Pebbles in the Lower Colorado River, Texas a Study in Particle Morphogenesis

  title={Pebbles in the Lower Colorado River, Texas a Study in Particle Morphogenesis},
  author={Edmund D. Sneed and Robert L. Folk},
  journal={The Journal of Geology},
  pages={114 - 150}
The Colorado River in its course from central Texas to the Gulf of Mexico carries quartz, chert, and limestone pebbles which can be traced for distances of up to 270 miles from their source. Limestone is so soft that it reaches its limiting roundness in the first few miles and thereafter undergoes no further increase. Harder quartz rounds much more slowly but eventually attains the same high limiting roundness value as limestone. Chert, being brittle, tends to spall and only rounds slightly… Expand
Pebble morphology in the Merced River (California)
Abstract Granitic pebble morphology was studied in the detritus of the Merced River, Sierra Nevada, California, where minimum distance of transport of granitic pebbles can be determined. ModernExpand
Quantifying the significance of abrasion and selective transport for downstream fluvial grain size evolution
It is well known that pebble diameter systematically decreases downstream in rivers. The contribution of abrasion is uncertain, in part because (1) diameter is insufficient to characterize pebbleExpand
Rapid downstream changes in particle size, form, sorting, and grain size distributions are demonstrated to occur in the bed sediments of Two O'Clock Creek, a small stream in the Canadian Rockies.Expand
Abrasion model of downstream changes in grain shape and size along the Williams River, Australia
[1] Modeling pebble abrasion during bed load transport is of fundamental importance in fluvial geomorphology, as it may help to understand downstream fining patterns along gravel bed rivers. Here weExpand
Multiphase Storm Deposits Eroded from Andesite Sea Cliffs on Isla San Luis Gonzaga (Northern Gulf of California, Mexico)
The 450-m long spit that extends westward from the northwest corner of Isla San Luis Gonzaga is one of the largest and most complex constructions of unconsolidated cobbles and boulders found anywhereExpand
The Shape of Fluvial Gravels: Insights from Fiji’s Sabeto River
This project aims to re-assess our understanding of the shape of fluvial bedload gravels by drawing together existing information on fluvial gravel shape. At its crux, however, is the interpretationExpand
Downstream fining in a rapidly aggrading gravel bed river
Downstream changes in particle size that occur in the Waipaoa River, a 104-km-long gravel bed river in which rapid aggradation in the historic (post-1800) period was triggered by the conversion ofExpand
This paper mainly describes experiments that have been carried out on two shingle beaches on the south coast of England. The results for the higher energy environment of Chesil Beach showed thatExpand
Sedimentation of Beach Gravels: Examples from South Wales
ABSTRACT On the basis of particle shape the surface layers of some South Wales beaches are subdivided into four zones:--a large disc zone landward, typified by cobble sized discs, having on itsExpand
The Siwalik group (Molasse) — Sediments shed by collision of continental plates
Abstract The Siwalik Group, with a thickness of more than 5000 m of clastic sediments, was deposited in an east—west elongated basin, a forerunner of the Indogangetic Plains. The basin was filledExpand


The Petrology and Origin of the Lafayette Gravel: Part 1. Mineralogy and Petrology
Extensive chert gravels underlying the Smithland and higher erosion surfaces of the uppermost portion of the Mississippi embayment are considered remnants of three coalescing alluvial fans related toExpand
Brazos River bar [Texas]; a study in the significance of grain size parameters
A bar on the Brazos River near Calvert, Texas, has been analyzed in order to determine the geologic meaning of certain grain size parameters and to study the behavior of the size fractions withExpand
Black Hills Terrace Gravels: A Study in Sediment Transport
Terraces were mapped along three streams which flow eastward from the Black Hills of South Dakota. Five erosional surfaces were found which represent major pauses in the downcutting activity of theExpand
A Laboratory and Field Study of Cobble Abrasion
In the course of field work at Baraboo, Wisconsin, in the summer of 1916, it occurred to me that by means of a suitably designed tumbling barrel an experimental study might be made of the abrasion ofExpand
Experimental Abrasion of Pebbles: 2. Rolling by Current
The abrasion of pebbles rolled in a large concrete basin by a revolving current, both on a sandy and on a pebbly floor, was studied-a setup believed to be a substantial improvement on the customaryExpand
Some observations on the effect of particle shape on the movement of coarse sediments
During a study in which information was gathered to improve the design of unlined canals in coarse granular materials, an opportunity was afforded to study the effect of particle shape on theExpand
The Effects of Abrasion on the Size, Shape and Roundness of Rock Fragments
Earlier work on the abrasion of rock fragments in tumbling barrels is reviewed, and the main principles are summarized. Most earlier work concerned one or another aspect of abrasion without includingExpand
Shape Variation of Some Lake Superior Beach Pebbles
ABSTRACT The measured roundness and sphericity' of originally angular rock fragments derived from a rhyolite cliff on Lake Superior show a progressive increase with linear distance of travel as beachExpand
Pebbles from a Pothole: A Study in Shape and Roundness
ABSTRACT An assemblage of pebbles collected from a pothole in even-grained sandstone is described. Variation in shape and roundness for the different lithologic types of pebbles is given. TheExpand
Settling‐velocity and flume‐behavior of non‐spherical particles
The importance of particle-shape in sediment-transportation has been pointed out by numerous writers. Comparatively few experimental data are available, however, and even these are partly confused byExpand