Late Serpukhovian Foraminifers Near the Mississippian-pennsylvanian Boundary At South Syncline Ridge, Southern Nevada, Usa: Implications For Correlation

2019 ◽  
Vol 49 (2) ◽  
pp. 229-240
Author(s):  
Paul L. Brenckle ◽  
Walter L. Manger ◽  
Alan L. Titus ◽  
Tamara I. Nemyrovska
Keyword(s):  
North America ◽  
Test Site ◽  
The South ◽  
Foraminiferal Assemblage ◽  
Southern Nevada ◽  
Low Diversity ◽  
Group B ◽  
Upper Boundary ◽  
Serpukhovian Stage ◽  
Bashkirian Stage

AbstractA few, thin, Mississippian siliciclastic limestone beds, interbedded with ammonoid (uppermost Eumorphoceras Zone)-bearing shales within the South Syncline Ridge section on the Nuclear Test Site in southern Nevada, contain an abundant, low-diversity assemblage of late Serpukhovian/late Chesterian calcareous foraminifers dominated by the archaediscaceans Neoarchaediscus altiluminis, Brenckleina rugosa, Eosigmoilina robertsoni, and Betpakodiscus of the group B. attenuatus. These limestone beds were deposited in a shallow-water, clastic facies of the Scotty Wash Formation and, based on common conodont occurrences, correlate southeast to the Bird Spring Formation below the Mississippian-Pennsylvanian GSSP at Arrow Canyon, Nevada. The South Syncline Ridge foraminifers are comparable to those found in coeval beds at Arrow Canyon and represent the only other known foraminiferal assemblage to exist in association with uppermost Eumorphoceras Zone ammonoids in North America outside of Arkansas in the southern Midcontinent. Reconciliation of regional conodont and ammonoid zonations shows that the range of eosigmoiline foraminifers (E. robertsoni and B. rugosa), now generally considered an upper Serpukhovian index, extends from a position either just below or at the lower-upper boundary of the Serpukhovian Stage into the lower part of the Bashkirian Stage in North America; their upper range falls within the lower part of the Homoceras ammonoid zone beginning in the upper part of the Serpukhovian Stage. Discussion of the foraminiferal taxa includes support for retaining the genus Betpakodiscus rather than synonymizing it under Tubispirodiscus, as proposed by some specialists during the past few years.

Middle Ordovician (Whiterockian) trilobites from the Sunblood Formation, District of Mackenzie, Canada

1991 ◽  
Vol 65 (5) ◽  
pp. 801-824 ◽  
Author(s):  
James V. Tremblay ◽  
Stephen R. Westrop
Keyword(s):  
New Species ◽  
North America ◽  
The South ◽  
Middle Ordovician ◽  
Low Diversity ◽  
Shallow Subtidal ◽  
Three New Species

In the South Nahanni River area of the District of Mackenzie, the Middle Ordovician Sunblood Formation comprises mainly limestones and dolostones of intertidal and shallow-subtidal origin, as indicated by the presence of desiccation polygons, fenestral fabric, and oncolites. Faunas of well-preserved, silicified trilobites from a low-diversity, nearshore, Bathyurus-dominated biofacies are compositionally distinct from faunas in correlative strata around North America that represent different shelf to upperslope biofacies. A temporal biostratigraphy applicable to nearshore biofacies through much of the Whiterockian Series consists of five zones, in ascending order: Bathyurus mackenziensis, B. sunbloodensis, B. margareti, B. nevadensis, and B. granulosus. Twenty-six species are assigned to 18 genera, of which Ludvigsenella is new. Three new species of Bathyurus are B. mackenziensis, B. sunbloodensis, and B. margareti.

Calcareous foraminifers from the Bashkirian stratotype (Middle Carboniferous, south Urals) and their significance for intercontinental correlations and the evolution of the Fusulinidae

1988 ◽  
Vol 62 (3) ◽  
pp. 368-399 ◽  
Author(s):  
John R. Groves
Keyword(s):  
North American ◽  
Western Slope ◽  
South Urals ◽  
Foraminiferal Assemblage ◽  
Lower Carboniferous ◽  
The North ◽  
Middle Carboniferous ◽  
First Time ◽  
Serpukhovian Stage ◽  
Bashkirian Stage

The stratotype for the Bashkirian Stage of the Soviet Middle Carboniferous is located on the Askyn River in Gornaya Bashkiria (western slope of south Urals). Twenty-four rock samples, mostly from the lower part of the section, yielded abundant and diverse assemblages of calcareous foraminifers which are systematically described and illustrated here for the first time.The foraminiferal assemblage from the Siuransky Horizon at the base of the Bashkirian is essentially identical to that from the top of the underlying Lower Carboniferous Serpukhovian Stage. Thus, foraminifers do not provide a basis for identifying the Soviet Lower–Middle Carboniferous boundary. This notwithstanding, the presence of the foraminiferGlobivalvulina bulloides(Brady) (=G. moderataReitlinger) and the conodontIdiognathodus parvus(Dunn) in both the upper Serpukhovian and Bashkirian indicates that the base of the Bashkirian can be no older than medial to late Morrowan of the North American succession. The primitive fusulinidPseudostaffella(Pseudostaffella) appears at the bases of the lower Bashkirian Akavassky Horizon and the North American Atokan Series. The base of the Akavassky is interpreted to be somewhat older than early Atokan, however, becausePs.(Pseudostaffella) appeared in the Urals in phylogenetic continuity with its immediate ancestor, whereas in most of North America it was an immigrant.The type Bashkirian succession contains a seemingly complete phylogeny from advanced eostaffellids to primitive fusulinids.Plectostaffella jakhensis, immediate ancestor to the fusulinids, arose from a member of theEostaffella postmosquensisplexus in the late Serpukhovian.Plectostaffella jakhensis, in turn, gave rise toPs.(Semistaffella)variabilisin the early Bashkirian (late Siuransky), from which evolvedPs.(Ps.)antiquashortly thereafter (earliest Akavassky). An as yet unidentified but advanced species ofPs.(Pseudostaffella) is the most likely ancestor to late BashkirianNeostaffella ivanovi. The evolutionary series leading from theE. postmosquensisplexus to primitiveNeostaffellaapparently developed exclusively in the Eurasian–Arctic faunal realm, asPl. jakhensis, Ps.(Semistaffella)variabilis, andPs.(Ps.)antiquaare unknown in the Midcontinent–Andean region. DiversePs.(Pseudostaffella) spp. appeared in the latter area pursuant to an adaptive radiation aided by periodic interchange between faunal realms.

scholarly journals How geographic and climatic factors affect the adaptation of Douglas-fir provenances to the temperate continental climate zone in Europe

2021 ◽  
Author(s):  
Marzena Niemczyk ◽  
Daniel J. Chmura ◽  
Jarosław Socha ◽  
Tomasz Wojda ◽  
Piotr Mroczek ◽  
...  
Keyword(s):  
North America ◽  
Climatic Factors ◽  
Genetic Material ◽  
Test Site ◽  
Douglas Fir ◽  
Additional Advantage ◽  
Seed Sources ◽  
Precipitation Seasonality ◽  
Seed Origin ◽  
Continental Climate

AbstractThe contribution of Douglas-fir (Df) to European forests is likely to increase as the species is a potential adaptation option to climate change. In this study, we investigated growth and survival of Df seed sources to fill a knowledge gap regarding recommendations for the future use of Df provenances in Poland. Our experimental test site represents the most continental climate among all Df trials installed in the IUFRO 1966–67 test series in Europe. At this unique single site, we evaluated the performance of 46 Df provenances from North America, and nine local landraces of unknown origin. Repeated measurements of tree diameter, height, and volume were analysed, to age 48, representing integrated responses to geographic and climatic conditions. Significant variation in survival and productivity-related traits were found, with the interior Df provenances performing best, in contrast to previous European reports. The higher survivability and volume of the interior provenances resulted from their superior frost resistance. The low precipitation seasonality at the location of seed origin provided an additional advantage to the trees at the test site. Geographic and climatic factors of seed origin explained most of the variation in productivity (77 and 64%, respectively). The tested landraces exhibited diverse performance, implying that naturalized local seed sources in Poland need improvement and perhaps enrichment with new genetic material from North America, while considering geography and climate. Assisted migration programs should consider the limitations imposed by both frost and drought events in guiding future Df selections for continental climates. Further field testing, early greenhouse screening and DNA testing are also recommended.

Carboniferous conodont biostratigraphy of the Dianzishang section, Zhenning, Guizhou, South China

2013 ◽  
Vol 151 (2) ◽  
pp. 311-327 ◽  
Author(s):  
YUPING QI ◽  
KEYI HU ◽  
QIULAI WANG ◽  
WEI LIN
Keyword(s):  
South China ◽  
North American ◽  
Primitive Form ◽  
Conodont Biostratigraphy ◽  
The World ◽  
Kasimovian Stage ◽  
Moscovian Stage ◽  
Stage Boundaries ◽  
Serpukhovian Stage ◽  
Bashkirian Stage

AbstractA preliminary summary of the lower Visean to uppermost Moscovian (Carboniferous) conodont succession and biostratigraphy of the Dianzishang section in Zhenning, Guizhou, South China is presented. Eleven conodont zones, in ascending order, can be recognized:Gnathodus praebilineatus,Gnathodus bilineatus,Lochriea ziegleri,Declinognathodus noduliferus,Neognathodus symmetricus, ‘Streptognathodus’expansus(primitive form), ‘Streptognathodus’expansus,Mesogondolella donbassica – Mesogondolella clarki,Idiognathodus podolskensis,Swadelinafauna andIdiognathodus swadeizones. The first occurrences ofLochriea ziegleriat the base of the Serpukhovian Stage,Declinognathodus noduliferus noduliferusat the base of the Bashkirian Stage and ‘Streptognathodus’expansusat the base of the Moscovian Stage are recognized. The definitions of these stage boundaries, as well as that of the base of the Kasimovian Stage are discussed. Correlations with the Naqing section in South China, Russian and North American sections, as well as other important sections in the world, are considered.

Early Silurian Benthic Foraminifera from Saudi Arabia - including the oldest known multichambered lituolids

Stratigraphy ◽  
2020 ◽  
pp. 141-185
Author(s):  
Michael A. Kaminski ◽  
Pramudya R. D. Perdana
Keyword(s):  
Saudi Arabia ◽  
New Species ◽  
North America ◽  
Benthic Foraminifera ◽  
Early Evolution ◽  
Foraminiferal Assemblage ◽  
New Findings ◽  
New Finding ◽  
Agglutinated Foraminifera

ABSTRACT: A diverse assemblage of early Silurian agglutinated foraminifera is described from the transitional facies between the Qusaiba and Sharawra Formations of theQalibah Group of Saudi Arabia. The agglutinated foraminiferal assemblage consists of 73 species belonging to 24 genera, and is found in in dark graptolite-bearing claystone of Aeronian age. The assemblage is highly diverse compared with coeval early Silurian assemblages reported from Europe and North America. The assemblage is comprised mainly of species belonging to the monothalamid genera Saccammina, Psammosphaera, Lagenammina, Thurammina, Thuramminoides, Amphitremoida, Bathysiphon, Rhabdammina, and the tubothalamid genera Hyperammina, Tolypammina and Turritellella. The new species Thuramminoides ellipsoidalis n. sp. is described herein, but many of the species left in open nomenclature are also likely to be new. The assemblage also includes rare specimens belonging to the globothalamid (lituolid) genera Ammobaculites and Simobaculites. This new finding revises our understanding of the early evolution of the multichambered globothalamid foraminifera. Although the simple multichambered with rectilinear chamber arrangement are known from the Ordovician, our new findings show that the coiled globothalamids belonging to the order Lituolida are older than previously thought, and were already present in Gondwana by about 440 Ma.

Frequency-dependent attenuation in eastern Kazakhstan and implications for seismic detection thresholds in the Soviet Union

1990 ◽  
Vol 80 (6B) ◽  
pp. 2089-2105 ◽  
Author(s):  
Thomas J. Sereno
Keyword(s):  
Soviet Union ◽  
North America ◽  
Test Site ◽  
Eastern North America ◽  
Detection Capability ◽  
Detection Thresholds ◽  
Frequency Dependent ◽  
Noise Characteristics ◽  
The Soviet Union ◽  
Eastern Kazakhstan

Abstract The frequency-dependent attenuation of regional seismic phases recorded by three stations near the nuclear explosion test site in eastern Kazakhstan is estimated by inverting spectra from 21 events with magnitudes between 2.3 and 4.6 at distances between 200 and 1300 km. The Pn spectra are inverted between 1 and 10 Hz, and the Lg spectra are inverted between 0.5 and 2.5 Hz. The motivation for this study is that previous estimates of detection capability in the Soviet Union are based on data recorded in other regions (eastern North America and Scandinavia) and therefore have large uncertainty. The data recently recorded in eastern Kazakhstan provide an excellent opportunity to compare regional wave propagation and noise characteristics at these sites to conditions assumed in previous detection capability simulations. It is found that attenuation in eastern Kazakhstan is not much different from attenuation in Scandinavia, but it is greater than attenuation in eastern North America. This implies that estimates of detection thresholds that assume attenuation like that observed in eastern North America will be lower than estimates of detection thresholds that assume attenuation like that observed in eastern Kazakhstan or Scandinavia. However, it is not known how well data recorded in eastern Kazakhstan represent conditions in other areas of the Soviet Union.

The Nature of the South

2018 ◽  
Author(s):  
Richard Lyman Bushman
Keyword(s):  
Seventeenth Century ◽  
North America ◽  
Temperature Gradient ◽  
Growing Season ◽  
Western Hemisphere ◽  
The South ◽  
The North ◽  
The Caribbean ◽  
Plantation Agriculture ◽  
Southern Colonies

Plantation agriculture in the western hemisphere extended from Brazil northward through the Caribbean to the northern boundary of Maryland. This geography created a line in North America noted by seventeenth-century imperial economists. The southern colonies produced crops needed in the home land making the South far more valuable to the empire than the North. Plantation agriculture stopped at the Maryland-Pennsylvania border because the climate made slavery impractical north of that line. Only farmers who produced valuable exports could afford the price of slaves. Tobacco, though it could be grown in the North, was not commercially feasible there. The growing season had to be long enough to get a crop in the ground while also planting corn for subsistence, allow the tobacco to mature, and harvest it before the first frost. Tobacco was practical within the zone of the 180-day growing season whose isotherm outlines the areas where slavery flourished. Within this zone, the ground could be worked all but a month or two in winter, giving slaves plenty to do. Cattle could also forage for themselves, reducing the need for hay. Southern farmers could devote themselves to provisions and market crops, increasing their wealth substantially compared to the North where haying occupied much of the summer. Differing agro-systems developed along a temperature gradient running from North to South with contrasting crops and labor systems attached to each.

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