Early Miocene (Ottnangian) Coastal Upwelling Conditions Along The
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ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Beiträge zur Paläontologie Jahr/Year: 2006 Band/Volume: 30 Autor(en)/Author(s): Roetzel Reinhard, Coric Stjepan, Galovic Ines, Rögl Fred Artikel/Article: Early Miocene (Ottnangian) coastal upwelling conditions along the southeastern scarp of the Bohemian Massif (Parisdorf, Lower Austria, Central Paratethys) 387-413 ©Verein zur Förderung der Paläontologie am Institut für Paläontologie, Geozentrum Wien Beitr. Paläont., 30:387-413, Wien 2006 Early Miocene (Ottnangian) coastal upwelling conditions along the southeastern scarp of the Bohemian Massif (Parisdorf, Lower Austria, Central Paratethys) by Reinhard R o e t z e l 1),Stjepan C o r ic 1),Ines G a l o v ic * 2) & Fred R o g l 3) Roetzel , R., Coric , S., G alovic , I. & Rogl , R, 2006. Early Miocene (Ottnangian) coastal upwelling conditions along the southeastern scarp of the Bohemian Massif (Parisdorf, Lower Austria, Central Paratethys). — Beitr. Palàont., 30:387-413, Wien. Abstract Zusammenfassung Lower Miocene clays of the Zellerndorf Formation and In den untermiozänen Tonen der Zellerndorf-Formation intercalated diatomites of the Limberg Member from und den darin eingeschalteten Diatomiten der Lim- the Alpine-Carpathian Foredeep in Lower Austria show berg-Subformation der Alpin-Karpatischen Vortiefe in distinct features for coastal upwelling conditions along the Niederösterreich sind deutliche Hinweise auf „coastal steep southeastern scarp of the Bohemian Massif during upwelling“ entlang des südöstlichen Steilrandes der Böh the Ottnangian. The sediments were deposited in a deep mischen Masse während des Ottnangiums zu erkennen. marine sublittoral environment, in a pelagic, deep-neritic Die marinen, sublitoralen Sedimente stammen aus der pe zone. The communities of diatoms, calcareous nanno- lagischen, tiefneritischen Zone. Die Vergesellschaftungen plankton and planktonic foraminifera clearly point to the von Diatomeen, Nannoplankton und planktonischen influence of cold and nutrient-rich deep-water currents, Foraminiferen lassen deutlich den für „upwelling“-Zonen typical for upwelling zones. The very high content of typischen Einfluss von kalten und nährstoffreichen Tie smectitic clay minerals in both the sediments and vol- fenströmen erkennen. Die sehr hohen Anteile von smek- caniclastics of time-equivalent strata in this area indicate titischen Tonmineralen in beiden Sedimenttypen weisen prominent acidic volcanic input at this time. Thus, besides in Verbindung mit vulkanoklastischen Einschaltungen in the nutrient-rich deep-water currents, the induced high zeitgleichen Ablagerungen dieses Gebietes auf maßgeb silica content in the sea also boosted biogenic productivity, lichen Eintrag von sauren Vulkanoklastika zu dieser Zeit especially for diatoms. hin. Der dadurch hervorgerufene hohe Anteil gelöster The new species Nonion gudrunae Rogl n. sp. is described Silikate im Meerwasser war neben den nährstoffreichen from the Ottnangian Zellerndorf Formation in the diat- Tiefenströmen sicher ein zusätzlicher Faktor für die hohe omite pit Parisdorf, and a lectotype of Nonion commune biogene Produktivität, vor allem bei den Diatomeen. (d’ORBiGNY, 1846) is designated. Aus der Foraminiferenfauna von Mergeln der Zellern dorf-Formation (Ottnangium) aus der Diatomitgrube Keywords: Limberg Member, Zellerndorf Formation, dia- Parisdorf wird die neue Art Nonion gudrunae Rögl n. sp. tomite, coastal upwelling, Nonion gudrunae Rogl n. sp. beschrieben und für Nonion commune (d‘ORBiGNY, 1846) ein Lectotyp bestimmt. 1. Introduction 0 Dr. Reinhard Roetzel , Dr. Stjepan Coric , Geologi Coastal upwelling is a very common phenomenon along cal Survey of Austria, Neulinggasse 38, A-1030 Vi coasts all over the world (Summerhayes et al., 1992,1995). enna, Austria, e-mail: [email protected] , Winds blowing nearly parallel to a continental coastline, [email protected] combined with the effect of the earth’s rotation, push the light coastal surface water toward the open ocean and away 2) Dr. Ines G alovic , Geological Survey of Croatia, Sachso- from the land. This offshore-moving water is replaced by va 2, P.O. Box 268, HR-10000 Zagreb, Croatia, e-mail: cooler and saltier water, which upwells from the ocean’s [email protected] depths (Smith , 1995). Typically, this water has a high concentration of nutrients such as nitrates, phosphates 3) Dr. Fred Rogl , Museum of Natural History, Burgring and silicates, which sustain biological production. Areas 7, A-1014 Vienna, Austria, e-mail: fred.roegl@nhm- under coastal upwelling are highly productive, resulting wien.ac.at in big populations of marine plankton and fish shoals, in ©Verein zur Förderung der Paläontologie am Institut für Paläontologie, Geozentrum Wien 388 Beitr. Palaont., 30, Wien, 2006 turn attracting marine mammals and sea birds. Coastal Burgschleinitz Formation. The erosional contact is over- upwelling systems have been studied in detail over the last lain by sandy shallow marine limestones of the Zogelsdorf decades because of their prime economic importance and Formation (uppermost Eggenburgian), which laterally impending anthropogenic impacts and interference. and vertically pass into deepwater pelitic sediments of The very high nutrient supply in coastal upwelling areas the Lower Miocene (Ottnangian) Zellerndorf Formation. fuels high production rates of phytoplankton. Diatoms Drillings in this area show that the pelites above the Zo are the dominant phytoplankton under these conditions, gelsdorf Formation are about 25 -100 m thick (R aschka , forming the base of the food chain (H utchings et al., 1912; Schaffer & G rill, 1951; Roetzel , 1994, 1996a). 1995). In geological time this phytoplankton helped cre At the top part of the Zellerndorf Formation, diatomites ate diatomites, which are indicative for such upwelling of the Limberg Member are intercalated in the clays conditions in the past. In the geological record, however, (Roetzel , 1996a; Roetzel et al., 1991, 1999b). Laterally diatomites are not very common and are concentrated towards the E, the diatomites thin out, interfingering with mostly in Miocene and Pliocene deposits. the Ottnangian pelites. The occurrences of the diatomites In the Alpine-Carpathian Foredeep in Austria, the most are restricted to the surroundings of Limberg, Oberdtirn- prominent deposit of diatomites is located about 60 km bach and Parisdorf, very close to the Diendorf fault scarp NW of Vienna, close to the SE margin of the Bohemian (Fig.l). Massif, near the town of Maissau. In the older literature, Marine silts and fine sands with gravelly intercalations these diatomites are known as “diatomites of Limberg” above the Zellerndorf Formation belong to the Lower or “diatomites of Limberg-Parisdorf” More recently, the Miocene (Karpatian) Laa Formation (Roetzel , 1996a). diatomites were defined as the Limberg Member (Roetzel Additionally, in parts they are overlain by erosional relicts et al., 1999a). of the Middle Miocene (Lower Badenian). These clays, Diatomites were once mined in the surroundings of Lim fine- to medium sands and gravel belong to the marine berg and Oberdiirnbach and were used as filler material, Gaindorf Formation (D axner -H ock , 2002; Roetzel , filtering agent, absorbent and clarifier (F.H.R., 1922; R eidl , 1996a). South to Southeast of this area, fluvial gravel and 1939; L echner , 1956; O truba , 1987). Currently, diatomites sands of the Hollabrunn - Mistelbach Formation lie above are mined only in the Parisdorf diatomite pit of the Wien- the Lower to Middle Miocene marine formations. These erberger AG, 2.5 km ESE of Maissau and about 400 m SE Upper Miocene (Pannonian) sediments were deposited by of Parisdorf. This material is used as insulator in bricks a pre-Danube river (N ehyba & Roetzel , 2004). (Roetzel et al., 1999b; M andic et al., 2005). All these formations E of the Diendorf fault are affected The present paper discusses the indications for coastal by intensive horst-graben tectonics (cross section, Fig.l). upwelling conditions based on the records of diatoms, On the surface, most of the area is covered by Pleistocene foraminifera and nannoplankton in the Limberg Member loesses. diatomites and the overlying pelites of the Zellerndorf The diatomites of the Limberg Member occur between Formation. the villages Parisdorf, Oberdiirnbach, Limberg and Niederschleinz, E to NE of Maissau (Fig.l). Outcrops of the diatomites are very rare because of the widespread 2. Geological setting Quaternary cover and the intensive agricultural land use in this area. A few natural outcrops are located in small The geological situation of this area was described by ditches 150 m N of the Limberg railway station and 670 m Schaffer (1914), G rill (1976) and Roetzel (1994,1996a, NW of the chapel of Niederschleinz (G rill 1976; Roetzel b, 2004), and is shown in detail on the Austrian geological 1996a). In the outcrop at Niederschleinz, diatomites and map GOK22 Hollabrunn (Roetzel et al., 1998; Fig. 1). diatomitic pelites are intercalated in silt-clays, showing The crystalline upland of the Bohemian Massif in Aus a more distal facies of the Limberg Member (R ehakova , tria is bordered at its SE margin against the Miocene 1996; Roetzel , 1996a). Recently the best profiles are open sedimentary area of the Alpine Carpathian Foredeep by a in the diatomite pit of Parisdorf (Pl.l) and the abandoned prominent fault zone. This Diendorf