Sole markings produced by fish bones acting as tools

A N N A L E S D E L A S O C l f i T E G E O L O G I Q U E D Ę P O L O G N E Tom (Volume) XXX — i960 Zeszyt (Fascicule) 2 Krakow 1960

STANISŁAW DŻUŁYŃSKI I ANDRZEJ SLĄCZKA

Ś

NA SPĄGU PIASKOWCÓW

(Tabl. X X V II — XXX)

Sole markings produced b y fish bones acting as tools

(PI. XXVII — XXX)

A b s t r a c t : An unusual asemblage of hieroglyphs w ith p reserved fish bones a t the d o w n -cu rren t ends of various tool-m arkings is described from th e Menilite beds (Upper-Eocene) in R udaw ka Rymanowska, C entral C arpathians.

STRESZCZENIE

Na spągowej powierzchni jednej z ławic piaskowca z w arstw m enili- towych w Rudawce Rymanowskiej zostały odnalezione liczne przykłady hieroglifów uderzeniowych i śladów toczenia kości rybich z zachowanymi kośćmi. Przynajm niej część tych kości została w ym yta przez prąd z m ułu dennego już w stanie częściowo skamieniałym. Dzięki tem u kości te, cięższe niż zwyczajnie toczone, były przez prąd zawiesinowy przy dnie.

Autorowie przypuszczają, że wiele hieroglifów uderzeniowych w drob­

noziarnistych piaskowcach krośnieńskich i menilitowych zawdzięcza swo­

je pochodzenie toczonym i wleczonym* kawałkom szkieletów rybich. Jest to jeden z zasadniczych powodów, dla których w arstw y krośnieńskie i niektóre piaskowce w w arstw ach m enilitowych m ają zespół hieroglifów uderzeniowych odmienny od zespołu w tych seriach, w których szczątki rybie są rzadsze.

INTRODUCTION

The present w riters have already called attention to the fact th at some inorganic m arkings on the undersurfaces of the Oligocene flysch sandstones m ight have originated through fish bones acting as tools,

while carried by a turbidity current. ( D ż u ł y ń s k i , S l ą c z k a 1958).

An unusual asemblage of such markings has been recently found on a joint trip w ith Mr. St. C z a r n i e c k i to the exposures of the Menilite beds in Rudawka Rymanowska 1.

The examples here discussed w ere collected from a single sandstone bed, exposed over a distance of a few meters. The most rem arkable point about this bed is the fact th a t almost every piece of its bottom surface contains a m ultitude of drag-, prod- and roll-m arkings which term inate abruptly w ith fragm entary remains of fish skeletons. The bones are commonly broken and small vertebrae are often devoid of processes. All these fish remains are very slightly attached to the bottom surface of the sandstone which otherwise is unfossiliferous.

A considerable variety of bones extends over the variety of markings produced. We have no special names for these m arkings and there is hardly any need for them.

Emphasis should be put on the fact, th at the shape and size of fish bones correspond closely to the outline of the tool-m arkings 2. This leaves any irrelevant and incidental association entirely out of question.

The findings at Rudawka Rymanowska may be of assistance in deci­

phering the nature of tools responsible for m any m arkings in the flysch sandstones.

It is w ell know n th a t the Menilite beds contain a great num ber of fossil fish (see K r a m b e r g e r 1879, R y c h l i c k i 1909, B o ś n i a c k i 1911) The black shales of this series have yielded m any fish skeletons in an excelent state of preservation. The fish fauna from the Menilite beds shows affinity to th a t from the G larner Fischschiefern in the Alps.

( B o ś n i a c k i 1911).

MARKINGS PRODUCED BY FISH VERTEBRAE!

In the previous paper the present w riters expressed the opinion th at peculiar ring-like m arkings on the soles of the Oligocene Krosno beds, resulted from rolling of fish vertebrae by turbidity currents over a soft m uddy bottom. This explanation is now confirmed by the finding of preserved fish vertebrae at the ends of such hieroglyphs. PI. XXVII fig. 1, 2.

We shall not give here a detailed description of the markings in question. Few points only will be stressed.

The ring-like impressions w ere made alternately by anterior and posterior articular surfaces (term inal faces) of vertebrae centra. In some cases the fragm entary remains of processes have left their record in form of off-shoots, extending outw ard from the walls of a ring (fig. 1

1 The p resen t w riters wish to acknow ledge w ith thanks the help .and assistance of Mr. C z a r n i e c k i in finding and collecting the specimens and m any helpful

suggestions.

2 T he te rm suggested fo r m arkings produced by objects strik in g th e bottom while carried by a cu rren t ( D ż u ł y ń s k i , S a n d e r s -in press).

PI. XXX). In other cases, the processes vere effective in producing the delicate grooves.

The up-current part of a ring is usually more elevated above the bottom surface of the sandstone bed than t h e dow n-current one. Such an asym m etry prevails w hen rolling is involved. The centrae set to saltate may leave also hoof-like impressions pointing w ith th eir convex­

ities the up-current direction. A different structure, however, appears when a centrum is made to prod the bottom w ith the border of its te r­

m inal face. The resulting structure is a prod-m ark or a series of prod- -marks or skip-m arks 1 pointing obviously w ith their crescentic edges the dow n-current direction. PL XXX fig. 2.

Different markings appear, w hen the concave sides of centrae are in continuous contact w ith the bottom. The borders of term inal faces move like wheels, leaving two parallel grooves behind. Such a mo­

vem ent is possible only w hen the processes are lacking or broken off short at the point of their beginning. In the latter case the residual rem nants of such processes or other forms on the sides of the centrae m ay leave their record in form of transverse cuts, enclosed by the parallel grooves already mentioned. Such structures can be easily repro­

duced by simple experim ents w ith fish vertebrae (fig. 4, PI. XXVIII).

A sim ilar case is afforded by th e m arkings from the Menilite beds illu­

strated by fig. 1, 2, 3 Pl. XXVIII.

It may be noted th at m uch of our ring-like m arkings exactly answer the description of the Engi-M att problem aticum from the Oligocene Fischschiefern in the Alps. This problematicum has been recently inter­

preted by P e y e r (1957) as the impressions of Salpa colonies.

PROD-AND DRAG-MARKS PRODUCEND BY FISH BONES

A great num ber of various fish bones have been found at the down- -cu rren t ends prod-and drag-m arkings. PI. XXIX fig. 1, 2. Conside­

rable variety of these m arkings m ay easily be accounted for by the variety in shape and size of fish bones. In num erous instances a conti­

nuous drag-m ark passes into a series of knobs reflecting the change in the mode of transportation from sliding to rolling.

It m ay be noted th a t some drag m arks do not rest upon a level sur­

face but undulate up and down so as to rem ind of the behaviour of jolts o r „cahots” (see V. C o r n i s h 1914) along a path of a sledge pul­

led over a snow surface. This phenomenon, bearing relation to the Helmholtz waves finds its explanation in the fact th a t a body sliding w ith a moderate speed over a soft surface, seldom remains on the same level. Even sm all irregularities may start a slight up and down motion.

This undulations should be distingushed from undulations of the bottom surfaces of sandstones which are due to the post-depositional gliding or load-casting.

1 F o r explanation of term s see D z u l y n s k i , I T s i q z k i e w i c z , K u e n e n 1959.

ZIGZAG ROLL-M ARKINGS PRODUCED BY FISH BONES (?)

PI. X X IX fig. 3 shows an interesting case of roll-m arkings w hich resemble organically produced hieroglyphs. There is however no satis­

factory evidence to bear out the idea of the organic nature of these markings. In our opinion they could only have originated through me­

chanical agencies, nam ely by rolling of objects having a triangular o u t­

line. Here again the fish bones come to mind.

GENERAL. REMARKS

The foregoing considerations have made it sufficiently clear th a t th e fish bones m ay leave their record on the soles of the flysch sandstones in form of various tool-markings. Many of these markings, w hen devoid of the bones preserved, can in no w ay be distinguished from those made by other objects such as pieces of shale or wood and fragm entary remains of shells. This pertains especially to such hieroglyphs as prod-, brush-, bounce-, drag-, and chevron-m arkings 1; These m ight or m ight not have been produced by fish bones. There are, however, markings, like the ring-m arks described, w hich are highly sugestive of fish bones acting as tools, even in cases w hen the bones have not been preserved.

In now seems quite probable th a t a great num ber of tool-markings in the Menilite and Krosno beds w ere produced by fragm entary remains of fish-skeletons.

The m ultitude of diagnostic ring-m arks, the abundance of sharp deli­

cate roll- and saltation-m arkings having a definite and recurrent geo­

m etric pattern (PI. X X X fig. 3) m ake the tool-markings assemblage of these strata differ from such assemblages in other units of the Carpa­

thian flysch. W hen it is borne in m ind th a t the Menilite beds contain very abundant fish remains, it is obvious th a t the fish bones w ere eve­

ryw here available for the turbidity currents to pick them up and bring into action as tools capable of grooving and scratching the bottom.

It seems probable, th a t m any of these bones w ere excavated from the bottom sediments by erosion of the current. This seems to be corrobo­

rated by the presence of num erous fragm ents of black shales scattered randomly, or -imbricated in clusters w ithin the sandstone beds. These fragments w ere apparently derived from the underlying shales. Many of the bones washed out from the black muds covering the bottom, m ight have been already partly fossilized and heavier th an it is the case w ith the unfossilized remains of fish skeletons. This would answer the question, w hy the bones have been found concentrated at the base of the sandstone.

The findings at Rudawka Rymanowska give also point to the ques­

1 „chevron-m arks” ( D u n b a r , R o d g e r s 1957), or „herringbone stru ctu res”

( K u e n e n 1957) a re closely spaced chevron-like m arkings. These hieroglyphs are q u ite common in th e C arpathian flysch. They w e re m ad e prolbably by an object brushing rapidly the bottom touching slightly th e surface of the plastic m ud ( D ż u ł y ń s k i , S a n d e r s — in press).

tion, w hy in so m any beds showing sim ilar assemblages of tool-m ark—

ings, the fish bones are very rare or practically absent. There appears to be no particular reason compelling us to assume some special course of diagenesis, favouring the preservation of fish bones in th a t particular bed. In seeking for an explanation of this phenomenon, attention should be directed to the fact th a t the tools brought into action by a current m ay leave innum erable m arkings before they finally come to rest.

The couple produced by the propulsive force of the current and th e resistance of the bottom ( G i l b e r t 1914), the „hydraulic lift”

(R u b e y 1938) to which the bigger particles are more susceptible than those of the sand grade, m ay prevent the perm anent deposition of bones even w hen sedim entation of th e fine sand has already begun.

A nother factor is the progressive fragm entation of the tools in the course of th eir transportation. Hence it is more likely to find m arkings produced by saltating objects than th e objects themselves.

The present discussion should not end w ithout a brief reference to th e structure of the bed w ith the bones described.

The sandstone is fine-grained. Its lower part is roughly laminated, the upper one cross-stratified on a small scale w ith incipient convolute lamination. It should be noted th at the tool-m arking assemblages sugges­

tive of fish bones acting as tools seem to be associated w ith fine-grained sandstones only, showing sim ilar structures. The m arkings them sel­

ves, as it is commonly the case in the Carpathian flysch, are underlain by a thin layer of gray shales. No m arkings w hatsoever have been found resting directly upon the black siliceous shale.

Geological Laboratory

Polish Academ y of Sciences in K rakow Geological S u rvey of Poland

Carpathian Branch

REFERENCES

1. B o ś n i a c k i Z. (1911), Flisz europejski — D er europeische Flysch. K osm osr vol. XXXVI, fasc. 10—12, p p 871—899.

2. C o r n i s h V. (1914), Waves of sand and snow. Fisher. Univer. Press. London.

3. D u n b a r C. O. R o d g e r s J. 1957, Principles of S tratigraphy, John W iley &

& Sons Inc. Publishers.

4. D ż u ł y ń s k i S t., S i ą c z k a A. (1958), D irectional structures and sedim en­

tation of .the Krosno beds (C arpathian flysch) Rocz. Pol Tow. Geol. (Ann. Soc, Geol. de Pologne), vol. XXV III, fasc. 3 pp 205—258.

5. D ż u ł y ń s k i S t., K s i ą ż k i e w i c z M. K u e n e n Ph. H. 1959, T urbidites in flysch of the Polish C arpathian M ountains, Bull. Geol. Soc. of America, vol. 70 pp. 1089—1959.

6. D ż u ł y ń s k i S t., S a n d e r s J. E. — in press, M arkings on firm lu tite substratum .

7. G i l b e r t G .K . (1914) The tran sp o rtatio n of debris by ru n n in g w ater, U.S.

Geol. S u rvey Professional Pap. 86

8. K r , a m b e r g e r D. (1879), Beitrage zu r Kenntniis der fossilen Fische der K a r- p ath en . Paleontographica, 26 Lief. 3 pp 59—68.

9. K u e o e n Ph. H. (1957), Sole m arkings of graded grayw acke beds. J o u m . of Geol. vol. 65, no 3 pp. 231—257.

10. P e y e r B. (1957), Uiber bish er als F a h rte n gedeutete problem atishe B ildun- gen aus den Oligozanen Fischsohiefern des Sem ftales. Schweiz. Pal. Abh. Bd 73.

11. R u b e y W .W . (1938), The force req u ired to m ove particles on a stream bed.

U. S. Geol. Surv. Prof. Pap. 183-E.

12. R y c h l i c k i J. (1909), Przyczynek do fauny ryb karpackich łupków m enili- towych. B eitrag z u r Keruntnis der F ischfauna aus den K arpathischen M enilit- schiefern. Kosmos v. 34. pp. 749—764.

EXPLANATIONS OF PLATES OBJAŚNIENIA TABLIC

Tablica XXVII Plate XXVII

Fig. 1, 2. Zachowane 'kręgi przy końcu śladów toczenia (1), kaw ałki łupku przy końcu 'drobnego śladu uderzenia (2), w arstw y m enilitowe. R udaw ka Rym anowska

Fig. 1. P reserved fish v erteb rae at th e dow n^current end of roll-m arkings (1), (2) — fragm ent of shale at th e en d of a short prod-m arks. M enilite beds.

R udaw ka Rym anowska

Fig. 2. Preserv ed fish centrum a t th e dow n -cu rren t end of roll-aind slide-m arks.

M enilite beds R udaw ka Rym anowska Tablica X XVIII

P la te X X V III

Fig. 1, 2. Siady toczenia kręgów rybich. W czasie toczenia oś k ręgu pozostawała w płaszczyźnie równoległej do dna. W arstw y Menilitowe. R udaw ka R y ­ m anow ska

Fig. 3. Siad z zachow anym kręgiem . W arstw y Menilitowe. R udaw ka Rym anowska Fig. 4. Podobne ślady uzyskane przez toczenie kręgu n a m iękkim podkładzie Fig. 1, 2. R oll-m arkings produced by fish vertebrae. The concave sides of centrae

w ere in continuous contact w ith th e bottom . M enilite beds. R udaw ka Rym anowska

Fig. 3. T he same m arkings w ith the fish v erteb ra preserved. M enilite beds.

R udaw ka Rym anowska

Fig. 4. Sim ilar m arkings reproduced by rolling of fish v erteb rae o v er soft plasteline

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 1.

Fig. 2.

Fig. 3.

Tablica X X IX P la te X X IX

Kość rybia przy końcu śladu uderzenia (i). W arstw y menilitowe. R u ­ d a w k a Rym anowska

W ydłużona koić ry b ia przy końou śladu wleczenia- (I) Zygzakow ate ślady toczenia

F ragm ent of a fish bone at th e do w n -cu rren t end of a pro d -m ark . Memilite beds. R u d aw k a Rym anowska

Elongate fish bone at the dow n -cu rren t end of a groove-cast (1).

M enilite beds. R udaw ka Rym anowska.

Zigzag roll-m arkings

Tablica X X X P la te X X X

Pierścieniow e ślady toczenia kręgów rybich. W arstw y krośnieńskie. R u ­ daw ka Rym anowska

Siady uderzeniow e pozostaw ione przez kręgi uderzające o dno. W arstw y krośnieńskie. R udaw ka Rym anowska

Pow tarzający się w zarysie ślad w śró d zespołu hieroglifów uderzenio­

wych. W arstw y krośnieńskie. R udaw ka R ym anow ska

R ing-like m arkings m ade by a rtic u la r surfaces of fish vertebrae.

Im pressions of b ro k en processes visible on the sides of m arkings. Krosno beds (Oligocene), R udaw ka Rym anowska

P ro d -m ark s produced by fish v ertebrae. Krosno beds. (Oligocene), R u ­ d a w k a Rym anowska

R ecurrent geom etric p attern am ongst typical tool-m arkings 'assemblage suggestive of fish bones acting as tolls. Krosno beds. R udaw ka R y m a­

now ska

S. D żulyński, A. Ślączka

S. D żułyński, A. Ślączka

S. D źulyński, A. Slączka