GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 ›...
Transcript of GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 ›...
![Page 1: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/1.jpg)
GY 402: Sedimentary Petrology
Lecture 2: Grain size and Descriptive Parameters
Instructor: Dr. Douglas W. Haywick
UNIVERSITY OF SOUTH ALABAMA
![Page 2: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/2.jpg)
Lecture 2 Agenda
A) Basic sediment grain size B) Ternary plots C) Interpreting grain size data D) Grain size parameters
![Page 3: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/3.jpg)
Grain size
There are several different schemes: 1) US Army Corp of Engineers (mesh size) 2) Soil scientists 3) Academic geologists (metric)
![Page 4: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/4.jpg)
Udden-Wentworth grain size (Wentworth, 1922)
Gravel: (>2.00 mm)
Sand: (0.063 mm – 2.00 mm)
Silt: (0.004 mm – 0.063mm)
Clay: (< 0.004mm)
From
: Lew
is, D
.W.,
1984
. Pra
ctic
al S
edim
ento
logy
.van
Nos
trand
Rei
nhol
d, N
ew Y
ork,
229
p.
![Page 5: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/5.jpg)
Phi () grain size
= -log2d
From
: Lew
is, D
.W.,
1984
. Pra
ctic
al S
edim
ento
logy
.van
Nos
trand
Rei
nhol
d, N
ew Y
ork,
229
p.
![Page 6: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/6.jpg)
Phi () grain size
= -log2d 16 mm = -4 4 mm = -2 2 mm = -1 1mm = 0
500 m = +1 250 m = +2 125 m = +3 62.5 m = +4
4 m = +8
From
: Lew
is, D
.W.,
1984
. Pra
ctic
al S
edim
ento
logy
.van
Nos
trand
Rei
nhol
d, N
ew Y
ork,
229
p.
![Page 7: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/7.jpg)
Grain size classification (simplified)
![Page 8: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/8.jpg)
Grain size classification
With grain size data, you have 4 variables that you need to be able to visualize. Graphically, this is not easy as we only have 2 dimensions to work with. The solution…..
![Page 9: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/9.jpg)
Grain size classification
With grain size data, you have 4 variables that you need to be able to visualize. Graphically, this is not easy as we only have 2 dimensions to work with. The solution….. Ternary plots.
![Page 10: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/10.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
![Page 11: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/11.jpg)
Symbol Index
C-clay; Z-silt; S-sand;
sC-sandy clay; zS-silty sand; sZ- sandy silt; zC- silty clay
cS-clayey sand; szc-sand-silt-clay;
cZ-clayey silt
Sand-Silt-Clay Scheme 2
Sheppard (1954)
![Page 12: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/12.jpg)
Symbol Index M-mud; G-gravel; S-sand;
sM –sandy mud; mS-muddy sand;
(g)M-slightly gravelly mud; (g)S-slightly gravelly sand;
(g)sM-slightly gravelly sandy mud; (g)mS-slightly gravelly
muddy sand;
gM-gravelly mud; gms-gravelly muddy sand; gS-gravelly sand;
mG-muddy gravel; MsG-muddy sandy gravel; sG sandy gravel
Gravel-Silt-Fines Scheme
Folk (1954)
![Page 13: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/13.jpg)
Plotting data Folk (1954)
![Page 14: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/14.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
100% Sand
100% clay 100% Silt
![Page 15: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/15.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
50% clay, 50% sand,
![Page 16: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/16.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
50% clay, 50% sand,
50% clay, 50% silt,
![Page 17: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/17.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
50% clay, 50% sand,
50% clay, 50% silt,
50% silt, 50% sand,
![Page 18: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/18.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand
sand triangle
50% line
100% line
0% line
![Page 19: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/19.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand clay triangle
![Page 20: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/20.jpg)
Sand-Silt-Clay Scheme 1 Folk (1954)
Symbol Index
C-clay; Z-silt; M-mud; S-sand;
sC-sandy clay; sM-sandy mud; sZ- sandy silt;
cS-clayey sand; mS-muddy sand;
zS-silty sand silt triangle
![Page 21: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/21.jpg)
Plotting data Folk (1954)
Example data point:
Sand: 46%; Clay 25%; Silt: 29%
Step 1: Plot sand (46%)
Step 2: Plot clay (25%)
Step 3: Confirm silt (29%)
![Page 22: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/22.jpg)
46%
Plotting data Folk (1954)
Example data point:
Sand: 46%; Clay 25%; Silt: 29%
Step 1: Plot sand (46%)
Step 2: Plot clay (25%)
Step 3: Confirm silt (29%)
![Page 23: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/23.jpg)
25%
Plotting data Folk (1954)
Example data point:
Sand: 46%; Clay 25%; Silt: 29%
Step 1: Plot sand (46%)
Step 2: Plot clay (25%)
Step 3: Confirm silt (29%)
![Page 24: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/24.jpg)
30%
Plotting data Folk (1954)
Example data point:
Sand: 46%; Clay 25%; Silt: 29%
Step 1: Plot sand (46%)
Step 2: Plot clay (25%)
Step 3: Confirm silt (29%)
![Page 25: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/25.jpg)
Plotting data Folk (1954)
Example data point:
Sand: 46%; Clay 25%; Silt: 29%
Step 1: Plot sand (46%)
Step 2: Plot clay (25%)
Step 3: Confirm silt (29%)
46%
25%
30%
Your sample is sandy mud (sM)
![Page 26: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/26.jpg)
Grain Size Histograms: Case Study 1
![Page 27: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/27.jpg)
Fine grained sediment. Depositional energy ___________ ?
Grain Size Histograms: Case Study 1
![Page 28: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/28.jpg)
Grain Size Histograms: Case Study 2
![Page 29: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/29.jpg)
Moderately sorted sediment. Depositional energy ________ ?
Grain Size Histograms: Case Study 2
![Page 30: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/30.jpg)
Grain Size Histograms: Case Study 3
![Page 31: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/31.jpg)
Bimodal sediment. Depositional energy ___________ ?
Grain Size Histograms: Case Study 3
![Page 32: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/32.jpg)
Bimodal sediment. Depositional energy ___________ ?
Depositional environment: ____________________?
Grain Size Histograms: Case Study 3
![Page 33: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/33.jpg)
Descriptive parameters
Source: Blatt, Middleton and Murray (1980)
![Page 34: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/34.jpg)
Descriptive parameters
Source: Blatt, Middleton and Murray (1980)
![Page 35: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/35.jpg)
Descriptive parameters
Source: Blatt, Middleton and Murray (1980)
![Page 36: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/36.jpg)
Descriptive parameters
Median = Φ50
Source: Blatt, Middleton and Murray (1980)
![Page 37: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/37.jpg)
Descriptive parameters
Mean (average) =
Φ16 + Φ50 + Φ84
3
Source: Blatt, Middleton and Murray (1980)
![Page 38: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/38.jpg)
Descriptive parameters
Sorting = Φ84 - Φ16 + Φ95 - Φ5 4 6.6
Sour
ce: B
latt,
Mid
dlet
on a
nd M
urra
y (1
980)
![Page 39: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/39.jpg)
Descriptive parameters
Mode = the most frequent particle size
Source: Blatt, Middleton and Murray (1980)
![Page 40: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/40.jpg)
Positive (fine) skewness Symmetrical Negative (coarse) skewness
Descriptive parameters
Skewness: Φ16 + Φ84 +2 Φ50 + Φ16 + Φ84 +2 Φ50
2(Φ84 - Φ16) 2(Φ95 - Φ5)
![Page 41: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/41.jpg)
Descriptive parameters
• Kurtosis (curve peakedness) = Φ95 - Φ5
2.44(Φ75 - Φ25)
Platykurtic Mesokurtic Leptokurtic
![Page 42: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/42.jpg)
Other descriptive parameters
Roundness Particle shape
![Page 43: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/43.jpg)
Other descriptive parameters
Roundness Particle shape
very angular very round
square rectangular
![Page 44: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/44.jpg)
Other descriptive parameters
Roundness Particle shape
Both of these can be quantitatively measured but what a pain in the ass! Much better to use qualitative methods.
![Page 45: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/45.jpg)
Roundness (comparison of determination
techniques)
Qua
litat
ive (
Pow
ers,
1953
)
![Page 46: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/46.jpg)
Roundness
Figure 14: Grain Sphericity: Composite Sample 4
0
10
20
30
40
50
60
0.15 0.20 0.30 0.40 0.60 0.85
Roundness Scale (Powers, 1953)
Perc
enta
ge Modal AModal BBulk
![Page 47: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/47.jpg)
Descriptive parameters (simple visual comparisons)
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Sampling Techniques
• Unconsolidated (soft) sediment (grab, coring, hand sampling)
• Lithified sedimentary rock (hammer, drill, saw)
![Page 49: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/49.jpg)
Upcoming Stuff Homework
Writing Assignment 1 (Paper structure): Due Thursday 2) Read Grain Size Lab Manual (online) 3) Formalize your 2 person sed team
Thursday: No Lecture
Botanical Gardens walkabout (grain size assignment prep) meet as usual at 11 AM in LSCB 316
This Weekend
Think about your project; get your samples
Next Tuesday: Sedimentary Rock Classification
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Check the Calendar!
![Page 51: GY 402: Sedimentary Petrology - University of South Alabama › geology › haywick › GY402 › 402-pp2.pdfFrom: Lewis, D.W., 1984. Practical Sedimentology.van Nostrand Reinhold,](https://reader034.fdocuments.in/reader034/viewer/2022042316/5f0452cd7e708231d40d692e/html5/thumbnails/51.jpg)
Writing Assignment
1
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GY 402: Sedimentary Petrology
Lecture 2: Grain Size
Instructor: Dr. Doug Haywick [email protected]
This is a free open access lecture, but not for commercial purposes. For personal use only.