Baba Senowbari-Daryan

Anisian (middle triassic) buildups of the Northern Dolomites (Italy): The recovery of reef communities after the permian/triassic crisis

SummaryAfter the end-Permian crisis and a global ‘reef gap’ in the early Triassic, reefs appeared again during the early Middle Triassic. Records of Anisian reefs are rare in the Tethys as well as in non-Tethyan regions. Most Anisian reefs are known from the western part of the Tethys but there are only very few studies focused on biota, facies types and the paleogeographical situation of these reefs. From the eastern part of the Tethys, Anisian reefs, reefal buildups or potential reef-building organisms have been reported from different regions of southern China. Most of the Anisian reefs known from western and central Europe as well as from southern China seem to be of middle and late Pelsonian age.The study area is situated in the northern Dolomites (South Tyrol, Italy) southeast of Bruneck (Brunico). It comprises the area between Olang (Valdaora) and Prags (Braies). The study is based on detailed investigations of the regional geology, stratigraphy and lithofacies (R. Zühlke, T. Bechstädt) as well as on a comprehensive inventory of Anisian reef organisms (B. Senowbari-Daryan, E. Flügel). These data are used in the discussion of the controls on the recovery of reefs during the early Middle Triassic.Most late Anisian reef carbonates studied are represented by allochthonous talus reef blocks of cubicmeter size. Small biostromal autochthonous mounds are extremely rare (Piz da Peres). The reef mounds as well as most of the reef blocks occur within the middle to late Pelsonian Recoaro Formation. They were formed on the middle reaches of carbonate ramps in subtidal depths, slightly above the storm wave base with only moderate water energy. Most lithotypes observed in the reef blocks correspond to sponge and/or algal bafflestones. Low-growing sessile organisms (Olangocoelia (sponge, alga?), sphinctozoan sponges, bryozoans, soleno-poracean algae, corals) and encrusting epibionts (sponges, porostromate algae, cyanophycean crusts, foraminifera, worms, microproblematica) created low cm-sized biogenic structures (bioconstructions) which baffled and bound sediment. Organic framework was only of minor importance; it is restricted to theOlangocoelia lithotype. Framework porosity was small in these reef mounds. Submarine carbonate cements, therefore, are only of minor importance s compared with Permian or Ladinian reefs. The relatively high number of lithotypes encountered in the reef blocks indicates a high biofacies diversity.Regarding the relative frequency, the diverse biota consist in descending order ofOlangocoelia, sponges (sphinctozoans, inozoans, siliceous sponges), bryozoans, porostromate algae and worm tubes. The sphinctozoans are characterized by small, mostly incrusting forms. The numerical diversity (species richness) is low compared with late Permian or Ladinian and late Triassic sphinctozoan faunas occurring within reefs.Following the sponges, monospecific bryozoans (Reptonoditrypa cauticaSchäfer & Fois) are the most common organisms in the reef limestones. Porostromate algae were restricted to areas within the bioconstructions not inhabited by sponges. The low-diverse corals had no importance in the construction of an organic framework.Surprisingly, microbial crusts are rare or even lacking in the investigated Anisian bioconstructions. This is in contrast to late Permian and Ladinian as well as Carnian reefs which are characterized by the abundance of specific organic crusts. The same comes true for‘Tubiphytes’ which is a common constituent in Permian, Ladinian and Carnian reef carbonates but is very rare in the Anisian of the Olang Dolomites. Instead of‘Tubiphytes’ different kinds of worm tubes (spirorbid tubes, Mg-calcitic tubes and agglutinated tubes) were of importance as epifaunal elements. Macrobial encrustations consisting of characteristic successions of sponges, bryozoans, algae, worm tubes and microproblematica seem to be of greater quantitative importance than in Ladinian reefs.Destruction of organic skeletons (predominantly of bryozoans) by macroborers (cirripedia?) is a common feature.The Anisian reef organisms are distinctly different from late Permian and from most Ladinian reef-builders. No Permian Lazarus taxa have been found.New taxa: Sphinctozoan sponges—Celyphia? minima n.sp.,Thaumastocoelia dolomitica n. sp.,Deningeria tenuireticulata n. sp.,Deningeria crassireticulata n. sp.,Anisothalamia minima n.g. n.sp., Inozoan sponges-Meandrostia triassica n.sp. Microproblematica-Anisocellula fecunda n.g. n.sp., Porostromate alga-Brandneria dolomitica n.g. n.sp.Most of our data are in agreement with the model described byFois & Gaetani (1984) for the recovery of reef-building communities during the Ansian but the biotic diversity seems to be considerably higher than previously assumed.Anisian deposition and the formation of the reef mounds within the Pelsonian Recoaro Formation of the Dolomites were controlled by the combined effects of synsedimentary tectonics and eustatic changes in sea-level. During several time intervals, especially the early Anisian (northern and western Dolomites: tectonic uplift), the early Pelsonian (eastern Dolomites: drowning) and the late Illyrian (wide parts of the Dolomites: uplift and drowning), the sedimentation was predominantly controlled by regionally different tectonic subsidence rates. The amount of terrigenous clastic input associated with synsedimentary tectonics (tectonic uplift of hinterlands) had a major influence on carbonate deposition and reef development. The re-appearance of reef environments in the Olang Dolomites was controlled by a combination of regional and global factors (paleogeographic situation: development of carbonate ramps; decreasing subsidence of horst blocks; reduced terrigenous input; moderate rise in sea-level).

Fazielle und paläontologische Untersuchungen in oberrhätischen Riffen (Feichtenstein- und Gruberriff bei Hintersee, Salzburg, Nördliche Kalkalpen)

ZusammenfassungIm Hangenden der Kössener Schichten sind in den Nördlichen Kalkalpen zahlreiche kleine Riffe (“patch-reefs”) eingeschaltet, die in der Literatur verschieden benannt werden und im allgemeinen als “Oberrhät”-Riffe bekannt sind (vgl. Fabricius 1966:20; Tollmann 1976:258).Mehrere dieser Riffe befinden sich im Land Salzburg (Osterhorngruppe). Vier nahe beieinander liegende Riffe bildeten das Thema von zwei Dissertationen im Paläontologischen Institut der Universität Erlangen-Nürnberg. P. Schäfer bearbeitete das Rötelwand-Riff im Mörtelbachtal und das Adnet-Riff bei der Ortschaft Adnet (beide nahe Hallein, vgl., P. Schäfer 1979). In der vorliegenden Arbeit werden die Untersuchungsergebnisse des Feichtenstein- und des ca. 3 km südlich gelegenen Gruber-Riffes vorgestellt (österreichische Topographische Karte 1∶25000, Bltt Hintersee, 94/2; 47° 42′, 25″;−13° 17′ 50″ bzw. 47° 41′ 10″;−13° 18′, 14″).Der Schwerpunkt der Untersuchungen liegt auf der paläontologischen Bearbeitung der riffbildenden Organismen. In Abschnitt 4.3.1 findet sich eine übersichtsliste der festgestellten Arten.

Triassic Reefs of the Tethys

The evolution of Triassic reefs started with a long-lasting global crisis of the metazoan reef ecosystem after the Permian—Triassic mass extinction (about 12 Ma), followed by a relatively rapid recovery during the Middle Triassic. Reef systems were differentiated during the Upper Triassic but were severely affected by a global crisis at the Triassic—Jurasic boundary. The present contribution is focused on the biological controls of Triassic reefs, particularly in the Tethyan realm, and on the major changes in reef ecosystems recorded by differences in reef types and reef biota. The term “reef” as used in this chapter refers to bioconstructions characterized by (1) biological control during the formation of the structure (predominantly by sessile benthic organisms), (2) a laterally restricted topographic relief, and (3) (inferred) rigidity of the structure.

Microfacies and depositional structure of allochthonous carbonate base-of-slope deposits: The late permian Pietra di Salomone megablock, Sosio Valley (Western Sicity)

SummaryThe carbonate breaccias and calcarenites of the extremely fossiliferous Pietra di Salomone megablock southwest of Palazzo Adriano, Sosio Valley (Monti Sicani, Western Sicily) represent debris-flow and turbidite sediments deposited in a base-of-slope position.Microfacies criteria (22 localities, 240 samples) and paleontological data (especially sphinctozoan and inozoan sponges,Tubiphytes, Archaeolithoporella, fusulinids, conodonts) provide evience of long- and short-lasting erosion of Middle to Upper Permian carbonate platform marginal reefs formed by binder/encruster and baffler guilds, probably on the uppermost slope. Subsequent to repeated reworking, lithified material (rudstones, boundstones) was transported downslope by sedimentary gravity flow processes and deposited, possibly, as fillings in channels incised in the deep-water basinal marly sediments of the Torrente San Calogero section adjacent to the Pietra di Salomone outcrop.The coincidence in the biostratigraphical age of the pebbles and the marly matrix of the breccias and of the basinal sediments indicates that the destruction of the platform margins and the platform lasted at least from the Murghabian to the Dzhulfian.The comparison of the reef biota preserved in the Pietra di Salomone limestone with reef biota occurring in Lower Permian allochthonous blocks within the Lercara ‘Formation’ (Cozzo Intronata, River San Filippo) points to a turnover in the composition of algal and sphinctozoan sponge associations after the Artinskian, probably during the lower Middle Permian (Kubergandian).RiassuntoLa Pietra di Salomone è il maggiore fra i famosi blocchi calcarei permiani della Valle del Sosio, ubicato a sudovest di Palazzo Adriano (Monti Sicani, Sicilia occidentale) e noto fin dal secolo scorso per la straordinaria ricchezza di fossili. Questo blocco calcareo risulta costituito da carbonati clastici risedimentati, prevalentemente da debris-flow, alla base di una scarpata.L’analisi delle microfacies e i dati paleontoloigici basati principalmente sulle spugne calcaree,Tubiphytes, Archaeolithoporella, fusulinidi e conodonti, indicano che le aree di alimentazione del materiale clastico erano costituite da complessi di scogliera ubicati al margine di piattaforme carbonatiche del Permiano medio e superiore.Il materiale clastico (per lo più elementi già litificati di rudstones e boundstones) prodottosi in seguito a ripetuti eventi erosivi, è stato trasportato lungo la scarpata mediante flussi gravitativi e potrebbe aver costituito il riempimento di canali incisi nei depositi permiani di bacino rappresentati nella sezione del Torrente San Calogero, contigua alla Pietra di Salomone.I dati biostratigrafici ricavati dagli elementi e dalla matrice marnosa delle brecce e quelli provenienti dai depositi di bacino, indicano che lo smantellamento dei margini della piattaforma si è protratto almeno dal murgabiano allo Giulfiano.Il confronto fra le faune di scogliera presenti nella Pietra di Salomone con quelle del Permiano inferiore presenti nei carbonati clastici della ‘Formazione’ Lercara (Cozzo Intronata, Fiume San Filippo) evidenzia una variazione nella composizione delle associazioni algali e delle spugne calcaree, variazione registrata dopo l’Artinskiano, probabilmente alla base del Permiano medio (Kubergandiniano).

Microfacies of carbonate slope boulders: Indicator of the source area (Middle triassic: Mahlknecht cliff, western Dolomites)

SummaryPaleontological and microfacies criteria of limestone boulders occurring within megablocks deposited on clinogonal slopes provide indications of the source area of Middle Triassic allochthonous carbonates exposed in the Mahlknecht cliff, Seiser Alm, Dolomites. Microfacies, biotic composition, a high percentage of low-growing binding and baffling communities (sponges, algae, microproblematica) as well as the remarkable coincidence with distributional patterns observed on other Ladinian paleoslopes indicate a source area characterized by common bioconstructions, which is situated on a subtidal upper and middle foreslope and not at the platform/slope-margin or on the carbonate platforms.RiassuntoI megablocchi calcarei del Trias medio affioranti vicino al Rif. Molignon (Alpe di Siusi, Dolomiti) sono costituiti di clasti carbonatici risedimentati. Il loro studio ha permesso di formulare un’ipotesi sull’area di alimentazione dei clasti stessi.I dati paleontologici, l’analisi e la distribuzione delle microfacies, l’alta percentuale di organismi ‘binding’ e ‘baffling’ a basso tenore di crescita) spugne, alghe e microproblematici) indicano una sorgente di alimentazione caratterizzata da biocostruzioni simili a quelle osservate in altre paleoscarpate ladiniche. In particolare tale sorgente doveva essere ubicata in ambiente subtidale nella parte media ed alta della scarpata e non al margine piattaforma/scarpata o sulla piattaforma stessa.

Upper permian segmented sponges from Djebel Tebaga, Tunisia

SummaryUpper Permian (late Murgabian and early Pamirian) reefs and interbedded terrigenous rocks exposed in Djebel Tebaga (southern Tunisia), represent the only marine deposits in the whole of the African continent. These carbonates contain one of the best preserved and most diverse sponge assemblages of Permian age. These fossiliferous deposits contain a rich faun and flora.The sponge fauna of the reef carbonates of Djebel Tebaga include representatives of the Demospongea, ‘Sclerospongea’, and Inozoa, as well as the thalamid sponge (‘Sphinctozoans’). The thalamid sponges are described in this paper and the taxa described by TERMIER & TERMIER (in TERMIER, TERMIER & VACHARD 1977a, this paper is cited as TERMIER & TERMIER 1977a) from the some locality are compared and evaluated. The following taxa are described as new:Amblysiphonella obliqua n. sp.,Amblysiphonella ramosa n. sp.,Amblysiphonella? bullifera n. sp.,Colospongia cortexifera n. sp.,Platythalamiella newelli n. g., n. sp.,Tristratocoelia rhythmica n. g., n. sp.,Pseudoamblysiphonella polysiphonata n. g., n. sp.,Cystothalamia ramosa n. sp.,Tebagathalmia cylindrica n. g., n. sp.,Solenolmia permica n. sp.Enoplocoelia interchora n. sp.,Sollasia? amaurosa n. sp. undAmphorothalamia cateniformis n. g., n. sp..A representative of the thalamid demosponges with monaxial spicules and with a new type of filling tissue is described asPisothalamia spiculata n. g., n. sp. (family Pisothalamiidae n. fam.) This sponge differs from other demosponges by having well developed outer and inner segmentation, by a new type of pisoid-like filling tissue and by other features. The new order Pisothalamida is proposed for this group of demosponges.Pisothalamia represents the first ‘sphinctozoan’ sponge with spicules, known from the Permian.The described fauna shows strong affintities on generic and specific levels to the sponge fauna known from the somewhat older allochthonous reef limestones of the Sosio Valley in Sicily.Observations on some specimens of thalamid sponges indicate that living sponges occupied more than the uppermost chambers in at least some species.ZusammenfassungDas einzige Vorkommen von marinem Perms auf dem afrikanischen Kontinent, die oberpermischen Riffkalke im Gebiet des Djebel Tebaga in Süd-Tunesien (oberes Murgab bis tiefes Pamir bzw. Midin), ist durch die reiche Fossilführung und durch die ausgezeichnete Erhaltung der Faunen-und Florenelemente berühmt.Die Schwämme sind durch Demospongien, Sclerospongien, Inozoen und durch thalamide Formen (“Sphinctozoa”) vertreten. Letzte werden im Rahmen dieser Arbeit aufgrund von umfangreichen Aufsammlungen systematisch dargestell und den von TERMIER & TERMIER (1977a, 1977b) beschriebenen Taxa gegenübergestellt (Tab. 4).Insgesamt konnten 24 Gattungen (darunter 6 neue Genera) und 29 Arten (14 neu) unterschieden werden. Folgende Taxa sind neu:Amblysiphonella obliqua n.sp.,Amblysiphonella ramosa n. sp.,Amblysiphonella? bullifera n. sp.,Colospongia cortexifera n. sp.,Platythalamiella newelli n. g., n. sp.,Tristratacoelia rhythmica n. g., n. sp.,Pseudoamblysiphonella polysiphonata n. g., n. sp.,Cystothalamia ramosa n. sp.,Tebagathalamia cylindrica n. g., n. sp.,Solenolmia permica n. sp.,Enoplocoelia interchora n. sp.,Sollasia? amaurosa n. sp., undAmphorithalamia cateniformis n. g., n. sp..Ein Vertreter der thalamiden Demospongia mit monaxonen Mikroskleren und einem neuen (‘pisoidischen’) Füllskelett-Typ wird alsPisothalamia spiculata n. g., n. sp. (Familie Pisothalamiidae n. fam., Ordnung Pisothalamida n. ord.) beschrieben.Pisothalamia stellt den ersten bekanten thalamiden Schwamm mit einem spikulärem Skelett im Perm dar.In der Fauna des Djebel Tebaga überwiegen Vertreter der ‘poraten’ Kalkschwämme.Ein Vergleich der in Tunesien auftretenden Taxa mit Schwammfaunen aus älteren Schichten (Venezuela— Word, etwa Kubergand; Sosio/Sizilien—etwa hohes Kubergand und tiefes Murgab) sowie aus jüngeren Schichten des höheren Perms (Texas—Capitan, etwa Midin bis unteres Pamir; Lichuan/China—Changsing, etwa Dorasham) zeigt, daß die größten Übereinstimmungen auf Gattungs-und Artenebene mit der aus Sizilien beschriebenen Fauna gegeben sind (Tab. 3). Einige der in der tunesischen Fauna vorkommende Gattungen treten auch in der Trias auf.Ein zur Lebzeiten der Schwämme erfolgter Algenbewuchs, der die Ostien ausspart, kann als Hinweis darauf angesehen werden, daß bei einigen thalamiden Schwämmen das Gewebe des lebenden Schwammes mehr als nur die “oberste” Kammer erfüllte.

Obertriadische Riffe und Rifforganismen in Sizilien (Beiträge zur Paläontologie und Mikrofazies obertriadischer Riffe im alpin-mediterranen Raum, 27)

ZusammenfassungIn Nordwest- und Zentralsizilien (Panormide-Gebirge westlich Palermo; Madonie-Gebirge) sind am Rand ausgedehnter Karbonatplattformen obertriadische Riffe entwickelt, deren norisches Alter durch Heterastridien und Ammoniten belegt ist. Es handelt sich um Schwamm-Bryozoen-Riffe, deren Faunen- und Florenbestand weitgehende Übereinstimmung mit etwa gleich alten Riffen in den Nördlichen Kalkalpen (Dachsteinkalkriffe) besitzt. Es sind folgende Organismengruppen vertreten (Die im Rahmen dieser Arbeit als Bryozoen bezeichneten Organismen stellen höchstwahrscheinlich keine Bryozone dar. Alle diese Organismen sind vermutlich zu den Chaetetiden oder Sclerospongien zu stellen): lien und Astraeomorphen); 3. Hydrozoen (selten bis auf Disjectoporiden); 4. Bryozoen/Tabulozoen (häufig und hochdivers; bei Chaetetiden-ähnlichen Fossilien dürfte es sich um Sclerospongien handeln); 5. Algen (überwiegend an den Lagunenbereich und an den Übergangsbereich Lagune/Riff gebunden; es treten Dasycladaceen, Solenoporaceen sowie porostromate und spongiostromate Cyanophyceen auf; von Interesse ist das Vorkommen von Dasycladaceen-Sporen (Taf. 23/11)); 6. Foraminiferen (im Artenbestand mit den Foraminiferen-Assoziationen der nordalpinen Obertrias übereinstimmend; hierzu tretenFoliotortus PILLER & SENOWBARI-DARYAN sowie vasenförmige Gehäuse, die unter den NamenCucurbita, Amphorella etc. bisher nur aus der Obertrias der Westkarpaten sowie von der Hohen Wand bei Wien bekannt (wurden); 7. Problematika (ähnlich wie in der Riff-Fazies der alpinen Obertrias).Am Cozzo di Lupo, W Palermo können die Faziestypen des Riffes und der Lagune lateral verfolgt werden: An eine durch Schwamm-Bryozoen-Biolithite mit zahlreichen, zementerfüllten Hohlräumen gekennzeichnete Zone schließt sich eine durch Korallen (Thecosmilien), Algen (Dasycladaceen, Solenoporaceen, Cayeuxien), Gastropoden und Megalodonten charakterisierte Zone an (Korallen-Algen-Biolithit), in welcher sich Bänke mit Korallen und Bänke mit Megalodonten vertikal ablösen. Vereinzelt treten kleine Riffknospen auf, deren Fazies derjenigen der Schwamm-Bryozoen-Biolithite entspricht. Die Korallen-Algen-Biolithit-zone geht in eine zone mit Stromatolithen und Fenstergefügen über (Loferit-Fazies).Die Verteilung der Organismen innerhalb der Faziesbereiche kann mit ähnlichen Assoziationen in der nordalpinen Obertrias verglichen werden (Abb. 3): 1. Korallen sind jedoch im Gegensatz zu vielen alpinen Riffen in der Schwamm-Bryozoen-Biolithit-Fazies als Gerüstbildner nur von geringer Bedeutung. Thecosmilien treten insbesondere im Übergangsbereich zwischen Riff und Lagune sowie in der Lagune auf, wo sie Biostrome bilden.—2. Kalkschwämme, Hydrozoen, sowie Bryozoen/Tabulozoen waren auf geringenergetische, tiefere Wasserbereiche beschränkt. Epi- und Endofauna dieser Assoziationen entspricht der von Kalkschwamm-Biozönosen aus der nordalpinen Obertrias.—3. Algen zeigen stark differenzierte Verbreitungsmuster; Spongiostromen sind auf die Schwamm-Bryozoen-Biolithit-Fazies beschränkt, Cayeuxien finden sich in der Lagune zusammen mit Thecosmilien und Megalodonten. Ebenfalls in der Lagune sind Dasycladaceen (insbesondereHeteroporella undDiplopora) weit verbreitet. Solenoporaceen sind vor allem in der Riff-Fazies sehr häufig.—4. Foraminiferen sind mitGaleanella, Ophthalmidium und “Lituosepta” auf die Schwamm-Bryozoen-Biolithit-Fazies beschränkt, während eine zweite, durchAlpinophragmium, Aulotortue, Glomospira und andere Gattungen gekennzeichnete Gruppe in der Korallen-Algen-Biolithit-Fazies der Lagune auftritt. In Riffhöhlen der Schwamm-Bryozoen-Biolithit-Fazies finden sich als wichtige FaziesindikatorenFoliotortus, Cucurbita und ähnliche Mikrofossilien, die wahrscheinlich als Foraminiferen anzusehen sind.—5. Auch die Mikroproblematika weisen bestimmte Verteilungen auf (Microtubus, Radiomura, Baccanella in der Schwamm-Bryozoen-Biolithit-Fazies;Bacinella, Thaumatoporella, Aeolisaccus undTubiphytes häufig in der Lagunenfazies).Der Ablagerungsraum des Cozzo di Lupo-Riffes (Abb. 4) ist durch eine, in etwas tieferem Wasser liegende Riffzone (Schwamm-Bryozoen-Biolithit-Fazies) gekennzeichnet, an welche sich in Richtung zur Lagune eine relativ hochenergetische Übergangszone anschloß. In der gut durchlichteten, flachen Lagune entstanden Korallen-Siedlungen, Dasycladaceen-Rasen und Megalodonten-Bänke. In geschützten, lagunären Bereichen konnten durch Schwämme und Bryozoen/Tabulozoen kleine Riffknospen gebildet werden. Die Lagune dürfte sich gegen Norden und Nordosten verflacht haben (angedeutet durch Stromatolithen, Fenstergefüge, geringe Diversität). Grundsätzlich ergeben sich auffallende Ähnlichkeiten mit dem Faziesmodell der Steinplatte (PILLER & LOBITZER 1979).SummaryUpper Triassic reefs were built at the margins of carbonate platforms in north-western and central Sicily (Panormide Mountains west of Palermo; Madonie Mountains). The Norian age of these reefs is evidenced by ammonites and the occurrence ofHeterastridium. The reefs are represented by Sponge-Bryozoan reefs; fauna and flora are very similar to those of Upper Triassic reefs of the Northern Calcareous Alps (Dachsteinkalk reefs). The biota consists of:1. Calcisponges (especially sphinctozoans; more than 30 species); 2. Corals (of minor importance, low-diverse, predominantlyThecosmilia andAstraeomorpha); 3. Hydrozoans (rare, except disjectoporids): 4. Bryozoans/Tabulozoans (abundant, high-diverse; some chaetetid-like fossils may represent sclerosponges); 5. Algae (common within the transition area between the reef and the lagoon and in the lagoon; dasycladaceans, solenoporaceans as well as porostromate and spongiostromate cyanophyceans occur; of special interest is the occurrence of dasycladacean spores (P1. 23/11); 6. Foraminifera (the same species as in the Alpine Upper Triassic; in additionFoliotortus PILLER & SENOWBARI-DARYAN and amphora-like tests (Cucurbita, Amphorella etc., until now only known from the Upper Triassic of the Western Carpathians and from the Hohe Wand near Vienna, Austria); 7. Problematica (similar to the species found in Alpine reef limestones).A lateral transition of the facies types can be followed at the Cozzo di Lupo, west of Palermo: (1) Sponge-Bryozoan Biolithite-zone (central reef area) characterized by low-growing framebuilders and abundant cement infillings in cavities; (2) Coral-Algal Biolithite-zone (lagoon) withThecosmilia, algae (dasycladaceans, solenoporaceans,Cayeuxia), gastropods and megalodontid pelecypods; some small reef patches (similar in facies with the sponge-bryozoan-biolithite facies) may occur within this zone; (3) Loferite zone (lagoontidal flat) with stromatolites and fenestral fabrics.The distributional patterns of the fossils within the facies units can be compared with those of the reefs in the Northern Calcareous Alps (Fig. 3): 1. Corals are of minor importance within the spongebryozoan facies, but occur predominantly in the transitional area between the reef and the lagoon, and within the lagoon (biostromes withThecosmilia).—2. Calcisponges, hydrozoans and bryozoans/tabulozoans were restricted to somewhat deeper, low-energy environments. Epi- and endofauna of these associations are similar to those of calcisponge biocoenoses of the Alpine Upper Triassic.—3. Algae exhibit strongly differentiated distributional patterns: Spongiostromate algae and solenoporaceans occur predominantly within the sponge-bryozoan biolithite. The lagoonal environment is characterized byCayeuxia (together withThecosmilia and with megalodontid pelecypods) and dasycladaceans (Heteroporella, Diplopora).—4. Foraminifera are useful facies fossils: The association withGaleanella, Ophthalmidium and “Lituosepta” is restricted to the sponge-bryozoan biolithite facies, whereas the association withAlpinophragmium, Aulotortus, Glomospira and other genera occurs in the coral-algal biolithite facies. A third association, characterized byFoliotortus, Cucurbita and similar microfossils, is typical of biotopes within reef cavities.—5. Microproblematica show special distributional pattens:Microtubus, Radiomura, andBaccanella in the sponge-bryozoan biolithite facies;Bacinella, Thaumatoporella, Aeolisaccus andTubiphytes in the lagoonal facies.The environment of the Cozzo di Lupo reef complex (Fig. 4) is characterized by a reef zone, which developed in a slightly deeper area (sponge-bryozoan biolithite facies), bordered by a moderate to high-energetic transitional zone. The shallow, well-lighted lagoon was characterized by coral biostromes, dasycladaceans and megalodontids flourishing on the mud bottoms. Small reef patches were formed by calcisponges and bryozoans/tabulozoans in more protected areas of the lagoon. A shallowing of the lagoon might have occurred to the north and northeast, as indicated by stromatolites, fenestral fabrics and a generally low-diversity. The facies model of the Cozzo di Lupo reef is similar in many respects to that of the Upper Rhaetian Steinplatte reef near Waidring, Austria (PILLER & LOBITZER 1979).

The late jurassic ‘Massenkalk fazies’ of Southern Germany: calcareous sand piles rather than organic reefs

SummaryUpper Jurassic (Malm δ to ζ1) massive limestones (‘algal-sponge-reefs, sponge-reefs, reef-complexes, reefs, algal-sponge-bioherms, biolithites, Massenkalk, bioherms, Stillwasser-Mudmounds’) were analyzed in the Southern Swabian Alb, the Southern Franconian Alb and in drilling wells in the Molasse basin (Southern Bavaria). This analysis was carried out within the frame of a multidisciplinary DFG-study with the objective of decifering the controls on the development of Upper Jurassic spongiolites, their three-dimensional distribution, their characteristic faunal composition, and the diagenetic trends of the different primary facies.The data base consists of detailed facies mapping in the areas of the Eybtal and the Blautal (1300 samples) as well as comparative studies in the Upper Donautal (Swabian Alb) and the Southern Franconian Alb (400 samples). All together about 500 thin sections were studied. The distribution of the most important components (ooids, intraclasts, peloids, corals, sponges, sponge spicules, cyanobacterial crusts, brachiopods, molluscs, echinoids, bryozoans, serpulids,Terebella, Tubiphytes), and diagenetic features (dolomite, dedolomite, silicification, stylolites, clay flasers, hematite patches) results in a spatial distribution pattern of facies types.The largest part (70 %) of the massive limestones consists of a peloid-lithoclast-ooid sand facies rich in completely or partly micritized ooids. These ooids, especially in beds of the Malm δ to ε, might be the clue to a reinterpretation of the water depth. True biogenic constructions occur (about 30 % of the volume; sponge-algalmudmounds, algal-sponge-boundstones, and brachiopod-algal-sponge-mounds) within and at the margins of this facies and are interpreted as platform sands. The spatial distribution of the buildups in relation to the sand facies was probably controlled by hydrodynamic conditions. In addition, zoned sponge-algal-mounds occur in intraplatform channels and nodular sponge-algal-mudmounds in the marly basin sediments between platform sand areas.Breccias and slumpings in beds older than the Malm ζ have to be reinterpreted. Most of the breccias found originated from the flanks of the sand platforms, reflecting the faunal composition of the algal-sponge-boundstones which stabilized the flanks. Breccias of this composition occur throughout the Malm δ-ζ1 and differ markedly in their composition from the sand facies. The boundary breccia (Malm ε/ζ1) is interpreted as marking a regressive maximum. The increasing growth of buildups, rich in brachiopods in the Malm ζ1, is ascribed to an increase of reef growth at the beginning of a transgression.Detailed facies analyses necessary for the reconstruction of the spatial distribution of different facies types are in progress. Most of the older data on faunal distributions cannot be used for detailed facies analysis because they differentiated only between massive facies and bedded facies. Therefore Upper Jurassic limestones of Southern Germany should be restudied in order to recognize the volumetric importance of sand facies and buildups within massive limestones.

The Upper Triassic Pantokrator Limestone of Hydra (Greece): An example of a prograding reef complex

The Pantokrator Limestones from the Island of Hydra and the Didymi Mountains (southern Argolis, Greece) form a heterogenous complex up to 1000 m thick, with lateral and vertical interfingerings of different facies units (Fig. 3).Sedimentation in the Didymi Mountains (Fig. 1) was dominated by the deposition of lagoonal to tidal shallow-water platform limestones of Carnian to Liassic age.The vertical section of the Upper Triassic rocks exposed on Hydra (Fig. 2) shows a variety of facies units: Laminated cherty mud-limestones (“Hornsteinplattenkalke”) occur at the base of the complex and dominate the southern portion of the island. The thickness of the shallow-water carbonates (Pantokrator Limestones) increases towards the north. Sedimentation started with the deeper-water deposition of biodetrital mud-limestones, which are overlain by reef-limestones and finally by lagoonal to tidal carbonates. According to the faunal and floral associations, the laminated cherty mud-limestones and the biodetrital mud-limestones are thought to be of Carnian age, the reef limestones of Carnian/Norian age, and the loferites and lagoonal sediments of Norian/Rhaetian age.The biota of the reef-limestones on Hydra shows a vertical zonation (Fig. 4), which first starts with a coral-sponge-association followed by a sponge-(coral-) association and finally, a coral-association. This sequence is believed to have been caused by the continuous shallowing of the marginal platform and reef areas.The environmental analysis and interpretation of the facies units are based mainly on the occurrence and distribution of calcareous algae as well as their roles in carbonate production (Figs. 6–7).Reconstruction of the depositional environment was carried out by a study of the relationship between the facies units, indicating a basinward progradation of the platform margin towards the south (Fig. 5).ZusammenfassungDer Pantokrator-Kalk der Insel Hydra und des Didymi-Gebirges (südliche Argolis, Griechenland) bildet einen bis zu 1000 m mächtigen, heterogenen Karbonatkomplex, der aus verschiedenen Fazies-Einheiten besteht (Abb. 3).Im Didymi-Gebirge (Abb. 1) wurden im Zeitraum Karn bis Lias überwiegend lagunäre bis tidale Flachwasserkarbonate gebildet.In der Obertrias der Insel Hydra (Abb. 2) können vier, vertikal übereinanderfolgende Fazies-Einheiten festgestellt werden, wobei die nördlichen Flachwasser-Karbonate entlang einer E-W gerichteten Störung auf eine südliche Einheit mit Tiefwasser-Karbonaten aufgeschoben ist. Die Basis des Kalkkomplexes bilden “Hornsteinplattenkalke” (laminated cherty mud limestones). Die Mächtigkeit der Flachwasser-Karbonate (Pantokrator-Kalk) nimmt gegen Norden zu, wobei die Sedimentation zunächst noch im tieferen Wasser einsetzt. Dieses Stadium ist durch gut gebankte biodetritische Schlammkalke (biodetrital mud-limestones) gekennzeichnet, in welchen intraformationelle Brekzien sehr häufig sind. Diese Kalke werden von grobgebankten Riff-Kalken und schließlich durch lagunäre und tidale Karbonate überlagert. Die laminierten Hornsteinplattenkalke und auch die biodetritischen Schlammkalke sind aufgrund von Makro- und Mikrofossilien in das Karn einzuordnen, die Riffkalke enthalten sowohl karnische als auch norische Faunen- und Florenelemente; die Loferite und lagunären Kalke sind in den Bereich Nor/Rhät zu stellen.In der Zusammensetzung der Riff-Fauna drücht sich eine vertikale Zonierung aus (Abb. 4), die mit einer Korallen-Kalkschwamm-Assoziation beginnt, an welche sich eine Kalkschwamm- (Korallen)-Assoziation und schließlich eine Korallen-Assoziation anschließen. Diese Zonierung zeigt die kontinuierliche Verflachung des Plattformrandes und des Riffgebietes im Zeitraum Karn bis Nor/Rhät.Das aus der Verteilung der Fazies-Einheiten ableitbare Fazies-Modell (Abb. 5) entspricht dem eines fortschreitenden Riffkomplexes, der sich mit dem Plattformrand in der Zeit beckenwärts verlagert.Die Rekonstruktion der Ablagerungsbedingungen der einzelnen Fazies-Einheiten fu\t im wesentlichen auf den Verteilungsmustern der Kalkalgen (Abb. 6 und 7), die bei der Bildung der Pantokrator-Kalke als Gerüstbildner, als Riffbewohner, als Produzenten von biodetritischen Sedimentpartikeln, als bohrende Organismen, als Sedimentfänger und-Binder sowie als karbonatfällende Organismen von wesentlicher Bedeutung sind. Dies gilt insbesondere für die sehr hohe Zahl von porostromaten Algen und von Tubiphyten.

THE OLDEST TRIASSIC PLATFORM MARGIN REEF FROM THE ALPINE - CARPATHIAN REGION (AGGTELEK, NE HUNGARY): PLATFORM EVOLUTION, REEFAL BIOTA AND BIOSTRATIGRAPHIC FRAMEWORK

The 1:10,000 scale mapping of the southern part of the Aggtelek Plateau (Western Carpathians, Silica Nappe, NE Hungary) and the study of five sections revealed two Middle Triassic reef bodies. In the late Pelsonian the uniform Steinalm Platform was drowned and dissected due to the Reifling Event. A connection with the open sea was established, indicated by the appearance of gladigondolellid conodonts from the early Illyrian. Basins and highs were formed. In the NW part of the studied area lower - middle? Illyrian basinal carbonates were followed by a platform margin reef (early?-middle Illyrian; reef stage 1) developed on a morphological high. This is the oldest known Triassic platform margin reef within the Alpine-Carpathian region. The reef association is dominated by sphinctozoans and microproblematics. The fossils are characteristic of the Wetterstein-type reef communities. Differently from this in the SE part of the studied region a basin existed from the late Pelsonian until the early Ladinian. During the late Illyrian- early Ladinian, the reef prograded to the SE, and reef stage 2 was established. Meanwhile, on the NW part of the platform a lagoon was formed behind the reef. Based on our palaeontological study the stratigraphic range of Colospongia catenulata, Follicatena cautica, Solenolmia manon manon, Vesicocaulis oenipontanus must be extended down to the middle Illyrian. Synsedimentary tectonics were detected in the 1. Binodosus Subzone, 2. Trinodosus Zone - the most part of the Reitzi Zone, 3. Avisianum Subzone.