciences: Faculty Publications

The distributions of the hydraulic head and velocity components of the transient groundwater flow in an unconfined compressible aquifer of finite thickness under constant uniform circular recharge are obtained from the linearized mathematical model by the use of integral transforms. The result generalizes Dagan’s (1967) solution which was derived by neglecting the compressibility. By treating the compressibility parameter as a small value, the formula for the hydraulic head is analyzed by asymptotic methods, resulting in approximations to the exact solutions for the head and velocities on small and large time scales. The hydraulic head and flow velocities can be accurately …

Dissociation Quotients Of Malonic Acid In Aqueous Sodium Chloride Media To 100°C1, Richard Kettler, David J. Wesolowski, Donald A. Palmer

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotients of malonic acid were measured potentiometrically in a concentration cell fitted with hydrogen electrodes. The hydrogen ion molality of malonic acidJbimalonate solutions was measured relative to a standard aqueous HCI solution from 0 to 100°C over 25° intervals at five ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a seven-term equation. This treatment yielded the following thermodynamic quantities for the first acid dissociation equilibrium at 25°C: log K_1a = -2.852 ± 0.003. ΔH_1̊a = …

Biogeography Of Campanian-Maastrichtian Calcareous Plankton In The Region Of The Southern Ocean: Paleogeographic And Paleoclimatic Implications, Brian T. Huber, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

Analysis of biogeographic distribution patterns among Campanian-Maastrichtian calcareous nannoplankton and planktonic foraminifera from the southern high latitudes provides insight to changes in circum-Antarctic climate and surface circulation surface routes. Both microfossil groups are similarly characterized in the early Campanian by low-diversity, cosmopolitan species with few or no austral provincial taxa. This changes by late Campanian-early Maastrichtian time as austral species diversified and began to dominate the high-latitude assemblages. Maximum diversity of austral provincial taxa occurs during the late Campanian among the planktonic foraminifera and in the early Maastrichtian among the calcareous nannoplankton. Climatic cooling is considered the cause for the …

Hallazgo De Gasterópodos En La Formación Sijes (Mioceno Superior) Salta, República Argentina, R. N. Alonso, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Se da a conocer el hallazgo de gasterópodos en una secuencia sedimentaria continental rica en evaporistas y muy pobre en fósiles. Los gasterópodos fueron descubiertos en capas tufáceas, diatomíticas, del Miembro Esperanza de la Formación Sijes, de edad Mioceno superior. El análisis taxonómico permitió ubicarlos como pertenecientes a una nueva especie del género Littoridina. La sección sedimentaria, de origen lacustre tipo playa-lake, contiene mineralizaciones económicas de boratos que son minadas actualmente. La presencia de estos gasterópodos fósiles tiene importancia desde el punto de vista ambiental y son aquí utilizados en la interpretación sobre la génesis de los boratos.

The …

Ages Of The Whitewater And Fairhaven Tills In Southwestern Ohio And Southeastern Indiana, Barry B. Miller, William D. Mccoy, William J. Wayne, C. Scott Brockman

Department of Earth and Atmospheric Sciences: Faculty Publications

Alloisoleucine/isoleucine (aIle/Ile) ratios obtained from fossil mollusc shells collected at localities in southwestern Ohio and southeastern Indiana, where they occur in silt beds associated with the Whitewater and Fairhaven tills, indicate a pre-Wisconsinan age for these tills, which had previously been thought to be early or middle Wisconsinan.

The aIle/Ile ratios in shells from beneath the buried soil (Sidney soil) and till exposed near Sidney, Ohio, are most similar to values in shells obtained from Illinoian sediments at Clough Creek in Hamilton County, Ohio; Mechanicsburg southwest, Illinois; and Trousdale Mine in Vermillion Co., Indiana. The first well-developed weathering profile in …

Paleontology Of The Cretaceous Of The Central Kerguelen Plateau, David K. Watkins, Patrick G. Quilty, Barbara A.R. Mohr, Shaozhi Mao, J. E. Francis, Carole T. Gee, Millard F. Coffin

Department of Earth and Atmospheric Sciences: Faculty Publications

A synthesis of the Cretaceous calcareous nannofossil, foraminifer, terrestrial and marine palynomorph, macrofauna, and macroflora data from drill sites on the Central Kerguelen Plateau indicates a complex sedimentary history spanning the Albian through the Maestrichtian. Nonmarine Albian sediments from the eastern part of the central plateau record the initial colonization and subsequent succession of plant communities on the basaltic islands left by edifice-building events during the Early Cretaceous. The eastern and northern parts of the central plateau foundered during the early Late Cretaceous. Disconformity-bounded sequences of pelagic calcareous sediment accumulated there throughout the Cenomanian to early Campanian. Following a widespread …

Upper Cretaceous Nannofossils From Leg 120, Kerguelen Plateau, Southern Ocean, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

Drilling on the Kerguelen Plateau during Leg 120 cored the most complete, best preserved record of the Late Cretaceous of the Southern Ocean to date. Two calcareous pelagic sedimentary sections (Sites 747 and 750) provide a record from the upper Turonian(?)-lower Coniacian through the Maestrichtian. Two major disconformities interrupt the record: upper Coniacian-lower Santonian and mid-Campanian. Site 748 contains a Campanian-Maestrichtian record of neritic sedimentation dominated by nannofossil-bearing, intermittently silicified, glauconitic bioclastic grainstones to wackestones. Parts of the upper Maestrichtian and the mid-Campanian are absent at this site.

A set of 21 biostratigraphic events were used to correlate these sections. …

8. Cretaceous Subtropical Weathering Followed By Cooling At 60°S Latitude: The Mineral Composition Of Southern Kerguelen Plateau Sediment, Leg 120, Mary Anne Holmes

Department of Earth and Atmospheric Sciences: Faculty Publications

Kaolinite, goethite, minor hematite, and gibbsite were found in fluvial upper Lower Cretaceous basal sediment from the Southern Kerguelen Plateau, Sites 748 and 750, 55°S latitude. This mineral assemblage, derived from the weathering of basalt, indicates near-tropical weathering conditions with high orographic rainfall, at least 100 cm per year. The climate deteriorated by the Turonian or Coniacian, as indicated by the decline in kaolinite content of this sediment.
The Upper Cretaceous sediment at Site 748 consists of 200 m of millimeter-laminated, sparsely fossiliferous, wood-bearing glauconitic siltstone and clay stone with siderite concretions deposited on a shelf below wave base. Some …

9. Composition And Origin Of Cr-Rich Glauconitic Sediments From The Southern Kerguelen Plateus (Site 748), Peter Rene Bitschene, Mary Anne Holmes, James Brezza

Department of Earth and Atmospheric Sciences: Faculty Publications

Five hundred meters of a unique Upper Cretaceous Cr-rich glauconitic sequence (Unit III) that overlies a 3-m-thick alkali-basalt flow with underlying epiclastic volcanogenic sediments was drilled at ODP Leg 120 Site 748. The Cr-rich glauconitic sequence is lithostratigraphically and biostratigraphically divided into three subunits (IIIA, IIIB, IIIC) that can also be recognized by the Cr concentration of the bulk sediment, which is low (<200 ppm) in Subunits IIIC and IIIA and high (400-800 ppm) in Subunit IIIB. The Cr enrichment is caused by Cr-spinel, which is the only significant heavy mineral component beside Fe-Ti ores. Other Cr-bearing components are glauconite pellets and possibly some other clay minerals.
The glauconitic sequence of Subunit IIIB was formed by reworking of glauconite and volcanogenic components that were transported restricted distances and redeposited downslope by mass-transportation processes. The site of formation was a nearshore, shallow inner shelf …

Dissociation Quotients Of Oxalic Acid In Aqueous Sodium Chloride Media To 175c, Richard Kettler, Donald A. Palmer, David J. Wesolowski

Department of Earth and Atmospheric Sciences: Faculty Publications

The first and second molal dissociation quotienls of oxalic acid were measured potenliometrically in a concentration cell filled with hydrogen electrodes. The emf of oxalic acid-bioxalate solutions was measured relative to an HCI standard solution from 25 to 125°C over 25° intervals at nine ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a five-term equation that yielded the following thermodynamic quantities at infinite dilution and 25°C: logK_Ia = -1.277±0.010, ΔH_l̊a = -4.1± 1.1 kJ-mol^-1, ΔS_l̊a = 38±4 J-K …

Quaternary Geology Of The Northern Great Plains, William J. Wayne, James S. Aber, Sherry S. Agard, Robert N. Bergantino, John P. Bluemle, Donald A. Coates, Maurice E. Cooley, Richard F. Madole, James E. Martin, Brainerd Mears Jr, Roger B. Morrison, Wayne M. Sutherland

Department of Earth and Atmospheric Sciences: Faculty Publications

The Great Plains physiographic province lies east of the Rocky Mountains and extends from southern Alberta and Saskatchewan nearly to the United States-Mexico border. This chapter covers only the northern part of the unglaciated portion of this huge region, from Oklahoma almost to the United StatesCanada border, a portion that herein will be referred to simply as the Northern Great Plains (Fig. 1). This region is in the rain shadow of the Rocky Mountains. Isoheyets are roughly longitudinal, and mean annual precipitation decreases from about 750 mm at the southeastern margin to less than 380 mm in the western and …

Evolution Of The Aeluroid Camivora: Hyaenid Affinities Of The Miocene Camivoran Tungurictis Spocki From Inner Mongolia, Robert M. Hunt Jr., Nikos Solounias

Department of Earth and Atmospheric Sciences: Faculty Publications

Among the mammalian fossils discovered in were crania and mandibles of rare carnivorans, 1930 by the Central Asiatic Expedition of the including the first complete skulls of several Asian American Museum of Natural History (New York) mid-Miocene lineages. Most of these fossils came in the Tung Gur Formation of Inner Mongolia from a single locality termed Wolf Camp Quarry that produced, among other striking finds, a small fox-sized cranium referred to a new genus and species Tungurictis spocki Colbert 1939. Today this remains the only known cranium of Tungurictis yet discovered. Preparation and reinterpretation of the auditory region demonstrate that …

Evolution Of The Aeluroid Camivora: Viverrid Affinities Of The Miocene Camivoran Herpestides, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

Although the time of origin of viverrid and hyaenid carnivorans has not been clearly documented in the fossil record, their theater of evolution has long been established by a mid-Cenozoic fossil distribution entirely confined to the Old World. Recent examination of the basicranial morphology of important early aeluroid crania from Europe and Asia significantly alters earlier views of viverrid and hyaenid origins. The early Miocene carnivoran Herpestides antiquus, considered a potential ancestral hyaenid or herpestid in earlier studies, is identified as a true viverrid on the basis of a large sample of skulls of both juveniles and adults from …