Encrinurine trilobites from the Silurian Brownsport Formation of Tennessee

1990 ◽  
Vol 64 (6) ◽  
pp. 961-967 ◽  
Author(s):  
Gregory D. Edgecombe
Keyword(s):  
Geographic Range ◽  
West Central ◽  
Stratigraphic Range

Encrinurinae from the Ludlovian Brownsport Formation in west central Tennessee include Balizoma ramskoeldi n. sp., Fragiscutum glebale Campbell, 1967, and Mackenziurus sp. Balizoma ramskoeldi is most similar to Ludlovian species in England and Gotland. The discovery of F. glebale in Tennessee extends the geographic range of this species, known also from the correlative Henryhouse Formation in Oklahoma. Fragiscutum is an eastern/southern Laurentian endemic; Balizoma is of Wenlockian–Přidolían range, with its most widespread Euramerican distribution in the Ludlow. The stratigraphic range of Mackenziurus is extended into the Ludlow.

Lamottia (Favositida, Tabulata) from the Decorah Formation (Kirkfieldian, Ordovician) of Iowa

1988 ◽  
Vol 62 (3) ◽  
pp. 424-426
Author(s):  
Jeffrey C. Edwards
Keyword(s):  
New York ◽  
Thin Section ◽  
Geographic Range ◽  
Upper Ordovician ◽  
North Central ◽  
The North ◽  
Tabulate Coral ◽  
Longitudinal Pattern ◽  
Stratigraphic Range ◽  
Diagenetic Feature

The early tabulate coral Lamottia heroensis has been identified from the Ion Member of the Decorah Formation (Upper Ordovician) in northeast Iowa. This extends the stratigraphic range of this species upward from Lower Chazyan to Kirkfieldian, and extends the geographic range from the Vermont-New York border area to include the north-central Midcontinent. Thin section and SEM studies strongly support the contention that the longitudinal pattern of alternating light and dark bands observed in corallite walls reflects a primary structural grain rather than a secondary diagenetic feature.

Мicrobiota of bauxites in the Eva deposit (Guinea-Bissau)

2019 ◽  
pp. 557-567
Author(s):  
A. F. Georgievskiy ◽  
E. A. Zhegallo ◽  
V. M. Bugina
Keyword(s):  
Microbial Communities ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Geographic Range ◽  
Bauxite Deposit ◽  
Electron Microscopic ◽  
Ore Genesis ◽  
Quaternary Period ◽  
Stratigraphic Range

The important role of the biogenic factor in sedimentary ore genesis now, after more than a hundred years after the publication of V. I. Vernadskys and Ya. V. Samoylovs papers, has become an indisputable fact for everyone. Discussions mainly take place as to how productive the activity of organisms was in the formation of specific exploitable minerals. In 2004, a joint monograph of Russian geologists Biomorphic Structures in Bauxite was published. Using the examples of dozens of deposits of a huge stratigraphic range from the Late Proterozoic age to the Quaternary period and wide geographic range (Africa, Eurasia, Australia and America), active participation of various microbial communities in the bauxite formation was shown in the monograph. This article demonstrates new results of electron microscopic study of ores from Eva bauxite deposit, which is little known in Russia, and continues researching this topic, which was initiated by E. L. Shkolnik.

Dzirulina (Brachiopoda; Terebratellidina) from California, U.S.A.—Additional record of an Early Cretaceous transatlantic brachiopod genus

1995 ◽  
Vol 69 (5) ◽  
pp. 838-845 ◽  
Author(s):  
Michael R. Sandy ◽  
Michael A. Murphy ◽  
Peter U. Rodda
Keyword(s):  
Early Cretaceous ◽  
Western Europe ◽  
Geographic Range ◽  
Low Latitude ◽  
The Caucasus ◽  
Internal Structures ◽  
Great Valley Group ◽  
Central Atlantic ◽  
Great Valley ◽  
Stratigraphic Range

Investigation of specimens of “Terebratella” ovula Anderson, 1938 from the upper Lower Albian Upper Chickabally Member of the Budden Canyon Formation, Great Valley Group, California has allowed the examination of the species' internal structures by serial sectioning. “Terebratella” ovula Anderson is now referred to the genus Dzirulina Noutsoubidze, 1945. The stratigraphic range of the genus is extended from the Hauterivian–Aptian to the Albian. The geographic range of Dzirulina is increased from central and western Europe, the Caucasus and Georgia of eastern Europe, and northern Zululand, Africa to now include northern California, North America. This represents an additional record of an Early Cretaceous brachiopod genus with a low-latitude, transatlantic distribution, most probably related to dispersal across the opening Central Atlantic Ocean.

Two new cirroidean genera (Vetigastropoda, Archaeogastropoda) from the Emsian (Late Early Devonian) of Alaska with notes on the early phylogeny of Cirroidea

1998 ◽  
Vol 72 (2) ◽  
pp. 265-273 ◽  
Author(s):  
Jiří Frýda ◽  
Robert B. Blodgett
Keyword(s):  
New Species ◽  
Lower Devonian ◽  
New Genus ◽  
New Genus And Species ◽  
Early Devonian ◽  
West Central ◽  
The Family ◽  
First Time ◽  
Stratigraphic Range

Two new cirroidean gastropod genera, Alaskiella (family Porcelliidae) and Alaskacirrus (family Cirridae), from the Emsian (late Early Devonian) of west-central Alaska (Medfra B-4 quadrangle) are described. The shell of Alaskiella medfraensis new genus and species exhibits inclined heterostrophic coiling. This shell character is known among other members of the subclass Archaeogastropoda, but is recorded for the first time within members of the superfamily Cirroidea. Inclined heterostrophic coiling of the shell was probably developed independently in several different groups of the subclass Archaeogastropoda. The new genus Alaskacirrus, represented by Alaskacirrus bandeli new species, is the oldest and only known Paleozoic member of the family Cirridae. This suggests that the family Cirridae was separated from the family Porcelliidae since at least Early Devonian time and that it most probably developed from the subfamily Agnesiinae of the family Porcelliidae. Thus, the stratigraphic range of the family Cirridae is at least from Lower Devonian to Cretaceous, an interval of about 350 million years.

First recognition of the genus Verneuilia Hall and Clarke (Brachiopoda, Spiriferida) from North America (west-central Alaska)

1994 ◽  
Vol 68 (6) ◽  
pp. 1240-1242 ◽  
Author(s):  
Robert B. Blodgett ◽  
J. G. Johnson
Keyword(s):  
New Species ◽  
North America ◽  
Middle Devonian ◽  
Geographic Range ◽  
Good Evidence ◽  
Systematic Relationship ◽  
West Central ◽  
Internal Structures ◽  
First Time ◽  
A New Species

The brachiopod genus Verneuilia Hall and Clarke, 1893, is recognized for the first time in North America, where it is represented by a new species described here, V. langenstrasseni. This occurrence not only extends the geographic range of the genus, but also the lower age and stratigraphic limit into the Eifelian (early Middle Devonian). Previously, the oldest known species was the type, V. cheiropteryx d'Archiac and de Verneuil, 1842, from the Givetian (late Middle Devonian) of Germany. Internal structures of V. langenstrasseni n. sp. are similar to those of genera in the ambocoeliid subfamily Rhynchospiriferinae, providing the first good evidence of a systematic relationship.

Trend of Extreme Precipitations Indices in West-central Côte d’Ivoire: Case of the Lobo Watershed

2020 ◽  
Vol 5 (10) ◽  
pp. 1281-1287
Author(s):  
F. B. Allechy ◽  
M. Youan Ta ◽  
V. H. N’Guessan Bi ◽  
F. A. Yapi ◽  
A. B. Koné ◽  
...  
Keyword(s):  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Crop Yields ◽  
Extreme Rainfall ◽  
Cote D’Ivoire ◽  
West Central ◽  
Côte D'ivoire ◽  
Northern Half ◽  
Agricultural Potential ◽  
Annual Total

The Lobo watershed located in the west-central part of Côte d'Ivoire is an area with high agricultural potential, influenced by climate variations and changes that reduce crop yields. The objective of this study is to analyse trends in ETCCDI extreme rainfall indices from rainfall data from 1984 to 2013 using ClimPACT2 software. This study shows that the trend of the indices: number of consecutive wet days (CWD), number of rainy days (R1mm) and the cumulative annual total rainfall (PRCPTOT) is decreasing. On the other hand, the number of consecutive dry days (CDD) is on the rise. In general, the whole basin has experienced a decrease in rainfall as well as wet sequences and an increase in dry sequences. These different trends observed in this study are more pronounced in the northern half of the watershed.

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