scholarly journals Preservation of latest Cretaceous (Maastrichtian)—Paleocene frogs (Eorubeta nevadensis) of the Sheep Pass Formation of east-central Nevada and implications for paleogeography of the Nevadaplano

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9455
Author(s):  
Joshua W. Bonde ◽  
Peter A. Druschke ◽  
Richard P. Hilton ◽  
Amy C. Henrici ◽  
Stephen M. Rowland
Keyword(s):  
Late Cretaceous ◽  
Microbial Mats ◽  
High Elevation ◽  
Lake Basin ◽  
Storm Activity ◽  
East Central ◽  
Temperate Lake ◽  
Exceptional Preservation ◽  
Bedding Planes ◽  
Mode 3

Here we report on exceptional preservation of remains of the frog Eorubeta nevadensis in deposits of the Sheep Pass Formation, ranging from Late Cretaceous to Eocene, in the south Egan Range, Nevada. This formation represents a lacustrine basin within the Sevier retroarc hinterland. The formation is subdivided into six members (A–F); of interest here are members B and C. The base of member B is ?uppermost Cretaceous-Paleocene, while member C is Paleocene. Member B frogs are preserved in three taphonomic modes. Mode 1 frogs are nearly complete and accumulated under attritional processes, with frogs settling on microbial mats, as evidenced by crenulated fabric of entombing limestone. Mode 2 involves accumulation of frogs as a result of attritional processes. These frogs are mostly complete with some showing evidence of invertebrate scavenging. Possible scavengers are gastropods, ostracods, and decapods. Mode 3 is represented by isolated, reworked remains of frogs as a result of storm activity, supported by the association of elements with disarticulated bivalves and mud rip-up clasts. Member C preserves frogs in two taphonomic modes. Mode 4 are nearly complete frogs that accumulated during discrete mass mortality events. Numerous individuals are preserved along bedding planes in identical preservational states. Mode 5 is beds of frog bone hash, which represent increased energy to the depositional system (likely tempestites) and reworking of previously buried frog remains. Taphonomy of the frogs, along with the associated fauna and flora, are consistent with preservation in a cool, temperate lake basin, supporting previous interpretations that the Nevadaplano was an elevated plateau during the late Cretaceous through the Eocene. This is a period of time coincident with a climatic thermal optimum, thus the most parsimonious explanation for a temperate lake at the latitude of east-central Nevada is to invoke high elevation, which is consistent with independent structural and clumped stable isotope studies.

scholarly journals A taxonomic revision of Gaultheria series Trichophyllae (Ericaceae)

2020 ◽  
Vol 14 (2) ◽  
pp. 289-341
Author(s):  
Peter W. Fritsch ◽  
Lu Lu
Keyword(s):  
New Species ◽  
Central Asia ◽  
Taxonomic Revision ◽  
High Elevation ◽  
Key To Species ◽  
East Central ◽  
Present Treatment ◽  
Taxonomic Changes ◽  
Species Descriptions ◽  
The Himalaya

The last taxonomic revision of Gaultheria series Trichophyllae (Ericaceae), a clade of high-elevation species endemic to the Himalaya-Hengduan Shan region of east-central Asia, was published in 1941. Since then, a number of new species have been described and other taxonomic changes have occurred in the group, prompting the need for a comprehensive revision. The present treatment of the series comprises 21 species, including Gaultheria x biluoensis, a newly described hybrid between G. crassifolia and G. major. A key to species and species descriptions is provided, and lectotypes are newly designated for G. cardiosepala, G. gonggashanensis, G. marronina, and G. stenophylla.

scholarly journals Seasonal Habitat Use and Movements of Mountain Goats, Oreamnos americanus, in East-central British Columbia

2003 ◽  
Vol 117 (4) ◽  
pp. 565 ◽  
Author(s):  
Kim G. Poole ◽  
Douglas C. Heard
Keyword(s):  
British Columbia ◽  
Adverse Effects ◽  
Home Range ◽  
Habitat Use ◽  
High Elevation ◽  
East Central ◽  
Oreamnos Americanus ◽  
Mountain Goats ◽  
Mineral Licks ◽  
Forest Use

To identify the potential for adverse effects of forest development on Mountain Goats (Oreamnos americanus), we documented the patterns of forest use by goats and the factors influencing goat habitat use. We used a combination of 15 very high frequency (VHF) and six global positioning system (GPS) radiocollars to document the distribution and movements of 21 (15 female, 6 male) goats from 1997 to 1999 in the mountains surrounding the Robson Valley in east-central British Columbia. Because canopy closure reduces the likelihood that a GPS receiver will obtain a location fix, we estimated that GPS collars underrepresented forest use by about 23%. Three goats used separate winter and summer ranges separated by 8–13 km, while most simply exhibited seasonal shifts in elevation. In winter, goats were more often at lower elevations, in commercial forest stands, on southerly aspects, and moved less each hour and over the course of the winter. Goat use declined in areas >500 m from escape terrain and goats were found lower in elevation from evening to dawn compared to daylight hours. Collared goats used high elevation licks, which were either within their home range, or in two cases, 6 and 14 km from their typical home range. We documented use of known mid-elevation mineral licks by three collared goats, but no use of known low elevation (valley bottom and lower slopes) mineral licks. Robson Valley goats appeared to be at relatively low risk from disturbances related to logging, because although forest use was documented during winter, it occurred primarily on high elevation, steep slopes where trees are currently of low commercial value, and goats made little use of low elevation mineral licks. We recommend that in this area a forested buffer of 500 m around cliffs be left to reduce the possibility of adverse effects on goats especially, on southerly aspects above 1300 m.

scholarly journals Precipitation of Mn Oxides in Quaternary Microbially Induced Sedimentary Structures (MISS), Cape Vani Paleo-Hydrothermal Vent Field, Milos, Greece

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 536
Author(s):  
Stephanos P. Kilias ◽  
Magnus Ivarsson ◽  
Ernest Chi Chi Fru ◽  
Jayne E. Rattray ◽  
Håkan Gustafsson ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrothermal Vent ◽  
Microbial Mats ◽  
Paramagnetic Resonance ◽  
Sedimentary Structures ◽  
Mn Oxide ◽  
Bedding Planes ◽  
Transmission Electron ◽  
Aerobic Methanotrophs ◽  
Hydrothermal Vent Field

Understanding microbial mediation in sediment-hosted Mn deposition has gained importance in low-temperature ore genesis research. Here we report Mn oxide ores dominated by todorokite, vernadite, hollandite, and manjiroite, which cement Quaternary microbially induced sedimentary structures (MISS) developed along bedding planes of shallow-marine to tidal-flat volcaniclastic sandstones/sandy tuffs, Cape Vani paleo-hydrothermal vent field, Milos, Greece. This work aims to decipher the link between biological Mn oxide formation, low-T hydrothermalism, and, growth and preservation of Mn-bearing MISS (MnMISS). Geobiological processes, identified by microtexture petrography, scanning and transmission electron microscopy, lipid biomarkers, bulk- and lipid-specific δ13Corganic composition, and field data, and, low-temperature hydrothermal venting of aqueous Mn2+ in sunlit shallow waters, cooperatively enabled microbially-mediated Mn (II) oxidation and biomineralization. The MnMISS biomarker content and δ13Corg signatures strongly resemble those of modern Mn-rich hydrothermal sediments, Milos coast. Biogenic and syngenetic Mn oxide precipitation established by electron paramagnetic resonance (EPR) spectroscopy and petrography, combined with hydrothermal fluid flow-induced pre-burial curing/diagenesis, may account for today’s crystalline Mn oxide resource. Our data suggests that MISS are not unique to cyanobacteria mats. Furthermore, microbial mats inhabited by aerobic methanotrophs may have contributed significantly to the formation of the MnMISS, thus widening the spectrum of environments responsible for marine Mn biometallogenesis.

Late Cretaceous to Middle Eocene Magmatism and Metallogeny of a Portion of the Southeastern Anatolian Orogenic Belt, East-Central Turkey

2013 ◽  
Vol 108 (4) ◽  
pp. 641-666 ◽  
Author(s):  
I. Kuscu ◽  
R. M. Tosdal ◽  
G. Gencalioglu-Kuscu ◽  
R. Friedman ◽  
T. D. Ullrich
Keyword(s):  
Late Cretaceous ◽  
Middle Eocene ◽  
Orogenic Belt ◽  
East Central ◽  
Central Turkey

scholarly journals Temporal and Spatial Characteristics of Snowstorms in the Contiguous United States

2006 ◽  
Vol 45 (8) ◽  
pp. 1141-1155 ◽  
Author(s):  
Stanley A. Changnon ◽  
David Changnon ◽  
Thomas R. Karl
Keyword(s):  
United States ◽  
Great Lakes ◽  
Temporal Distribution ◽  
The United States ◽  
High Elevation ◽  
High Plains ◽  
Deep South ◽  
Storm Activity ◽  
Lower Elevation ◽  
Temporal And Spatial Characteristics

Abstract A climatological analysis of snowstorms across the contiguous United States, based on data from 1222 weather stations with data during 1901–2001, defined the spatial and temporal features. The average annual incidence of events creating 15.2 cm or more in 1 or 2 days, which are termed as snowstorms, exhibits great spatial variability. The pattern is latitudinal across most of the eastern half of the United States, averaging 0.1 storm (1 storm per 10 years) in the Deep South, increasing to 2 storms along the Canadian border. This pattern is interrupted by higher averages downwind of the Great Lakes and in the Appalachian Mountains. In the western third of the United States where snow falls, lower-elevation sites average 0.1–2 storms per year, but averages are much higher in the Cascade Range and Rocky Mountains, where 5–30 storms occur per year. Most areas of the United States have had years without snowstorms, but the annual minima are 1 or more storms in high-elevation areas of the West and Northeast. The pattern of annual maxima of storms is similar to the average pattern. The temporal distribution of snowstorms exhibited wide fluctuations during 1901–2000, with downward 100-yr trends in the lower Midwest, South, and West Coast. Upward trends occurred in the upper Midwest, East, and Northeast, and the national trend for 1901–2000 was upward, corresponding to trends in strong cyclonic activity. The peak periods of storm activity in the United States occurred during 1911–20 and 1971–80, and the lowest frequency was in 1931–40. Snowstorms first occur in September in the Rockies, in October in the high plains, in November across most of the United States, and in December in the Deep South. The month with the season’s last storms is December in the South and then shifts northward, with April the last month of snowstorms across most of the United States. Storms occur as late as May and June in the Rockies and Cascades. Snowstorms are most frequent in December downwind of the Great Lakes, with the peak of activity in January for most other areas of the United States.

Fossil crabs (Crustacea: Decapoda) from the Late Cretaceous cárdenas Formation, east-central Mexico

1995 ◽  
Vol 69 (2) ◽  
pp. 340-350 ◽  
Author(s):  
Francisco J. Vega ◽  
Rodney M. Feldmann ◽  
Francisco Sour-Tovar
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
New Genus ◽  
Gulf Coast ◽  
Central Mexico ◽  
New Genus And Species ◽  
East Central ◽  
The Family ◽  
Marine Lagoon ◽  
First Time

Twenty-four nearly complete carapace samples were collected at three different localities of the Maastrichtian (Late Cretaceous) Cárdenas Formation in San Luis Potosí, east-central Mexico. The material has been assigned to five families: the Callianassidae, Dakoticancridae, Carcineretidae, ?Majidae, and Retroplumidae. Two genera of callianassid shrimp are described, Cheramus for the first time in the fossil record. Dakoticancer australis Rathbun is reported as the most abundant crustacean element; one new genus and species of carcineretid crab, Branchiocarcinus cornatus, is erected, and a single, fragmentary specimen is questionably referred to the Majidae. The three localities reflect paleoenvironmental differences, exhibited by different lithologies, within marginal marine, lagoon environments. The record of dakoticancrid crabs in the Cardenas Formation extends the paleobiogeographic range of the family and the genus Dakoticancer. Carcineretid crabs, although not abundant, seem to have been a persistent element of crustacean assemblages in clastic environments during the Late Cretaceous of the ancestral Gulf Coast of Mexico.

scholarly journals The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska

Geosphere ◽  
2014 ◽  
Vol 10 (6) ◽  
pp. 1432-1455 ◽  
Author(s):  
C. R. Bacon ◽  
C. Dusel-Bacon ◽  
J. N. Aleinikoff ◽  
J. F. Slack
Keyword(s):  
Late Cretaceous ◽  
East Central ◽  
Middle Fork
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