Monitoring Potential Transport of Radioactive Contaminants in Shallow Ephemeral Channels: FY2018

LITHOBIOTOPES OF THE NEMEGT GOBI BASIN

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2020-0148 ◽

2021 ◽

Author(s):

Tomasz Jerzykiewicz ◽

Philip J. Currie ◽

Federico Fanti ◽

Jerzy Lefeld

Keyword(s):

Upper Cretaceous ◽

Alluvial Plain ◽

Gobi Desert ◽

Large Species ◽

Physical Processes ◽

Desert Region ◽

Ephemeral Channels ◽

Temporal Succession ◽

Asymmetric Distributions ◽

Rich Fauna

Three distinct but overlapping dinosaur-dominated faunas characterize the Upper Cretaceous Djadokhta, Baruungoyot and Nemegt formations of the Nemegt Basin of Mongolia. Documented faunal differences cannot be explained easily by temporal succession, but can be understood in the light of physical processes controlling life, death, and burial of taxa. The stratigraphy of the Gobi Desert region records tectonically driven geometries, clearly documenting preservational processes different than those acting in most other dinosaur-dominated beds worldwide. Small, asymmetric tectonic grabens were filled with Upper Cretaceous, dinosaur bearing deposits showing asymmetric distributions of facies, here termed Lithobiotopes. The water-lain fluvial and alluvial plain facies of the Nemegt Lithobiotope supported and preserved a fauna dominated by gigantic dinosaurs, but had a preservational bias against smaller animals. The Nemegt passed laterally into interdune facies of the Baruungoyot Lithobiotope, which represented a hostile environment for large species, but preserved smaller animals. This in turn passed laterally into the aeolianite facies of the Djadokhta Lithobiotope, which is characterized by remains of small dinosaurs and a rich fauna of other animals. The Nemegt Gobi Basin can be visualized as an oasis with a central pond supplied with water from ephemeral channels and surrounded by a semi-arid alluvial plain and dune fields.

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High Density Metal Contaminant Transport in Arid Region Ephemeral Channels

Military Geosciences and Desert Warfare - Advances in Military Geosciences ◽

10.1007/978-1-4939-3429-4_10 ◽

2015 ◽

pp. 139-151

Author(s):

Julianne J. Miller ◽

David S. Shafer ◽

Charalambos Papelis ◽

Craig A. Refosco ◽

Nathan A. Krzyaniak

Keyword(s):

Contaminant Transport ◽

Arid Region ◽

High Density ◽

Ephemeral Channels ◽

Metal Contaminant

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Modeling scour and deposition in ephemeral channels after wildfire

CATENA ◽

10.1016/j.catena.2005.03.013 ◽

2005 ◽

Vol 61 (2-3) ◽

pp. 273-291 ◽

Cited By ~ 17

Author(s):

H. Evan Canfield ◽

Cathy J. Wilson ◽

Leonard J. Lane ◽

Kelly J. Crowell ◽

William A. Thomas

Keyword(s):

Ephemeral Channels

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Remote semiautomatic instrumentation for intermittent streamflow measurement and suspended sediment sampling

Canadian Journal of Civil Engineering ◽

10.1139/l84-113 ◽

1984 ◽

Vol 11 (4) ◽

pp. 993-996 ◽

Cited By ~ 2

Author(s):

John L. Honsaker ◽

Ian A. Campbell ◽

R. B. Bryan

Keyword(s):

Solar Cells ◽

Key Words ◽

Suspended Sediment ◽

Stream Flow ◽

Intermittent Stream ◽

Battery Charging ◽

Stream Discharge ◽

Ephemeral Channels ◽

Solar Battery ◽

Sediment Sampling

Stream discharge and suspended sediment in ephemeral channels are measured by battery-powered instruments adapted for control by detection of rainfall. Solar cells recharge batteries between flow events. Key words: instruments, ephemeral channel, intermittent stream flow, suspended sediment, rain-activated, solar battery charging.

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A geomorphic classification of ephemeral channels in a mountainous, arid region, southwestern Arizona, USA

Geomorphology ◽

10.1016/j.geomorph.2014.06.005 ◽

2014 ◽

Vol 221 ◽

pp. 164-175 ◽

Cited By ~ 32

Author(s):

Nicholas A. Sutfin ◽

Jeremy R. Shaw ◽

Ellen E. Wohl ◽

David J. Cooper

Keyword(s):

Arid Region ◽

Ephemeral Channels

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Abandoned Mine Tailings Affecting Riverbed Sediments in the Cartagena–La Union District, Mediterranean Coastal Area (Spain)

Remote Sensing ◽

10.3390/rs12122042 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2042 ◽

Cited By ~ 1

Author(s):

Tomás Martín-Crespo ◽

David Gómez-Ortiz ◽

Silvia Martín-Velázquez ◽

Pedro Martínez-Pagán ◽

Cristina de Ignacio-San José ◽

...

Keyword(s):

Mine Tailings ◽

Open Pit ◽

Drainage Pattern ◽

Mining Operations ◽

Geochemical Composition ◽

Ephemeral Channels ◽

Metallurgical Wastes ◽

Riverbed Sediments ◽

Intermediate Unit ◽

Mining Works

This study presents the results of the geoenvironmental characterization of La Matildes riverbed, affected by mine tailings in the Cartagena–La Unión district, Murcia (southeast Spain). Soils and riverbeds in this area are highly polluted. Two Electrical Resistivity Imaging (ERI) profiles were carried out to obtain information about the thickness of the deposits and their internal structure. For the mine tailings deposits of La Murla, a tributary of the El Miedo riverbed, the geophysical method imaged two different units: the upper one characterized by low resistivity values and 5–8 m thickness, correlated with the mine tailings deposits; and the lower more resistive unit corresponding to the Paleozoic metasediments bedrock. The ERI profile transverse to the Las Matildes dry riverbed revealed the existence of three different units. The uppermost one has the lowest resistivity values and corresponds to the tailings deposits discharged to the riverbeds. An intermediate unit, with intermediate resistivity values, corresponds to the riverbed sediments before the mining operations. The lower unit is more resistive and corresponds to the bedrock. Significant amounts of pyrite, sphalerite, and galena were found both in tailings and riverbed sediments. The geochemical composition of borehole samples from the riverbed materials shows significantly high contents of As, Cd, Cu, Fe, Pb, and Zn being released to the environment. Mining works have modified the natural landscape near La Unión town. Surface extraction in three open-pit mines have changed the summits of Sierra de Cartagena–La Unión. Rock and metallurgical wastes have altered the drainage pattern and buried the headwaters of ephemeral channels. The environmental hazards require remediation to minimize the environmental impact on the Mar Menor coastal lagoon, one of the most touristic areas in SE Spain.

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Process and discharge estimation in ephemeral channels, Canadian Rocky Mountains

Canadian Journal of Earth Sciences ◽

10.1139/e84-109 ◽

1984 ◽

Vol 21 (9) ◽

pp. 1050-1060 ◽

Cited By ~ 20

Author(s):

Joseph R. Desloges ◽

James S. Gardner

Keyword(s):

Debris Flow ◽

Rocky Mountains ◽

Canadian Rocky Mountains ◽

Alluvial Channels ◽

Channel Processes ◽

Cross Sectional ◽

Ephemeral Channels ◽

Multiple Process ◽

Instantaneous Discharge ◽

Discharge Estimation

Process determinations and discharge estimates are made for 10 steep alpine channels in the Front and Main ranges of the southern Canadian Rocky Mountains. The catchments, which range in size from 0.17 to 1.13 km2, are sufficiently small that their runoff patterns are dominantly ephemeral and are characterized by processes that include water floods, debris flows, and snow avalanches.Longitudinal and cross-sectional channel profiles demonstrate the importance of bedrock control and the influence of one or more dominant processes. Debris flow channels have been partially scoured by water floods, and avalanche and debris flow sediments are noted in modified alluvial channels. The distribution and sorting of sediments support the multiple-process origin of specific channels or channel reaches.The discrimination of channel processes is essential for estimates of channel discharge. Slope/area and competence methods employed in fluvially dominated reaches of the 10 channels yield maximum instantaneous discharge estimates of between 1.1 and 12.2 m3 s−1. These discharges are generally not representative of the potential volumes of water and sediment released from the channels because of augmentation by both debris flow and avalanche processes. The design of roads and railways traversing these channels requires consideration of a range of processes of varying magnitudes.

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