Possibility of Sequence Stratigraphic Subdivision of the Zechstein in the Polish Basin
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Geological Quarterly, Vol. 41, No.4, 1997, p. 457-474 PROJEKT KBN PBZ 02-03 Possibility of sequence stratigraphic subdivision of the Zechstein in the Polish Basin 1 2 Ryszard WAGNER , Tadeusz Marek PERYT 1Panstwowy lnstytut Geologicmy, Rakowiecka 4, 00-975 Warszawa, Poland 2Zaklad Geologii Surowcow Mineralnych, Paristwowy lnstytut Geologiczny, Rakowiecka 4, 00-975 Warszawa, Poland (Received: 28.11 .1997) Applying the Exxon method for sequence distinction, four depositional but afterwards a general change of sedimentary regime occurred and the sequences can be distinguished in the Polish Zechstein, out of which the first uppermost part of the Zechstein is dominated by terrigenous-evaporite litho commenced during the deposition of the upper portion of the Rotliegend and facies. Because it is not possible to distinguish typical depositional sequences the fourth continued up to the lower portion of the Buntsandstein. In our in the Zechstein terrigenous-evaporite lithofacies, it was decided to distin opinion the Exxon approach is not a significant step in understanding the guish climatic sequences. Despite of fundamental differences between the principles controlling the Zechstein basin evolution during the deposition of origin of climatic and eustatic sequences, they have an important common carbonate and evaporite-dominated, lower and middle parts of the Zechstein. feature; their boundaries are isochronous. The fourth depositional sequence commences with evaporite deposits ofLST, INTRODUCTION The Zechstein is a specific megafacies developed in the whether they are related to the eustatic movements of the Late latest Permian during its last 5-7 Ma. The Zechstein sedi Permian ocean or rather to the local activity of the barrier in ments originated in a shallow, vast epicontinental marine the Viking Graben yet await convincing answers. Considering basin extending over Central Europe. This basin had a very the isolation of the Zechstein basin, only the most intensive reduced connection with the Upper Permian open sea which transgressive impulses could assumingly be related to global occupied the site of the present Barents Sea. Connection was eustatics whereas lower order oscilJations could have been through a narrow strait between Greenland and the Scandina due to local factors. vian Peninsula in their palaeogeographic position. This over Proposing a new sequence stratigraphy for the Polish 1000 km long strait was formed due to tectonic activity of the Zechstein Basin the present authors discuss the possibility of Greenland-Norwegian Sea rift. The isolation ofthe Zechstein replacing or complementing the traditional cyclothem ap basin was accentuated by the existence of a possible barrier proach. In search of convincing arguments and solutions of in the Viking Graben the mobility of which could have been the existing problems we have benefited from the experience responsible for periodical interruptions in connection with the of our predecessors from the English (M. E. Tucker, 1991) Upper Permian sea. and German (c. Strohmenger et at., 1996b; C. Strohmenger, The majority of the Zechstein sediments were formed C. Strauss, 1996) Basins. Therefore, in this paper the Exxon during transgressive-regressive carbonate-evaporitic cycles method has been adopted for the distinction of sequences. embracing cyclothems from PZl to PZ3, and the uppermost Special attention is focused on the upper part of the Zechstein, Zechstein cyclothems from PZ4a to PZ4e - during terrige as it is just the Polish Basin where the most complete and best nous-evaporitic climatic cycles reflecting climatic changes known sequence representing the decline of Zechstein deposi from humid to arid. tion exists. Factors directly responsible for the existence of trans gressive-regressive cycles are not well known. Questions 458 Ryszard Wagner, Tadeusz Marek Peryt CHRONO I LITHOSTRATIGRAPHY Z STRATIGRAPHY W ~ U ~ z ~ z 0 Tp3 Barwice Formation LITHOLOGY is (J) ~ ~ :2::f Z Z '-----+-----------------------j 0:::: (J) 0 «....J <t:-' <t: - ~ - (J)W Tp2 Pokzyn Formation :> iY: z .t :J z 1-1- Pomerania Formation Z I- :3 ffi ~ ~:;!; Z (J) r---lr------------------+---=------=---I-~W~ o !!!:r: > (:l ::J - 0 - 0 - .~ ~ 9,; () -=--- ca Tp1 Baltic Formation 0 - 0 - 0 - ro ~ u ~-i-~~-t----------~,--,--~~-4-==~--==---==-~~E~ 251 PZ4e § M~~b~r 1-->--~>H ~ Ma z Rewal ~ Walcz > - c PZ4d Formation E Member - H - (J) « z Top ~ Jastrowie Mbr. > --- -;- ~ ~ <.9 Ter.rigenous ~ Pila ~ H - H ~ z PZ4c Series PZt Jl1 Member f-> H - H - '-' z a.. ZIot6w Member H - H =- H r--=- Na4b Top Youngest Halite ro E H H H « >< 2 ~LL H H <.9 Upper Red Pelite ---~- z I- - upper part - ---7H":":" H PZ4b Miroslawiec H H H « Na4b1 Intrastratal Halite Member H H (J) I Upper Red Pelite ---==-~- U Z « -lower part - -~":":"H « Upper l Na4a2t Kluczewo Mbr. H - H - H Youngest Halite c H H ~ Upper Pegmatite o ~ Anhvdrite c « oE H H H I PZ4a Na4a1 Lower Youngest Halite LL H H Lower Pegmatite 19 (])' LLI C/) I Anhydrite ~ ro H H H « Na4ao Underlying Halite a.. H H n:: · ro Drawno I- -/H - H T4a Lower Re d P e IIte. "'0 E Member ,..----/H ~ H .- a.. 1-- --+- - - --1--' I- - -N-a-3-t - --I Jl LL Tuczno Member H - H - H Na3 Younae~rTH~a~lit~e~+~P~o~t~as'h-+-~~~~~==+-~~H~~H-~~ ~ \? - ?- \ A3 Main Anhydrite PZ3 z :::c Ca3 Platy Dolomite II II z -:-: ..-.-. « T3 Grey Pelite e---:- ' . -'-' . -'-' . 0::: A2r Screening Anhydrite »»> H H H n:: c.,) Na2r Screening Older Halite H H LLI K2 Older Potash K K It « It It PZ2 H H H I- Na2 Older Halite H H A2 Basal Anhydrite a.. « 11.1 I- Ca2 Main Dolomite I A1g Upper Anhydrite E a.. H H N n:: Na1 Oldest Halite H H W N PZ 1 A1d Lower Anhydrite o a.. Ca1 Zechstein Limestone 1 T a.. T1 Copper Shale - 258 1------< r--~--~---~-------~ Ma CAPITA- :::> UPPER ROT- Notet Formation NIAN LlEGEND ..' .. I C-Jclaystone/mudstone f-I TrIl----'"--"TTII-11 dolomite I H H H Ihalite 1-; ~ -; 1clayey halite I• : • : • : • : • : • sandstone 0 claystone/mudstone h-lL--...-illimestone 1 1anhydrite 1 KKK 1 potash ff --;oj > > > o - 0 with oolite Fig. 1. Zechstein stratigraphy in the Polish Zechstein Basin Stratygrafia cechsztynu w polskim basenie cechsztynskim Sequence stratigraphic subdivision of the Zechstein ... 459 Lithostratigraphy Sequences Polish Basin German Basin English Basin Polish Basin (R. Wagner, 1994) (R. Wagner, T. M. Peryt, (C. Strohmenger (M. E. Tucker, this paper) et al., 1996b) 1991) Lower Buntsandstein Baltic Formation LST/TST - - - - ?--- Tpl r- - - --?- - Rewal Formation/Top Terrigenous Series PZt ..J.~ ~'" Naklo ~u Member c:: M 1I Walcz 0 U .~ "d Member ..J.~ .J. ~ E ~M ~ 0.. Jastrowie 0 ~u N Member J.I.. 0.. Z I- oj Pila u Member 7r- ~ ~M ~ 0.. 0.. Zlotow ~u Member ZS 8 Na4b Top Youngest Halite 1:l S z -J.I.. ZS 7 -. 7 c:: 0 .D T4b Upper Red Pelite - upper part 'J:l N z oj .~ ~ U 0.. Miroslawiec .D Na4b] Intrastratal Halite E0 .J. u Member J.I.. ~ N N'" oj 0.. T4b] Upper Red Pelite - lower part u LST .~ ~ Kluczewo Na4azt Upper Youngest Clay Halite Member ~ Na4az Upper Youngest Halite c:: 0 -U 'p A4az Upper Pegmatite Anhydrite oj .J. ~ oj E N r - - - ?- -- f--; 7 0 0.. N Na4a] Lower Youngest Halite J.I.. 0.. oj PZS4 ." A4a] Lower Pegmatite Anhydrite ~ oj 0.. Underlying Halite Na4ao ZS 7 ZS 6 Drawno c:: C/) T4a Lower Red Pelite Member .g ..§ Tuczno ~ § Na3t Younger Clay Halite °0 Member J.I.. Na3 (IQ) Younger Halite (Younger Potash) ZS 5 '"c:: 'a) ('I') tlN ZS 6 .Do.. A3 Main Anhydrite ::r: .,u N Ca3 Platy Dolomite HST mfs T3 Grey Pelite A2r Screening Anhydrite TST ZS 5 U Na2r Screening Older Halite PZS 3 ZS4 N .~ N K2 Older Potash tlN .DP-. u Na2 Older Halite LST N'" ZS4 ~ A2 Basal Anhydrite Ca2 Main Dolomite HST ZS 3 Upper Anhydrite mfs Alg~ Anhydrite Breccia TST PZS2 ZS 3 N Nal Oldest Halite LST ZS 2 .S- <1.l- AId Lower Anhydrite tlN .Do.. u ZS 2 <1.l Cal Zechstein Limestone HST N mfs ZS I Tl Copper Shale TST PZS I ZS I Zpl Basal Conglomerate LSTITST Fig. 2. Stratigraphy of the Polish Zechstein Basin comparing lithostratigraphy (Zechstein cyclothems PZI to PZ4) with Zechstein depositional sequences in Poland, Germany and England LST -lowstand systems tract, TST - transgressive systems tract, HST - highstand systems tract, mfs - maximum flooding surface Korelacja stratygrafii sekwencyjnej cechsztynu w basenach polskim, niemieckim i angielskim na tie litostratygrafii basenu polskiego LST - ciijg systemowy niskiego stanu wzgll;dnego poziomu morza, TST - cillg transgresywny, HST - cillg systemowy wysokiego stanu wzgll;dnego poziomu morza, mfs - powierzchnia maksimum transgresji 460 Ryszard Wagner, Tadeusz Marek Peryt TECTONIC, PALAEOGEOGRAPHIC AND CLIMATIC CONTROLS OF ZECHSTEIN SEDIMENTATION The Polish Zechstein Basin was situated in the eastem part of of the Precambrian Craton the average subsidence was minor the vast Central European Basin and constituted its natural closure. - 50 mJMa approximately. The maximum subsidence i.e. It was more than 1000 km away from the narrow strait in the Viking about 300 mJMa which was responsible for the formation of Graben (N part of the North Sea) through which intermittent the depocentre in the Polish Zechstein Basin took place in a connection existed with the Upper Permian open sea. specific tectonic zone between the Teisseyre-Tornquist (T -T) The Polish Zechstein Basin was flanked by three vast fractures in the north-east and the Variscan front in the south continents: the Scandinavian continent in the north, the vast west. This enabled the deposition of a 1500 m thick evaporitic peneplenized East European continent in the east and the series and, as a consequence, the formation of Europe's most morphologically diversified Caledonian and Variscan massifs complete Zechstein sequence. The Variscan Platform was in the south. distinctive by a slightly weaker but very differentiated sub The main structural features of the Zechstein basin are sidence (from 80 to 160 mJMa) depending on the geological older and were formed at the beginning of the Upper Rotlie structure of the Variscan orogen.