Ordovician and Mississippian stratigraphy in southwestern Missouri, USA

2021 ◽  
pp. 181-200
Author(s):  
Charles W. Rovey ◽  
Damon J. Bassett ◽  
Matthew P. McKay
Keyword(s):  
United States ◽  
Stratigraphic Sequence ◽  
Early Ordovician ◽  
Middle Mississippian ◽  
Carbonate Deposition ◽  
History Of ◽  
Tectonic Features ◽  
Deltaic Deposit ◽  
Southern Flank ◽  
Obvious Source

ABSTRACT A succession of Ordovician and Mississippian carbonates, separated unconformably, is exposed across the southern flank of the Ozark Dome in southwest Missouri. Deposits of both periods exemplify typical facies of the Midwestern United States: carbonate tidal-flat assemblages for the Early Ordovician and carbonate shelf environments for the Early–Middle Mississippian. The basic stratigraphic sequence of these deposits has been known for over a century, but interesting features remain to be addressed. Thin discontinuous sandstones are present within the Early Ordovician Cotter Dolomite, but the informal Swan Creek sandstone member seems anomalous. This sandstone can exceed 5 m in thickness and is fairly continuous across southwest Missouri. Most Ordovician sandstones in Missouri mark major transgressions above regional unconformities, but not the Swan Creek, and there is no obvious source of the sand. Therefore, we hypothesize that the Swan Creek represents reworked eolian dunes blown across the broad peritidal environment. Clastic sandstone dikes, apparently sourced from the Swan Creek, cut across beds of Cotter Dolomite near faults. We propose that these dikes are evidence of local faulting and seismicity during the Early Ordovician. Early and Middle Mississippian limestones comprise a sequence of shelf deposits, although mud mounds and other facies changes near the Missouri-Arkansas line mark the edge of the Mississippian shelf and the transition to a ramp setting. Early Mississippian carbonate deposition was interrupted by a short and localized influx of siliciclastic sediment comprising the Northview Formation. The Northview has additional characteristics consistent with a river-dominated deltaic deposit, which we suggest as its origin. If correct, this hypothesis implies that the history of tectonic features in the Midwest is more complicated than yet known. Finally, facies changes within and between the local Mississippian formations may record an early crustal response to the impending Ouachita orogeny farther to the south.

The Division of Zhangjiakou Formation of Later Jurassic at Jibei

2013 ◽  
Vol 275-277 ◽  
pp. 1578-1584
Author(s):  
Ying Fu Chen ◽  
Gen Hou Wang ◽  
Qing Tao Meng
Keyword(s):  
Large Scale ◽  
Mapping Method ◽  
Caldera Collapse ◽  
Stratigraphic Correlation ◽  
Stratigraphic Sequence ◽  
Phase Sequence ◽  
Lithostratigraphic Units ◽  
Long Time ◽  
History Of ◽  
Tectonic Features

There is not a unified division scheme on the lithostratigraphic unit of Zhangjiakou formation from later Jurassic at jibei for a long time, so it makes the divisions more confusion, the establishment of the reasonable stratigraphic sequence and regional stratigraphic correlation has been effected. The Zhangjiakou formation is divided into three lithologic members in turn based on lithology combination of the phase sequence at Zhangjiakou by author through the project of “the study of jibei Mesozoic continental volcanic-sedimentary basin 1:250000 mapping method”. The first section mainly includes lithology combination of weak eruption phase sequence. The second section is main the lithology combination of explosive phase sequence; the third section mainly includes lithology combination of the eruption phase sequence. These three sections respectively represent the stage of the initial outbreak, the large-scale outbreak and a caldera collapse deposition. This division method can reflect volcanic tectonic features, establishing reasonable stratigraphic sequence, this contribute to the study of the history of the volcanic evolution. It can also combine the lithostratigraphic units division and volcanic-sedimentary organically.

Review of A brief history of the United States.

1919 ◽  
Vol 10 (8) ◽  
pp. 414-414
Author(s):  
No authorship indicated
Keyword(s):  
United States ◽  
The United States ◽  
History Of

An American Language

2018 ◽  
Author(s):  
Rosina Lozano
Keyword(s):  
United States ◽  
National Policy ◽  
The United States ◽  
Spanish Language ◽  
Spanish Speakers ◽  
Language Recognition ◽  
Political Language ◽  
Political Issue ◽  
History Of ◽  
The U.S

An American Language is a political history of the Spanish language in the United States. The nation has always been multilingual and the Spanish language in particular has remained as an important political issue into the present. After the U.S.-Mexican War, the Spanish language became a language of politics as Spanish speakers in the U.S. Southwest used it to build territorial and state governments. In the twentieth century, Spanish became a political language where speakers and those opposed to its use clashed over what Spanish's presence in the United States meant. This book recovers this story by using evidence that includes Spanish language newspapers, letters, state and territorial session laws, and federal archives to profile the struggle and resilience of Spanish speakers who advocated for their language rights as U.S. citizens. Comparing Spanish as a language of politics and as a political language across the Southwest and noncontiguous territories provides an opportunity to measure shifts in allegiance to the nation and exposes differing forms of nationalism. Language concessions and continued use of Spanish is a measure of power. Official language recognition by federal or state officials validates Spanish speakers' claims to US citizenship. The long history of policies relating to language in the United States provides a way to measure how U.S. visions of itself have shifted due to continuous migration from Latin America. Spanish-speaking U.S. citizens are crucial arbiters of Spanish language politics and their successes have broader implications on national policy and our understanding of Americans.

Clinical Characteristics of Patients Diagnosed with Strongyloidiasis in a United States Urban Outpatient Dermatology Department: A Case Series

2017 ◽  
Vol 1 (3) ◽  
pp. 156-160
Author(s):  
Jacqueline Watchmaker ◽  
Sean Legler ◽  
Dianne De Leon ◽  
Vanessa Pascoe ◽  
Robert Stavert
Keyword(s):  
United States ◽  
Case Series ◽  
The United States ◽  
Screening Tools ◽  
Dermatology Department ◽  
Cutaneous Manifestations ◽  
Serologic Testing ◽  
Patient Reported ◽  
History Of ◽  
Endemic Areas

Background: Although considered a tropical disease, strongyloidiasis may be encountered in non-endemic regions, primarily amongst immigrants and travelers from endemic areas.  Chronic strongyloides infection may be under-detected owing to its non-specific cutaneous presentation and the low sensitivity of commonly used screening tools. Methods: 18 consecutive patients with serologic evidence of strongyloides infestation who presented to a single urban, academic dermatology clinic between September 2013 and October 2016 were retrospectively included.  Patient age, sex, country of origin, strongyloides serology titer, absolute eosinophil count, presenting cutaneous manifestations, and patient reported subjective outcome of pruritus after treatment were obtained via chart review.  Results: Of the 18 patients, all had non-specific pruritic dermatoses, 36% had documented eosinophila and none were originally from the United States. A majority reported subjective improvement in their symptoms after treatment. Conclusion:  Strongyloides infection and serologic testing should be considered in patients living in non-endemic regions presenting with pruritic dermatoses and with a history of exposure to an endemic area.Key Points:Chronic strongyloidiasis can be encountered in non-endemic areas and clinical manifestations are variableEosinophilia was not a reliable indicator of chronic infection in this case series Dermatologists should consider serologic testing for strongyloidiasis in patients with a history of exposure and unexplained pruritus

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