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3 THE EFFECTS OF LAKE SUPERIOR SHORE CURRENTS ON RECENT SE DIMENT S JOSEPH L. By ggtrick A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Geology 1955

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5 W Io Sé JOSEPH L. PATRICK ABSTRACT Sedimentologists have devoted considerable effort to the study of sediments in the laboratory and in field investigation attempting to determine the effects that transportation by water has upon grains of sand. This study is devoted to a laboratory analysis of an artificial sediment which has been subjected to abrasion by natural forces. During the mining of copper ore in the Keweenaw Peninsula of Michigan the finely ground waste rock from the milling operation was dumpediinto Lake Superior. The current and wave action has.formed this new sand into extensive beaches. Samples of sand were collected at regular intervals from one beach and analyzed in the laboratory. The data from the analysis show a definite increase in roundness and a corresponding decrease in sphericity with distance from the o riginal source. ii

6 ACKNOWLEDGMENT S The writer is indebted to many individuals who aided with the investigation and text. Particularly is he indebted to Dr. B. T. Sandefur for suggesting the problem and who gave freely of his time and knowledge. His patient direction in the laboratory and helpful suggestions with the organization of the text are greatly appreciated. He is indebted to Dr. S. G. Bergquist for his constant encouragement and for editing the text. Special thanks go to Dr. W. A. Kelly for his assistance in planning the field work and to Dr. Justin Zinn and Dr. J. W. Trow for their friendly interest and many helpful sugge stions. iii

7 TABLE OF CONTENTS INTRODUCTION... Purpose of the Study ooooooooooooooooooooooooo Location... FIELD SAMPLING. Location of Sample Sampling Method S... LABORATORY PROCEDURE... Quartile Measure 5 ooooooooooooooooooooooooooo Comparison of Quartile Measures Quartile Skewness and Kurtosis SPHERICITY AND R0UNDNESS General Statement ooooooooooooooooooooooooooo 28 Preparation for R0undness and Sphericity Analysis IIIIIIIIIIIIIIIIIIIIIIIIII 29

8 Page Shape and Roundness with Lateral Movement... CONCLUSION

9 LIST OF TABLES TABLE 1. Tyler Standard Screen Scale Sieves... Comparison of Sorting... Comparison of Kurtosis and Skewness... vi

10 LIST OF ILLUST RAT IONS Figure Page 1 Index Map Showing Sample Distribution... viii 2-12 Cumulative Curves Comparison of Sphericity and Roundness with Lateral Movement Photomicrograph of Control Sample Photomicrograph of Sample at Five Miles Photomicrograph of Sample at Ten Miles... 34

11 Figure 1. :E:E::JL'A.' to M -. o '.['. \ F: ' \i. "t on." 9 I I C3 6 " t I.. A ' f Q / \ T I I \1. c) I "8": Erin any I t. t I - $ I I ,' :52»; P I0 \v 0 I ' Edgm::3 «on mag. Fud'lgmfl Hill 0mm 'Chompio n Mill I Hou man 2 some [0050" 3 TrimouMoIn t Champion _ R Glob.. '( P \ L Porrago fairy p VA Q Q,.7 11 t f. I. Q I - -. U.\ f) LOCATION OF SAMPLE KEWEENAW 0 CDTIES F I i i i RAILROADS 2 NINES '- 5 PENINSULA O II,,- CG. DISTRIBUTION 5 I.0 : Locotlon 4 when sump!" won comer Nun-bu mm Ioculon mucou- "on" nunbov. LINE MILES. a -- _, I J

12 INTRODUCTION The Keweenaw district of the Upper Peninsula, Michigan, contains the world's outstanding deposits of native copper. Exploitation of the great ore reserve started in tinued to expand until World War I. 1844, and mining Operating con Since then there has been a constant decrease in the number of active properties. Entire communities have been abandoned and in many places only the founda tions of the mills and houses remain. Some of the striking features, remaining as monuments to man's industry, are the beaches of black sand which mark the location of the mill sites. It is estimated that a total of 600 million tons of ore has been processed since the beginning of mining in the area. The mills crushed and processed the ore for the native c0pper which it con tained. The tailings, or waste rock, from the process was dumped into the nearest convenient body of water, there to be moved and rearranged by current and wave action into extensive beaches. The writer was intrigued by the possibility of making a study to determine the effects of transportation by water upon the particles of waste rock.

13 Purpose of the Study Krumbein and Griffith (1938) describe a sediment which would be ideal for study as: One in which the environment is relatively self-contained; that is in situations in which the complete history of the sediments may be traced from source to final deposit. If, in addition a simple lithological setup is involved so that variables in terms of particle density and the like may be avoided, it seems likely that a more complete picture may be obtained, free of complexities which cannot be evaluated directly. The sediment described in this report is of simple composition. It began its transportation cycle from a known point as a well sorted, angular sand. The wave and current action of Lake Superior has been active in translocéating and abrading the material for almost a century. The purpose of this study was to determine what effect the wave and current action had on the size and shape of the individual grains involved in the process. Location The beach chosen for this study lies on the west side of the Keweenaw Peninsula. It extends for a distance of ten miles from the Champion Mill in the Village of Freda to the breakwater of the Portage Lake canal. Long-shore currents produced by prevailing westerly winds have carried the new material northeastwardly until

14 it has completely isolated the old beach with its towering wave-cut cliffs of Freda (Cambrian) sandstone. Indentations of the old shore line have been filled, and in these local areas the beach is often a mile wide. Its average width, however, is approximately 100 yards.

15 FIELD SAMPLING Location of Samples The points at which the samples were collected along the beach are shown in Figure l. The first sample, taken immediately below the tailing flume of the Champion Mill, had not been subjected to any natural abrasive wave action and was used as the "control" for the experiment. The other ten samples were collected at onemile intervals along the beach, the distance between samples being measured by pacing. The boldness of the cliffs along the shore was such that the writer was able to mark the position of each sample on aerial photographs. The pacing was checked by measuring from easily identifiable natural and man-made landmarks. Sampling Method Each of the eleven serial samples collected for study weighed approximately four pounds. With the exception of the first, or "control," the samples were taken within three feet of the water's edge, At each site a small trench was dug to a depth of 18 inches and one wall of the trench was very carefully channeled from top to 4

16 bottom. The material was collected in a paper bag placed at the bottom of the trench, then carefully transferred to regular sample bags which were labeled in consecutive order.

17 LABORATORY PROCEDURE Preparation for Analysis Laboratory preparation for the analysis was limited to drying and then reducing the samples to 200 grams. The wet samples were placed in an electric oven and dried for approximately two hours. A Jones sample splitter was used after the drying operation to reduce the sample. Sieving The sieving analysis was made with the aid of a shaking machine using the Tyler standard screen scale Ro-Tap sieves shown in Table 1. Each ZOO-gram sample was subjected to sieving in the Ro-Tap machine for 15 minutes. At the end of the sieving period the screens were removed and cleaned; each sieve fraction was weighed and placed in a separate container for later analysis. Mineralogy Under microscopic examination the mineralogy of the grains proved to be simple and homogeneous. The bulk of the material is 6

18 TABLE I TYLER STANDARD SCREEN SCALE SIEVES Size of Ope ning Screen Number Openings per Square Inch Inche s Millimete r

19 very fine-grained basalt consisting of pyroxenes, epidote, and olivine. Grains of secondary calcite are common and usually are quite spherical and well rounded.

20 STATISTICAL ANALYSIS The curriulative curve is a graphic statistical device commonly used in the study of sediments. The cumulative frequency curve is a curve based on the original histogram data and is made by plotting ordinates which represent the total amount of material larger or smaller than a given diameter. [Krumbein and Pettijohn, 1938.] Cumulative curves based upon the weight and size of the individual fractions were constructed for each of the eleven samples. These curves, Figures 2 to 12, have the independent variable sizes plotted along the "X" axis, and the dependent variable, frequency, plotted along the verticle "Y". axis. Quartile Measure 5 Quartile measures, introduced by Trask (1930), have been widely used in comparing sediments. In his paper Trask describes a quartile: As that fraction of the sediment which is composed of particles larger 'in diameter than the dimension given for that percentile. Thus, if the three quartiles were 15, 4 and 11 respectively, it would mean that 25 per cent. by weight of the sample was composed of particles larger in diameter than 15 K, 50 per cent. of the constituents greater than 4}!, and 75 per cent. larger than 1%. This, with the percentage by weight 9

21 KURTOSIS Figure 2 I O 20 CUMULATIVE CURVE OF CONTROL SAMPLE / / sxewuess.555 SORTING.77 2 I : SIZE m MILLIMETERS Percent Weight

22 CUMULATIVE CURVE OF SAMPLE AT I MILE 80 SKEWNESS SORTING.05 KURTOSIS.l / I 0.5 O. SIZE IN MILLIMETERS 11 Figure 3 40 Percent Weight

23 80 / SKEWNESS son'rmc l SIZE IN MILLIMETERS 12 Figure 4 IOO CUMULATIVE CURVE OF SAMPLE AT 2 MILES f Kun'rosns.3" I 0.5 ' O. 40 Percent Weight

24 Figure 5 CUMULATIVE CURVE OF SAMPLE AT 3 MILES IOO 60 Snewuess.772 soarmc Ls? xumosns I 0.5 OJ SIZE IN MILLIMETE RS 40 Percent Weight

25 BO SIZE l4 Figure 6 CUMULATIVE CURVE OF SAMPLE AT 4 MILES SKEWNESS SORTING I..289 kurtosis O.I 0.5 IN MILLIMETERS IOO 40 Fe rcent Weight

26 15 Figure 7 CUMULATIVE CURVE OF SAMPLE AT 5 MILES IOO / 80 / SKEWNESS sommc l.33 / KURTOSIS I 0.5 O.I SIZE IN MILLIMETERS Percent Weight

27 80 SIZE IN MILLIMETERS 16 Figure 8 CUMULATIVE CURVE OF SAMPLE AT 6 MILES IOO / =- SKEWNESS.975 SORTING 1.34 / KURTOSIS o _ I I 0.5 O.I Percent Weight

28 CUMULATIVE CURVE 0F SAMPLE AT 7 MILES 80 I.I60 SKEWNESS I.66 SORTING KURTOSIS O.I 0.5 IN MILLIMETERS SIZE l7 Figure 9 IOO 4O Percent Weight

29 OOI 09 O? Figure 10 V/\., $31M 8 1V HIdWVS :IO 3AIzIIIO BAIIVIIIWIIO au- LI'I ZZI'I SISOLUOX ONILUOS SS3NM3NS 9'0 SUBLBWI I'IIW NI EZIS 08 Percent Weight

30 60,0 / 19 Figure 11 CUMULATIVE CURVE 0F SAMPLE AT 9 MILES SKEWNESS.953 SORTING I.03 KURTOSIS , I I SIZE IN MILLIMETERS I00 Percent Weight

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32 SKEWNESS.3I3 O.I 20 Figure 12 N CUMULATIVE CURVE 0F SAMPLE AT I0 MILES I f SORTING L43 KURTOSIS IN MILLI METERS SIZE 0.5 Percent Weight

33 21 of the sand, silt, clay and colloid gives an adequate picture of the sediment. Percentiles are especially advantageous for comparing deposits with each other, as they give exact numerical criteria for classifying the size-distribution. " Quartile deviation when used with the median is a measure of the average Spread of the sizes and may be shown as arithmetic, geometric, or logarithmic quartile deviation. The arithmetic quartile deviation is the average between the difference of the two quartiles, and it serves to illustrate the size factor. In the formula shown immediately below, QDa represents the arithmetic mean, Q3 the larger quartile, and Q1 the smaller quartile. The geometric deviation or sorting coefficient (Trask, 1930) is the square root of the ratio of the quartiles. So zl/q3/ Q1 The logarithmic quartile is simply the log of sorting to the base 10.

34 22 Comparison of Quartile Measures The cumulative curve of the control sample, Figure 2, shows that the material, as it comes from the mill, is distributed rather evenly throughout the various sizes. The succeeding curves, Figures 3 to 12, become progressively steeper and Show that a preferential sizing occurs very soon in the transportation cycle. The quartile data, Table 2, taken from each of the cumulative curves, illustrate that coarse particles continue to be separated from the fine as the material is transported along the beach. The first and third quartiles show a decrease in the size distribution about the median and an increase in the general size of the material as it is carried away from its source. The mechanical sizing and screening during the milling operation precludes the possibility of poor sorting in the original sediment. The control sample, as may be suspected, falls within the 2.5 wellsorted classification of Trask. Of interest, however, is the fact that the sorting coefficient of already well-sorted sediment continues to increase with distance from the source. A comparison of the log quartile deviation, the last column in Table 2, further confirms the sorting effect of transportation.

35 23 TABLE 2 COMPA RISON O F SORTING Median Q1 Q3 Sample (mm) (mm) (mm) QDa So Log 1050 Control Mile Mile Mile Mile Mile Mile Mile Mile Mile Mile

36 24 The material under consideration undergoes progressively in creased sorting during transportation. Small sizes are reduced to very fine particles which are carried away in suspension, possibly to be deposited in the deeper portions of the lake. Larger particles, which are moved either by traction or saltation, continue to be moved along the shore until reduced and carried away in suspension. In this study of a beach sand, Krumbein (1938) shows that a variation of the phi standard deviation exists along a beach. Variation in size and sorting of the sand grains may be either an expression of changing conditions of deposition, or the result of changes in direction of movement of the sand or the SIOpe of the beaches. In certain local areas any change in the character of the shore line may vary the intensity of wave action with a resulting change in the size of the material being deposited. An unknown factor which influences the grain size and Spread is the "travel distance" perpen dicular to the axis of the beach. Quite obviously, the horizontal distance along the beach is not an exact measure of travel distance for the material as it does not take into consideration the forward and backward movement caused by wave action, and undertow, which at times may be perpendicular or nearly perpendicular to the direction of horizontal movement.

37 25 Quartile Skewness and Kurtosis Quartile skewness is a measure of the "degree of symmetry" of the size distribution. If the median coincides with a point halfway between the quartiles, the curve is symmetrical. Skewness is the measure of the departure from the median. In its simplest form the arithmetic skewness emphasizes the size factor, and a symmetrical curve has a value of one. If the value is greater than unity the sorting of the specimen lies on the coarse Side, or if the Spread is greater on the small side the value will be less than unity. Coefficient of the geometric quartile skewness is derived by use of the following formula (Twenhofel and Tyler, 1941). Q1 QB SK = T M Q1 2 first quartile Quartile kurtosis is a measure of "peakedness" of a frequency curve. 3 = third quartile 2. M = square of the median Pettijohn (1938) defines kurtosis as: A comparison of the Spread of the central position of the curve to the spread of the curve as a whole, the values decrease with increasing peakedness.

38 26 The formula for kurtosis according to Kelley (1924) is: K = Q3 - Q1 2(P10 P90) K = kurtosis Q3 = third quartile Q1 = first quartile P90 2 ninetieth percentile P10 == tenth percentile Values for skewness and kurtosis are shown in Table 3. The kurtosis of the various samples used in this study does not show any great degree of departure from that of the control sample, and the inference is that the degree of spread of the central position to the Spread of the curve remains constant. The skewness curves of all samples approach unity and may lie very slightly to either the coarse or fine side with a preference shown for the fine. This preference may be a function of the original sediment.

39 TABLE 3 COMPARISON OF KURTOSIS AND SKEWNESS Sample Kurtosis Skewness _..._ K Q3 - Q1 Q1 Q3-2(P10 - P90) - M2 0 (control) O

40 SPHERICITY AND ROUNDNESS General Statement Two important fundamental properties of sediments which have received considerable attention in field studies and laboratory experiments are Sphericity and roundness. Wadell (1932), who was probably the first to consider Sphericity and roundness as inde pendent variables, expressed Sphericity as: A ratio of the surface area of a Sphere of the same volume as the particle to the actual surface area of the particle. He expressed the degree of Sphericity by the formula: 3 = degree of true Sphericity Where "s" is equal to the surface area of a sfiiere of the same volume as the grain and "S" is the surface area of the particle. This method of determining the Sphericity of small grains is not only time-consuming, but also difficult. The short method, as used by Pettijohn (1938), is expressed as a ratio of the diameters of the inscribed circle to that of the circumscribed circle. Measurements are made in the projected plane of the grains. 28

41 29 The concept of roundness differs from Sphericity in that the former is a measure of the angularity of the respective corners of a fragment. Roundness of a particle is the summation of the roundness of the individual corners divided by the number of corners measured in the plane of projection. Wadell (1934) expressed the formula for roundness as: 3:" Roundness z _ R- N- Preparation for Roundness and Sphericity Analysis Analysis for Sphericity and roundness measurements was completed on a portion of each of the eleven samples. The fraction between 0.42 and millimeter diameter was carefully split to approximately 100 grains. This portion was mounted on slides in a chemical compound with an index of The slide was placed in a microscope for magnification and grains were projected with the aid of a camera lucida. The diameter of the individual corners, as well as the diameters of the largest inscribed and smallest circumscribed circles of fifty grains from each slide, were measured. A celluloid circle scale such as described by Wadell (1935) in his study on the "Volume, Shape and Roundness of Quartz Particles"

42 30 was used. A scale of this type is made by drawing a series of concentric circles, with an increasing diameter of 2 mm per circle, on a small sheet of celluloid. Shape and Roundness with Lateral Movement A graphic comparison of shape and roundness with lateral movement is shown in Figure 13. Roundness of the grains in the control sample, as. may be suspected, is very low. Examination of the grains, Figure 14, shows them to be angular with many small corners. The data show that rounding progresses at a rapid rate for the first mile of movement. This accelerated rounding is probably accomplished by fracturing and removal of corners which may have been partially broken during the milling process. After the initial mile the rate of rounding continues at a reduced pace, but in general, it increases with distance from the source. Results of this roundness study closely parallel the experimental findings in the tumbling barrel studies by Krumbein (1941). In his study, values for roundness show a rapid increase from 0.16 at zero miles to 0. 5 at 1 mile. In this study the rounding is not as rapid; the rounding progresses from 0.18 at zero miles to 0.25 at 1 mile. Unlike the tumbling barrel, the distance in this case is not a

43 0 6 a L 9 0 t 2 z I o \. I I v", 7 8 Il. 'I g.0" \\\\ II, \4 I or 22' I 31 Figure 13 SSEINONIIOH ONV AllOIHEHdS :IO NOSIUVcIWOO.LNEWBAOIN 'IVEIEILV'I HJJM M \\ I" at. a. o i /\ I \o. 0 " m -< I! s ' cat}, I 7'0 \ \ 'A-T s '," o 0,. [3' 81; /\q \, ' a" \\ I '7' z'm 91:2 I,. I: I oz - 27: muounou ,', Ailamauds I 1 '31) 10). I mm zv-o-snoum so 3215 '7'. 228 u 2 '1' I 1 22% 2 Gig m f or «or

44 32 Photomicrograph 1 Figure 14

45 33 Photomicrograph 2 Figure 15

46 34 Photomicrograph 3 Figure 16

47 35 true measure of travel. The distance actually traveled may be many times greater. Comparative slowness of rounding may be due in part to the hardness of the material, or possibly the material is not subjected to as rigorous abrasion in natural transportation as was the case in the tumbling barrel. Sphericity of the individual fragment as it leaves the mill is quite high, which may be the result of the mechanical Sizing during processing. Sphericity does not increase with distance, but varies about a very slightly decreasing line of values] Krumbein (1941) advanced the theory that: Roundness and Sphericity approach asymptotes which depend upon initial size, shape or both. He further states that neither roundness nor Sphericity may ever reach the value 1.00.

48 CONCLUSION Data resulting from the study indicate that reduction of the fine material occurs quite soon in the transportation cycle. Sorting of the material, although very high in the initial stage, continues to increase as the small grains are reduced. The data suggest that as the sorting continues, the end result will be a sand whose grain size will be approximately the same, and further abrasion will maintain a size equilibrium once it is established. Anderson (1926), in his experiment on the rate of abrasion of sand grains, states that: From the slow rate of reduction which has taken place, it does not appear likely that sand grains in a single journey from the central part of a continent to the sea would experience sufficient wear to become rounded. In order to become rounded by either wind or water, sand grains must probably make several such journeys through more than one cycle of erosion, transportation and deposition. In the short time in which the sand under consideration in this report was subjected to wear, a considerable amount of rounding has occurred. It is quite likely that a sand of this type would be well rounded by the time it reached the sea. Roundness measurements show a rapid initial rounding and a general increase with 36

49 distance, while Sphericity tends to decrease. An interesting rela 37 tionship between Sphericity and roundness is indicated by the data. As the roundness increases, Sphericity values decrease. This relationship of decreasing Sphericity with increased roundness is supported by the data from a study of the Mason esker (Erickson, Unpublished Masters Thesis, Michigan State College). Mr. Erickson, a graduate student, did considerable work on the Sphericity and roundness of sand grains from samples which were collected at various points along the esker. Seven samples were studied, and it was found that Sphericity decreased from to , while roundness increased from to in a distance of twenty miles.

50 SUGGESTIONS FOR FURTHER STUDY An interesting laboratory experiment, which was considered, as a continuation of this study would be mechanical abrasion of the control sample. Such a study would determine the distance which the sand described in this report has traveled. Continued abrasion of the sand may Show whether the sand particles reach a maximum. rounding and then become fractured. Further study would show if the relationship of increasing roundness with decreasing Sphericity with distance from the source continues. 38

51 BIBLIOGRAPHY Anderson, G. E. (1926). Experiments on the Rate of Wear of Sand Grains; lournal of Geglcgy, Vol. 34, pp Butler, B. S., and Burbank, W. E. (1929). The C0pper Deposits of Michigan; Professional Paper 144. U.S.G.S. Erickson, Ralph L. (1938). A Petrographical Investigation of the Longitudinal Deposition within the Mason Esker Relative to its Origin; unpublished Masters thesis, Michigan State College, East Lansing, Michigan. Kelley, T. L. (1924)., "Statistical Methods"; London, p. 77. Krumbein, W. C. (1935). Volume, Shape and Roundness of Quartz Particles; Journal of Gemgy, Vol. 43, pp Krumbein, W. C. (1938). Local Areal Variation of Beach Sands; Bulletin of the Geological Society of America, Vol , pp. Krumbein, W. C. (1941). The Effects of Abrasion on the Size, Shape, and Roundness of Rock Fragments; Journal of Geology, Vol. 49, p Krumbein, W. C., and Griffith, J. S. (1938). Beach Environment in Little Sister Bay, Wisconsin; Bulletin of the Geological Society of America, Vol. 49, p Krumbein, W. C., and Pettijohn, F. J (1938). Manual of Sedimentary Petrography; Appleton-Century Crafts, Inc., New York. Trask, P. D. (1930). Mechanical Analysis of Sediments by Centerfuge; Economic Geology. Vol. 25, pp Twenhofel, W. A., and Tyler, S. A. (1941). Methods of Study of Sediments; McGraw-Hill Book Company, Inc., 39 New York.

52 40 Wadel, H. (1932). Volume Shape and Roundness of Rock Particles; Journal of Geology, Vol. 40, pp Wadel, H. (1934). Shape Determinations of Large Sedimental Rock Fragments; Pan American Geologist, Bulletin 61, pp

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