CHARLES DOWNIE Dept. Geology, University of Sheffield, Sheffield, England

Glaciations of Mount Kilimanjaro,

Northeast Tanganyika

Abstract: On Kilimanjaro six glacial episodes are glacial features belong to the Fourth Glaciation recognized. At the principal volcanic center of which covered about 150 sq mi. The Little and Kibo these were interrupted by volcanic activity. Recent Glaciations are smaller in extent and post- The smaller volcanic center of Mavvenzi has been Pleistocene. The climatic pattern was probably extinct longer, and the glaciations have been super- similar at all times to that of today, and the thick- imposed. Shira, the lowest of the three volcanoes est and longest glaciers were generally always on in the group, has been only slightly affected by the south and west slopes. Comparison with other glaciation. The successive glacial episodes are glaciated regions in East Africa shows some sim- named the First, Second, Third, Fourth (Main), ilarities, and a similar sequence has been suggested Little, and Recent, of which the Third was the for the East African pluvial periods. most extensive; however, most of the obvious

CONTENTS Introduction and acknowledgments 1 2. Details of the section in the Bastionsbach, south- Previous investigations 2 west of Kibo Peak, Mount Kilimanjaro, at Erosional features produced by the glaciers ... 3 13,100 feet showing the moraine of the Depositional features produced by the glaciers . 4 Second Glaciation ...... 8 Relationships between volcanic activity and ice cover 5 Plate Facing Sequence of glaciations on Kibo 6 1. Kibo Peak, Mount Kilimanjaro from the north- Sequence of glaciations on Mawenzi 10 west ...... 6 Sequence of glaciations on Shira 11 2. Kibo Peak, Mount Kilimanjaro from the south- Fourth (Main) Glaciation 11 east ...... 7 General statement 11 3. Moraines of Mount Kilimanjaro, northeast Tan- Main Glaciation on Kibo 11 ganyika ...... 16 Main Glaciation on Mawenzi 13 Little Glaciation 13 Table Recent Glaciation 14 1. Correlation of glaciations on Mount Kiliman- Comparisons and conclusions 14 jaro, northeast Tanganyika 7 References cited 15 2. Altitudes of moraines on Mount Kilimanjaro, Figure northeast Tanganyika 12 1. Cross section along the Machame Escarpment, 3. Comparison of the sequence of glaciations on southwest of Kibo Peak, Mount Kiliman- Mount Kilimanjaro with other Pleistocene jaro, showing the relationships between the sequences 14 moraines and the lava series 8

INTRODUCTION AND since disappeared from all but the last three, ACKNOWLEDGMENTS and on these it is clear that the glaciers have Kilimanjaro, 19,340 feet in height, is the retreated a long way from their maximum ex- highest of the three mountain groups in Africa tent. that still carry glaciers. During the Pleistocene, The climatic contrasts between the past and however, glaciers were present on several East the present indicated by these events on the African mountains, among them Mount mountain tops are more widely reflected in Elgon, the Aberdare Mountains, the Abys- tropical regions by the dwindling and disap- sinian Highlands, Mount Ruwenzori, Mount pearance of large lakes that once existed in the Kenya, and Mount Kilimanjaro. They have area and by other signs of a once heavier, more

Geological Society of America Bulletin, v. 75, p. 1-16, 2 figs., 3 pis., January 1964

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continuous rainfall. There has long been a The author would like to stress that the tendency to equate these pluvial periods with field work on which this paper was based was the glacial periods of Europe, but Flint (1959) done while participating in the Sheffield ex- has pointed out some of the difficulties under- peditions to Kilimanjaro in 1953 and 1957 and lying such a simple assumption. that he is indebted to all the members of these It is even more tempting to correlate the expeditions for assistance in various ways. He African pluvial periods with the period of is particularly grateful to Mr. P. Wilkinson maximum glaciation on the local mountains, for drawing his attention to the occurrence of but so far no direct evidence linking the events striations outside the Main moraines and to on the plains with those on the mountains has Dr. G. P. Leedal for information about the been found; the two areas are invariably separa- glacial deposits north of Kibo. The expeditions ted by long, forest-covered slopes extending up- received financial support from the Govern- ward for many thousands of feet. ment of Tanganyika, the Royal Society, and It was hoped when the expeditions from Shef- the University of Sheffield, and for this the field went to Kilimanjaro in 1953 and 1957 author as a member of the expeditions is very that it would be possible to bridge this gap grateful. using characteristic lava flows to link events on The photographs forming Plates 1 and 2 are the summit with those on the surrounding reproduced by permission of the Air Survey plains. To some extent this has been done. A Division, Ministry of Lands, Forests and Wild- succession of glaciations interspersed with peri- life, Dar-es-Salaam, Tanganyika. ods of volcanic activity has been determined on the mountain top, and many of the lava PREVIOUS INVESTIGATIONS flows have been traced to the plains both to The former great extent of the glaciers on the north, where they pass under the Amboseli Kilimanjaro has been known since the first Lake Beds, and to the south where they meet exploration of Meyer (1900) at the end of the the Pangani River deposits. Unfortunately 19th century. He photographed and recorded these extensive areas of sedimentary deposits large moraines and glacial striae far below the are still imperfectly examined and as far as is glacier snouts and in addition discovered fluvio- known have yielded no fossils or artifacts which glacial sands below lava flows on the west permit correlation with other lacustrine or slopes of Kibo. Early in the present century alluvial beds in East Africa or with any of the Jaeger (1909) saw the moraines southwest of pluvial periods. Kibo and Klute (1920) travelled widely over Nevertheless Kilimanjaro provides much the summit area and published the first accurate additional information about the succession map. On this map he showed many of the large of glaciations in East Africa, and it is considered moraines, recognizing two series, the outer worth-while to record the sequence of events older group and the inner younger group. on the summit in the hope that at some future Others which he found in intermediate posi- date the geology of the surrounding plains tions he interpreted as retreat stadia. will be better known and the correlation be- In 1932 Nilsson published an account of his tween glacial and pluvial periods firmly es- studies of the lacustrine and glacial deposits tablished. of East Africa, in the course of which he In determining the succession of glaciations briefly visited Kilimanjaro. There he examined Kilimanjaro has certain advantages over the in detail the large moraines in the southern other mountains in East Africa. On Mt. valleys of Mawenzi and some smaller moraines Ruwenzori, a horst of Precambrian rocks, and farther west. He summarized the previous on Mt. Kenya, which became extinct before work and recognized a number of stages in the glaciation began, each successive glaciation glaciation which he correlated with the pluvial largely obliterated the evidence for those pre- periods. ceding. Whereas this is true for parts of Kili- The present account is based on two visits manjaro, activity continued at the main Kibo extending over four months during which center and at several small parasitic centers nearly all the mountain above the forest was until Recent time so that glacial deposits have explored. The data collected considerably at many places been protected beneath various amplify those given by Klute (1920) regarding groups of lava flows; consequently, a greater the distribution of moraine and also amplify the number of glacial episodes are distinguished sequence of glaciations deduced by Nilsson than on any of the other East African moun- (1932). Many additional occurrences of glacial tains. deposits among the lava flows have been dis-

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covered and placed in relationship to the lava fined but short and extend only for about a succession. It was also observed that the ice is mile from the caldera edge. Excellent examples still retreating and has receded a long way from are found on the south and west slopes of Kibo, its position when Meyer first visited the glacier probably the finest on the mountain being the snouts, but these recent changes will not be 500-foot-deep trough of the upper Garanga discussed in this account. Tal. In contrast, on the north and west slopes The work of these expeditions has not yet of Kibo the valleys seldom exceed 200 feet in been published in full. Preliminary reports of depth, and none can be described as U-shaped. the first expedition have been published by That this contrast is mostly due to fresh lava Wilcockson (1956) and Downie and others flows continuing until fairly recently is shown (1956). Subsequent discoveries necessitate by the presence on the northern slopes of Ma- some modification of these reports but not in wenzi of well-marked U-shaped valleys. These any way that substantially affects this paper. are somewhat shallower than the main valleys on the south slopes, and it appears that the EROSIONAL FEATURES PRODUCED thickness of the ice was greater on the southern BY THE GLACIERS slopes. CIRQUES : Well-developed cirques with floors The outstanding valley on Kilimanjaro, the at about 15,600 feet surround the summit of Great Barranco on the northeast side of Ma- Mawenzi (17,060 feet), the most easterly of wenzi, shows special features. It is the deepest, the three volcanoes of Kilimanjaro (PI. 1); on most precipitous valley on the mountain and the east they have been partially destroyed by originated in the final stages of Mawenzi's the exceptionally rapid erosion at the head of activity with the collapse of a large segment of the Great Barranco. the crater wall and the formation of the ex- Cirques are also present on Kibo, the main tensive Mawenzi lahar field. Since then the and central volcano of Kilimanjaro, but these valley has had advantages in the collection of are in the main shallow scoops in a rudimentary surface and subsurface drainage, enabling it to stage of development (PI. 2); only on the south surpass all the other valleys on Mawenzi. It is slopes are there any approaching the well- now more than 3000 feet deep in places with an developed forms seen on Mawenzi. This is the average gradient of 50°-60° on its walls. There consequence of glacial erosion being inter- can be no doubt that very large glaciers oc- rupted by lava emission which tended to fill cupied the valley at some times, and a U-shaped and obliterate the early-formed cirques. Con- cross section is in part preserved, but erosion is sequently, the cirques on Kibo are entirely the so active that other traces of glaciation have work of the last glaciation, whereas on Mawenzi been almost completely removed. erosion continued uninterruptedly throughout GLACIATED PAVEMENTS AND STRIATED SUR- the Pleistocene up to the present. FACES! Glacially smoothed surfaces are fer- This contrast in the development of the quently conspicuous in many regions high on cirques on Kibo and Mawenzi applies, for the the mountain, but not all the rock types present same reasons, to all the other features produced preserve the striations to the same degree. by glacial erosion. In the same way the contrast Weathering and subaerial erosion of the flow in topography between Mt. Kenya and Kibo breccias and agglomerates forming the peak of is explained, for Mt. Kenya also was largely ex- Mawenzi have removed all traces of smoothing tinct during Pleistocene and Recent times. and striation, but lower down they are magnifi- On Shira, the lowest (13,140 feet) and most cently preserved on the more massive trachy- westerly of the three volcanoes, the valley heads basalt lavas. On Kibo smoothed surfaces are below the caldera rim on its outer side are steep- common in the glaciated region, even on the sided and cirquelike and are presumably cirques old alluvial beds in the Garanga Tal. Striations since other signs of glaciation are also present. are not so common, a fact that must depend on The low altitude of the neve field severely the petrographic character of the rocks. No restricted the extent of the glaciation in com- striated surfaces have been found in the Shira parison with the other summits, and the re- region, but a number of planed rock surfaces sulting cirque forms are far less definite. on the floors of the upper radial valleys may be U-SHAPED VALLEYS: The valleys on the weathered glacial pavements. southern slopes of Kilimanjaro are most con- The striae in every case conform in orienta- spicuously U-shaped; on the north they are tion to the flow direction indicated by the generally indefinite and shallower. The U- topography and nearby moraines and, with shaped valleys of Shira are deep and well de- two exceptions, are confined within the limits

marked by the large terminal moraines of the the outer, and their total length is often more Fourth (Main) Glaciation. One of these ex- than 3 miles. ceptions is a glacial pavement about 100 yards The thickness of ice in the middle reaches of in front of the terminal moraines of the 3rd the valley glaciers during the last glacial maxi- Mawenzi Sud Tal; the other was recorded by mum was 400-700 feet on the southern slopes, Meyer (1900) on the north slopes of the Saddle whereas on the northern slopes it appears to at a height of 11,300 feet. No other evidence have been at most 200-400 feet. In Mawenzi for glaciation was found in this region, and the Barranco it may well have greatly exceeded existence of these striae could not be confirmed. 1000 feet. OTHER FEATURES: Giant steps occur in the The valley glaciers were also long in relation- higher parts of several of the valleys, e.g., in the ship to their width on the south and southwest Drei Konigs Tal at 13,000 and 13,700 feet and slopes; consequently, the lateral moraines form in the Garanga Tal at 13,700 feet. long lobate extensions down the valleys. In Rock basins are few, and the only tarn re- contrast some of the glaciers on the north slopes sembling these characteristic features of Ru- of Kibo and on the esat slopes of Mawenzi were wenzori and Mt. Kenya is in the See Tal at short and broad. Their lateral moraines are 14,300 feet. insignificant, and the positions of the glaciers Roches moutonnees are abundant on the are marked by lobate embayments in a more or heavily glaciated southern slopes of Kibo and less continuous wall of terminal moraine. A Mawenzi but much rarer elsewhere. similar wall of moraine with small embayments marking the positions of individual glaciers is DEPOSITIONAL FEATURES formed by the Recent terminal moraines below PRODUCED BY THE GLACIERS the south face of Kibo. MORAINES: At the glacial maxima the sum- In most of the valleys various series of mo- mits of Kibo and Mawenzi were covered, above raines can be recognized marking retreat stadia about 15,000 feet, by a continuous ice cap or and readvances of the ice. Lateral moraines on carapace. Below 15,000 feet the carapace the flanks of the main moraines and crescents broke up into valley glaciers separated by rocky of terminal moraine across the valley floors ridges. These continued down to heights that are common and in most cases follow the pat- ranged from 15,000 to about 13,000 feet where tern of the main moraines. But on the south the valley glaciers began to diverge. It is prob- side of Kibo a large lobate glacier 2 miles wide able that this far the rock ridges remained bur- was later replaced by four distinct valley gla- ied, but now the glaciers became separated by ciers occupying much the same area. deposits of lateral moraine which appeared as A mixture of sand, rock flour, and boulders ridges between adjacent glaciers. Glaciers on of various sizes forms the moraine. Some of both sides contributed to these moraines, which the boulders are enormous. The degree of continued the line of the rock ridges down to rounding and faceting is to some extent de- below 13,000 feet where they split and fol- pendent on the size, but the nature of the rock lowed the edges of their respective glaciers. is also important; for example, the trachy- The point of divergence is related to the level basalts are frequently striated but the rhomb finally reached by the ice and is higher on the porphyries rarely so. Pockets of well-washed north slopes than on the south. At heights current-bedded sand commonly occur near the ranging from 14,000 to below 9000 feet the terminal moraines, but elsewhere they are pairs of lateral moraines in most cases curved rarely found within the moraine. around the snouts of the glaciers to form the Some of the moraines, especially the older terminal moraines. ones, are to some degree cemented, and the The crests of the moraine ridges are very of- cores are often indurated. The cementing ma- ten more than 300 feet above the valley floors, terial is usually hydrated iron oxide. but it is not easy to estimate how much of this The relative age of the moraines can be is due to ovcrdeepening of the valleys. Near assessed to some extent by the degree of weath- the snouts, however, there is no question that ering and erosion, their induration,and the state the whole height of the moraine is due to ac- of their colonization by plants. In some places cumulation, and here the heights often exceed important evidence is provided by their physi- 200 feet. The crests of ridges are nearly always cal relationship and in others by the age of the sharp and simple, the inner slope steeper than incorporated lava fragments.

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The youngest moraines are soft and uncon- moraines of the Mawenzi Sud Tal. In the vicin- solidated, much rock flour is present on their ity there are several low mounds of gravel surfaces, and they have very sharp crests. with some boulders; their occurrence is sporadic Wind, rain, and snow have winnowed away the and their limits ill-defined, but they may repre- finer material in the older moraines; their sent older moraines now greatly reduced by surface is harder; and sandy, large residual erosion. blocks are concentrated along their rather OTHER FEATURES: Boulder trains are promi- broader surfaces. The cores of the older mo- nent on the southern slopes of the Saddle. Old raines are usually indurated, and in places kettle-hole lakes have been found only in the erosion has sculptured them into groups of 1st Mawenzi Sud Tal. Crag and tail is a com- earth pillars. The fresh moraine is dark gray, mon feature of which there are many fine exam- but weathering of the ferruginous minerals ples. alters this to a paler brown. The progressive colonization of the younger RELATIONSHIPS BETWEEN moraines by plants has not been studied in VOLCANIC ACTIVITY AND ICE detail, but in general plants are absent or in- COVER conspicuous, whereas on the older moraines The main volcanic activity of Kilimanjaro Euryofs, Hehchrysum, and Protea grow pro- during and after the Pleistocene was concen- fusely at suitable altitudes. trated at Kibo, and it is here that it is most Moraines fail to occur in some areas where necessary to consider the possible effects of they might be expected. One notable instance volcanicity on the glacial carapace. is in the Great Barranco of Mawenzi where no There is considerable evidence indicating moraine has been found above 9000 feet. Its that for long periods during the Pleistocene absence here, however, is readily attributable and afterward the ice cover of Kibo was either to subsequent erosion. absent or greatly reduced and that much of the There is also an absence of well-defined termi- volcanic activity took place during such periods. nal moraine all along the flanks of the Saddle The absence of ice may be attributed to melting both on the north and south slopes. Here the by the great masses of lava that were erupted outer limit reached by the ice could not be or to the existence of a true interglacial period. definitely determined; although many low It would, however, be a surprising coincidence mounds and sheets of sand and gravel, some- if the volcanic activity invariably took place times with boulders, occur, it is not possible during interglacial periods, and evidence was to separate glacial and fluvioglacial deposits, sought to determine the conditions prevailing and the boundaries of the deposits are very at the top of the mountain when the various indefinite. This is attributed to the absence of volcanic episodes began. valleys deep enough to confine the ice which Numerous accounts provide evidence as to therefore spread out as a sheet, depositing its what might be expected in the event of erup- moraine more thinly and haphazardly over a tion beginning while the ice carapace was wider area than was the case with the valley present. Attention is directed to the work of glaciers. Peacock (1926), Nielsen (1937), and Thorarins- Well-defined terminal moraines are also ab- son and others (1959) in Iceland, Fuller (1951) sent below the Machame Escarpment. This in the Columbia River Plateau, Robinson erosional escarpment with its discontinuous (1948) in the Aleutian Islands, Mathews (1947; line of cliffs 250 feet high existed during the 1952a; 1952b; 1958) in British Columbia, and Fourth Glaciation when the valley glaciers in Whymper (1892, p. 125-127) in the Andes. the Lagerbach and Bastionsbach valleys reached From these accounts it is evident that if its edge and passed over. Below the cliffs patches lavas were extruded while there was still an of morainelike deposits occur, but they do not extensive cover of ice, then the following fea- fit into a pattern, and it is thought that the ice tures might be expected to be found: (a) ex- re-formed below the cliffs as a thin sheet excessive chilling of the lavas; (b) explosive con- tending for a short, but indeterminate, dis- tact of the lava and ice producing widespread, tance from their foot. but thin, pyroclastic deposits, including palago- No terminal moraines have been found to nite breccia or glassy vesicular cinder, below mark the limit of the ice that formed the the basal lavas of the group; (c) torrential glacial pavement below the foot of the Main deposits produced by melt water; and (d)

deflection of flows due to encountering ice FIRST INTERGLACIAL PERIOD: The absence of barriers. The presence of glacial or fluvio- agglomerate, breccia, tuff, or signs of excessive glacial deposits beneath the lavas would also chilling at the base of the Lavaturm Phonolite be expected, but this in itself would not mean Series suggests that they flowed out when that ice was still present. little or no ice was present. More positive On the other hand, if renewed volcanic ac- evidence, however, is found at the top of the tivity began while there was little or no ice at series which is deeply weathered and overlain the summit, the lower contacts would be ex- by the nonglacial Amphitheatre Sediments at pected to be normal, without excessive chilling, 11,000-14,500 feet. or thin widespread tuffs; underlying moraines Lavas of the Lower and Upper Rectangle and glaciated pavements might be absent. In- Porphyry and the Upper Trachybasalt Series stead one may find alluvial deposits and boles followed without any prolonged break, and beneath and among the lavas of the group but nowhere is there any sign of ice cover during within the limits of maximum ice cover. the period. Considerable erosion did occur, Evidence for interglacial periods on Kibo however, before the succeeding Penck and depends on the presence of beds of alluvial Main Rhomb Porphyry Series were formed, origin and lava groups without abnormal and there is evidence that this may possibly features occurring within the limits of maxi- have been in part accomplished by the ice. mum ice cover and between successive deposits SECOND GLACIATION: There is considerable of till. On Mawenzi their recognition depends evidence for the existence of this glaciation, on the morphological evidence for the retreat but there is some doubt about whether it and advance indicated by the moraines, on began before or after the Main Rhomb the presence of older and younger glacial Porphyry Series. Two pieces of evidence deposits, and on the occurrence of sands be- point to the possibility of the earlier date. tween the moraines. On Shira no evidence has The first is the presence of lahar deposits been found for an interglacial period. beneath the Main Rhomb Porphyries in the Garanga Tal at 2700 feet, near the foot of the SEQUENCE OF GLACIATIONS mountain. These may have been formed by ON KIBO the melting of large masses of ice. The second The climatically controlled sequence of is the occurrence of glassy lava rolls or pillows glacial and interglacial periods on Kibo is at the base of the Penck Rhomb Porphyries interspersed with the various lava series pro- in valleys cut into the Upper Rectangle duced by episodes of volcanic eruption. The Porphyry Series on the west side of Kibo at succession of events that can be established is about 15,000 feet. These valleys appear to discussed in chronological order. have a U-shaped cross section, but there is no FIRST GLACIATION: The oldest known till is other evidence to show whether they were cut exposed in the Kibo Barranco at 13,500 feet by ice or river erosion. where it rests on the eroded surface of the However, if it is doubtful whether this Lower Kibo Trachybasalt Series (Table 1) and glaciation began before or after the Main is overlain by the Lavaturm Phonolites. Rhomb Porphyry Series, it certainly lasted This boulder bed closely resembles the kind well beyond the completion of this volcanic of moraine usually on Kilimanjaro, but only episode, for its lavas are deeply eroded and a few of the boulders are striated. Its maximum overlain by thick moraine deposits. thickness is about 50 feet, and all the boulders At the edge of the Machame Escarpment, are of porphyritic trachybasalts. Current- southwest of Kibo, at about 13,000 feet where bedded sands up to 4 feet thick occur at the it is crossed by the Lagerbach and Bastionsbach, base. boulder beds occur below the Main Phonolite The only other exposure of this horizon is Series (Fig. 1). At the Lagerbach they rest on in the Bastionsbach below the Lavaturm, the rhomb porphyries and the boulders are all where the position of the boulder bed is rhomb or rectangle porphyry, ranging up to 3 occupied by a thin weathered band at the feet in size. They are exposed in the cross top of the trachybasalts. section of a lateral moraine 110 feet high, Since exposures are restricted to two locali- which separates valleys with bare rhomb- ties, little can be said about this glaciation porphyry floors down which the phonolite other than that the ice extended below 13,500 flowed. Irregular patches of sand occur within feet. the moraine.

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Credner Glacier leading down into the upper Lent Tal is in the center. The cliff (upper right) is the Breschenwand on the east side of Kibo Barranco; Uhuru Peak (the highest point in Africa) lies near its top. Mawenzi is visible in the left across the Saddle.

KIBO PEAK, MOUNT KILIMANJARO, FROM THE NORTHWEST

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Period Shira Kibo Mawenzi Terminology Retreat to present position Recent retreat Fresh moraines 300-1300 Scree formation Recent moraines feet below present snouts. In two main, and four f lib subphases. Saddle outwash Phases -i and upper valley outwash Post- Interglacial phase possible Pleistocene Small moraines about Small moraines 1100 feet below highest 3000 feet below Little Glaciation moraines summit Interglacial phase, Inner Crater Phonolite Series formed Stadial moraines, large Stadial moraines, large well-preserved moraines well-preserved moraines. Fourth (Main) showing evidence of two Average height 11,900 Glaciation: at phases. Average height feet least two phases 12,100 feet Interglacial phase, Interglacial phase, Main parasitic cones Main parasitic cones formed formed Short Very large extensive Very large extensive valley ice sheets with no ice sheets with no glaciers prominent terminal moraines prominent terminal on outer preserved; maximum moraines; maximum slopes known ice extent known ice extent Third Glaciation Nepheline Rhomb Porphyry Series contemporaneous with later stages Interglacial Small-Rhomb Pleistocene Porphyry Series formed Main Phonolite Series formed Garanga Tal old outwash, glacial deposits below flows, Second moraines at Machame Glaciation Escarpment Main Rhomb Porphyry Series formed ? Interglacial Penck Rhomb Porphyry Series formed Upper Rectangle Porphyry Series formed Upper Trachybasalt Series formed Interglacial Amphitheatre Sediments Lavaturm Phonolite Series formed Glacial deposits in First Glaciation Lower Barranco Lower Trachybasalt Series formed Mawenzi Trachybasalt Series Late ppreglacial Pliocene- pearly Shira Mawenzi basalts Pleistocene basalts with intercalated and red boles trachybasalts

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I4OOO ' LAGERBACH BASTIONSBACH RHOMB PORPHYRY I3OOO_ feet PHONOLITE TRACHYBASALT ile MORAINE Figure 1. Cross section along the Machame Escarpment, southwest of Kibo Peak, Mount Kilimanjaro, showing the relationships between the moraines and the lava series

The Bastionsbach crosses the escarpment 1 but these are now known to be the Main mile to the east, and here a similar boulder bed Phonolite Series above and the Main Rhomb rests on the Upper Trachybasalt Series (Fig. Porphyry Series below. Elsewhere on the 2). This also seems to be the cross section of a mountain exposures of the base of the Main lateral moraine exceeding 20 feet in height Phonolite Series show it resting on an erosion with up to 15 feet of current-bedded sand at surface with no intervening sediment. the base. The boulders are often striated and Toward the end of the Second Glaciation, mainly consist of rectangle porphyries and as the ice melted, the valleys were choked by basalt from an unknown source. Correlation thick outwash deposits. These can now be seen of the two moraines implies the prior erosion only in the Garanga and Klute Taler at 10,000- of the Main Rhomb Porphyry Series from the 13,000 feet, where they are extremely well Bastionsbach area. exposed on the valley sides. They consist of The importance of this period is further great lenses of sand, gravel, and conglomerate demonstrated by the occurrence of current- with blocks up to 15 feet across, filling to a bedded sands and gravels, apparently fluvio- depth of about 350 feet a U-shaped valley glacial, at the Galuma Caves west of Kibo at cutting obliquely across the ridge between the about 11,000 feet. Meyer (1900) first recorded Klute and Garanga Taler. The valley was cut these deposits at this site. He did not record the in the Main Rhomb Porphyry Series, and the types of lava with which they were associated, deposits are overlain by flows of the Nepheline

20 feel

PHONOLITE

0 feet

SANDS

KIBO TRACHY BASALT RIVER Figure 2. Details of the section in the Bastions- bach, southwest of Kibo Peak, Mount;Kiliman- jaro, at 13,100 feet showing the moraine of the Second Glaciation

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Rhomb Porphyry Series and are cut across by a few are striated. The agglomerate contains the glaciated troughs of the Klute and Garanga many isolated feldspar crystals and many frag- valleys. No direct contact is made with the ments of black cinder derived from nepheline Main Phonolite Series, but the age of the rhomb-porphyry lava; the matrix is of palagoni- deposits is indicated by the absence of any tic tuff. These pyroclastic rocks are widespread included pebbles of phonolite, although flows but do not occur outside the limits of glaciation. of this type are not far away. They do not show any signs of thickening SECOND INTERGLACIAL PERIOD: The OlltWash toward the summit, evidence which also points deposits herald the onset of the Second Inter- to the explosive contact of the nepheline rhomb glacial Period during which the Main Phonolite porphyry and a pre-existing ice cover. At a Series was extruded from Kibo. There are no few localities, as in the Klute Tal at 14,000 signs of explosive contacts at the base of the feet, nepheline rhomb porphyries rest directly phonolites, except locally, and although it did on the underlying lavas. It is not thought, flow between moraine ridges, the ice is thought however, that these few exceptions alter the to have already disappeared. The abundance circumstances deduced from the other evi- of obsidian at the base of the flows may indicate dence. rapid chilling, but it is a feature not confined THIRD INTERGLACIAL PERIOD: Ice later re- to the basal flows or to the upper parts of the turned in the Fourth Glaciation, and its effects mountain. are readily visible all around the summit area. The Small-Rhomb Porphyry Series that Evidence for an intervening interglacial period, followed is separated from the Main Phonolite however, is not at all obvious and depends on Series in the Sud Ost Tal by a small lens of evidence associated with the parasitic Saddle boulder-bearing gravel at 15,000 feet. There cones. is little evidence, however, to show under what Beneath the Camelrucken on the west side conditions it was formed. of Mawenzi at 15,000 feet there is a tillite During this interglacial period there was overlain by parasitic ankaramite lava. These much erosion on the flanks, and a new caldera lavas are slightly younger than the nepheline formed on the summit. rhomb porphyries, and the tillite therefore THIRD GLACIATION: During the period that must belong to the Third Glaciation. Immedi- followed, when ice covered the summit down ately to the north of the Camelrucken is a to relatively low levels, the Nepheline Rhomb field of nonporphyritic ankaramite of a slightly Porphyry Series was erupted. This series in- later date, whose lavas abut against lateral variably rests on an erosion surface and trans- moraines without showing any signs of ab- gresses markedly over flows of the older series. normal chilling, explosive contacts, or peculiar At its base, below the lowest lava flow, there is structures other than the incorporation of a a bed of tuff and agglomerate, beneath which few boulders from the moraines in the noses of a boulder bed is frequently found. The follow- the flows. Both the lava field and the Camel- ing succession was measured on the west side rucken have been eroded by the ice of the of the Sud Ost Tal at 13,000 feet: Fourth Glaciation, and it is therefore clear that there was an interval between the Third Nepheline rhomb-porphyry lava and Fourth Glaciations when ice was absent. Orange-brown palagonitic agglomerate During this period the parasitic activity at the and bed of black highly vesicular Camelrucken took place, the lavas flowing glassy cinders 2-5 feet down valleys from which the ice had melted. Yellow current-bedded sand 0-3 feet During this period there were extensive Boulder bed 20 feet changes in the topography of Kibo, the most Phonolite lavas notable being the Barranco landslips which formed the Kibo lahar field at the foot of the Similar successions are known in the Oehler mountain. Tal and Lent Tal. Beneath some of the Saddle FOURTH (MAIN) GLACIATION: This glacial cones, in the Lagerbach Tal, and at the top period has left abundant evidence of its passage of the Kibo Barranco the boulder bed and over all the upper part of the mountain, and sands are absent, but the characteristic ag- at no subsequent time did the ice descend so glomerate and tuff occurs. far. It resulted in the formation or at least the The boulders, up to 2 feet in size, were de- final form of the great moraines at 11,000- rived from several of the older lava series; only 14,000 feet and the mass of other glacial

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phenomena. At present it is only intended to establish its position in the sequence. SEQUENCE OF GLACIATIONS The maximum of the Main Glaciation oc- ON MAWENZI curred before the Inner Crater Phonolite There is an abundance of glacial phenomena Series, for the great moraines in the Barranco on Mawenzi, most of which can be attributed include no fragments of this distinctive aegirine confidently to Main Glaciation. There are, phonolite. This period is the last of the major however, a number of anomalies attributed to glaciations. the earlier, and greater, Third Glaciation. FOURTH INTERGLACIAL PERIOD: Only one Evidence for this earlier glaciation occurs in eruptive phase, the Inner Crater Phonolite three ways: as tillites below lavas from the Series, occurred after the Main Glaciation. parasitic cones, as glaciated pavements beyond Its basal lavas show no unusual features and the terminal moraines of the Main Glaciation, rest directly on underlying lavas of various and possibly as degraded moraines beyond the types without any intervening sediment or limits of the Main moraines. tuffs, and it is concluded that at the time of West of Mawenzi at 14,500 feet current- their eruption there was little or no ice present. bedded sands and a boulder bed with striated LITTLE GLACIATION: The Inner Crater Phono- blocks rest on a glaciated surface of Mawenzi lite Series, however, has been glaciated, and in trachybasalts and are overlain by lavas from the Barranco large moraines containing numer- a parasitic vent. A few hundred yards north ous aegirine phonolite blocks extend below similar parasitic lavas have flowed against a 14,000 feet. The relative youth of these lateral moraine which controlled their direc- moraines is indicated by their being softer, tion, and in turn the lavas have picked up darker, less-vegetated, and sharper in profile boulders from the moraine. Southwest of than those of the Main Glaciation. Similar Mawenzi, on the west side of the Drei Konigs moraines occur inside the limits of the Main Tal at 10,500 feet, a deposit of sand and gravel, moraines in other valleys on Kibo proving the probably fluvioglacial in origin, occurs under- re-establishment of the ice cap and its expansion neath lavas from parasitic vents and on top of to well below its present level, but not so far Mawenzi trachybasalts. as in the Main Glaciation. Since the Main Parasitic Group to which RECENT GLACIATION: Since the formation of these lavas belong is older than the Main the moraines of the Little Glaciation, only one Glaciation, the glacial deposits that underlie important episode can be recognized in the them must belong to an earlier episode. glacial history of Kibo. Further evidence of the earlier glaciation is A short distance below the snouts of the given by the ice-scratched pavement below the present glaciers well-preserved moraines can terminal moraines of the Main Glaciation south be seen all around the summit of Kibo, indi- of Mawenzi. This pavement, at 11,050 feet, cating a prolonged period when the ice front lies about 300 yards below the toe of the Main fluctuated about a position a little way below moraine. Beyond it occur only spreads of its present limits. That the ice began to retreat fluvioglacial outwash with occasional low from these positions only about 200 years ago mounds at a height of about 10,700 feet; these is shown by photographs and drawings made may be the relics of an old terminal moraine. during Meyer's expeditions at the end of the Comparable evidence is provided by Meyer's last century (Meyer, 1900). The extreme youth record of striations on the north slopes of the of these moraines is also shown by their com- Saddle at 11,300 feet. This is about 2000 feet plete lack of vegetation, their sharp uneroded below the level reached by the Main Glaciation crests, their dark unoxidized appearance, and on this part of the mountain, and, as on the their soft unindurated nature. south side, no recognizable moraines occur in No evidence has been found to tell if the the neighborhood. Unfortunately the existence Recent Glaciation marks a pause in the retreat of these striations could not be confirmed, and of the ice from the Little Glaciation maximum little time was available for a thorough search or a readvance following an interglacial period. of the area. Since the retreat began from the Recent There is therefore abundant evidence on moraines, however, it has been continuous and Mawenzi for the Main Glaciation and for the may lead to the complete disappearance of ice earlier Third Glaciation, but of the still earlier from Kilimanjaro within a century (Humph- glaciations no trace is recognizable. It is, how- ries, 1959). ever, clear that volcanic activity ceased on

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Mawenzi before the onset of glacial conditions, patches of ice but no true glaciers. At the for there is no trace of glacial deposits among maximum, ice covered about 150 sq mi, form- the rocks of the summit, and any sediments ing continuous carapaces over the two higher that have been found are indicative of warmer, summits and obscuring the rocks down to moister conditions. about 14,500 feet. Below this level ridges of There is also some evidence of younger rock and moraine began to appear, and at glaciations. In nearly all the valleys there are 14,000-11,500 feet the glaciers began to sepa- mounds of moraine on the floors and frequently rate into isolated tongues which terminated at distinct lateral and terminal moraines within 13.700-9000 feet. those of the Main Glaciation. In the Lavahugel The radial pattern of the glaciers was broken Valley there are four sets which can be corre- on the Saddle where the glaciers from Kibo lated with moraines in some other valleys, and and Mawenzi met head on and deflected each there is evidence of an interrupted retreat from other down the flanks of the Saddle to north the last maximum of the Main Glaciation. and south. Those from Kibo were the more Small moraines higher in the valleys may powerful (PI. 3). represent the Little Glaciation, but there is no evidence for the presence of ice on Mawenzi Main Glaciation on Kibo during the Recent Glaciation of Kibo, except On Kibo the Main Glaciation left enormous perhaps as small pockets and sheets in the high, moraines on the south and west sides, but on shaded cirques. the north and east, although the moraines are still large, they are smaller, less definite in SEQUENCE OF GLACIATIONS pattern, and in places difficult to locate. This ON SHIRA applies especially on the east side where they On Shira the little evidence remaining of are all but completely obscured by the outwash any glaciation is entirely subsequent to the deposits on the Saddle. volcano becoming extinct. The lowest limits reached by the ice (Table On the south and west slopes the heads of 2) are on the south slopes, and here the glaci- the valleys at 12,000-13,000 feet are cirquelike ated valleys are both longer and deeper than and in places distinctly U-shaped. Thick de- on the north side; some on the south side reach posits of sand and boulder beds occur on the 5 miles in length and 700 feet in depth. This floors of some of them at 10,500-11,000 feet, shows that a much greater quantity of ice was generally with no clear form. In contrast to present on the south side of the mountain, and the well-formed ridges of the Main Glaciation when east is compared with west, it is clear elsewhere, these are rounded and indefinite, that the north and east sides of Kibo were to and for this reason they are thought more some extent sheltered from precipitation at likely to belong to the Third Glaciation. If the this time, just as they are today. Main Glaciation affected Shira at all, it formed In detail the form of the glaciers and the only small patches of ice at the very heads of moraines that they left varies from valley to the valleys. valley. The Sud Ost Tal at one time was The small size of the glaciers during the occupied by a glacier system that embraced Third Glaciation and their absence during the the valleys on either side. At this stage the Main Glaciation is due to the lesser height of glacier was more than 3 miles wide and bounded this volcano. At 13,000 feet it barely reaches by two large moraines that converge at 11,800 the height required for glaciers to form at this feet. This stage was followed by a retreat and latitude, even in extreme climatic conditions. read vance when the glacier was split into three, one in the Sud Ost Tal and one in the valleys FOURTH (MAIN) GLACIATION on either side. The Garanga Tal is remarkable for the per- General Statement fection of its glacial features, having at its Whereas evidence for the earlier glaciations head a fine giant step and being flanked by is too patchy and inadequate to form an over- smooth bare rock walls. The adjacent Klute all picture of the mountain during these Tal is in contrast a wide-open shallow valley periods, traces of the Main Glaciation are floored by bare rock and subdivided by numer- obvious everywhere. ous crags. The rocks are ice-scratched, but Kibo and Mawenzi formed the only two above about 12,500 feet there is little morainic centers of ice dispersal, Shira at this time having debris. Below this level, however, the valley

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TABLE 2. ALTITUDES OF MORAINES ON MOUNT KILIMANJARO, NORTHEAST TANGANYIKA Main Glaciation Little Recent Ice front Valley Terminal Stadial Glaciation Glaciation moraines moraines South Kibo Sud Ost Tal 11,950 12,200-12,800 15,100 16,600 18,000 Garanga Tal 11,200 12,000 ?13,500 14,800 16,000 Klute Tal 10,300 14,600 15,400 Southwest Kibo Barranco ?9,000 13,300 13,600 14,800 West Kibo Bastionsbach -12,800 12,900 13,700 15,200 15,600 Lagerbach -12,800 Oehler Tal ?12,500 15,600 16,100 Lent Tal 12,400 12,600 15,800 16,600 North Lent Tal 12,500 12,700 North Kibo North Slopes ca 13,000 13,800 14,800 17,000 18,400 East Kibo East Slopes 17,200 18,400 Southeast Mawenzi Drei Konigs Tal 10,900 ?12,600 South Mawenzi 1st Sud Tal 11,300 11,700-12,500 3rd Sud Tal 11,600 11,800 13,200 Forster Tal 11,700 11,900 Dreispitzen Tal 11,800 Egg Valley 11,800 12,000-12,700 Peters Hut Valley -12,100 ca. 12,500 Lavahugel Valley -13,000 13,000-13,500 North Mawenzi North Saddle Valley -13,300 13,300-14,000 North West Valley 11,600 12,900 See Tal 11,000 Little Barranco ?9,000 Great Barranco ?8,300 East Mawenzi Liebert Tal 12,000 Neumann Tal 11,800 Zwischen Tal 11,800

begins to deepen and narrow, and lateral mountain. The moraines of the Bastionsbach moraines develop at the sides terminating at and Lagerbach valleys are truncated by the 10,300 feet. recession of the Machame Escarpment, and it In Kibo Barranco the glacier was diverted by is difficult to be certain how far below 13,000 a rock barrier across the valley at about 13,000 feet the ice descended. Two phases at least can feet. A great moraine sweeps in an arc across be recognized in the Bastionsbach Valley. the valley to the head of the Umbwe gorge. West of Kibo there is no clear evidence of Beyond this point all evidence to show how two distinct phases in the Main Glaciation, far down the ice penetrated has been lost. although the terminal part of the Lent Tal Cross-cutting moraines indicate the presence moraine shows signs of several fluctuations in of at least two phases in the Main Glaciation. the ice front. The core of indurated moraine Beyond the Barranco is west Kibo where exposed near the head of the Lagerbach Valley the large glaciers occupied the Bastionsbach, and eroded into innumerable earth pillars may Lagerbach, Oehler, Lent, and North Lent represent an earlier phase of glaciation, but valleys, all of which are typically U-shaped and there is no evidence to support this. flanked by some of the largest moraines on the Along the north side of Kibo the moraines

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are smaller, less distinct, and do not descend deposited recognizable terminal moraines, and as far as those on the south. This is particularly it is uncertain how far their ice extended. true on the northeast slopes where the valleys The See Tal north of Mawenzi resembles the are very shallow, seldom exceeding 300 feet; Klute Tal of Kibo, the upper part being a there are few distinct lateral moraines to indi- wide-open, rock-floored valley which narrows cate that the ice was in the form of separate and deepens rapidly at about 13,000 feet to valley glaciers. continue between high and closely spaced East of Kibo also there is a similar absence of moraines down to 11,000 feet. East of this distinct lateral moraines, and the ice probably valley lie the Barrancoes, similar to each other formed a continuous sheet deflected onto the in form, but the eastern much larger and slopes north and south of the Saddle by the deeper. Little evidence of glaciation remains in Mawenzi glaciers. There it spread out as broad either due to the intense river erosion, but it is sheets, leaving behind low mounds of moraine certain that they contained the largest glaciers which can be traced down to about 13,000 feet on Kilimanjaro, whose limits are marked by on the north side and on the south side to about moraines in the forest at about 8000-9000 feet. 12,000 feet. On east Mawenzi the glaciers were small, having been starved by the great glacier in the Main Glaciation on Mawenzi Barranco at their heads. They formed short The lowest limits reached by the ice on broad glaciers with coalescing moraines. Mawenzi are given in Table 2. The pattern is less regular than on Kibo, and the heights LITTLE GLACIATION reached on different sides of the mountain are The relationships between the moraines and more uniform. The lowest points reached do the lavas of the Inner Crater Phonolite Series not as accurately reflect the climatic control in the Kibo Barranco show that an interglacial as they do on Kibo, where the topography was period separated the Main Glaciation and the much less mature and the climatic shadow much Little Glaciation. It is only at this locality that greater. However, with the exception of the such evidence is available, for on the north and Barranco glaciers, the thickness of the glaciers east flanks of Kibo, where the Inner Crater on the northern slopes was notably less than Phonolite Series lavas also occur, the poorly on the south. developed moraines, the cover of recent out- At the maximum of the Main Glaciation, wash, and a lack of detailed observations of the ice completely covered the summit down to boulders in the moraines makes their use in about 14,500 feet, except for a few small separating the moraines impracticable. nunataks. At about this level ridges of moraine The lateral moraines of the Little Glaciation appeared, and the glaciers separated into in the Barranco and Bastionsbach Valley can isolated tongues. A number of these glaciers be identified by the contained blocks of Inner were about 3 miles long and that in the Great Crater phonolite and are traceable down to Barranco reached 5 miles. 13,700 feet. On the southern slopes the valleys resemble Moraines bearing a similar relationship to those on the same side of Kibo and are flanked those of the Main Glaciation occur in some by well-preserved moraines. The valleys farther other valleys (Table 2; PI. 3) and are correlated west, however, have no terminal moraines, the with those in the Barranco. They have not been ice front here having apparently spread out on recognized in every valley, and even where the hillside leaving behind only irregular present they are often fragmentary or of doubt- patches of moraine and striae. Deep gorges ful status. through some of the terminal moraines expose On Mawenzi moraines attributed to the sections of moraine 100-200 feet thick which Little Glaciation have been found only in a include large wedges of interbedded fluvio- few places high on the mountain. They cannot glacial sands. At least two phases of the Main objectively be distinguished from the stadial Glaciation can be recognized here and a number moraines of the glaciers of the Main Glaciation, of retreat stadia. and in the Lavahugel Valley, where four West of Mawenzi the glaciers were deflected distinct sets are visible, positive separation is north and south by those coming from Kibo. impossible. From the pattern they make at least two phases These moraines show that the glaciers of the can be recognized in the Main Glaciation and Little Glaciation stopped about 1000 feet above several retreat stadia. None of these glaciers those of the Main Glaciation and that the Little

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Glaciation was of shorter duration than the powerful, these moraines are largest. From the Main Glaciation, producing smaller and less head of the Garanga Tal around the west continuous moraines. These are the youngest side to the Lent Tal they are extremely large. moraines known on Mawenzi. Whereas on the north and east sides they occur higher up the slopes and are often indistinct. RECENT GLACIATION Clearly the present pattern of glaciation was Surrounding the present-day ice on Kibo is inherited with little change from this relatively a set of very fresh moraines forming an almost stable ice cap. complete girdle. Each tongue of the present- The ice retreating from the Little Glaciation day ice has a corresponding lobate moraine on Mawenzi disappeared completely, and if it

TABLE 3. COMPARISON OF THE SEQUENCE OF GLACIATIONS ON MOUNT KILIMANJARO WITH OTHER PLEISTOCENE SEQUENCES

Period Pluvial periods Glaciations of Kilimanjaro Alpine glaciations Retreat to present position Nakuran Recent Glaciation (2 phases) ends ca. 200 years B.P. Post-Pleistocene Possible deglaciation Makalian Little Glaciation Interglacial Late Pleistocene Gamblian (2 phases) Fourth (Main) Glaciation( +2 phases) Wurm (3 phases) Interglacial Kanjeran Third Glaciation Riss Middle Pleistocene Interglacial Kasmasian Second Glaciation Mindel Early Pleistocene Interglacial Kageran First Glaciation Gunz Late Pliocene ?preglacial

farther down (PI. 3). The edge of the present returned at all during the Recent Glaciation. ice lies 200-1200 feet above the inner edge of it formed only small patches in the upper these moraines; it is closest where the glaciers cirques. are still active on south and west Kibo and most distant where the ice is "dead," as on COMPARISONS AND CONCLUSIONS north and east Kibo. Nilsson, during his stay in East Africa, visited Comparison of the present ice front with Elgon, Kenya, and Ruwenzori as well as Kili- that when the summit was first visited in the manjaro and suggested correlations among the 1880's shows that the ice has retreated rapidly, moraines of all four mountains and with the and backward extrapolation indicates that the pluvial periods. These were divided as far as valleys would have been occupied by ice up to possible into groups numbered I to VII. On the Recent moraines about 200 years ago. Kilimanjaro groups I, II, and III correspond These moraines are not simple but in nearly to the Main Glaciation, group IV to the Little every instance show two separate ridges 100- Glaciation, and groups V to VII to the Recent 200 yards apart; in some cases four distinct Glaciation. Among the pluvial periods, I to III sets can be distinguished. The several elements were phases of the Gamblian, IV the Makalian, in these complex moraines are, however, very and V to VII phases of the Nakuran. This similar in all respects and clearly belong to the correlation, if accepted, implies that the Main same glacial phase indicating a brief but rapid Glaciation belongs to the Gamblian and is recession between two prolonged stadia. Pleistocene, whereas the Little Glaciation is Where the present-day glaciers are more Makalian and post-Pleistocene.

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The moraines of Mt. Kenya have recently the dangers in oversimplifying correlation in been re-examined by B. H. Baker (1959; 1961, the Pleistocene of Africa and has shown what a personal communications) who has found a flimsy basis some of the pluvial periods rest on, series of moraines divisible into several groups, it is nevertheless tempting to compare the The succession appears to be very similar to sequence of glacial and pluvial periods in the that found on Kilimanjaro, and equivalents to area (Table 3).1 The sequence of pluvial periods the Main, Little, and Recent Glaciations can is taken from Leakey (1948) and that of the readily be discerned in his sequence. The glacial periods from Zeuner (1959). There is a moraines thought to be equivalent to the Main striking similarity, which does not, however, Glaciation of Kilimanjaro are suggested by validate their correlation. It was hoped that him to be equivalent to the Wiirm Glaciation the lavas of Kilimanjaro would provide a firmer of the Alps. This also implies that the Little link between the pluvial and glacial episodes, Glaciation is post-Pleistocene. but unfortunately the succession in the Am- There is no impediment to conforming with boseli and Pangani lacustrine basins is inade- the correlations implied above by placing the quately known. top of the Pleistocene at the end of the Main —; Glaciation, for a distinct break occurs between 1^to{- G' H' c»nis of the University of California made d CWe det tlons ( A e ag f a spec the Main and Little Glaciation... .s as i.s show. ,n... b'y men o™f obsidia™ n( from~ the Mam° Phonoht. e" Serie° s sen"t to the presence of lavas at this horizon in the Kibo hlm by the author Jt is yery dose to mooo yeafs o,dj Barranco, and it is here that the division has indicating that it erupted near the beginning of the been made on Kilimanjaro. Great Interglacial Period (Zeuner, 1959, p. 213) which Although Flint (1959) pointed out some of confirms the interpretations given in the paper.

REFERENCES CITED Downie, C., Humphries, D. W., Wilcockson, W. H., and Wilkinson, P., 1956, Geology of Kilimanjaro: Nature, v. 178, p. 828-830 Flint, R. F., 1959, On the basis of Pleistocene correlation in East Africa: Geol. Mag., v. 96, pt. 4, p. 265- 284 Fuller, R. E., 1931, Aqueous chilling of basaltic lava on the Columbia River Plateau: Am. Jour. Sci., v. 221, p. 281-300 Humphries, D. W., 1959, Preliminary notes on the glaciology of Kilimanjaro: Jour. Glaciology, v. 3, p. 475-478 Jaeger, F., 1909, Forschungen in den Hochregionen des Kilimandscharo: Mitt. Deutsche Schutzgebiet., v. 22, pt. 2, p. 113-146, 161-197 Klute, F., 1920, Ergebnisse der Forschungen am Kilimandscharo 1912: Berlin, Dietrich Reimer, 436 p. Leakey, L. S. B., 1948, The lower limit of the Pleistocene in Africa: London, 18th Internal. Geol. Cong. Proc., pt. 9, p. 62-65 Mathews, W. H., 1947, "Tuyas," flat-topped volcanoes in northern British Columbia: Am. Jour. Sci., v. 245, p. 560-570 1952a, Ice-dammed lavas from Clinker Mountain, southwestern British Columbia: Am. Jour. Sci., v. 250, p. 553-565 1952b, Mount Garibaldi, a supraglacial Pleistocene volcano in southwestern British Columbia: Am. Jour. Sci., v. 250, p. 81-103 1958, Geology of the Mount Garibaldi map-area, southwestern British Columbia, Canada: Geol. Soc. America Bull., v. 69, p. 179-198 Meyer, H., 1900, Der Kilimandjaro: Berlin, Dietrich Reimer, 436 p. Nielsen, N., 1937, A volcano under an ice-cap; Vatnajokull, Iceland, 1934-6: Geog. Jour., v. 90, p. 6-23 Nilsson, E., 1932, Quaternary glaciations and pluvial lakes in British East Africa: Geog. Annaler v 13 pt. 4, p. 249-349 Peacock, M. A., 1926, The geology of Videy, S.W. Iceland: a record of igneous action in glacial times: Royal Soc. Edinburgh Trans., v. 54, p. 441-465 Robinson, G. D., 1948, Exploring Aleutian volcanoes: Natl. Geog. Mag., v. 94, p. 509-528 Thorarinsson, S., Einarsson, T., and Kjartansson, G., 1959, On the geology and geomorphologv of Iceland: Geog. Annaler, v. 41, p. 135-169

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Whymper, E., 1892, Travels amongst the Great Andes of the Equator: London, John Murray, 456 p. Wilcockson, W. H., 1956, Preliminary notes on the geology of Kilimanjaro: Geol. Mag., v. 93, p. 218-228 Zeuner, F. E., 1959, The Pleistocene period: London, Hutchinson, 447 p.

MANUSCRIPT RECEIVED BY THE SOCIETY, OCTOBER 31, 1961

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MORAINES OF MOUNT KILIMANJARO, NORTHEAST TANGANYIKA

DOWNIE, PLATE 3 Geological Society of America Bulletin, volume 75

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