نتایج جستجو برای: alluvial fans

تعداد نتایج: 7388  

Journal: :تحقیقات جغرافیایی 0
شهرام بهرامی گروه جغرافیای طبیعی، دانشکده جغرافیا و علوم محیطی، دانشگاه حکیم سبزواری

the aim of this paper is to evaluate the effect of tectonic on the volume of alluvial fans around danehkhoshk anticline. to achieve the purpose of this study, at first, borders, sweep angle(s) and radius(r) of alluvial fans were obtained based on quick bird satellite image and then difference in the altitude between the apex and toe of alluvial fans (h) were calculated based on topographic map ...

2011
John A. Grant Sharon A. Wilson

[1] Crater statistics indicate alluvial fans, crater floor, and fill/mantling deposits within impact craters >50 km in diameter in southern Margaritifer Terra were likely emplaced during multiple epochs: fans formed during the Amazonian or near the Amazonian‐Hesperian boundary, crater floor deposits are likely Hesperian in age, and most fill/mantling deposits are Amazonian. The regional distrib...

2001
G. A. Smith

Alluvial slopes are piedmonts characterized by parallel steam channels rather than alluvial fans. They are common landforms in extensional basins of the south-western United States but have received little attention from geomorphologists or sedimentologists. Persistence of channellized flow across piedmonts, as opposed to sheetflooding due to loss of flow confinement on alluvialfan surfaces, di...

Alluvial fans are one of the most important of types of geomorphic landforms in mountainous regions, especially in dry and semi-dry region, which flow processes create them with reducing the slope and opening the valley after leaving the mountain.This study investigate the effects of geographic directions on the dimensions of alluvial fans in down streams in Shirkouh Mountain in the central par...

2017
Luca C. Malatesta Michael P. Lamb

Waterfalls commonly exist near bounding faults of mountain ranges, where erosional bedrock catchments transition to depositional alluvial fans. We hypothesize that aggradation on alluvial fans can bury active faults, and that the faults accumulate slip in the subsurface to produce a bedrock scarp. Following entrenchment of the alluvial fan, the scarp can be exposed as a waterfall. To explore th...

Journal: :پژوهش های جغرافیای طبیعی 0
مجتبی یمانی استاد دانشکدة جغرافیا، دانشگاه تهران ابوالقاسم گورابی استادیار دانشکدة جغرافیا، دانشگاه تهران سید محمد زمان زاده استادیار دانشکدة جغرافیا، دانشگاه تهران عارفه شعبانی عراقی دانشجوی کارشناسی ارشد ژئومورفولوژی دانشگاه تهران

introduction interaction between internal and external processes of the earth during time plays an important role in formation and landforms transformation. we can identify course of their process changes with landform survey. in the middle parts of iran, there are several geomorphologic evidence of arid and rainy climate changes. playaes and lakes or generally internal holes had an important r...

2005
MICHAEL WAGREICH

Middle Miocene alluvial fans in the intramontane Fohnsdorf Basin of the Eastern Alps originated along normal faults and linked strike-slip faults in a continental half-graben setting. The fans display considerable facies differences. Debris flows of the Rachau fan are characterized by a sandy matrix and large boulders, whereas debris flows of the Apfelberg fan are characterized by higher silt a...

Journal: Geopersia 2020

The present research focuses on a detailed facies description and interpretation of five alluvial fans of the Qazvin Plain. Beside the tectonic activity that leads to the localization of the fans on the northern margin of the Qazvin Plain, the climate has a significant role in the occurrence of their facies. The alluvial fans are divided into three facies groups: group 1, group 2, and group 3. ...

2006
Rebecca M. E. Williams James R. Zimbelman Andrew K. Johnston

[1] Longitudinal profiles from six alluvial fans surveyed in southwestern California have quantitative attributes that can distinguish formation processes. The radial slope of fans where debris flow processes dominated is constant while fluvially-fed fans have a concave-upward shape. We find the power law regression of upstream slope-distance profiles is the preferred approach for assessing con...

Landforms and geomorphological processes is the most important factors that affecting dispersion and quality of building materials.  Case study, consisting of both new and old alluvial fans is located in the West of the city of Sabzevar. The aim of this study was to investigate the process of freezing and thawing in the durability and quality of materials taken from the alluvial fans old and ne...

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