Leszczyński S., Malik, K., Kędzierski, M., Margle krzemionkowe i fukoidowe w rejonie Rybotycz: nowe dane litofacjalne i stratygraficzne (płaszczowina skolska, kreda, Karpaty) (dyskusja)

Abstract

Leszczyński S., Malik, K., Kędzierski, M., New data on lithofacies and stratigraphy of the siliceous and fucoid marl of the Skole Nappe (Cretaceous, Polish Carpathians) (a discussion) The author wishes to suppress by this polemic article the appearance of papers written without reliability required in science. In a detailed analysis to which the article of S. Leszczyński, K. Malik, M. Kędzierski (further as LMK) is submitted the slips and mistakes are treated step by step and the correctness of the conclusions drawn is questioned. The most important reservations will by given below. 1. The authors have not defined accurately the aim of the investigation undertaken. It may be assumed that the purpose of the research was to obtain merely new data (as it was underlined in the title of the paper) without the intention to elucidate the problems unsolved, as e.g. the raised problem of the nonturbiditic origin of some layers of calcarenites and calcilutites (cf. Kotlarczyk, 1985), particularly of beds in which cross-laminae (nota bene not observed by the authors) are formed by heavy minerals concentrations (Wieser, 1974). Undertaking the solution of this problem required of course microscopic examination, localization of the diagnostic sedimentary structures on the stratigraphical profiles and their statistical description, finding diagnostic features being characteristic of mud turbidites (e.g. according to the suggestion of Piper & Stow, in Einsele et al. eds. 1991), and carrying out a discussion on the genesis of the cross lamination with heavy minerals in turbidites. In place of this the authors have confined themselves to quoting the structures observed which is not sufficient to undertake a decision on the single-turbiditic model of the genesis of all the calcarenite and calcilutite layers. 2. In order “to make their opinion precise” the authors investigated in general one (sic !) profile of the Hoiownia Siliceous Marls (futher on as HSM) -“Kanion” and two profiles of the Kropiwnik Fucoide Marls (further on as KFM) - “Dolinka” and “Wiar”, while they investigated in details only the first profile (ca 50 m) and selected sections of the remaining two (totally ca 12 m) which constituted 1/18 and 1/26 part relatively of the KFM sediment sequence of these profiles. In the “Dolinka” profile the boundaries of the KFM complex accepted in literature had not been taken into consideration while the younger than KFM complexes were included in the analysis (Fig. 1). 47 samples were collected to investigate the chemical composition of the marls and in 25 samples analysis of nannoflora was carried out (only these last ones were localized, namely in the “Kanion” and “Wiar” profiles solely). Both the range of investigation carried out and the sampling of the profiles is insufficient and unrepresentable. It is unjustified to draw on this basis general conclusions referring to the mechanism of sedimentation and the stratigraphy of both lithosomes. Diversity of the results meaning is deepened by the fact of joint characteristics (i.e. of both HSM and KFM complexes) of the chemical composition, of sedimentary structures, and succesion of the identified members of Bouma sequence in the calcilutites as well as the comprehensive characteristics of the remaining lithologies. This makes it impossible to seize the conceivable differences between the complexes. 3. The authors have in majority presented falsely (LMK, Table 1) my opinions refering to the age of the boundaries of lithosomes being in elaboration (Fig. 3) as well as the location of the Early/Late Maestrichtian boundary (LMK, Fig. 2) which I have always placed below the olistoliths of the Węgierka Marls. 4. In both marls complexes the autors have distinquished 9 lithofacies without giving a clear quantitative criteria for their differentiation. The classification suggested is imposible to be applied objectively. Without the required evidences the authors accept the presence of pelagites in both marls sequences and without any ground write about interturbidites occuring allegedly in the bedding rhythms. The latter boundaries have been determined arbitrally whereby the authors were guided by the diminishing diameter of the grains while within one calcilutite bed by some unrevealed rules. The detailed profiles, presented by the authors, of very short sections of both sequences (LMK, Figs. 4-8) gave no basis to arrive at the conclusion about the presence of various order sedimentation cycles (LMK, p. 58) and apart from this no generally known methods were applied to discover the cycles. In the lithofacial description the authors emphasized the presence of noncalcareous shales in HSM complex. From the four (sic !) chemical analyses of the shales from HSM it results, however, that besides the noncalcareous there occur here also poorly calcareous shales which is in accordance with earlier statements of other autors. As in KMF also noncalcareous shales occur besides the calcareous ones the suggestion of the authors to consider the calcium content of the shales as a criterion of differentation of the both complexes is groundless. The authors rather freely use the petrographies terms by naming e.g. as marls also the rocks with a CaCO(3) content from 14 to 25%. 5. The conclusions referring to the biostratigraphy of the complexes under investigation are mostly ungrounded. This refers also to the main thesis of the article according to which the age of the Rybnik Flysch (the complex occuring between HSM and KFM) is confided to the CCI6 zone exclusively. The scheme of sampling in the profiles of the lower part of the Ropianka Formation (Fig. 2) makes it impossible to univocally define a priori the age of the boundaries of the marls lithosomes investigated and by the same the age of the Rybnik Flysch. Admitting the correctness of determination of the diagnostic taxa found in the very modest nannoplankton assemblages one cannot agree with the method of its interpretation by the authors. 1. The ascertainment of taxa; Reinhardites anthophorus, Micula decussata, M. concavct in the top of the HSM complex does not settle the occurrence here of a whole CCI5 zone; the marls profile may reach merely the lower part of the zone since the location of the CC15/CC16 boundary is unknown. 2. The ascertainment of taxon Aspidolitus parcus parcus, appearing in the CC 18 subzone (Early Campanian), in the bottom of the KMF complex (in both profiles -samples: D7 and W3) and apperance (in the Wiar profile - sample W1 directly under sample W3) of taxon Arkhangielskiella specillata, with FO in the upper part of the CCI7 zone (Early Campanian), makes it possible to assess the age of the marls bottom as Early Campanian, however, it does not settle the position of the Santonian-Campanian boundary within the Rybnik Flysch. 3. On the basis of the appearance in the single sample (6 m below KFM) of taxa: Lucianorhabdus cayeuxii and of other Santonian- Campanian and as well as of Petrarhabdus copulatus one cannot arrive unhesitating at a conclusion about the Santonian age of this part of Rybnik Flysch (the authors themselves admit the presence of the earliest Campanian) nor about FO of the last taxon in the CC16 zone (Santonian). It is worthwhile to note that the authors have ignored the data published earlier (including the dating by nannoplankton - Gaździcka in: Kotlarczyk, 1988) which prove the Early Campanian age of the upper part of the Rybnik Flysch (cf. Fig. 3B). A correct interpretation of the data presented by the authors themselves leads (even within the faulty sampling) to defining the age of the Rybnik Flysch within the boundaries: upper part of CC15 zone - top of CC17 zone. This gives a two to threefold longer period of sedimentation of these beds than it is suggested by the authors.