Cherty Limestone Research Articles

Late Triassic radiolarians from the Grivska formation, internal Dinarides, SW Serbia

Upper Triassic (upper carnian - rhaetian) grey cherty limestone are known in the internal Dinarides under the name of ?Grivska Formation?. Sediments of the Grivska Formation are characterized by microfossils only - conodonts and radiolarians, and did not yield any macrofossils. Micropa - laeontological research of Upper Triassic siliceous rocks was performed at the locality Lim river, in the vicinity of Bistrica Village in SW Serbia. Radiolarian assemblages are characterized by such species as Capnodoce anapetes De Wever, C. sarisa De Wever, Sarla hadrecaena (De Wever), Praehexasaturnalis tenuispinosus (Donofrio & Mostler), Xiphothecaellla longa (Kozur & Mock). According to the radiolarian data, the investigated cherts are of latest carnian to early norian age.

New paleontological and stratigraphical data on the upper - cretaceous transgression of the Pelagonian zone s.l. (Marmeiko, Ptoon Mt. NE Beotia)

This paper concerns the study of a transgressive series, which overlies the upperjurassic oolitic limestones of subpelagonian zone, as well as the lateritic deposits, resulting from the alteration of the ophiolitic and fill the karstic cavities of the above mentioned limestones in NE Beotia (Fig.l). The purpose of this study is to• elucidate the age of the transgression, that occurred on the Jurassic limestones of the pelagonian platform at this region.• Discuss about the observed diachronism of the Late Cretaceous transgression on the Pelagonian platform.It is based on the study of micro- and macrofauna occurred in a section we describe in the "Marmeiko" area, on the Ptoon mountain. NOETH (1931) was the first who defined as Upper Turonian the age of the transgressive series, based on the study of Rudists. Later, BIGNOT & GUERNET (1968) studied the microfauna and attributed an age of lower Senonian. STEUBER (1993) based on the study of Hippuritidae, defined as Turonian and later (1995) as Turonian - Coniacian the age of the transgessive series. The basal part of the series consists of marls and marly limestones alternations. An abundant micro and macrofauna is found in this part of the section, as well as the first Rudist biostrome. In the middle part of the section 2 Rudist biostroms alternate with bioclastic limestones, containing abundant microfauna. In the upper part marls alternate with cherty limestones. The determinated micro- and macrofauna (Fig. 1), precises the age of the transgressive series as Santonian. This result confirms the diachronism of the transgressive phenomenon on the Pelagonian Upper- Jurassic limestones and the overthrusted ophiolites (AUBOUIN et al. 1960, BRUNN et al. 1972, KALLERGIS & ALBANTAKIS 1970, MAVRIDIS et al. 1979, NOETH 1931, BIGNOT & GUERNET 1968, CLEMENT & FERRIERE 1973, BIGNOT et al. 1973, STEUBER 1993, 1995, SKARPELIS & ZAMBETAKIS – LEKKAS 1998)

Early Cambrian trace fossils at the northern margin of the Arabian Plate; Telbesmi Formation, Turkey

The Telbesmi Formation, at the northern margin of the Arabian Plate, Turkey, is composed of alternating darkbrown, pinky-brown fluvial arkosic sandstone/mudstones with thin-bedded cherty limestones and channel conglomerates. The formation contains rare and poorly diversified trace fossils. The siltstone/sandstone beds of levels 1 and 2 of the formation yielded, however, a moderately diverse assemblage composed of: Cochlichnus isp., Palaeophycus isp., Planolites beverleyensis , Teichichnus isp. and ? Treptichnus rectangularis . This assemblage, made up of traces left by deposit feeding organisms, represents the Scoyenia ichnofacies. Treptichnus rectangularis and Palaeophycus isp., of the assemblage, can be considered markers for the base of the Cambrian in southeast Turkey.

1:5,000 geological map of the upper Cretaceous intraplatform-basin succession in the "Gravina di Matera" canyon (Apulia Carbonate Platform, Basilicata, southern Italy)

Along the slopes of the Gravina di Matera canyon, below and in front of the Sassi di Matera, i.e., the old Matera town (Basilicata, southern Italy), an about 200 m thick succession of upper Cretaceous carbonates extensively crops out. These carbonates belong to the Apulia Carbonate Platform and, in the official geological map, are referred to the Calcare di Altamura Fm, a lithostratigraphic unit composed of shallow-marine peritidal limestones. In order to study the whole outcropping succession, a geological survey was performed in the area and an unaspected intraplatform shallow-basin suite of limestones has been recognized within the Calcare di Altamura Fm. On the basis of lithologic characters, the whole succession has been divided into informal lithostratigraphic units a-g. The base of the succession (unit a) is represented by a crudely stratified bioclastic floatstone-rudstone locally interested by in situ brecciation, a phenomenon that often is the precursor of deep changes in a carbonate platform. Unit a sharply passes upward to thinly bedded and finely planar-laminated mudstone interested by slumps (unit b), conformably covered by dolostones (unit c). Dolostone gradually passes to cherty limestones (unit d) that in turn pass to wackestones (unit e) covered by a megabreccia (unit f). All these units (a-f) indicate that this area of the Apulia Platform performed a change from classic platform environments to slope- and to basin-ones, before the restarting of typical facies of shallow-marine carbonate platform environments (unit g). This subdivision in units of the outcropping succession led us to informally define a member, the Matera member (ALT1), within the upper Cretaceous Calcare di Altamura Fm (ALT). Most likely, the Matera member (units a-f) represents a shallow-basin developed within the Apulia Platform during Late Cretaceous, most likely related to extensional tectonics. Other examples of slope-to-basin sedimentary suite were previously observed within the upper Cretaceous succession of the Apulia Platform and the occurrence of another shallow-basin in the interior of the same platform opens a new and still understimated regional tectonic- and paleogeographic-scenario. Moreover, it should be highlighted that the geological surveyed area belongs to a Regional Natural Park since the 1990 (Parco Archeologico Storico Naturale delle Chiese Rupestri del Materano also known as Parco della Murgia Materana) and that Matera, besides being in the Unesco Word Heritage list since the 1993, has been voted European Capital of Culture 2019. Therefore, the obtained 1:5,000 geological map, apart from documenting some lithostratigraphic evidences of the intraplatform basin, represents an essential tool for both (i) future studies regarding the upper Cretaceous tectono-stratigraphic evolution of the Apulia Platform, and (ii) a geological base for many visitors interested in the cultural and geological heritage of Matera and its territory.

Discovery of a long-term refuge for ostracods (Crustacea) after the end-Permian extinction: a unique Carnian (Late Triassic) fauna from the Mersin Mélange, southern Turkey

The Mersin Mélange, located in southern Turkey north-west of the city of Mersin, includes blocks and tectonic slices of different origins. The Kilek section in the Mersin Mélange was sampled for a thorough examination of its lithology, biostratigraphy and fossil content. Two samples from the cherty limestone layers within the Huglu Tuffites at the top of the section yielded a rich silicified ostracod fauna of late Early Carnian (based on a two-fold Carnian subdivision) or middle Middle Carnian age (based on a three-fold Carnian subdivision), deposited in an open marine environment, in the outer platform-upper slope zone. We report 121 ostracod species belonging to 53 genera. Two new genera are described: Edithobairdia Forel gen. nov. and Gencella Forel gen. nov., as well as 16 new species: Acanthoscapha mersinella Forel sp. nov., Bairdia hugluensis Forel sp. nov., Acratia kollmanni Forel sp. nov., Citrella? carniana Forel sp. nov., Cytheropteron? schornikovi Forel sp. nov., Eucytherura lacerata Forel sp. nov., Gencella taurensis Forel sp. nov., Kerocythere dorsidenticulata Forel sp. nov., Kerocythere tricostata Forel sp. nov., Monoceratina praevulsaformis Forel sp. nov., Patellacythere tourkosella Forel sp. nov., Polycope kilekensis Forel sp. nov., Ptychobairdia praekristanae Forel sp. nov., Simeonella daginikella Forel sp. nov., Spinomicrocheilinella reliquiaella Forel sp. nov. and Triassocythere tavuscayiriensis Forel sp. nov. The diagnosis of Acratia goemoeryi Kozur is emended. The Kilek fauna retains primitive characteristics illustrated by the first known occurrence of Palaeocopida and Rectonariidae (typical Palaeozoic forms) in the Late Triassic, associated with typical Triassic–modern elements such as thick-shelled and ornamented Bairdiidae and diverse Cytheroidea known from the Middle and Late Triassic worldwide. The unique composition of Palaeozoic and Mesozoic taxa from the Kilek section illustrates unexpected long-term survival in a deep-sea refuge zone following the end-Permian extinction, and the diachronous character of the ostracod recovery in different environments.http://zoobank.org/urn:lsid:zoobank.org.pub:662C3D5C–2B86–4D7B–BDB5–8F8B6A1AD1E7

A Reiflingi esemény hatása az Északi-Mészkőalpok és az Aggteleki-hegység középső-triász fejlődésére

A Neotethys-óceán északi selfjének üledékképződésében jelentős változás következet be a középső-triász Binodosus szubzónájában (anisusi korszak, pelsói alkorszak). A sekélytengeri karbonátokat éles határral pelágikus mészkövek váltották fel, melyek bázisán gyakran tufitok is megjelennek (Reiflingi esemény). Az üledékképződésben bekövetkezett változás a pelsói korú karbonátrámpa ideiglenes megfulladását jelentette. Bár a jelenséget az Alp–Kárpáti–Dinári-térség számos feltárásából leírták, a rámpa megfulladásának időpontját illetően megoszlik a kutatók véleménye.Kutatásainkban két, jelenleg egymástól több száz km távolságra lévő területen, az Északi-Mészkőalpokban és az Aggteleki-hegységben vizsgáltuk a Steinalmi rámpa megfulladásának időpontját, és megállapítottuk, hogy mi okozta a karbonátrámpa megfulladását.Az Északi-Mészkőalpokban vizsgált szelvények: a Juvavikumban Schreiergraben, Schreierkogel, a Bajuvarikumban pedig Nixhöhle, Hocheck és Palfau. A karbonátrámpa (Steinalmi, illetve Annabergi Mészkő) megfulladása mindenütt a pelsói során következett be. Szárazföldi kitettségre (meteorikus diagenezis, karsztosodás) utaló nyomokat nem találtunk. A Bajuvarikum szelvényeiben a sekélytengeri képződményeket fedő pelágikus medencében képződött Reiflingi Mészkő legalsó része is pelsói korú. A schreiergrabeni feltárásban a Schreyeralmi Mészkő legalsó részén lévő mélytengeri lejtőbreccsa szintén pelsói korú. Schreierkogelnél a Schreyeralmi Mészkő alsó szintje csak a Steinalmi Mészkő felső részét harántoló késő-pelsói és kora-illír korú hasadékkitöltésekben őrződött meg.Az Aggteleki-hegységben (Szilicikum) a pelsói korú Steinalmi Mészkő vastagsága (145–155 m) és az egymást követő mikrofáciesek sorozata a vizsgált területen azonos. A Baradla-barlangban a Steinalmi Mészkövet harántoló neptuni telérekben talált conodonták három különböző időszakot jeleznek: 1) Binodosus szubzóna (késő-pelsói), 2) késő-pelsói, kora–középső-illír, 3) Trinodosus–Reitzi zóna (kora–középső-illír). A Schreyeralmi Mészkő a késő-pelsói–középső-illír időszak alatt ülepedett le.A Nagy-Jenei-tető ÉK-i részén felvett szelvényben a Steinalmi Mészkő egyenetlen felületére települő Schreyeralmi Mészkő bázisán pelsói és kora–középső-illír korú conodonták együtt fordulnak elő (kondenzált üledékképződés).A Steinalmi rámpa befulladása mindkét területen a késő-pelsóiban kövekezett be. A Neotethys-óceán riftesedése miatt a kéreg kivékonyodott, az aljzat lesüllyedt, a kéreg felső része szegmentálódott, a blokkok kibillentek és félárkok jöttek létre. A pelágikus mészkövek mindkét területen a differenciálódott aljzaton ülepedtek le.

Coastal types of graben: the Gulf of Gökova, Mugla-SW Turkey

Grabens are formed under the influence of extensional forces in a normal fault system. The Gulf of Gokova is an active graben located in SW Turkey. Active grabens such as the Gokova enclose highly faulted rocky coasts. Despite the existence of these rocky coasts, examination of google earth images, field studies, DEM analysis and previous studies in the Gulf of Gokova graben revealed that there could be different types of coasts in the region. In this study the factors causing the occurrence and potential environmental effects of the diverse coast types are evaluated. By using the Fairbridge (2004) coastal classification system, the coast types identified in the Gulf of Gokova graben can be classified as; A. Soft-less consolidated-erodible; A1: relatively Insoluble: detrital and loose beach, A2: soluble: beachrock and eolinite B. hard-cliffed-rocky, B1: longevity of hard-rock coast and B2: fault controlled cliffs. The percentages of these classes generally decreased from B1 (79%), A1 (12.4%), B2 (8.3%) and A2 (0.3%) in the study area. As a result of longshore currents, A1-type coasts usually develop as large plain adjacent streams and also in pocket beaches as narrow-long strips near rocky coasts. A2 type is observed in one location within the Gokova region, possibly due to local environmental conditions. However, B1 type developed in peridotites, cherty limestone and cliffs probably because of the active fault system and where the fault plane cut the coast, B2 type occurred. Possible threats to the Gokova region can be attributed to sea level rise owing to tectonism and global warming. It is anticipated that inundation, coastal erosion and salt water intrusion may also affect it.

The Grajcarek Succession (Lower Jurassic–mid Paleocene) in the Pieniny Klippen Belt, West Carpathians, Poland: a stratigraphic synthesis

A concise stratigraphic synthesis of the Grajcarek Succession of the Pieniny Klippen Belt (West Carpathians,Poland) is presented. This succession consists of 12 lithostratigraphic units with the rank of formation, and two with the rank of member, spanning the geological time from middle Toarcian (late Early Jurassic) to Maastrichtian (Late Cretaceous) and mid Paleocene. The stratigraphical column starts with deep-water flysch (the Szlachtowa Fm; Toarcian–Aalenian through Bajocian–?lower Bathonian), followed by dysoxic shales, marls and limestones (the Opaleniec Fm; Bajocian–Bathonian). The previously distinguished Krzonowe and Stembrow formations, are downgraded to members. Late Bathonian–Oxfordian times were characterized by the widely occurring deposition of abyssal radiolarites and shales, which is represented by the Sokolica Radiolarite Fm and the Czajakowa Radiolarite Fm, common to both the Grajcarek and Klippen successions. Red nodular limestones and aptychus marls (the Czorsztyn Limestone Fm; Kimmeridgian–lower Tithonian) overlie the radiolarites. Above, pelagic cherty limestones occur (the Pieniny Limestone Fm; Tithonian–Aptian). These are followed by Lower Cretaceous predominantly dark shales and marls (the Kapuśnica Fm; Aptian–Albian, the Wronine Fm; Albian, and the Hulina Fm; Albian–Cenomanian), succeeded by abyssal, red shales (the Malinowa Shale Fm; upper Cenomanian–Campanian), and these in turn by grey, marly, flyschoid strata (the Haluszowa Fm; ?Campanian). The Grajcarek Succession terminates with the Jarmuta Fm (Maastrichtian–mid Paleocene). It consists of sedimentary breccias, often with large olistoliths of Jurassic–Cretaceous rocks, and conglomerates and sandstones in a southern zone, giving way to proximal flysch and distal flysch facies further north. This was the time of orogenic Laramian folding events, associated with subaerial and submarine erosion. A sedimentary hiatus separates the Jarmuta Fm flysch (Maastrichtian) from the Szczawnica Fm (Upper Paleocene–Eocene) in both the Klippen and Grajcarek successions. This hiatus seems to diminish and finally close in a northward direction, in the Magura Nappe succession.

Basin evolution model during cretaceous in the northeastern of Arabian plate in Kurdistan region

The research area concentrates in a part of the main Zagros fold and thrust belt in the Kurdistan region (Northern Iraq). From study tectono-stratigraphy we constrain the story of the basin evolution of Kurdistan during Cretaceous. However we mainly investigated the evolution of the pre-Subduction and Pre-collision periods, focusing on the relationship between tectonics and sedimentation. For this purposes we developed (1) a biostratigraphic approach using nannofossil analysis, (2) a fault tectonic analysis, and (3) a stratigraphic study. The Zagros fold belt in Kurdistan exhibits many lateral and vertical environmental and facies changes, especially during the Cretaceous times. During the Jurassic period the Kurdistan is occupied by the restricted Gotnia Basin. This basin disappeared and the Kurdistan area changed to open marine of a southwest Kermanshah Basin during the Cretaceous. During the Berriasian to Barremian the Kurdistan was covered by the carbonates of the Balambo and Sarmord formations. In the east and southeast the neritic Sarmord Formation gradationally and laterally passes to the basinal facies of the Balambo Formation. In the Aptian to Cenomanian period shallow massive reefal limestone of the Qamchuqa Formation deposited. The normal faulting that initiates during the Aptian is associated with an abrupt lateral change of the reefal Qamchuqa Formation to the Aptian-Cenomanian part of the Balambo Formation. During the Cenomanian-Early Turonian periods the graben formed in the Dokan Lake in eastern Kurdistan, where developed a deeper restricted environment (Dokan and Gulneri formations) surrounded by a shallow marine platform. During the Turonian the marine pelagic micritic cherty limestones of Kometan Formation covered northeast of Kurdistan, whereas in the Safeen, Shakrok and Harir anticlines the formation was totally, or partially, weathered during the Coniacian-Early Campanian period. The deposition during the Late Cretaceous is very heterogeneous with a gap in the Coniacian-Santonian times probably related to a non-deposition. Associated with extensive tectonics a basin developed during the Campanian with the deposition of shales, marls and marly limestones of the Shiranish Formation. The first appearance is the Kurdistan of the flysch facies of the Tanjero Formation was precisely dated of the Upper Campanian in northeastern Kurdistan. The Tanjero Formation conformably overlaying the Shiranish Formation and was deposited in the foredeep basin associated with the obduction of Tethyan ophiolites onto the Arabian Platform. The Early to Late Campanian period is a time of non-deposition in Central Kurdistan (Safeen, Shakrok and Harir anticlines). During the Late Campanian the Bekhme carbonate platform in the north disappeared when the marly limestones of the Shiranish Formation transgressed over the Bekmeh Platform. In the Aqra area the Maastrichtian Tanjero Formation laterally changed to the thick reefal sequence of the Aqra Formation that unconformably overlies by the Late Paleocene-Early Eocene lagoonal carbonate of the Khurmala Formation. The Campanian sedimentation is mainly controlled by NE- oriented normal faults forming Grabens in Dokan, Spilk and Soran areas. During the Maastrichtian in the extreme northeastern Kurdistan the NE-SW and NNW-SSE normal faults developed in the foredeep basin and originated horsts and grabens.

NEOGENE STRATIGRAPHY OF THE İZMİR -OUTER- BAY ISLANDS

The volcaniclastics, derived from calcalkaline acidic-intermediate volcanism in the region during late Early Miocene, and lacustrine deposits of Middle Miocene and alkaline volcanics are exposed on Uzun Ada , Hekim Adasi, Cicek Adasi and Karantina Adasi in the Outer Gulf of Izmir. Kocadag volcaniclastics derived from Kocadag volcanism, by extruding mainly calcalkaline andesitic-dacitic products during Late Early Miocene, represents the exposed oldest rock unit. The volcaniclastic succession extending in the north of Uzun Ada is composed of pyroclastics in ignimbrite and blocky ash flow facieses, and epiclastics in volcanic mass flow (lahar) facies. Foca tuff, represented by rhyolitic ignimbrites, originated from an area around Foca and moving to an area around Uzun Ada, emplaced onto the Kocadag volcaniclastics in two main explosive stages. The Degirmentepe Member alluvial deposits composed of coarse volcanic detritus were deposited during a inactive period between the explosion stages. A K/Ar age of 16.0 Ma was obtained from a rhyolite dome, which shows lateral relationship with the correlant ignimbrites in Foca Peninsula, and so it is considered that Foca tuff emplaced onto the region at the end of late Early Miocene. Lacustrine-dominated Middle Miocene succession, which overlies the Foca tuff unconformably, differentiated as the Urla group. Urla group consists of alluvial Besiktepe Formation, the Pirnalli island volcaniclastics, which is composed of sublacustrine volcanic density-flow deposits and felsic ignimbrites, Hekim Adasi basalt comprising basic volcanics and lacustrine Urla limestone, respectively from bottom to top. Besiktepe Formation only exposed on Uzun Ada, overlies the Foca tuff with an unconformity indicating a basin margin deposition during the Middle Miocene. Pirnalli island volcaniclastic succession, which its lower boundary does not expose within the area on Hekim Adasi and Cicek Adalari, is mainly composed of epiclastics deposited by the dynamics of sublacustrine gravity flow and includes trachytic ignimbrite layers in various welding degrees. The main lithologic components of Pirnalli island volcaniclastics derived from alkaline trachytic volcanism, which was active during the Middle Miocene in Mentes Yarimadasi (peninsula). The eruption center of Hekim Adasi basalt intruding as a sill to the bottom of Urla limestone succession is on Hekim Adasi. Along the upper contact of the basalt intruding backshore deposits at the bottom of Urla limestone, the peperites occurred reflecting the interaction between molten lava and unconsolidated sediment. A K/Ar age of 14,8±0,8 Ma is obtained from the basic lavas called as trachybasalt and basaltic trachyandesite according to the major element composition. Hekim Adasi basalt, which exposed at the center of Foca Depression, can be correlated with both the Ilipinar basalt in Foca Yarimadasi the Ovacik basalt in Urla basin with respect to chrono- and lithostratigraphy. Urla limestone succession, which transgressively overlies Hekim Adasi basalt, begins with backshore mudstones, continues with foreshore deposits comprising stromatolitic oncoids and algal bioclasts and lasts with cherty limestones.

Paleoceanographic evolution and chronostratigraphy of the Aptian Oceanic Anoxic Event 1a (OAE1a) to oceanic red bed 1 (ORB1) in the Gorgo a Cerbara section (central Italy)

We performed a detailed study of the stratigraphic transition of Oceanic Anoxic Event 1a (OAE1a) to oceanic red bed 1 (ORB1) from the classic Gorgo a Cerbara section in the Umbria region of central Italy. We focused on a 25.5-m-thick stratigraphic succession, from which we analyzed 305 samples for total organic carbon (TOC), CaCO3, magnetic susceptibility, diffuse reflectance spectrophotometry and the stable carbon and oxygen isotopic composition of both bulk samples and organic matter. In the Gorgo a Cerbara section, the Selli Level of OAE1a (∼1.81 m thick) consists of laminated to bioturbated dark gray to black mudstones and shales with medium to dark gray radiolarian-rich silty to sandy layers and a maximum TOC content of 20.22%. The carbon isotopic values show a negative excursion (C3 stage, ∼0.14 m) at the base of the Selli Level, followed by a stepwise positive excursion (C4–C6 stages, ∼1.67 m) in the upper part of the Selli Level. The transition from OAE1a to ORB1 (∼3.19 m thick) is characterized by bioturbated greenish gray cherty limestones and marly limestones with subordinate marls, corresponding to stable carbon isotopic C7 stage and lasts for ∼0.75 Ma. The ORB1 interval (∼13.15 m) consists of reddish marly claystones, dark-red marlstones, red marly limestones and red calcareous shales which indicate a highly oxic environment. Our results reveal a stepwise transition from a predominantly mesotrophic and dysoxic to anoxic environment at the time that the OAE1a black shales were deposited to an oligotrophic and oxic environment during the transitional interval and finally to highly oxic conditions during the ORB1 interval. The nannoconid crisis occurs at the top of the C2 stage, just 0.34 m below the negative excursion in δ13C isotopic values. The massive CaCO3 dissolution phase occurs 0.25 m above the negative excursion; it persisted for 0.85 Ma and probably resulted from excess CO2, ocean acidification, and carbonate compensation depth (CCD) shoaling. Deposition of massive black shales occurs at the base of the C6 stage and lasted for 0.4 Ma.

Carbonate-to-biosilica transition at the Norian–Rhaetian boundary controlled by rift-related subsidence in the western Tethyan Lagonegro Basin (southern Italy)

The Lagonegro Basin, located in the Southern Apennines, Italy, records a transition from carbonate sediments of the Calcari con Selce Fm. (“Cherty Limestone”) to biosiliceous sediments of the Scisti Silicei Fm. (“Siliceous Shale”) around the Norian–Rhaetian boundary (NRB), Upper Triassic. Sedimentologic and chemostratigraphic analysis of three sections (Pignola-Abriola, Monte Volturino, and Madonna del Sirino) representing a proximal-to-distal transect across the basin document marine productivity, redox, and chemical weathering conditions. The basin was characterized by low to moderate productivity and mainly oxic deep waters, with no systematic secular variation throughout the ~10-Myr-long study interval. A weathering proxy, the chemical index of alteration (CIA*), shifts toward higher values (from ~0.70 to ~0.80) in all three study sections, suggesting development of warmer and/or more humid conditions just before the NRB. The lack of evidence for changes in marine productivity or redox conditions and the time-transgressive nature of the carbonate-biosilica transition suggests that the latter was caused not by changes in planktonic communities but, rather, by a rise in the CCD, the most likely cause of which was seafloor subsidence within the actively rifting Ionian Ocean (i.e., the westernmost branch of the Tethys Ocean). The tectonically active character of the Lagonegro Basin is also reflected in evidence of synsedimentary paleoseismic activity, e.g., numerous debris flows around the basin margins. The present study thus documents sedimentologic changes within a marginal basin in a geologically young ocean.

The relationships between soft-sediment deformation structures and synsedimentary extensional tectonics in Upper Triassic deep-water carbonate succession (Southern Tethyan rifted continental margin — Central Sicily)

We describe soft-sediment deformation structures into the Upper Triassic cherty limestone outcropping in the Pizzo Lupo section (Central Sicily, Italy), pertaining to the deep-water palaeodomain of the Southern Tethyan margin.In the study section, mainly consisting of thin-bedded mudstone/marl alternations with bedded chert intercalations, some lithofacies have been separated on the basis of the abundance of the calcium carbonate/clay content and the overall textural features.The deformational structures, displaying different deformational styles as folded and faulted beds, disturbed layers, clastic dikes, and slumps occur mainly in the deformed horizons that involve marl-dominated lithofacies. Small-scale water-escape structures involve beds with nodular fabric. Synsedimentary faults affect the mud-limestone dominated lithofacies, which are characterized by fault-rotating blocks producing lateral thinning. These bodies appear to have moved coherently along an overall planar surface.We relate these soft-sediment deformations to slump sheets, associated with down-slope sliding of sedimentary masses. The deformation mechanism and driving force for these soft-sediment deformations are due essentially to gravitational instability and dewatering. Detailing, rotational (slump) and translational (glide) slides and water-escape are the main processes causing the distinguished deformational styles.The synsedimentary extensional tectonics that affected the Upper Triassic pelagic deposits was the triggering process responsible for the instability of the seafloor inducing loss of coherence of the unconsolidated sediments on the sea bottom, developing a large number of gravity-driven slides.The analysis of both of these SSDSs and their relationships with the structural scenario allow us to hypothesise that they are seismically-induced.

Sea–land geology of Marettimo (Egadi Islands, central Mediterranean sea)

ABSTRACTWe present a 1:10,000 scale geological map of Marettimo Island and its offshore (Egadi Archipelago, central Mediterranean Sea). The map was achieved by integrating a new geological survey with data from recent, marine, geological and geophysical surveys acquired along the adjacent continental shelf. The island is composed of a Mesozoic, mostly carbonate platform succession, which is overlain by continental to coastal marine Quaternary deposits. Extensional tectonics have affected the carbonate platform since the Late Triassic producing an initial increase of accommodation space that was filled by interbed breccias, marls and calcareous marls. During the Jurassic, a NE-SW-directed normal fault-bounded structural lows where thick beds of megabreccias accumulated followed upwards by cherty limestone and bedded cherts. During the building of the chain, the compressional tectonics generated a southeast-verging tectonic wedge, displaced by subsequent transpression. During the Quaternary, repeated sea-level changes shaped a rough erosional surface along the inner shelf and controlled the lateral facies variation of the continental and marine coastal deposits along the present day coastline.

The Oligocene–Miocene stratigraphic evolution of the Majella carbonate platform (Central Apennines, Italy)

The stratigraphic architecture of the Bolognano Formation documents the evolution of the Majella carbonate platform in response to global and local changes that affected the Mediterranean area during the Oligocene–Miocene interval.The Bolognano Formation consists of a homoclinal ramp that developed in a warm, subtropical environment. Five different lithofacies associations have been identified: Lepidocyclina calcarenites, cherty marly limestones, bryozon calcarenites, hemipelagic marls and marly limestones, and Lithothamnion limestones. Each association corresponds to a single lithostratigraphic unit except for the Lepidocyclina calcarenites that form two distinct lithostratigraphic units (Lepidocyclina calcarenites 1 and 2). These six units reflect alternation of shallow-water carbonate production and drowning. Specifically, two of the three stages of shallow-water carbonate production regard the development of wide dune fields within the middle ramp, one stage dominated by red algae and a sea-grass carbonate factory, whereas the two drowning phases are represented by marly cherty limestones and calcareous marls. A new biostratigraphic framework for Bolognano Formation is presented, based on high-resolution analysis of calcareous nannofossil assemblages, which proved to be very useful for biostratigraphic constraints also in shallow-water settings. Using this approach, we have linked the first drowning phase, late Chattian–Aquitanian p.p. in age, to western Mediterranean volcanism and the Mi-1 event, and the second drowning phase, late Burdigalian–Serravallian in age, to the closure of the Indo-Pacific passage and the occurrence of the global Monterey event. These results permit a new deciphering, in terms of sequence stratigraphy, of the Bolognano Formation that is interpreted as a 2nd-order super-sequence that can be subdivided into 3 transgressive–regressive sequences.

The Permian and Triassic in the Albanian Alps

AbstractThe sedimentary succession of the Permian to Middle Triassic of the Albanian Alps is described, as part of the eastern Adria passive margin towards the Tethys. A carbonate ramp deepening towards NE in present day coordinates developed during the Middle Permian and was affected by block faulting with the deposition of carbonate breccia. The Early Triassic was characterized by intense terrigenous deposition with several cobble conglomerate units up to 80 m-thick, and by oolitic carbonate shoals. The fine clastic deposition ended gradually during the earliest Anisian and a wide calcarenitic ramp occupied the area, with small local carbonate mounds. Basinward, the red nodular limestone of the Han Bulog Formation was interbedded with calcarenitic material exported from the ramp. Drowning to more open conditions occurred towards the end of the Pelsonian. Subsequently, cherty limestone and tuffitic layers spread over the entire area. Towards the end of the Ladinian, with the end of the volcanic activity, red pelagic limestone was deposited locally for a short period. By the latest Ladinian most of the area returned to shallow-water conditions, with a peritidal carbonate platform. In the Theth area, in contrast, a basin with black organic-rich dolostone and limestone developed which seems to be unique in that part of the Adria passive margin. The occurrence of cobble conglomerate units in the Lower Triassic testifies to very active block faulting and high accommodation, not yet described for the area.

From rift to drift in South Pamir (Tajikistan): Permian evolution of a Cimmerian terrane

Here, we describe the Permian–Lower Triassic sedimentary succession of South Pamir and the associated biota of conodonts, foraminifers and brachiopods. The studied succession comprises the Carboniferous-Lower Permian siliciclastic Uruzbulak and Tashkazyk formations (Bazar Dara Group), which are unconformably covered by upper Lower to Upper Permian units, deposited both in platform settings (Kurteke Formation), and on the slope and basin (Kochusu Formation, Shindy Formation, Kubergandy Formation, Gan Formation, and Takhtabulak Formation). These formations comprise bioclastic limestones, cherty limestones, shales, volcaniclastic rocks, basalts, sandstones and conglomerates, and are locally very rich in fossils (fusulinids, ammonoids, brachiopods, corals and conodonts). The Permian succession is then overlain by shallow water carbonates of the Induan to Anisian Karatash Group. Subsidence analysis and volcanics of the Permian and overlying Triassic successions constrains the timing of rifting of South Pamir from Gondwana in the Early Permian (=Cisuralian), and its docking to Central Pamir, the Eurasian margin and the interposed volcanic arcs at the end of the Triassic. The sedimentary successions of the Pamirs represent a key-point to refine the correlations between the Tethyan regional scale and the International Time Scale. The analyses of the fusulinids and conodonts of the Kubergandian and Murgabian stratotypes of SE Pamir suggest that: (1) the upper Bolorian and the lower part of the Kubergandian correlate to the upper Kungurian; (2) the upper Kubergandian and the lower Murgabian correlate to the Roadian; (3) the mid-upper Murgabian correlates to the Wordian; (4) possibly the uppermost Murgabian and the lower Midian correlate to the lower Capitanian.The Kubergandian is thus a defined regional stage, based on fusulinids, ammonoids and conodonts and can be correlated to the Kungurian and the Roadian; still problematic remains the Murgabian correlation which needs to be investigated and resolved in other Tethyan sections.

Characterization of historical mortars from the bell tower of St. Nicholas church (Pisa, Italy)

The aim of this research is to characterize the binder and aggregate fractions of sixteen mortar samples from the bell tower of the St. Nicholas church at Pisa, using X-ray fluorescence (XRF), X-ray powder diffraction (XRPD), simultaneous thermogravimetric/differential scanning calorimetry analysis (TG/DSC), optical microscopy (OM) and electron microscopy equipped with a microanalysis system (SEM/EDS).The analytical procedure used for studying the mortars is based on TG/DSC analyses performed on the binder fractions, obtained by disaggregation of the mortar samples, and on micro-analytical data directly collected on the mortar binders combined with chemical, mineralogical (qualitative composition) and petrographic (modal composition) data measured on the bulk mortar samples.The collected data indicate that the examined samples are hydraulic lime mortars with natural river sands (average binder/aggregate ratio 1:1), except for two of them which are artificial pozzolanic mortars with cocciopesto. The most probable raw materials used to produce the mortars are the binding materials obtained by firing carbonate rocks locally available, cherty limestone and subordinately Mt. Pisano marble, and the Arno River sands or, more likely, natural admixtures of Arno and Serchio River sandy sediments.

EVIDENCE FOR LADINIAN (MIDDLE TRIASSIC) PLATFORM PROGRADATION IN THE GYULAKESZI AREA, TAPOLCA BASIN, WESTERN HUNGARY: MICROFACIES ANALYSIS AND BIOSTRATIGRAPHY

A shallowing-upward carbonate sequence was studied from the outcrop at Gyulakeszi, Tapolca Basin (western Hungary), and it is interpreted as a Middle Triassic ( Curionii or younger) platform progradation. Two lithostratigraphic units are distinguished. Microfacies analysis and micropaleontological investigation conducted on the red nodular, cherty limestone (Vaszoly and Buchenstein formations) suggest that the lower unit was deposited during the Reitzi and the Secedensis ammonoid zones. The overlying white platform limestone (upper unit) is typical of a prograding platform and includes gravity-driven deposits at the base followed by periplatform facies deposited in shallow marine warm waters around the fair-weather wave base. The section at Gyulakeszi was unaffected by fabric-destructive dolomitization, which is uncharacteristic of similar platform facies in the Balaton Highland. Isopachous and radiaxial fibrous calcite cement found in the grainstone and boundstone facies are indicative of early lithification and diagenesis in the marine phreatic zone. “Evinospongiae”-type cement is described for the first time from the Balaton Highland and it is similar to the outer platform cements published previously from the Alps (Italy and Austria). The progradation could have advanced over the pelagic limestones as early as the Curionii zone, which is an undocumented event in the Veszprem Plateau. Similar event, however, is well known from the Western Dolomites, where aggradation was followed by intense progradation during the Gredleri and Archelaus ammonoid zones. The length of this progradation event at Gyulakeszi, however, is ambiguous since proven Ladinian (Longobardian) rocks are not exposed in the study area and were not penetrated by boreholes in the Tapolca Basin.

The Permian succession of the Shaksgam Valley, Sinkiang (China)

The biostratigraphy, fusulinid and microfacies from the Permian succession of the Shaksgam Valley (Aghil and Karakorum ranges) are described. The succession starts with a terrigenous prism, consisting of shale and siltstone covered by litharenite, several hundreds m-thick. They represent an alluvial to shore-face terrigenous prism, on which gradually progrades a marine shallow water complex with bioclastic calcarenite and wackestone/mudstone. A reappraisal of the litharenite also with hummocky cross-lamination is overlain by progressively deeper mudstone/wackestone, and cherty limestone. Very thick calciruditic and pebbly limestone bodies are interbedded in the cherty limestone, in turn newly overlain by marls and shales, followed by thin bedded mudstone. Four fusulinid assemblages are identified, bottom to top: Monodiexodina (Yakhtashian-Bolorian), Leeina-Chalaroschwagerina (Bolorian), Cancellina-Pseudodoliolina-Parafusulina (Late Kubergandian), and Dunbarula-Codonofusiella (Late Murgabian-Midian) respectively. Two new Leeina species are described, Leeina karakorumensis Leven, and Leeina ellipsoidalis Leven.