scholarly journals Detrital zircon U-Pb data reveal a Mississippian sediment dispersal network originating in the Appalachian orogen, traversing North America along its southern shelf, and reaching as far as the southwest United States

Lithosphere ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 581-587 ◽  
Author(s):  
Alan D. Chapman ◽  
Andrew K. Laskowski
Keyword(s):  
United States ◽  
North America ◽  
Detrital Zircon ◽  
Structural Data ◽  
Trade Wind ◽  
Long Distance ◽  
Sediment Dispersal ◽  
Sediment Routing ◽  
Appalachian Orogen ◽  
Peace River Arch

AbstractRecent detrital zircon U-Pb geochronology reveals an increasing proportion of Grenville-age (ca. 0.95–1.3 Ga) and ca. 300–480 Ma grains in late Paleozoic strata of the SW United States. These grain populations are interpreted to have been sourced from the Appalachian orogen, though the precise timing, transport mechanisms, and pathway(s) of sediment dispersal remain unclear. We combine 35,796 published detrital zircon U-Pb ages from Ordovician to Pennsylvanian strata of southern Canada, northern Mexico, and the U.S. with new data (1,628 ages) from Kansas, Missouri, Montana, and South Dakota. These data are integrated with sedimentary structural data and paleogeographic reconstructions to reveal temporal and spatial patterns of the sediment routing system at continent scale. In Ordovician time, North America was partitioned into western, central, and eastern domains in which strata were derived primarily from the Peace River Arch, the Superior Craton, and the Appalachians, respectively. Silurian–Devonian time saw limited integration of these domains, corresponding with the delivery of Appalachian-derived detritus to the Midcontinent via prograding deltas and westward-flowing rivers. Appalachian detritus flowed westward in Mississippian time, accumulating in the Appalachian foreland and continuing westward through Mississippi, Arkansas, Missouri, Oklahoma, Kansas, Colorado, Arizona, and California along the continental shelf. Given that North America was at equatorial latitudes and was inundated by the Kaskaskia sea at this time, westward dispersal likely occurred by trade wind–driven longshore drift, waves, tides, and marine currents, with the possible added contribution of hurricanes. Modern analogs for the southern margin of North America during Mississippian time (e.g., the Great Barrier Reef and the east coast of South America) indicate that long-distance (>1000 km) shelf-parallel sediment transport is readily accomplished through fair-weather processes and extreme events. Finally, Appalachian-derived detritus became widespread throughout North America following regression of the Kaskaskia sea in Pennsylvanian time, likely via fluvial, deltaic, and aeolian processes.

scholarly journals Supplemental Material: Early Pennsylvanian sediment routing to the Ouachita Basin (southeastern United States) and barriers to transcontinental sediment transport sourced from the Appalachian orogen based on detrital zircon U-Pb and Hf analysis

2021 ◽  
Author(s):  
I.J. Allred ◽  
M.D. Blum
Keyword(s):  
United States ◽  
Sediment Transport ◽  
Detrital Zircon ◽  
Southeastern United States ◽  
Isotopic Data ◽  
Dimensional Scaling ◽  
Data Table ◽  
Sediment Routing ◽  
Appalachian Orogen ◽  
Multi Dimensional Scaling

<div>Table S1: Detrital zircon (DZ) U-Pb isotopic data. Table S2: DZ U-Pb isotopic data from a higher-<i>n </i>approach. Table S3: DZ Hf isotopic data. Table S4: Multi-dimensional scaling (MDS) sample key. <br></div>

scholarly journals Early Pennsylvanian sediment routing to the Ouachita Basin (southeastern United States) and barriers to transcontinental sediment transport sourced from the Appalachian orogen based on detrital zircon U-Pb and Hf analysis

Geosphere ◽  
2021 ◽  
Author(s):  
Isaac J. Allred ◽  
Michael D. Blum
Keyword(s):  
United States ◽  
Detrital Zircon ◽  
Eastern United States ◽  
Ouachita Mountains ◽  
Sediment Dispersal ◽  
Continental Scale ◽  
The North ◽  
Sediment Routing ◽  
Proximal Site ◽  
Central United States

Carboniferous sediment dispersal from the Appalachian orogenic system (eastern United States) has become a topic of widespread interest. However, the actual pathways for continental-scale, east-to-west sediment transfer have not been documented. This study presents detrital zircon (DZ) U-Pb ages and Hf isotopic values from the Lower Pennsylvanian (Morrowan) Jackfork Group and Johns Valley Shale of the synorogenic Ouachita deepwater basin of Arkansas to document provenance and delineate the likely sediment-routing systems within the broader context of sediment dispersal across Laurentia. Twelve (12) DZ U-Pb age distributions are interpreted to indicate that sediments were derived from the Appalachians to the east and northeast, as well as the midcontinent region to the north. All samples display prominent ca. 500– 400 Ma, 1250–950 Ma, 1550–1300 Ma, and 1800–1600 Ma grains, consistent with ultimate derivation from the Appalachian, Grenville, Midcontinent, and Yavapai-Mazatzal provinces. DZ Hf values obtained from the Ouachita Basin are similar to published Hf values from Pennsylvanian samples in the Appalachian and Illinois Basins. Age distributions are generally consistent for seven samples collected from the Jackfork Group and Johns Valley Shale in the southern Ouachita Mountains through ~2400 m of stratigraphic section and are interpreted to indicate little change in provenance during the Morrowan in this part of the system. However, samples from the most northern and most source-proximal site in Little Rock, Arkansas, exhibit modest percentages of Appalachian ages and elevated contributions of Yavapai-Mazatzal ages when compared with samples collected farther to the south and west. We interpret differences between DZ signatures to indicate distinct sediment-routing pathways to the Ouachita Basin. We infer the strong Appalachian and Grenville signals to represent an axial system flowing through the Appalachian foredeep, whereas the more diverse signals represent a confluence of rivers from the northeast through the backbulge of southern Illinois and western Kentucky and from the north across the Arkoma shelf. Collectively, the Ouachita Basin represents a terminal sink for sediments derived from much of the eastern and central United States.

scholarly journals Supplemental Material: Early Pennsylvanian sediment routing to the Ouachita Basin (southeastern United States) and barriers to transcontinental sediment transport sourced from the Appalachian orogen based on detrital zircon U-Pb and Hf analysis

2021 ◽  
Author(s):  
I.J. Allred ◽  
M.D. Blum
Keyword(s):  
United States ◽  
Sediment Transport ◽  
Detrital Zircon ◽  
Southeastern United States ◽  
Isotopic Data ◽  
Dimensional Scaling ◽  
Data Table ◽  
Sediment Routing ◽  
Appalachian Orogen ◽  
Multi Dimensional Scaling

<div>Table S1: Detrital zircon (DZ) U-Pb isotopic data. Table S2: DZ U-Pb isotopic data from a higher-<i>n </i>approach. Table S3: DZ Hf isotopic data. Table S4: Multi-dimensional scaling (MDS) sample key. <br></div>

scholarly journals Supplemental Material: Early Pennsylvanian sediment routing to the Ouachita Basin (southeastern United States) and barriers to transcontinental sediment transport sourced from the Appalachian orogen based on detrital zircon U-Pb and Hf analysis

2021 ◽  
Author(s):  
I.J. Allred ◽  
M.D. Blum
Keyword(s):  
United States ◽  
Sediment Transport ◽  
Detrital Zircon ◽  
Southeastern United States ◽  
Isotopic Data ◽  
Dimensional Scaling ◽  
Data Table ◽  
Sediment Routing ◽  
Appalachian Orogen ◽  
Multi Dimensional Scaling

<div>Table S1: Detrital zircon (DZ) U-Pb isotopic data. Table S2: DZ U-Pb isotopic data from a higher-<i>n </i>approach. Table S3: DZ Hf isotopic data. Table S4: Multi-dimensional scaling (MDS) sample key. <br></div>

scholarly journals Oceanic Records of North American Bats and Implications for Offshore Wind Energy Development in the United States

2021 ◽  
Author(s):  
Donald Solick ◽  
Christian Newman
Keyword(s):  
United States ◽  
North America ◽  
Wind Energy ◽  
North American ◽  
The United States ◽  
Mitigation Strategies ◽  
Offshore Wind ◽  
Offshore Wind Energy ◽  
Long Distance ◽  
Terrestrial Environment

Offshore wind energy is a growing industry in the United States, and renewable energy from offshore wind is estimated to double the country’s total electricity generation. There is growing concern that land-based wind development in North America is negatively impacting bat populations, primarily long-distance migrating bats, but the impacts to bats from offshore wind energy is unknown. Bats are associated with the terrestrial environment, but have been observed over the ocean. In this review, we synthesize historic and contemporary accounts of bats observed and acoustically recorded offshore over North American waters to ascertain the spatial and temporal distribution of bats flying offshore. We integrate these records with studies of offshore bats in Europe and of bat behavior at land-based wind energy studies to examine how offshore wind development could impact North American bat populations. We find that most offshore bat records are of long-distance migrating bats and records occur during autumn migration, the period of highest fatality rates for long-distance migrating bats at land-based wind facilities in North America. We summarize evidence that bats may be attracted to offshore turbines for roosting and foraging opportunities, potentially increasing their risk of collision, but that higher wind speeds offshore can potentially reduce the amount of time that bats are exposed to risk. We identify knowledge gaps and hypothesize that a combination of mitigation strategies may be the most effective approach for minimizing impacts to bats and maximizing offshore energy production.

scholarly journals Phytophthora ramorum in Canada: Evidence for Migration Within North America and from Europe

2011 ◽  
Vol 101 (1) ◽  
pp. 166-171 ◽  
Author(s):  
Erica M. Goss ◽  
Meg Larsen ◽  
Annelies Vercauteren ◽  
Sabine Werres ◽  
Kurt Heungens ◽  
...  
Keyword(s):  
United States ◽  
North America ◽  
Host Plants ◽  
Genotypic Diversity ◽  
The United States ◽  
Phytophthora Ramorum ◽  
Long Distance ◽  
Migration Rates ◽  
Woody Ornamentals ◽  
Canadian Population

Phytophthora ramorum, the cause of sudden oak death on oak and ramorum blight on woody ornamentals, has been reported in ornamental nurseries on the West Coast of North America from British Columbia to California. Long-distance migration of P. ramorum has occurred via the nursery trade, and shipments of host plants are known to have crossed the U.S.–Canadian border. We investigated the genotypic diversity of P. ramorum in Canadian nurseries and compared the Canadian population with U.S. and European nursery isolates for evidence of migration among populations. All three of the P. ramorum clonal lineages were found in Canada but, unexpectedly, the most common was the NA2 lineage. The NA1 clonal lineage, which has been the most common lineage in U.S. nurseries, was found relatively infrequently in Canada, and these isolates may have been the result of migration from the United States to Canada. The EU1 lineage was observed almost every year and shared multilocus genotypes with isolates from Europe and the United States. Estimation of migration rates between Europe and North America indicated that migration was higher from Europe to North America than vice versa, and that unidirectional migration from Europe to North America was more likely than bidirectional migration.

U-Pb ages of detrital zircons in lower Permian sandstone and siltstone of the Permian Basin, west Texas, USA: Evidence of dominant Gondwanan and peri-Gondwanan sediment input to Laurentia

2019 ◽  
Vol 132 (1-2) ◽  
pp. 245-262 ◽  
Author(s):  
Li Liu ◽  
Daniel F. Stockli
Keyword(s):  
United States ◽  
Central America ◽  
Detrital Zircon ◽  
The United States ◽  
Detrital Zircons ◽  
Sediment Provenance ◽  
Early Permian ◽  
Permian Basin ◽  
Sediment Routing ◽  
West Texas

Abstract The Permian Basin of west Texas, one of the most economically significant hydrocarbon basins in the United States, formed along the southwest margin of Laurentia in the foreland of the Ouachita-Marathon orogen during the late Paleozoic. While its stratigraphic record temporally coincides with syn- and post-orogenic Ouachita-Marathon sedimentation, sediment provenance, sediment routing and dispersal, and paleo-drainage evolution have remained controversial. This study presents more than 2000 new detrital zircon U-Pb ages from 16 samples across the Permian Basin to elucidate early Permian sediment provenance and basin-fill evolution. The data show that Wolfcampian sandstones are dominated by 950–1070 Ma and 500–700 Ma detrital zircon U-Pb ages, whereas Leonardian sandstones and siltstones are dominated by 500–700 Ma and 280–480 Ma detrital zircon U-Pb ages. Most of these age clusters are not typical Laurentian basement ages, but rather indicative of a southern Gondwanan and peri-Gondwanan sources of Mexico and Central America. This interpretation is corroborated by zircons with peri-Gondwanan and Gondwanan rim-core relationships, as well as major age components of euhedral zircons, matching Maya block basement ages. Regional comparison of these new detrital zircon results with published data from Carboniferous and Permian sedimentary rocks in various terranes of Mexico and Central America, Appalachian foreland basins, Ouachita orogenic belt, midcontinent of United States, and Fort Worth Basin (Texas), indicates that most sediment influx to the Permian Basin during the early Permian (Wolfcampian and Leonardian) was derived from basement or recycled upper Paleozoic strata associated with Gondwanan and peri-Gondwanan terranes in modern Mexico and Central America. North American basements such as the Appalachian Grenville (950–1300 Ma), Granite-Rhyolite (1300–1500 Ma), and Yavapai-Mazatzal (1600–1800 Ma) provinces, appear to have provided only minor amounts of sediment. In light of depositional age constraints, the timing of Marathon-Ouachita collision, and careful detrital zircon U-Pb age spectra comparison, the sediment provenance shift from Wolfcampian to Leonardian points to a diachronous, oblique continent-continent collision between Gondwana/peri-Gondwanan terranes and Laurentia.

scholarly journals Fluid Spatial Dynamics of West Nile Virus in the United States: Rapid Spread in a Permissive Host Environment

2015 ◽  
Vol 90 (2) ◽  
pp. 862-872 ◽  
Author(s):  
Francesca Di Giallonardo ◽  
Jemma L. Geoghegan ◽  
Douglas E. Docherty ◽  
Robert G. McLean ◽  
Michael C. Zody ◽  
...  
Keyword(s):  
United States ◽  
West Nile Virus ◽  
North America ◽  
Adaptive Evolution ◽  
Sequence Data ◽  
The United States ◽  
Avian Species ◽  
Long Distance ◽  
West Nile ◽  
Permissive Host

ABSTRACTThe introduction of West Nile virus (WNV) into North America in 1999 is a classic example of viral emergence in a new environment, with its subsequent dispersion across the continent having a major impact on local bird populations. Despite the importance of this epizootic, the pattern, dynamics, and determinants of WNV spread in its natural hosts remain uncertain. In particular, it is unclear whether the virus encountered major barriers to transmission, or spread in an unconstrained manner, and if specific viral lineages were favored over others indicative of intrinsic differences in fitness. To address these key questions in WNV evolution and ecology, we sequenced the complete genomes of approximately 300 avian isolates sampled across the United States between 2001 and 2012. Phylogenetic analysis revealed a relatively star-like tree structure, indicative of explosive viral spread in the United States, although with some replacement of viral genotypes through time. These data are striking in that viral sequences exhibit relatively limited clustering according to geographic region, particularly for those viruses sampled from birds, and no strong phylogenetic association with well-sampled avian species. The genome sequence data analyzed here also contain relatively little evidence for adaptive evolution, particularly of structural proteins, suggesting that most viral lineages are of similar fitness and that WNV is well adapted to the ecology of mosquito vectors and diverse avian hosts in the United States. In sum, the molecular evolution of WNV in North America depicts a largely unfettered expansion within a permissive host and geographic population with little evidence of major adaptive barriers.IMPORTANCEHow viruses spread in new host and geographic environments is central to understanding the emergence and evolution of novel infectious diseases and for predicting their likely impact. The emergence of the vector-borne West Nile virus (WNV) in North America in 1999 represents a classic example of this process. Using approximately 300 new viral genomes sampled from wild birds, we show that WNV experienced an explosive spread with little geographical or host constraints within birds and relatively low levels of adaptive evolution. From its introduction into the state of New York, WNV spread across the United States, reaching California and Florida within 4 years, a migration that is clearly reflected in our genomic sequence data, and with a general absence of distinct geographical clusters of bird viruses. However, some geographically distinct viral lineages were found to circulate in mosquitoes, likely reflecting their limited long-distance movement compared to avian species.

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