نتایج جستجو برای: Fluvial

تعداد نتایج: 4448  

2017
JANE K. HART Jane K. Hart

At Aberdaron, north Wales, a complex sequence of homogeneous tills and fluvial sediments overlie a hard rock base. The lower diamicton association at the bottom of the sequence consists of deformed tills and lenses of stratified sediments. It is suggested that these represent deforming bed tills and subglacial fluvial units which have been deformed together by subglacial excavational deformatio...

2009
Jason P. Field David D. Breshears Jeffrey J. Whicker

Soil erosion is driven by not only aeolian but also fluvial transport processes, yet these two types of processes are usually studied independently, thereby precluding effective assessment of overall erosion, potential interactions between the two drivers, and their relative sensitivities to projected changes in climate and land use. Here we provide a perspective that aeolian and fluvial transp...

2009
Geoffrey C. Collins

[1] Observations of likely fluvial channels on the surface of Titan, along with Titan’s geologically youthful surface, motivate this study of comparative fluvial erosion rates on Titan and the Earth. The roles of bedload abrasion, suspended load abrasion, plucking, and cavitation are considered. Despite orders of magnitude differences in some of the physical parameters that control fluvial inci...

2013
Jennifer L. Aschoff

In addition, one of the following statements should be included. Abstract The Piceance Basin, CO is a type locale for unconventional tight-gas sandstone in the Rocky Mountains (Law, 2002). Productive Williams Fork sandstones are extremely heterogeneous fluvial to marginal marine reservoirs that have very low permeability (<0.1 md) that typically require expensive hydraulic fracturing with 10-20...

2012
Benjamin A. Black J. Taylor Perron Devon M. Burr Sarah A. Drummond

[1] Drainage networks on Titan, Earth, and Mars provide the only known examples of non-volcanic fluvial activity in our solar system. The drainage networks on Titan are apparently the result of a methane-ethane cycle similar to Earth’s water cycle. The scarcity of impact craters and the uneven distribution of fluvial dissection on Titan suggest that the surface may be relatively young. The purp...

2007
Alan D. Howard

On the highlands of Mars early in the history of the planet precipitation-driven fluvial erosion competed with ongoing impact cratering. This disruption, and the multiple enclosed basins produced by impacts, is partially responsible for a long debate concerning the processes and effectiveness of fluvial erosion. The role of fluvial erosion in sculpting the early Martian landscape is explored he...

2014
Peter B. Buhler Caleb I. Fassett Michael P. Lamb

Milna Crater, Mars (23.4S, 12.3W) exhibits signs of fluvial modification early in Mars history, including a large multi-lobed fan deposit cut by several sinuous valleys. We describe the past hydrologic conditions in Milna and the surrounding area, including a potential lake with a volume of 50 km 3. We also introduce new methods (i) to calculate the timescale of sediment deposition by consideri...

2017
Alessandro Ielpi Robert H. Rainbird Dario Ventra Massimiliano Ghinassi

Proterozoic rivers flowed through barren landscapes, and lacked interactions with macroscopic organisms. It is widely held that, in the absence of vegetation, fluvial systems featured barely entrenched channels that promptly widened over floodplains during floods. This hypothesis has never been tested because of an enduring lack of Precambrian fluvial-channel morphometric data. Here we show, th...

2014
Chukwuemeka Frank

The Benin Formation is well exposed along the Atamiri River, which traverses Uli town, in the Niger Delta Basin of Southeastern Nigeria. Lithologic sections were measured, described and sampled so as to decipher the paleodepositional environment, using an integration of lithofacies data, pebble morphology, grain size and paleocurrent analysis. The lithofacies study suggests that the Benin Forma...

Extended abstract 1- Introduction Fluvial and aeolian processes are important factors in changing the surface of morphology in the Earth. When rivers and sand dunes meet, the transportation of sediment  between them can lead to one of the systems or both  of them change. With their connection between river sediment and wind systems there would be lots of reactions, but very little has been st...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید