The steep-walled bedrock gorges of the Greater Himalayan rivers currently lack significant stored sediment, suggesting that fluvial erosion and transport capacity outpace the supply of sediment from adjacent hillsides. Despite this appearance of sustained downcutting, such rivers can become choked with sediments and aggrade during intervals of higher precipitation. Cosmogenic dating (10Be and 2...

Submitted to the Texas Water Development Board 2 PREFACE This report is submitted in fulfillment of contract no. 2005-483-564 between the Texas Water Development Board and Jonathan Phillips (doing business as Copperhead Road Geoscience). The report is presented in two more-or-less independent parts, reflecting the Scope of Work for the project. The first is a review and evaluation of geomorphic...

The Amazon river is subject to major geomorphological changes between the hydrologic periods of flood and dry. Such changes can be mapped and detected by remote sensing techniques. In this context, this research had as objective to evaluate the dynamics of this great fluvial system, in the stretch between the cities of Manaus and Itacoatiara, in the period of 20 years. The results showed the pr...

Introduction: Since Mariner 9 first imaged fluvial channels on the surface of Mars thirty years ago, one of the continuing problems of its hydrologic history has been the apparent absence of small, first-order tributaries to the large outflow channels and the larger integrated channels of the highlands [1]. Drawing on terrestrial examples from the northeast Sahara, where Quaternary climate has ...

The direct simulation of water age is outlined and applied for evaluating the flushing features in fluvial conditions. The local water age is considered as a mass-weighted average of residence time of waters with various past. Given the river flow field is numerically modelled on a twoor three-dimensional grid, the spatial distribution and time variation of the mean age of water masses entering...

Innate distributions or variability of nutrient concentrations within the fluvial system must be better understood to establish nutrient guidelines that are applicable and to discern which areas or landscape positions within the watershed are more vulnerable to nutrient losses. This work was conducted to (1) determine the system-wide spatial distribution of N and P concentrations in biweekly st...

In the desert of Abarkoh Basin, Central Iran, the influence of playa-lake level fluctuations on recent sedimentation mode of a terminal ephemeral fluvial-fan system and adjacent lacustrine/aeolian sediments of a playa fringe environment has been investigated. The surface geomorphology-sedimentology and its relationship with shallow subsurface sediments along a >25 km transect, has been studied....

Geological evidence for extensive non-polar ice deposits of Amazonian age indicates that the current cold and dry climate of Mars has persisted for several billion years. The geological record and climate history of the Noachian, the earliest period of Mars history, is less certain, but abundant evidence for fluvial channels (valley networks) and lacustrine environments (open-basin lakes) has b...

The hyper-arid Taflilat Basin, South-East Morocco, is dominated by two ephemeral fluvial networks and several ergs with various dune forms from barchans to mega dunes. Especially the genesis of star dunes remains an open research question. Therefore, a new multi-sheet geomorphological map describes surface dynamics in basin. Identification major features was done remote sensing data on-site sur...

The type section of the Lower Cenomanian Bahariya Formation at Gebel El-Dist (Bahariya Oasis, Western Desert), Egypt, comprises claystones, mudstones, siltstones and sandstones deposited in fluvial-deltaic coastal plain, lagoonal, estuarine and shallow marine environments. The formation is characterized by an abundance of ferruginous sandstones that locally weather to form prominent iron crusts...