8^
CHAPTER V-:
EROSION - SURFACE
5.1 Introduction
S»2 Methodology
S.3 Altimetric Analysis
5»4 Profile Analysis
5.5 Salient Features of Erosion Surfaces
5*6 Conclusion
Appendix
***#*»#*** 85
5.1) INTRODUCTION :
The general term "erosion surface " is employed to describe the geographically plain surface which is the end product of complete or incomplete cycle of erosion(Gibert, 1877)* It is synonymous with the term " planation surface "• Many scholars have described the planation surface in differ ent-ways since past as "Peneplain" (Davis 1906), "Pediplain" (Penckl953), "Panplain" (Johnson 1936), ,etchplain"(Wayland 1934 and 'stripped etchsurface*(Budel 1957). Extremely low relief over a flat surface is a salient feature of the planation surface* Erosion surface is an important phenomenon in the evolution of landforms, since it helps to understand geomor- phic processes acting on the land surface in the past and to interpret the present landscape wfcich is essential to know the geomorphic history of that unit area* Thus it leads to comprehend the denudation chronology* The present topographic expression of the Panzara basin has been caused by the continual interplay between geo morphic processes and the tectonic activities on the initial surface. They produce some micro-relief features* They may be either aggradational or degradational surfaces* This chapter aims at detecting different erosion surfaces at various altitudes and leads to comprehend the pily- cyclic nature of landforms in the Panzara basin* 86
5.2) METHODOLOGY : Methodology of the study is based on altimetric ana lysis (Bauling 1926)* Amongst the various altimetric techniques, b the simple frequency distribution of spot heights and the frequency distribution of highest and lowest points in superim posed grids have been adopted. Besides these, a series of super imposed profiles and longitudinal profiles are used for identi fication of knick points and erosional surfaces. One inch topo graphical maps of Survey of India have been uded for investi gation. The confirmation of erosion surfaces has been made in subsequent field check. The existence of mature soil over the surfaces Chambalbedi mal, Salia mal and Pimpal mal at 1500-1750 feet. Occurrence of calcareous deposits over Galana Fort at an altitude of 2250-2500 feet. Existence of residual hill at Bhamer over Chambalbedi mal, occurrence of numerous residual hills over Kondaibari surface are unmistakable evidences of erosion surfaces. 5«3) ALTIMETRIC ANALYSIS : It is a remarkable fact that the highest parts of the present topography will be residual remnants of the former surface • Remnants of former erosion surface can be recognised with the help of altimetric frequency analysis. Araingst the various altimtric techniques, two methods have been adopted in the present study, viz. (i) Simple frequency distributin of spot heights with or without summit frequencies. (ii) Frequency of the highest and lowest points in the super- 87 "I UJ li. oI I I LD o o < (J) < UJ en
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imposed square grid from one inch maps of Panzara basin Survey of India, The same techniques are widely used by Indian Geomor- phologists(Desai 1956, Rajkumar Rai 1979, Singh 1980, Mukhopa- tihyay 1981, Nageswar Prasad and Kodali 1984), (A) Simple Frequency Distribution of Spot Heights,: Table No.l shows spot heights frequencies in the height groups of 250 feet class interval. It reveals that the highest concentration of frequencies is observed in between 1500-1750 feet. Lowest frequencies are observed below 500 feet and in between 3750-4000 feet. There is a very slight increase of fre quency with a trace number above 500 feet till 1250 feet. In between 1250-1500 feet, the frequencies have decreases and then abruptly increases in the altitudinal range of 1500-1750 feet. Above 1750 feet altitude, frequencies have again decreased in number. Moreover, the histogram also reveals the same which appears like a bimodal one. For getting a better perspective of the distribution of frequencies, histograms with different altitudinal class intervals have been plotted on the same graph(Fig.l) which reveals the following points* (A.l) The histogram A (Fig.l) shows that the maximum frequen cies are concentrated in between 1000-2000 feet altitude. It suggests a single modal distribution. Moreover, more than 96% of the total frequencies lie below 3000 feet. Above 3000 feet, frequencies are abruptly decreasing which account for only 3.27 % of the total.
(A.2) A very low percentage of frequencies has been encountered below 500 feet and above 3000 feet(Fig.l.B) Nonetheless, one may have considered that the surface of the Panzara basin is Su
mostly confined to 500-3000 feet. The frequencies are also very low above 3000 feet* The area above 3000 feet mostly comprises of summits on the southern water divide of the Panzara basin. They axe eastern off-shoots of Sahyadri or locally they are faknown as Galana Hills, since the surface above 3000 feet is named as "Galana erosion surface"• (A.3) The histogram B(Fig.l) also appears like bimodal one* The two modal classes, 500-1000 feet and 1500-2000 feet, sftow a higher concentration of frequencies. The mid values of these two classes are 750 feet and 1750 feet,respectively. In the previous chapter(Chapter VI), knick points in a longitudinal profile have been identified at 750 feet and 1750 feet. It is the clear indication of erosion surfaces at altitudes of 750 and 1750 feet. Besides the histogram, cumulative frequency curves have also been drawn, which show marked inflexions(Fig.2). These inflexions points suggest different erosion surfaces. Fig.2 shows marked inflexions in cumulative frequency curves at 1250, 1750, 2250 and 3000 feet altitude.
(B ) THE FREQUENCIES OF ..HIGHEST AND LOWEST .POINTS. M SUPERIMPOSED GRIDS : Bauling's(1935) device is used t'o pervade some deficien cies in the spot heights. In his device, Bauling had used a square grid in which frequency distribution of the highest and lowest points is counted and plotted on graph, Bauling(1948) believed that the patterns of the highest points would define an upper enveloping surface which becomes closer to the real surface as the local relief becomes more gentle. He contended UJ - UJ • i 1 o o o _J If) o o < CM in o > cc ui 1 • H | z: J
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< n : B-PC 2l *- z. LU 1—ll ZE » t i H; -J , o I—H Lu o :z LU CO o 1—4 LU CO >- —J < X < o I—1 LU X 0 1—I ~F a: 3 1— 2 UJ 1—1 "^ < >—1 2 I— _J < aanmiv that the concave curves in the altimetric plot indicate the mature stage*,where the region is affected by a single cycle of erosion. The inflexions or segments produced in a curve suggest the different cycles or polycyclic nature of landforms. With reference to Bauling's device, one inch Survey of India map of the entire Panzara basin can be divided into square grids(0.5745 x 0*5745 inch on map) each of which covers 0.33 sq.mile of area. The highest and lowest points in each square grid have been estimated and tabulated in Table Nos.2 and 3 at 250 feet class intervals of altitude. Moreover, the histograms have also been plotted on the information obtained from Table Nos.2 and 3 (Figs. 3 and 4). It is obvious from Figs.3 and 4 that the maximum frequ ency belongs to 1000-1250 feet, which accounts for 17.35 per cent in the case of the highest elevated points in superimposed grids. However, maximum frequency of lowest point in superim posed grid is observed in the highest class 750-1000 feet. Owing to this fact one may be led to consider that the real surface has been observed belonging to 750-1000 feet, referring to the highest frequency which accounts for more than 21 %• (Table No.3, Fig,3). The upper enveloping surface to this real erosional surface lies in height group 1000-1250 feet which can be predicted from the observation of highest frequency of lowest point in superimposed grids in class 1000-1250 feet. (Table No*2, Fig.3). It is believed that the maximum elevation of the dykes range is 1250 feet which is explicit from the S.O.I, toposheets of Panzara basin. A very gentle scarp like surface is observed in between 1250-1500 feet in subsequent field check. It is also marked by the occurrence of low frequencies in the group 1250-1500 feet in both spot heights and frequency of highest and lowest points in superimposed grids. Following this class, frequencies have suddenly increased in class 1800-1750 feet* This tendency is observed in both spot heights and grid- wise frequency of highest and lowest points,(Table Nos.1,2,3 and Figs.l A,B,C)f which can be predominently marked by an eventful erosion surface. It covers an extensive plateau surface with mature soil cover. This surface covers an extensive table land bordering by steep edges like Chambarbedi Malt Pimpal Mal,Salia Mai, Trishul Mai, etc. The upper limit of this surface can lie till 2000 feet since the frequencies are still high belonging to the class 1750-2000 feet. Many residual hills rise upto 2000 feet over this surface. Trishul Mai is the residual hill over this surface rising above 1900 feet. The considerable frequencies are also observed in between 2250-2500 feet. THis can be evidenced by an extensive flat sur face above an altitude of 2250 feet. It includes Galana fort, Laling fort,Kp,ndaibari surface, etc. The area of Galana fort is flat and covers a thick mature soil with underlying layer of calcareous deposits. Calcarous deposition is very tremendous in the vicinity of Galana. Obviously, it is another erosion surface< Above 3000 feet, the frequencies are very low. They mostly comprise summits of flat topped Galana hills, It includes flat A* surface marked by steep edges. This is also another erosion sur face. The rocky stumps of peaks of Sahyadri stand above 4000 feet This is the uppermost surface in Panzara basin. It can be assumed as the initial surface of the Panzara basin. 9 b in UJ ta CO UJ -J *—t oU_ cr o_ Q UJ CO ao. -CT) UJ Q_ m -<£> -CO —v— O o o l-O O o o UJO in IX) UJIO n II < >• ILE 5 ILE 5 2 2 -r5 t—• CO LU _J »—< Li- _co O oc CL ^LO _m Q r—' r^ LU 10 lml O co _OJ -co -en K O o o F- 6 LU O LU O o sT o o LU O o o uJ o > I o o o ° LL n cs ~- LL co (^ ^ 86 if) UJ UJ 2 Loo LCD If) LLO LtD LU O U^ MNJ ccQ LU ID CL (£) CO O -en fen Q. -C0 a: -t£> UJ CL CO • rn foo —1 i 1 1 —(-' h- o O •> I" 1 LU o o o oc o UJ o o o o o o o ID in U_ • 00 IL E LE S >-*• 2 t z { "OJ *CM CO J 1 LU 11 | _J -co -eg 1i— » I ^» '< 1 m LL 1 o i 1 tr | | Q_ I 1 Q UJ 1| *~*\ / CO -CNI ^•** | -f^ O ) »-» O 2 | 2. | •—• 1 Al -o LU 1 "CT J CL J f ID 1 1 * CO -ID -CD -CO -en 1 — • ' ' u 1 1- O O t- O 6 6- LU O O UJ O o UJ o ir> UJ O ID U- ,- L_ *- lOx However, one may not have depicted all the erosion sur faces by the altimetric analysis alone. It requires further investigation* S.4) PROFILE ANALYSIS:(Superimposed and Logitudinal) A series of cross profile at one mile interval across the Panzara basin have been drawn in north-south direction as shown in Fig.5* The southern end of the profile is marked by the comparatively higher elevation than the northern end* They attain maximum mean sea level height above 4000 feet and 2750 feet respectively* Former erosion surface can be identified from the general uniformity levels of various profiles at different levels. The peaks rising over 4000 feet are clearly seen in the sets of superimposed profile(Fig#5)* They are seven in number* The highest peak among them is the fTungif(4366 feet) located 11*8 miles to the east of Scarp(Fig.6) of the Western Ghats* The details of the other peaks have been given in Table No»4* It is very interesting to note here that all these peaks are rising above 4000 feet and show a peculiar east-west pattern unlike that of the highest peaks in the remaining part of Maha rashtra plateau* Moreover, it is observed that these peaks are confined to the 20°-51« North latitude.(Fig.6)* These peaks rise abruptly above 3000 feet altitude of •Galana hills*. The crest of these peaks appear like the rocky stumps over a flat topped surface. Such type of peaks are absent over the northern water divide of the Panzara basin* Owing to the East-West confinement of the 4000 feet peaks along the latitude 200-51* N in between 73°-57'E to 102 74°-5,-30w E longitude and their absence further north and east, it has been presumed that prior to the formation of the Western Ghats, it was a continuous north-south central ridge* This part of Panzara basin might be the northern extremity of this ridge* At the time of Western Ghat formation, this northern end of the central ridge was subjected by tectonic activities*, since the corners are more susceptible than middle parts. T^is might be the probable cause of the confinement of peaks along the 20°-51l North latitude. Hence, the surface above 4000 feet might be the initial surface. This surface can be called Mangi-Tungi surface. The name is given after the name of Mangi-Tungi, peaks of the northern Sahyadri. The profile 2(Fig#5) again shows the concentration of flat topped hills above 3000 feet. These hills are observed on both northern and southern water divides of the Panzara basin. They depict the general uniformity level at 3000 feet. These hills form the remQant of the former erosion surface at 3000 feet altitude. This is known as 'Galana surface* after the name of Galana hills. The peaks are also concentrated in between 2500-2750 feet altitude(Fig.5-Profiles 3 to 5). This might be the upper enveloping surface observed at altitude 2250 feet. The uniformity level at altitude 2250 feet continued from the upper course of Panzara, through Jamkheli and Kan basin till the northern divide of the Panzara basin. The river Kan(tributary of Panzara)flows over this surface in conformity with the Kondaibari hills. This surface can be namdd after the Kondaibari pass, which is known as Kondaibari surface at 2250 feet altitude. 103 The remaining surfaces at altitudes 1500-1750 and 750- 1C00 feet have already been mentioned in the altimetric analy sis. The profiles(superimposed profiles in Figs.5,9 & 10)show extensive flat terrain. This is the alluvial terrain flanked on both sides of the river "Tapi". This surface is known as Tapi trough surface. (B) LONGITUDINAL PROFILE : Longitudinal profile has been drawn and discussed already in Chapter IV( Drainage Evolution). Although general thalwege is smooth, it is concave up ward and graded downwards. There appear some knicks of low mag nitudes at different altitudes as shown in Table No.5. The knicks are the points connecting ol^ and new base levels. They give some clue to the different uplifts. However, all the knicks shown in Table No.5 are not suggestive of different uplift. It is very difficult to contend the causes of knicks and the asoociated erosioaal surfaces. But the inflexions in profile rectify the polycyclic nature of the profile. Many times knicks of very low magnitude in the longitu dinal profile over trap topography are due to step-like nature of basalt or different exposed Lava-flows. Thus,it leads to detecting altogether six erosional surfaces at different altitude in Panzara basin with the help of foregoing altimetric and profile analysis. They are as follows: (i) Mangi-Tungi surface (above 4000 feet) (ii) Galana surface (3000-3500 -••- ) (iii) Kondaibari surface (2250-2500 -"- ) (iv) Bhatai surface (1500-1750 -"- ) (v) Dhulia surface ( 750-1000 -w- ) T M (vi) api Trough surface ( 500- 750 - - ) l£«i S.5) SALIENT FEATURES OF EROSION SURFACES : The erosion surfaces cannot be detected without subse quent field work* Field work is an essential tool to overhaul the deficiencies in map work. Every erosion surface differs from others gives different characteristics features* They can be noticed only in field work* These salient features have been discussed separately for every erosion surface* (1) MANGI-TUNGI SURFACE(Above 4000 feet): This surface lies at the highest altitude in Panzara basin, i.e. above 4000 feet* The name "Mangi-Tungi" is given after the highest peaks of the Sahyadri in the northern extre mity* It covers a very insignificant area of Panzara basin* The peaks above 4000 feet altitude appear like rocky stumps* They consist of massive basaltic rocks* A very striking feature is that this surface forming an east-west chain of seven peaks is mostly confiiaed to 20°-51» N latitude in between 73°-57»E to 74°-5*-30w E longitude. It can be considered as the central ridge prior to the formation of the Western Ghats* Hence, this is the oldest surface in the Panzara basin* Its origin might have been in eocene period* Tfiis surface slopes eastward as well as we stward from the Mangi-Tungi peaks* They have the ancient cave settlements* The flatness of the surface is observed at the base of the rocky stumps, bordered by very steep escarpment from the north side* The southern edge of this surface is comparatively gentler than northern side* It is difficult to climb up from the northern side, whereas the southern side is very easy* At the time of Western Ghat formation, the northern side of this surface might have been affected, since it appears like fault icb scarp. Tfcis surface covers thin layer of soil with grassy vegetative cover. (2) GALANA SURFACE( Above 3000 feet): The east-west stretching spur of the Sahyadri is known asHGalana Hills". Hence the surface is called Galana surface. This surface lies at an altitude of 3000 feet. It is a flat topped surface covered with a thick layer of mature soil along with boulders. The boulders might have been added by land sli- u des of scarp edge of Mangi-Tungi surfacet and remnant of sphero idal weathering of basalt rocks. Below the opper soil cover, there is a layer of calcareous deposition. T^is surface is having eastward, northwestward, westward and northward slope. Galana surface is observed on southern side of Panzara basin. Very few residual remnants of this surface are found to the north-western side of Panzara basin. They appear like an inselberg over the Knndaibari or Kan surface. This is a highly dissected surface. This surface is also older than down faulting of western coast of India. 01dham(l893) thought that faulting of western coast was probably in Miocene period. (3) KONDAIBARI SURFACE ( 2250-2500 feet): The name Kondaibari is given to this surface after the name of Kondaibari hill in the north-western part of Panzara basin. It forms the water dividebetween Kan and Raigan.(Raigan is north-westward flowing tributary of Tapi). This surface is a flat surface covering considerable area flanking on the north western, western and southern water divide of Panzara basin. This is also a highly dissected surface overlying residual hills at 2500 feet which envelop this surface. This surface has been 100 much influenced by major tectonic activity that led to the formation of Western Ghat escarpment. However, there are diff erent thoughts regarding the origin and mechanism of 'Western Ghat formation; but the widely accepted opinion is that the faulting is responsible for the present day nature of the West ern Ghat escarpment. At the time of faulting, east-west fractures had arisen in the plateau basalt which were responsible for the present eastward orientation of Panzara river. The westward, north-westward and northward flowing tributaries overlying the former surface diverted eastward. TJiis might be the cause of the formation of Kondaibari pass, which is the major gap towards north-western divide of Panzara basin. There are also gaps in the western divide of the Panzara basin which indicate the former channels of westward flowing rivers. (4) BHATAI SURFACE :( 1500-1750 feet) This is an extensive plateau surface in between 1500-1750 feet altitude. It lies on both sides of Panzara river. It covers Chambarbedi Mai, Trishul Mai, Dhamner plateau, Pimpal Mal,Salia Mai,etc. Amongst them, Chambarbedi Mai covers very extensive area. The ancient Bhatai temple is located in the vicinity of Chambarbedi Mai. The Bhatai temple is very popular in Khandesh. Hence this erosion surface is named after the Goddess Bhatai. Th*is surface is exteremely flat with zero relative relief and is bordered by steep edges. The soil covering this surface is light stony and immature. Such types of plateau with light soils are locally called "Malmatha". Few residual hills rising over this surface attain nearabout 2000 feet altitude. This surface is not much dissected like previous ones* The intrusions like dykes are u/ very numerous with east-west trend in these surfaces. The dykes are further exposed eastward forming a continuous chain. (5) DHULIA SURFACE:(750-1000 feet) The name Dhulia surface is given after the Dhule city, a major urban centre and district headquarters in the region. This is an extensive plain flanking on both sides of Panzara basin in between 750-1000 feet. It is a trough-like surface in between dyke range and scarp face of the plateau. It is occupied by alluvium and tremndous deposition of calcarious material. In the vicinity of Dhule city, strongly cemented sedimentary stru cture, beds of calcretic duricrust are exposed in the bed of Panzara river. Such a sedimentary structure is confined only to this surface, since this formation is called Dhulia formation which has been discussed in detail in later chapters.(Duricrust and Sedimentation). This surface is closely associated with dyke range. (6 ) TAPI ^TROUGH.SURFACE : (500-750 feet): This is a flat rolling plain of tremendous deposition of alluvium. It jas a northward slope and covers the final course of the Panzara basin. The thickness of alluvium ranges between 40-70 feet with tremendous deposition of calcareous material. This surface is found on both sides of Tapi river and forms a trough-like portion. Hence it is named as Tapi trough, Tapi it self is a rift valley. The trough faulting is associated with the Himalayan Orogeny. IQc 10b CONCLUSION : The present topographic expression of the Panzara basin is not only the product of fluvial process but also of the tectonic forces acting on the surface, which are responsible for the interruption of planation cycles, since they are marked by different erosion surfaces at 500-750, 750-1000, 1500-1750, 2250-2500, 3000-3500 feet and above 4000 feet. Hence the landforra of the Panzara basin is polycyclic. 11G TABLE NO. 1 SPOT HEIGHTS IN PANZARA BASIN Sr. : Height in i Normal : Cumulative i Percentage No.: feet ;s Frequency* Frequency 1 Normal Cumulative 1 3 Below 500 i: 1 : 1 s 0.1422 3 0.1422 2 s 500- 750 ii 84 i 85 $11.9483 312.0910 3 t 750- 1000 it 85 t 170 312.0910 324.1821 4 s 1000-1250 it 86 •* 256 312.2333 336.4154 5 : 1250-1500 <: 62 : 319 s 8.9616 345.3770 6 s 1500-1750 it 109 s 423 315.5050 360.8819 7 s 1750-2000 -i 85 • 513 312.0910 372.9730 8 : 2000-2250 !: 83 3 596 sll.8065 :84.7795 9 : 2250-2500 1: 49 S 645 3 6.9701 391.7496 10-» 2500-2750 Jl '21 S 666 3 2.9872 394.7368 11 : 2750-3000 '.i 14 I 680 : 1.9915 396.7283 12 : 3000-3250 it 5 J 685 3 0.7112 ;97.4395 13 « 3250-3500 sI 8 s 693 : 1.1380 :98.5775 14 : 3500-3750 tt 3 : 696 3 0.4257 399.0093 15 s 3750-4000 it 1 t 697 3 0.1422 399.1405 16 s Above 4000 it 7 t 703 s 0.8535 200.00 Ill TABLE NO. 2. GRIDWISE FREQUENCY OP MINIMUM HEIGHT IN THE PAftZARA BASIN sr.No •t Height i» Frequency! Curmilatlve i Percentage s (feet) ii I frequency i t ir i t Normal iiCumulatlv e t ii t 1 s Below 5001i 2 a 2 Ji 0.0611 iI 0.0611 2 t 500-750 i1 232 it 234 ir 7.0883 il 7.1494 3 1 750-1000 \I 705 iI 939 lI 21.5399 il 28.6893 4 11000-1250 J I 519 it 1458 jt 15.8570 Ji 44.5463 5 «1250-15C0 it 391 j1 1849 1l 11.9462 J l 56.4925 6 11500-1750 ir 622 it 2471 jl 19.0040 il 75„4965 7 »1750-2000 i» 515 Ji 2986 1l 15.7348 i\ 91.2313 8 12000-2250 ii 211 i6 3197 Jl 6.4*67 jt 97*6780 o 12250-2500 il 38 >I 3235 1{ 1.1610 \I 98.8390 10 12500-2750 1t 23 II 3258 1i 0.7027 j 95.5417 11 $2750-3000 1t 5 i: 3253 iI 0.1523 i\ 99.6945 12 I30C0-3250 J 1 9 it 3272 1i 0.2750 i 99.9694 13 13250-3510 J f 1 1i 3273 1 0.0305 i 100.0000 14 13500-3750 i 15 J3750-4000 1 t t 16 lAbove 40001 I t 112 TABLE NO. 3, GRIDWISE FREQUENCIES OF MAXIMUM HEIGHT IN THE mNZARA BASIN Sr.No.i l Height J\ Frequency!(Cumulativ e ii Percentage i (feet) i (Frequency i i Normal [Cumulative 1 !i Below 500 Ji 2 it 2 ir 0.0611 it 0.0611 2 ai 5CC-750 it 215 ii 217 i t 6.6506 ii 6.7217 3 il 750-1000 lt 506 il 723 It 15.4598 ii 22,1815 4 si 1000-1250 Ji 568 Jt 1294 <( 17,3541 ii 39.5356 5 it 1250-1500 1t 33C il 1621 !I 10.1742 ii 49.7097 6 ir 1500-1750 it 470 1I 2091 1t 14.3599 ji 64.0697 7 ji 1750-2000 Jt 468 1i 2559 lt 14.2983 I{ 78.3685 8 l\ 2000-2250 1i 405 it 2970 Ji 12.3740 1i 90.7424 9 il 2250-2500 Ji 130 it 3100 ii 3.9719 t ( 94.7143 10 it 2500-2750 «! 78 it 3173 it 2.3831 it 97.0975 31 ii 275C-3C00 :: 43 it 3221 ii 1.3133 i t 98.4112 12 '.i 3000-3250 ii 22 il 3243 It 0.6722 it 99.0834 13 ii 3250-3500 !I 17 3t 3260 it 0.5194 it 99.6028 14 r 3500-3750 it Q iI 3268 ie 0.2444 it 99.8472 15 » 3750-4000 i\ 2 il 3270 1[ 0.0 16 iAbove 4000 \\ 7 it 3273 iI 0.0917 1ilOO.OOO O 11 •t> fl> > O •Q C CO 00 o\ o vO CO VO CO 00 m •H CO ^J- vO CM ^ ^ -H CM CO CO +* • M- <* «* "tf "<* * ^ C> •+> •H V) Q> 0) • 4) •O *""» S^H W O > «> M-H «H M £ tl M *0"—' o CM CO 00 o CO O d) N C+» C C If) 00 <0 »0 «0«H en • (0 (0 (f4 (0 nj a •H to % o ? >* V) *o *o c (0 Oqu i •H •H 9) c +» c £s > en 0> U) c c P. X O CM CO m vO M 13, Erosion surfaces - Upper Galana hill, middle, old Pediment surface. Lower alluvial plain.