Sedimentary Textures Flashcards
(33 cards)
5 parameters of sedimentary texture
- grain size
- grain shape
- grain orientation
- porosity
- permeability
a diagram that describes particle sizes in epiclastic rocks and classifies them on a logarithmic phi scale
Udden-Wentworth Scale
phi value formula
-log2d
component of detrital sedimentary rocks with sizes ranging from sand to gravel
clasts
component of detrital sedimentary rocks that are mud sized
matrix
measure of particle population that represents the typical particle size
central measure
bar graph that compares the weight percentage vs the phi value of clasts
histogram
line graph that compares the weight percentage vs the phi value of clasts
frequency curve
line graph that shows the cumulative weight percent of all sizes coarser than the size under consideration
cumulative curve
most abundant particle size
mode
average size of particles
mean
average diameter of particles
graphic geometric mean
method of passing soil and sediment through a series of stacked mesh
sieving
factors affecting shape
- lithology
- hardness
spheroid, similar in all directions
equant
rod shaped, elongate that have on axis much longer than the other two
prolate
disk shaped, flattened cylindrical where two axes are shorter than the other
oblate
flattened shaped where three axes have different lengths
bladed
the more travelled a sediment is the more ____ it is
rounder and spheroidal
distribution of grain sizes present within a rock
sorting
quick method of determining the phi size value for any percentile
sorting coefficient
more complicated measure that involves finding values that are in standard deviation to the mean
inclusive graphic standard deviation
volume of void space in a rock
porosity
arrangement of grains in a rock
packing density