Archeological sites of hipparion’s fauna on Irtysh

Another expedition of the Osteological Department of the museum, which worked under the command of M.G. Prokhorov in the summer of 1929, turned out to be very interesting andsuccessful. This time, excavations were carried out on the Irtysh, near the city of Pavlodar, wherein 1928, as a resultof severalyears of searching, the hipparion’s faunawas discoveredfor the first time in Siberia. The wide scope of the work and the amazingabundance of material thatwas extracted by the expedition give theseworks exceptionalinterest and be entitled to the attention of not only paleontologists,but to a certainextent of all naturelovers in general. On this account, the QazaqstanTarihy portal considers it appropriate to give a briefdescription of the work of the expedition itself, which, in addition to conducting excavationsin Pavlodar,also managed to conduct reconnaissance work andmake smallcollections of fossil mammalsfrom newlocations. But the maintask of the expedition wasprecisely the excavation of the Pavlodar location.However, before proceedingto the description of these works, it is necessary to briefly dwellon the geological structure of the coast itself, in the outcrop of which thefauna wasfound.

The highright bank of the Irtysh near Pavlodarwas composed of loose rocks and shale and therefore was strongly eroded by the Irtysh. Whenexamining this coast, attention was involuntarily drawn toan outcropsomewhat downriver from the so-called GooseFlight, near the telegraphline crossing the Irtysh. Counting from top to bottom,we findhere (Fig.1):

1) yellowthin-layered sand, upto 1m thick; 

2) a layer of buried soil, about1 m;

3) yellowish-brown sand, in the upper horizonswith calcareousspots, about 2m.

Fig. 1. The right bank of the Irtysh near the GooseFlight in Pavlodar.

This sandy stratum wasvery typical for the right bank of the Irtyshin the Pavlodar region,where itusually contained scatteredremains of post-tertiary mammals.About the Goose Flight, she leanedon a blurreduneven surface of variegatedclay, which already belongedto the underlying, moreancient clay-sandy formation,in which it is possible to distinguish (Fig.1):

4) variegatedclays, reddish withgreen andblue spotsin the upper half(a), andin the lower (b)part reaching the point of a very dense,light graymarl, about2.5 m;

5) gray, highly sandyloam, turninginto heavilycemented sand at the bottom,1.5 m;

6) yellowand brownsands withcomplex layering, sometimesstrongly micaceous, up to 8 m

This secondclay-sandy stratum, containing the fauna of hipparion, is underlain by marly lightgray clay of indeterminate thickness (up to 2 mabove water),attributed here presumablyto the Paleogene. Layers4b and5 (sometimeslying lenticularly)turned out to be here, forabout 100m, containing a huge number of bones that stood out against the background of the sands with their whitecolor. The excavation wascarried out in the place of the largest accumulation of these bones,next to a small experimental excavation by P.I. Preobrazhenskyand Yu.A. Orlov. The vertical thickness of the bone-bearing horizon turned out to reach 3.5m here. It should be noted thatscattered remains of thesame faunafall out of the shoreboth downstreamand upstreamof the Irtysh fromthe excavation site, with a total complexityof almost a kilometer. Finally, the remains of thisfauna arein the sands, 1.5km from the Goose Flight downthe Irtysh. A significant number of bonesand teethlying along the shore prompted M.G.Prokhorov to set up an experimental excavation inthis place.However, it turned out that the fauna located in here is in a secondary occurrence,in the sands, which apparently have a Quaternary age. Therefore, all attentionwas subsequentlypaid to the excavation onGoose Flight.Initially, it was supposed towork in such a waythat, having reached the bone-bearing horizon, a20x15 marea would be exposed onit. However, the extension of the bone-bearing formation awayfrom the Irtysh, deep into the coast, was not known.Therefore, in order not to risk time andmoney, it was decided to change the work plan,reducing the excavation inwidth to8 mand increasing,instead, its lengthalong the coast to26 m. On June 3, the dumping of sands lying above the bone horizon began, and on June 23, the workreached the bone-bearing layer, onwhich a 26x8 m area wascleared.

At this time, the expeditionalmost suffered a catastrophe:during the measurement of the work, just beforethe start of the dismantling of the bone-bearing layer, the head of the expedition, M.G. Prokhorov, fell from a crumbling steepof a greatheight onto rock-hard clay.However, everything turned out relativelywell, and on June 26, theextraction of bones was started. The work was greatly hampered by the wind, whichoften blewall hours, moreover withterrible force, andliterally covered with clouds of sandpeople and extractedbones. This unfortunatecircumstance sometimes forcedeven localworkers accustomed tothis "Pavlodarrain" to stop working.Only the swifts were notdiscouraged, not only having managed to arrange a lot of nests in the cliffabove the excavated areasduring this time,but also having begun to hatchchicks.

The participants of the expedition watched the progress of the first collection work with intense attention.Alas, they did not bode well. The dense, strong asflint, marl-like clay hardly yielded even to the blows of a crowbar; the work progressedvery slowly.Meanwhile, the bones turned out to be very fragile and, in anycase, muchless durablethan the surrounding rock. One would involuntarily like toapply the method of developingsuch locations of fossil vertebrates used by large American paleontologicalexpeditions, like sendinghuge blocks of rock to theMuseum in order tocompletely postpone the extraction of the bonesto a morecomfortable and calmenvironment in the preparation room. In addition, only the smaller, more durablebones of the limbs andindividual teeth turned out to be intact; all thelarge parts of the skeleton, including theskull, were invariablycrushed and splitinto smallpieces by the weight of the overlying layers.To tell the truth, the marl claywas sooverflowing with the remains of mammalsthat it literally gave the impression of rubble fromfragments of bones andteeth, but itwas justrubble... In view of the doubts that arose about the success of the excavation, M.G. Prokhorovdecided to reduce the area of the developed site, andinstead of the estimated 200square m only 80 square m of bone-bearing thickness can be disassembled, located directlyat the cliff of the shore.

However, thisdreary picture began to change quickly when, after fifteen days of painful work inmarl clay, it was finally possible to reach thelower, sandy, half of the bone-bearing layer [Fig. 1(5)]. At first, one byone scattered bones and teeth with excellent preservation began to appear,then - whole piles of individual bones, largesections of spines and,finally, whole limbs(Fig. 3)and skulls of hipparions, rhinoceroses, giraffes, etc. In places, the bones turned out to be piled up in suchnumbers and, moreover, so mixed up with each other in a chaotic mess that it was necessary to abandon anythought of disassemblingthe intertwinedlimbs firmly connected to each other by the surrounding rock in here. The work went on insuch a way thatseveral of the most experiencedworkers carefully disassembled the formation with large knives,exposing large bonesand skulls,which were immediately soaked with glue and coated with clay (Fig. 4). These impressive sized resulting "pies" (Fig. 5),as the clay dried, went up on stretchersand were taken to the barnon a cart.Countless separate teeth,phalanges and othersmall bones of the limbs, which were found literallyat everystep, were packed separatelyfrom the large bonesand sent by mail to Leningrad.

Fig. 3. A giraffe's leg, exposed by excavation

Fig. 4. Coating large bones with clay. 

Fig. 5. Clay "pies"with bones. 

The success of the excavation became soobvious that it notonly made participants forget about the failures of the first weeks, butalso involuntarilyled M.G.Prokhorov to the ideaof expanding the work. It was decided to continue the excavation downstreamof the Irtysh, along the shore, in whichnumerous bones andteeth were seen inabundance. On July 14, workers again begandumping "waste rock(layers 1-3 andlayer 4a,Fig. 1), and on July25, thedissemblance of the bone-bearing layer began on a newly cleared site,measuring 26x6 mand continuingthe samework on the original site. Thisnewly exposedsite providedno lessabundant material than the first, and moreover magnificentin itspreservation.

The expeditioncontinued its workuntil the end of August,when theyhad to be stopped due to depletion of funds. In addition to many scattered teethand smallparts of the skeleton, which filled about a hundred postal parcels, the expedition delivered over16 tons of cargo in boxes to the Geological Museum, which required a special carriagefor theirtransportation. In order tocollect all thismaterial, it was necessary to "remove" about 15,000cubic meters of sand and clayin total.

Fig. 2. General view of the excavation from the leftbank of the Irtysh.