JoU/~ Indian Association oj Sedimentologists, Vol. 30. No. I (2011). pp. 65-73
Grain Size Statistical Parameters of Coastal Sediments around Tirumalairajanar River Mouth, Tamilnadu, East Coast of India I
VENKATRAMANAN,
s. *, RAMKUMAR,
T., AND ANITHA
MARY,
l.
Department of Earth Sciences, Annamalai University. Annamalainagar - 608 002 * E-mail:
[email protected] Abstract: Grain size statistical parameters studies were carried out for the sediments along Karaikal to Nagore stretch of the beach. The sediments are found to be mainly medium to coarse grained, moderately sorted, fine skewed to coarse skewed and leptokurtic to me okurtic in nature. Based on the eM pattern the sediment are concentrated in the environment of rolling and suspension. These textural parameters have been further examined to understand the hydrodynamics of the depositional environment. Keywords: Grain size analysis, beach sediments, Tirumalairajanar river, east coast.
Vettar and Vedaranyam canal are the main rivers flowing in this area. The study area is surrounded by Tanjore Analysis of grain size distribution has been widely . district in the west, Cuddalore district in the North, Palk straight in the South and Bay of Bengal in the used by sedimentologists to classify sedimentary environments and elucidate transport dynamics. The east. grain sizes of sediments provide an indication of the shear stress that must be applied by the medium to METHOD OF STUDY initiate and sustain particle movement. Grain size A total of twenty sediment samples collected from distribution is affected by other factors such as distance from the shoreline, distance from the source (river), the beach by using a plastic spatula at 20 sites,i covering source material, topography and transport mechanisms the period of Postmonsoon (2010). Samples were dried (Milligan et al. 2007 Hill et al. 2008, Moshood Niyi Tijani in an oven at 60°C for 24 hours to a constant weight et al. 20 I0, Bene dicte Ferre et at. 2010, Lluis Gomez(Holme and Mac Intyre, 1971). Sieving technique is Pujol et al. 2011). Musila (1998) found that the mean applied to separate the sediment of various size classes particle size of the sand was the most important factor (Ingram, \970). Initially 100 gm of sample is prepared by influencing vegetation composition, structure and removing carbonate and organic matter by treating with distribution in the Malindi Bay coastal sand dunes in 10% dilute hydrochloric acid and 6% hydrogen peroxide Kenya. Musila (1998) noted that geomorphological units respectively. Sieving was carried out in ASTM sieve at 12 0 intervals for about 20 minute in Digital sieve shaker consisting of fine grained sand had high species diversity in contrast to those with medium-grained sand (Retsch AS 200). This basic data i.e. weight percentage which were mostly un vegetated or sparsely vegetated; frequency data is converted into cumulative weight these differences may be accompanied by differences percentage, served as basic tool for the generation of in chemical composition and/or substrate processes. other statistical parameters. The data were subsequently In the present investigation the grain size processed using a PC grain size package GSSTAT parameters are used to interpret sediment movement in (USGS) which calculates graphical statistical parameters the beach segment of Karikal to Nagore with special using the Folk and Ward (1957) formulae. It is written in mention about the processes operating around the Microsoft Visual Basic 6.0 and provides a window to Tirumalairajanar and Arasalar river mouth. facilitate program execution. The input for the sediment fractions is weight percentages in whole-phi notation (Krumbein, 1934; Inman, 1952). STUDY AREA INTRODUcnO
The study area (Fig. 1) forms part of Karaikal and Nagapattinam district. It falls between the latitude N 11°00'00" to 10 50'00"and longitude E 79°40'00" to 79°50'00" and forms part of survey ofIndia Toposheet No 58M/13 and 16 on 1:50,000 scale. Distribution of the Cauvery, Arasalar, Tirumalarajanar, VelJar, Adappar, 0
RESULTS AND DISCUSSION The comparative study of the histograms of retained fractions of sieve analysis i.e. weight percentage cumulative curves (Mcbride, 1971). Similarly, most of the cumulative frequency curves shows same trend it is
Venkatramanan, S. et. al.
66
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Fig. 1. Location map of the area of the study.
may be due to limited inputs and weak wave energy condition (Fig.2).
Statistical Parameters Graphic measures derived from the cumulative frequency curve are the mean, sorting, skewness and kurtosis, which provide the descriptive statistics of the particle size distribution. According to Fuechtbauer and Mueller (1977), the Folk and Ward (1957) indices enable a more precise characterization of grain size distributions and also approximate the arithmetic moments. Mean size (Fig.3) of the different sediment samples has been presented in Table. I.The minimum to maximum value of the sediments varies from 1.35 to 2.38 0, suggesting thereby that these are fine to medium sand grade and it indicates the high energetic nature which is also supported by the presence of shell fragments in the beach. The beach segment between Karaikal to Nagore reveal that the mean grain size decreases on the either side of the Tirumalairajanar and Arasalar river. Higher values of standard deviation (FigA) poorer is the nature of sorting of sediments (Folk, 1974). The minimum and maximum values of the sediment samples vary between 0.53 to 1.03 0, suggesting that most of the sediments are moderately sorted to moderately well sorted in character.
This may be due to onshore winds which transport fine grained sediment further landward, leaving behind coarser particles at the berm and forming the dune field along this stretch. Skewness measures the asymmetry of the distribution (Folk, 1974). The skewness (Fig.5) value ranged from -0.25 to 0.17 0 indicates the fine-skewed, near- symmetrical, and some of them coarse skewed category it was purely due to fair weather season and relatively dominant low energy regime. In general, the sediments show the tendency of more material in fine tail. Kurtosis measures the ratio of sorting between tail and central portions. Folk and Ward (1957) have explained skewness and kurtosis in terms of the mixing of two normal grain sizes -.The graphic kurtosis is a measure of the part of the sediments already sorted elsewhere in an environment and later transported and modified by another type of environment. The minimum and maximum values of the sediments 0.91 to 1.61 0 indicates the most of the sediments fall in leptokurtic to mesokurtic nature (Fig.6).
Bivariate plots Bivariate plots between the different sensitive textural parameters throw light on information regarding
Grain Size Statistical Parameters of Coastal Sediments around Tirumalairajanar
River Mouth Tamilnadu
99.99
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Ph Fig. 2. Cumulative curves showing the trends of all the samples.
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1 2
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15 16 17 18 19 20
Station Fig. 3. Mean showing the trends of all the samples.
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I Station Fig. 4. Standard deviation showing the trends of all the samples.
67
Venkatramanan, S. et. al.
68
Table. 1. Graphic measure from the grain-size analysis of the samples.
Station 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Minimum Maximum Average
Median Phi
Mean Phi
2.09 1.69 1.8 1.87 1.9 1.59 1.64
2.05 1.69 1.78 1.89 1.92 1.57 1.68
2.3 1.52
2.23 1.52 1.98 1.97 1.85
1.95 1.96 1.92 2.38 2.3 2.41
Standard Deviation Phi 0.69 0.81 0.82 0.81 0.81 0.94 0.79 0.67
-0.03 0 -0.03 0.1" 0.12 0.02 0.07 -0.03 0.04 0.17 0.11 -0.25 -0.05 -0.13 0.03 -0.21 -0.02 -0.08 p.06 0.02 -0.25 0.17 -0.0077
0.88 0.73 0.82 0.56 0.64 0.73 0.64 0.53 1.03
2.33 2.2 2.38 2.2 1.86 1.35 1.63 1.48 1.35
2.27 1.97 1.4 1.6 1.48 1.4 2.41 1.902
Skewness Phi
0.61 0.59 0.79 0.53 1.03
2.38 1.876
0.747
Kurtosis Phi 1.06 1.02 1.05 1.28 1.28 0.94 1.15 1.41 1 1.18 1.3 0.91 1.46 1.3 1.62 1 1.31 1.35 1.26 1.09 0.91 1.62 1.204 .
2.5 -,---------------------------,-.
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2
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Station Fig. 5. Skewness showing the trends of all the samples.
Grain Size Statistical Parameters of Coastal Sediments around Tirumalairajanar
2.5
River Mouth Tamilnadu
69
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StatiQn Fig. 6. Kurtosis showing the trends of all the samples.
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Station Fig. 7. Bivariate plot of mean vs standard deviation.
the depositional environment of sedimentation and demarcate the fields of overlapping of closely related depositional environments. Inman (1952), Folk and Ward (1957), Friedman (1961 and 1978) have successfully used the scatter plots for understanding the geological significance of the four size parameters. The plot of mean size Vs. standard deviation (Fig.7) reveals that as the. grain size decreases, sorting improves. The concentration of coarser grain sediments at either side of the mouth of Tirumalairajanar and Arasalar rivers shows that they are not carried away by the coastal processes and the positive skewness is indication of the dominance of the fluviatile environment and later the beach was readjusted to the marine process--. The plot of mean vs. skewness (Fig.8) reveals that as the
grain size decreases, the skewness increased. It clearly indicates nature of sediments with higher percentage of sand and subordinate silt and also this may be due to the variations under the influence of littoral currents occasionally by opposing nature. The plot between mean vs. kurtosis (Fig.9) the grain size increases, the kurtosis in also increased. This may be due to the variation under the influence of littoral currents. the plot between skewness and standard deviation produce a scattered trend (Fig. I0) in the form the skewness is decreases, standard deviation improves it may be due to two conditions i.e. either unimodal samples with good sorting or equal mixture of two modes (Ashok et al., 2009, Harsha Sundar et al. 2010). The plot between stan rd deviation and kurtosis, most of the samples
Venkatramanan, S. et. al.
70
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Grain Size Statistical Parameters of Coastal Sediments around Tirumalairajanar
River Mouth 'Tamilnadu
71
are mesokurtic. and moderately sorted because of the wash, backwash and high turbulence result in bimodal dominance of medium sand-size sediments (Fig. 1 1). The character. plot between skewness vs kurtosis (Fig.12) depends on more or less equa\\)' scattered it ma)' be due to the C-M ""Pattern dominance of coarse sand size sediments. So, in this coastal track wave regime is characterized by short In order to affirm the flow type that transported the sediment to the study area, the samples were plotted at period waves which gave rise to erosion. Along with high wave energy regime, influx of sediments (Rabindra CM patteren (Passega, 1957, 1964) has considered the Nath Hota el al. 2008, Joanna Staneva et al. 2009, relationship between C the first percentile and Mmedian, the 50th percentile for the sediments from Abdullah Khan and Sarfaraz Ahmad, 2010) due to river different environments. During study period most of discharge resulted in coarse grained, unsorted and fine skewed nature of beach sediments. Poor sorting, sorting the samples fall in N-O region of sector I, which denotes
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Venkatramanan, S. et. al.
72
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rolled sediments with little or no suspension. This may be due to comparatively more percentage of fine sand grained material. (Fig. 13). CONCLUSIONS The investigation of the sedimentological aspects revealed that the size distributions (Postmonsoon, 2010) ofthe sediments are bimodal in nature. The mean value indicates the dominance of medium sand particles. The sediments, in generally, moderately sorted and are dominantly near-symmetrical to fine-skewed in nature. In majority of the cases, both peak and tails are equally sorted giving rise to leptokurtic condition. Various bivariate plots between mean, skewness, kurtosis and standard deviation are also interpreted. The indication of bimodal nature of sediment shows the sand-size is
the principle mode with subordinate silt respectively The sediments are mostly rolled and deposited by traction currents; however, a few samples showing suspension mode. Variations of grain size characteristics along this beach are believed to have resulted from wave refraction and longshore currents. This study demonstrates the usefulness of selecting several stations for better understanding beach environment of deposition.
Acknowledgements: We wish to gratefully acknowledge the valuable suggestions given by Prof. D. RajasekharaReddy and Editor in- Chiefwhich greatly helped in the final presentation ofthe pap~r. The authors are grateful to two anonymous referees for their constructive comments and suggestions which led to significant improvements to the manuscript.
References Abdullah Khan, M. D. and SarfarazAhmad (2010). Grain size Characteristics of bed sediments of rivers and ponds in a Valley-filled intermonate basin in the Eastern Himalayas, Jour. Indian Association of Sedimentologist 29,29-35. Ashok k Srivastava and Rupesh S. Mankar (2009). Grain Size Analysis and Depositional Pattern of Upper Gondwana Sediments (Early Cretaceous) ofSalbardi Area, Districts Amravati, Maharashtra and Betul, Madhya Pradesh, Journal Geological Society of India, 73, 393-406. Bene Dicte Ferre, Christopher R. Sherwood, Patricia L. Wiberg (2010). Sediment transport on the Palos
Verdes shelf, California, Continental Shelf Research 30,761-780. Folk, R.L.( 1974). Petrology of Sedimentary Rocks Hemphill Publishing Co., Austin. Folk, R.L. and Ward, W.C. (1957). A study in the significance of grain size parameters, Journal of Sedimentary Petrology, 27, 3-26. Friedman, GM. (1961). Distinction between dune, beach and river sands from their textural characteristics. Journal of Sedimentary Petrology 31, 514-529. Friedman, GM. and Sanders, I.E. (1978). Principles of Sedimentology. Wiley, New York, 792.
Grain Size Statistical Parameters of Coastal Sediments around Tirumalairajanar River Mouth Tamilnadu
Fuechtbauer, H., Mueller, G. (1977). Sedimente und sedimentgesteine. Stuttgart, 784. Harsha Sundar, E, Reddy, K.S.N, Vani Sailaja, V and Murthy, K.N.V.V. (2010). Textural Characteristics of Coastal sands between Kakinda bay and Tandava River Confluence, Andhra Pradesh, East coast oflndia, Jour. IndianAssociation of Sedimentologist 29, 61-69. Holme, N.A. and Macintyre, A.D. (1971). Methods for the studay of the marine benthos, I.B.P. Handbook No.16? Blackwell, Oxford .: Inman, D.L. (1952). Measures for describing size of sediments, Journal of Sedimentary Petrology, 19, 125-145. Joanna Staneva, EmilVStanev, Jorg-Olaf Wolff, ThomasH.Badewien, Rainer Reuter, BurghardFlemming, AlexanderBartholoma, KarstenBolding (2009). Hydrodynamics and sediment dynamics in the German Bight. A focus on observations and numerical modelling in the East Frisian Wadden Sea, Continental Shelf Research 29,302-319. Krumbein, w.e. (1934). Size frequency distribution of sediments, Journal of Sedimentary Petrology, 4, 6577. Lluis Gomez-Pujol, Alejandro Orfila, Amaya AlvarezEllacuria, Joaquin Tintore (2011). Controls on sediment dynamics and medium-term morphological change in a barred micro tidal beach (Cala Millor, Mallorca, Western Mediterranean) doi: I 0.10 16/ j.geomorph. 2011.04.026. Mcbride, E.F. (1971). Mathematical treatment of size distribution data. In: R.E. Carver (Ed.),
73
Procedures in Sedimentary Petrology. Wilson Interscience. Milligan, T.G, Hill, P.S., Law; B.A. (2007). Flocculation and the loss of sediment from the Po River plume. Continental Shelf Research 27,309-321. Moshood Niyi Tijani, Matthew Essien Nton, Ryuji Kitagawa (2010). Textural and geochemical characteristics of the Ajali Sandstone, Anambra Basin, SE Nigeria: Implication for its provenance C. R. Geoscience, 342,136-150. Musila, W.M. (1998). Floristic composition, structure and distribution patterns of coastal sand dune vegetation: a case study of the coastal dunes' between Malindi and Mambrui. M.Phil. dissertation, Moi University, EJdoret, Kenya, 160. Rabindra Nath Hota, Linashree Dalabehera and Arya Goutami Nath (2008). Textural characteristics and Discriminant analysis of Talchir and Karharbari sandstones of the Ong-River Gondwana basin of Orissa, Journal of Indian Association of Sedimentologist, 27, 77-86. Passega, R. (1957). Texture as a characteristic of clastic deposition. American Association of Petroleum Geology, 41, 1952-1984. Passega, R. (1964). Grain size representation by C-M pattern as a geological tool, Journal of Sedimentary Petrology, 34, 830-847. Philip, R. Hill, Kim Conway, D., Gwyn Lintern, Samuel Meule, Kim Picard, J. Vaughn Barrie, (2008). Sedimentary processes and sediment dispersal in the southern Strait of Georgia, BC, Canada, Marine Environmental Research, 66, 39-48.
