The Geomorphology of the Himalayan And
Total Page:16
File Type:pdf, Size:1020Kb
HiroshimaHiroshimaGeographicalAssociation Geographical Association THE GEOMORPHOLOGY OF THE HIMALAYAN FOOT-HILLS AND GLACIAL LANDFORMS OF THE LESSER HIMALAYAS IN THE PUNJAB HIMALAYAS Masahisa HAYASHI" ABSTRACT The geomorphic history of the Kangra Valley area and the glacial landforms of the Dhauladhar Range have been studied with special reference to the origin ef the huge beulders found in this area・ Six geomorphic surfaces are distinguishable in this area・ Of these, the three higher surfaces are depos- itionaL in origin. These deposits, including huge granitoid boulders, are probably caused by mudflows or earthflows・ A loesstc deposit covers the Palampur Surface. the secend higher surface・ In the area of the Siwaiik ridges, an uplift of upto 80m has taken place since the Kangra Surface, the third higher surface, was formecl・ ' Two sets ef cirque fermation are recognizable in the higher portions of the Dhau]adhar;the higher cirque floors stand about 4,200m above sea level and the lower about 3,2oom ln the seuthern face・ INTRODUCTION Fevv geomorphological studies of the Himaiayas have been carried out due Lo t'he area's unaccessi- bility and the laek of adequate preliminary data, although a large number of mountain expeditions have been sent here, However, the Himalayan Range is one of the most interesttng areas for studying both crustal movernents hnd glacial processes・ The Kangra Valley area was selected with the aim of throwing light upon the origin and the evo- lution of these geomorphic Silrfaces which are closet}r connected with the growth of the Himalayas, In this paper, the geomerphic history uf the Kangra Valley area is revealed・ The origin of the exten- siyely found higher fan-shaped surfaces, eomposed of huge granitoid boulders, and the glacial land- forms of the higher mountains of the Dhauladhar, one of the Lesser Himalayas, are noted・ The dia- "toposheets" gTams were based mainly upon the quarter inch to a mile (1:253,440) published by the Survey of Jndia, and a hand level was usec] for measuring the heights of terrace surfaces・ Preliminary resu]ts have been discussed in a report already published (Hayashi, 1974)・ PREVIOUS STUDIES ' The first report of the existence of huge granitoid boulders in the Kangra Valley was made by )"ledlicott (1864)- Later, Theobald (1874), and Coulson (1938) noted the boulders' di$tribution ancl the fact that they were laid unconformably on the Upper Siwalik Conglomerate・ They, more or less, postulated glacial origin for these boulder depositions・ Though nu dellnite evidence to show the age uf cleposition of these boulders has yet been found, Pascoe (1963) included the Kangra boulders in the Boulder Conglomerate of the Upper SiwaUks, On the other hand, Pilgrim (1944), and Sahni et at・ (1964) divided the Boulder Conglomerate into two beds ; stating the lower bed correlated with the first interglacial period and the upper with the second glacial or interg'tacial period・ Sahni et al・ Q964) reported the eccurr'ence of the Neogal Conglotnerate in the Palam Valley foi'tned during' the first inter- glacial period. Regarding the g'iacial aga, Dainelli (1923) defined the sequence of four glacials and three inter- 'l"erra glacials based on his observations of glacial deposits in the North-Western Himalayas, (1939) made an investigation of the terrace system in the Kashxnir Himalayas and concluded that there had -25- NII-Electronic Library Service HiroshimaHiroshimaGeographicalAssociation Geographical Association bf:en a four-fold glacial succession, the same as that found in the European Alps・ Recently, Porter {I1970) criticised Terra's opinion on the basis of his detaiL observation of moraine assembleges in the Swat Kohistan, Pakistan. He insisted on a three-f6Id Pleistocene glaciation fov the North-IVestern ' Hiinalayas・ In the Kangra Valley area, Johsi (1968), judging frem the fact that huge boulders xvere seen on the river terrace,, proposed the existence of, at least one phase of past giaciation, Mohapatra (1973). following [[ierra's postulation,' stuclieci the Banganga river and also deduced that there had beeri four glacial peviods, However, Nakata (1971) found evidence Ec)r three glacial periods svhen he stud[ed terrace systems along the Beas river an.d recognized the presence of three types of accurnulation terraces・ PHYSICAL SETTINGS ' A The Kangra Valley area covers a Iarge portion of the Sub-Himalayas of the Punjab Re-entrant- wide spread Tertiary zone extends between the I)unjab Plttins and the Main Boundary Fault. A geolo- gical setting ef the study area is shown in Fig. 1. N/ t/r' i1 ,..)i 7/M/t!D 1. -- --- oooo Y - ----- 5/ I/l:1l/ll1!I 11i .1k1]1Ii/ev xr' o ix N x-r- eoo [ K- . eltltkvt C/i/cl x o L ll-[ 1i't,,P o'6 1i11・/// eo /i X:1. 1.iif.> r ・・l/xl Iklhl xL le g,[ --t I 'x t- lK" ' ・・ ]l/:tlill : g o 1r EK:-v・.-3 oo. ・ - -tt-oo -.x lt[j!l x---- . ・1]= o o g o .. - -- K)l;/2fl.. xT. .,o.>oeeov -.x .. ... ' ・・.v-- ---o e o IY. --- .. o ---t - --- Iilt!ll1oo.Z・-/ ' 11 7C - --o -p; o oX,oe ]S.l']'.. x }Lh-'Sft' . o l txJN XQI . 1 br/!'r'{ 'q. -- --- "" :11' o'・K -v-.-. .. o -T x Do "x 'r .K--- m'i ... r. .x- ...- xe ,. //j,[ :'):g o.eooo ' g I / "--'' '""")'t""'ft' l l x / zl/i fvg ・1 li.-l,,Z,il/fL'tlt.. lt L' 1 N . ・ .<S)t (i6 lliiilr>;i2- x,--xts 3-' -ellr --t-t'x'ftre x" r --rT 1/ 'y. ' ' o-ot X.. - L- + --:ts i1 e eX .N, ttt'tH oo ."N ---x" M- kl・1・kk.zl':1 I ii1I1i'.e o o '.-. ・ A-. h.. .-- sttq. ' o s " xrvr'tsNv.TJ '1tL1r 1 ."'iX.1--'LSx.1-r g,・Hoe - 'N. ;tsl! 'in 1 e t-i 61' o oooo E[.': x.el- S':1 -- -O F' ili - 'i Y. so ii. i ..2LS X<Sll><・tiN !'''i' -.-g'itrti-- --t 1' I"l ' --- LEGEND 'i 't'' i- ' tiI //// L : MBFuJT Main Baundary Fauit 'JT ,- -pperSiwa[iks -,--・' Anticlinel A:is K, . - N -PA Jawalo Mukhi Thrust CGumberT.} --・--" Synelinel Axis lt ::: MiddleSivtoliks -LSPeraur Anticline Y Thrust with directian ef hede - lit72 -D"DG JN Jogindernagar Lower SiWaljks Lambagaonsyncljne g t/ - FouH K -Kangra ' Dharmsaia Pre-Siwplik pm 1lertiary N. -Nadaun -JMDehra GepTpur , O 4 BMiles P -・ Pre-Tertiary --"---"-==- Palarnpur m - JawataMukhi O 4 8 12km Fig. 1, Geological sketch map of the Kangra Valley Area ' (cempiled ・after Gill (1951b), S[-Lhni et al. (1964), I<iverman (1972)・Raju (1962) etc.) ' Range runs from the north-west to the south-east with To the north o[ the area, the Dhauladhar' an average sumrnit level of 4,500in above sea level・ This range is c['}Tnposed of granitoicl gneiss (Medricott, 1864). The southern slope of this range descends more abruptty t{) the Kangra Valley than -26- NII-Electronic Library Service HiroshimaHiroshimaGeographicalAssociation Geographical Association the northern face;avertiging 20 degrees to the south and 15 degrees to the north (Kayastha, 1964). Evlclence of previous glaciations is visible in the higher mountains, although small perpetual snow fields have been found on only a handful of mountain peaks・ To the south. a series of ]nonoclinal ridges, ' rarely rising above 1, OOOm in altitude and composed of the Siwalik group, demarcates the Kangra Val}ey area. AII riclges run in same direction as the Dhauladhar. and the arrangements aE river courses and rising yidges are quite clearly determined by the geological structure・ Numerous streams from the Dhau]adhar fiow into the Beas river, being locally called hhads. The Kangra Valley, lying between the Dhauladhar and the Siwalik ridges can be divided into two Valley parts : the Kangra VaLley proper to the west and the Palam Valley to thd east・ The Kangra is drained by the Banganga and the Gaj fehads. A chain of isolated low ridges composed of the Upper Siwaliks occur xvithin this vatiev. In the Palam Valley there are two drainage basins, the. Neogal and the Luni fehads. The Luni khad fiows through a gorge transversing a series of monoclinal.ridges・ Pest-Siwalik deposits usually cover the surface of both valleys. A tectonic depression in the Joginder- N 7beE8oe9oo o100 ooo 50040D clli.E.Vs$- N g-ShL1ik'-..,.s'rk ll oeN["li.o20.Kllls+-[L-iHIU x -gN)g3b L-xL')xw "i'K ft"vv) c= XNJr)e.rx "oo-g Y 6befo}is"si. x OLM Y Ct A L-X" n v t1 gl9S yk-" L tc x f --.ttL b ot1tiC6;Ooo .tZl:il'kua oa .,eK)- IO 1L x k<S% N N 6 "1i 'x", "}ebkK r'u7 xyvXL x oA ¢ .ttL9000 K XH ' n tsS.t L tio-1r) gcbo ))1rt'S.. h P x, lo C})NExgtso c-. - k,Jy S) r' lX.r-"1 Sk !S ]- Vsoo.. NM LX'L1 -..-"t 1" L ./ 1 xx" 1 J"Ss' o 1 x". ""l :1 L.. di t xt., 'E s r. , >Xxxl< cg 1 hi1t iy %・ ,F. h..)K rLi t IFIIj L... 'i g£ L ci" Wooo 1 ttt. 'r fcrx 70oo IL",.ilgill 1trhd[}vot N}ii),g'1 (N, glj・- L r- ( rl, tL /" ..-t r'.V{yP ,l}21" o lzirlg" "i."Xi. )eS N iN Y Nx ,t tx-nx l N x '1 t1t. -. x >< 1NNxM IabxiYxx /1l os ctb s x NNLag --s K・Yx l"・,{i' 'f-1' -tt (( x- x A lx' Lp ttt et hxlYl N JNM, h sk tlt. N,tZbs.[}.g・, g'xN 1 s N E"J xL LY". ...x K L-.1 1kL) eas xKr L i -"Li ]t o 4e 8MLIesI?km K'"'-N bGve L.