Anatomy of carbonate mounds from the Middle Anisian of Nakhlak (Central Iran): architecture and age of a subtidal microbial-bioclastic carbonate factory

The Anisian succession of Nakhlak (in Central Iran) is characterized by a siliciclastic succession with minor carbonate units, with massive carbonate mounds up to 50 m thick in its upper part. The mounds, constrained in age to the late Bithynian (Ismidicus Zone) by ammonoids and conodonts, are characterized by a flat top and a lateral pinch-out marked by clinostratified slopes (about 15A degrees in dip). Stratigraphic and microfacies analyses document an inner part of the mound characterized by massive microbial carbonates with open-space structures (stromatactis) filled with fine-grained internal sediments and marine cements. Isolated sponges (up to 5 cm), serpulids and bryozoans are present, which grew on the calcimicrobial limestone. A narrow bioclastic margin (mainly with crinoids and brachiopods) produces most of the slope facies (consisting of bioclastic grainstone and packstone, with intraclasts from the inner part of the mounds) which interfinger basinward with volcaniclastic sandstones. The demise of carbonate productivity is marked on the top of the carbonate mounds by a condensed surface, rich in ammonoids, glaucony grains, and articulated crinoids, documenting a rapid drowning. Paleolatitude data support deposition in a tropical setting, and sedimentological constraints indicate deposition close to the fair-weather wave base, within the photic zone. The late Bithynian Nakhlak carbonate mounds developed before the appearance (documented since the Pelsonian in different parts of the world) of scleractinians which, despite the favorable environmental conditions, are absent at Nakhlak. The Nakhlak mounds thus represent one of the last occurrences of the microbial factories (which developed after the Permo-Triassic extinction event and persisted for most of the Middle Triassic, but with a gradually increasing role played by scleractinians) before the first appearance of the Mesozoic corals

First record of Rhabdoceras suessi (Ammonoidea, Late Triassic) from the Transylvanian Triassic Series of the Eastern Carpathians (Romania) and a review of its biochronology, paleobiogeography and paleoecology

Abstract The occurrence of the heteromorphic ammonoid Rhabdoceras suessi Hauer, 1860, is recorded for the first time in the Upper Triassic limestone of the Timon-Ciungi olistolith in the Rarău Syncline, Eastern Carpathians. A single specimen of Rhabdoceras suessi co-occurs with Monotis (Monotis) salinaria that constrains its occurrence here to the Upper Norian (Sevatian 1). It is the only known heteromorphic ammonoid in the Upper Triassic of the Romanian Carpathians. Rhabdoceras suessi is a cosmopolitan species widely recorded in low and mid-paleolatitude faunas. It ranges from the Late Norian to the Rhaetian and is suitable for high-resolution worldwide correlations only when it co-occurs with shorter-ranging choristoceratids, monotid bivalves, or the hydrozoan Heterastridium. Formerly considered as the index fossil for the Upper Norian (Sevatian) Suessi Zone, by the latest 1970s this species lost its key biochronologic status among Late Triassic ammonoids, and it generated a controversy in the 1980s concerning the status of the Rhaetian stage. New stratigraphic data from North America and Europe in the subsequent decades resulted in a revised ammonoid biostratigraphy for the uppermost Triassic, the Rhaetian being reinstalled as the topmost stage in the current standard timescale of the Triassic. The geographic distribution of Rhabdoceras is compiled from published worldwide records, and its paleobiogeography and paleoecology are discussed

Towards a Better Definition of the Middle Triassic Magnetostratigraphy and Biostratigraphy in the Tethys Realm

Magnetostratigrapic and biostratigraphic data of Middle Triassic (Anisian) age were obtained from the Nderlysaj section from the Albanian Alps and the Dont-Monte Rite composite section from the Dolomites region of northern Italy. The Nderlysaj section is biochronologically bracketed between the late Bithynian and the early Illyrian (i.e., late Early and early Late Anisian), whereas the Dont-Monte Rite section is comprised between the late Pelsonian and the early Illyrian. The data from Nderlysaj and Dont-Monte Rite, in conjunction with already published data, allow us to construct a yet uncomplete composite geomagnetic polarity sequence tied to Tethyan ammonoid, conodont and benthic foraminifer biostratigraphy from the Late Olenekian (late Early Triassic) to the Late Ladinian (late Middle Triassic)

The Italian Journal of Geosciences is increasing its appeal among Geoscientists

This is an Editorial of the new Editorial Board of the Italian Journal of Geosciences, composed by Marco Balini (Milan), Hugo Bucher (Zürich), Simonetta Cirilli (Perugia), Laura Crispini (Genoa), Maurizio Mazzucchelli (Modena), and Giulio Ottonello (Genoa), which underlines the progress in the appeal of the journal among Geoscientists

Studio osservazionale e di intervento di educazione alimentare in popolazione con pregresso diabete gestazione a rischio per sviluppo di diabete melato di tipo 2: risultati preliminari

Il diabete mellito gestazionale (gestational diabetes mellitus, GDM) è definito come una condizione di iperglicemia diagnosticata durante il secondo o terzo trimestre di gravidanza che non è chiaramente diabete manifesto. Le donne affette da GDM presentano maggiore rischio di sviluppare successivamente sindrome metabolica o diabete mellito di tipo 2 (DMT2). Scopo dello studio. Esaminare i fattori di rischio associati ad alterazioni del metabolismo glucidico in donne con pregresso GDM. Pazienti e metodi. Sono state richiamate le pazienti con gravidanza complicata da GDM seguite a livello ambulatoriale tra il 2007 e il 2011. Sono stati raccolti: anamnesi, dati antropometrici ed ematochimici, abitudini alimentari e stile di vita. Sono stati consigliati dosaggi dei principali parametri glicometabolici e la compilazione di un diario alimentare di 3 giorni per valutare l’assunzione giornaliera energetica con le percentuali glucidica, lipidica e proteica. È stata anche valutata la conoscenza delle pazienti dei contenuti in macronutrienti degli alimenti. Risultati. Di 255 donne arruolabili, 66 hanno aderito (63 italiane, 3 nordafricane): età al concepimento 34,1 ± 4,7 anni; età attuale 39,6 ± 4,9 anni; peso pregravidico 67,6 ± 15,0 kg con BMI 25,7 ± 5,0 kg/m2; peso attuale 69,7 ± 16,5 kg con BMI kg/m2 26,6 ± 5,4; glicemia basale 94,5 ± 18,9 mg/dl alla settimana gestazionale media 20,8 ± 6,8; glicemia basale 106,7 ± 33,6 mg/dl al follow-up. Il 12% delle donne al controllo presentava già un DMT2 conclamato, il 24% rientrava nella categoria IFG (impaired fasting glucose), avendo una glicemia basale compresa tra 100 e 125 mg/dl. La curva da carico orale di glucosio (oral glucose tolerance test: OGTT 75 g) post-partum è stata eseguita nei tempi consigliati dalle linee guida solo dal 10,6% delle donne. Peso (p < 0,05), BMI (p < 0,05) e glicemia basale (p < 0,005) sono risultati allo stato attuale significativamente aumentati rispetto alla condizione pregravidica. Tra i fattori di rischio emergono la familiarità per il DMT2 e uno scorretto stile di vita. Conclusioni. I valori ematici e antropometrici rilevati appaiono peggiorati rispetto alla condizione pregravidica, con conseguente aumento dei fattori di rischio per la sindrome metabolica o DMT2. Nel prossimo futuro ci proponiamo di svolgere ulteriori controlli per verificare l’efficacia dell’intervento educativo che si sta operando sulle pazienti.Gestational diabetes mellitus (GDM) is diabetes diagnosed in the second or third trimester of pregnancy that is not clearly overt diabetes. GDM is a risk factor for the development of type 2 diabetes mellitus (T2DM) later in life. This study examined risk factors associated with abnormal glucose metabolism in women with previous GDM. Outpatients with pregnancy complicated by GDM between 2007 and 2011 were recalled and we recorded their medical history, anthropometric data and blood chemistry, eating habits and lifestyle. Blood tests for the main glyco-metabolic parameters were recommended, and they were asked to complete a three-day food diary to assess their daily energy intake of carbohydrates, proteins, and fats. We also assessed their knowledge of the macronutrient content in foods. In all, 255 women were recalled; 66 gave informed consent (63 Italian, 3 North African); their age was 34.1 ± 4.7 years (mean ± SD) at conception and 39.6 ± 4.9 at final observation; pre-pregnancy weight was 67.6 ± 15.0 kg, with BMI (kg/m2) 25.7 ± 5.01; current weight was 69.7 ± 16.5, BMI 26.6 ± 5.4; fasting plasma glucose (FPG: mg/dl) was 94.5 ± 18.9 at mean gestational week 20.8 ± 6.8, 106.7 ± 33.6 at follow-up. During the observation period, 12% developed T2DM, 24% had impaired fasting glucose (IFG). Only 10.6% of women were given an oral glucose tolerance test (75 g) within six months from delivery. Weight (p < 0.05), BMI (p < 0.05) and FPG (p < 0.005) were significantly higher at follow-up than before pregnancy. Among risk factors, family history of T2DM and improper lifestyle emerged. In conclusion, women with GDM had worse metabolic blood levels and anthropometric parameters after pregnancy, implying an increased risk of metabolic syndrome or T2DM. We plan further evaluation in the near future to verify the effectiveness of this educational intervention

Bio-chronostratigraphic calibration of the Upper Carnian-Lower Norian magnetostratigraphic scale at Pizzo Mondello (Sicani Mountains, Sicily).

Pizzo Mondello section is known since 15 years because of the continuous Late Triassic pelagic record of great significance for the establishment of an integrated chronostratigraphy of the Late Triassic (Gullo et al. 1996; Muttoni et al. 2001, 2004). During the last 4 years, Pizzo Mondello section has been studied in detail to provide a new and high resolution integrated bio-chronostratigraphy for the calibration of the magnetostratigraphy and chemostratigraphy proposed by Muttoni et al. (2001, 2004), and now it is one of the GSSP candidates for the definition of the base of the Norian. The lowest 143 m of the Cherty Limestone, straddling the C/N boundary have been studied in detail. The preliminary data of the ongoing research have been presented in all the meetings of the STS from Albuquerque 2007 and here we summarize the final results. The key correlation to the standard marine Triassic Scale is provided by the ammonoids. They are relatively rare, however the available collections document the Upper Carnian Discotropites plinii and Gonionotites italicus Subzones, from meter 15 to meter 80 from the base of the section. The following 15 meters are poor in ammonoids, while higher up the lower part of the Lower Norian Guembelites jandianus Zone is documented by Dimorphites cf. n. sp.1 of Krystyn, 1980. Conodonts are very abundant and have a great potential as practical tool for global correlations. The abundance of specimens at Pizzo Mondello gave the opportunity to point out clear relationships among the five most widespread Upper Camian/Lower Norian conodont genera (Paragondolella, Carnepigondolella, Metapolygnathus, Epigondolella and Norigondolella) and to identify trends of the generic turnovers (Mazza et al. 2010). The two biomarkers so far proposed as possible marker events for the GSSP were the FAD of E. quadrata (sample FNP88A) and the FAD of M. communisti (sample NA35). However, the FAD of E. quadrata occurs within the Gonionotites italicus Subzone, while the FAD of M. communisti is on its top. Halobiids are extremely common in the Cherty Limestone and they have also a great potential for large scale correlations. Nine species of Halobia have been recognized: Halobia carnica, H. lenticularis, H. simplex, H. superba, H. cf. rugosa, H. radiata, H. austriaca, H. styriaca and H. mediterranea. The best possible marker for the base of the Norian is the first occurrence of Halobia austriaca, that is recorded in the middle of the interval between the record of the Gonionotites italicus Subzone and the Guembelites jandianus Zone. Radiolarians were found in few samples but with high diversity assemblages. In the upper Gonionotites italicus Subzone to the Guembelites jandianus Zone there is an overlap of species previously considered Late Carnian with species usually regarded as Early Norian. About 4 m above the FAD of E. quadrata, in the Gonionotites italicus Subzone, the first assemblage with Capnuchosphaera deweveri Kozur & Mostler, Capnuchosphaera tricornis De Wever, Kahlerosphaera norica Kozur & Mock and Xiphothecaella longa Kozur & Mock, usually referred to Early Norian, occurs. These integrated bio-chronostratigraphic studies lead to identify some possible GSSP marker events especially on conodonts and halobiids, which occur in the upper part of magnetozone PM 4n, within PM 4r and in the lower part of PM 5n. Possibly the most suitable magnetostratigraphic event to recognize the basal Norian is the base of magnetozone PM 5n, as already suggested by Krystyn et al. 2002 and Muttoni et al. 2004

The case for the Global Stratotype Section and Point (GSSP) for the base of the Norian stage

The Norian Stage is the longest stage in the Phanerozoic, and some members of the boundary working group have been evaluating suitable Carnian-Norian boundary sections for roughly two decades. This has identified two possible candidate boundary sections, at Black Bear Ridge (British Columbia, Canada) and Pizzo Mondello (Sicily, Italy). After a formal voting procedure within the working group, ending on the 26th July, 2021, the Pizzo Mondello section was selected as the global stratotype section and point for the base of the Norian. We evaluated the global correlation potential of the two proposed primary markers, the conodont Metapolygnathus parvus and the ‘flat-clam’ Halobia austriaca. Secondary markers were also evaluated around these boundary datums for correlation potential, and the veracity of the proposed sections for GSSP status. Data and arguments for the proposed sections and datums are presented here. Through a two-stage process of option elimination in voting, conforming with ICS guidelines, the working group decided by 60% majority to propose that the first occurrence datum of Halobia austriaca in the Pizzo Mondello section at the base of bed FNP135A should become the ‘golden spike’ for the base of the Norian. A secondary biotic marker for this boundary is the first occurrence of Primatella (Carnepigondolella) gulloae, in sample NA43, ca. 0 m below FNP135A, and the FA of Dimorphites noricus (sample NA42.1) ca. 3.5 m above bed FNP135 (indicating the first subzone of the Jandianus Zone). The best physical secondary marker is the magnetozone PM5n with the proposed boundary ca.40% through the thickness of PM5n. Strengths of the chosen datum are: 1) it also maintains historical priority for ammonoid zonations, which had placed the base Norian near to this level in Europe, North America and probably NE Asia; 2) Halobia austriaca is widely distributed in all paleolatitudes and is a long-established taxon