Grain size analysis is an essential tool for classifying sedimentary environments. The calculation of statistics for many samples can, however, be a laborious process. A computer program called GRADISTAT has been written for the rapid analysis of grain size statistics from any of the standard measuring techniques, such as sieving and laser granulometry. Mean, mode, sorting, skewness and other statistics are calculated arithmetically and geometrically (in metric units) and logarithmically (in phi units) using moment and Folk and Ward graphical methods. Method comparison has allowed Folk and Ward descriptive terms to be assigned to moments statistics. Results indicate that Folk and Ward measures, expressed in metric units, appear to provide the most robust basis for routine comparisons of compositionally variable sediments. The program runs within the Microsoft Excel spreadsheet package and is extremely versatile, accepting standard and non-standard size data, and producing a range of graphical outputs including frequency and ternary plots. Copyright © 2001 John Wiley & Sons, Ltd.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/esp.261

GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments

A classification of channel-reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types: colluvial, bedrock, and five alluvial channel types (cascade, step pool , plane bed, pool rime, and dune ripple). Coupling reach-level channel processes with the spatial arrangement of reach morphologies, their links to hillslope processes, and external forcing by confinement, ripar­ ian vegetation, and woody debris defines a process-based framework within which to assess channel condition and response potential in mountain drainage basins. Field investigations demonstrate character­ istic slope, grain size, shear stress, and roughness ranges for different reach types, observations consistent with our hypothesis that alluvial channel morphologies reflect specific roughness configurations ad­ justed to the relative magnitudes of sediment supply and transport ca­ pacity. Steep alluvial channels (cascade and step pool) have high ratios of transport capacity to sediment supply and are resilient to changes in discharge and sediment supply, whereas low-gradient alluvial channels (pool rime and dune ripple) have lower transport capacity to supply ra­ tios and thus exhibit significant and prolonged response to changes in sediment supply and discharge. General differences in the ratio of transport capacity to supply between channel types allow aggregation of reaches into source, transport, and response segments, the spatial distribution of which provides a watershed-level conceptual model linking reach morphology and channel processes. These two scales of channel network classification define a framework within which to in­ vestigate spatial and temporal patterns of channel response in moun­ tain drainage basins.

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Channel-reach morphology in mountain drainage basins

Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations

Architectural-Element Analysis: A New Method of Facies Analysis Applied to Fluvial Deposits

Sandstones of the Paleozoic turbidite sequences of eastern Australia show a large variation in their major element geochemistry, reflecting the distinct sedimentary provenance and tectonic setting ...

Plate Tectonics and Geochemical Composition of Sandstones

Origin of sedimentary rocks , Origin of sedimentary rocks , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Origin of sedimentary rocks

The purpose in writing these notes has been to present a discussion of a few topics central to a physical understanding of the mechanics of sediment movement. Discussion has been confined to unidirectional flows (excluding waves) of relatively small scale (excluding Coriolis effects). A large number of topics have been not considered at all or only in passing, including one of the most important problems in sediment mechanics: theories for the prediction of bed-load and suspended-load discharge. It seemed more important to try to develop some physical insight about the elementary processes of sediment movement than to attempt to elaborate any comprehensive quantitative theories of sediment movement.

Mechanics of sediment movement

Sediment gravity flows : mechanics of flow and deposition

Turbidity currents were formed by releasing suspensions of plastic beads (density 152, median diameter 018 mm) from a lock into a horizontal water-filled flume Graded beds were formed; the mecha

Gerard V. Middleton

Papers

Origin of sedimentary rocks

Mechanics of sediment movement

Sediment gravity flows : mechanics of flow and deposition

Experiments on density and turbidity currents: iii. deposition of sediment

Sediment Deposition from Turbidity Currents