{"title":"Sedimentology and biostratigraphy of the Biancone Limestone Formation of the Tolmin Basin (Southern Alps, NW Slovenia)","authors":"","doi":"10.1016/j.cretres.2024.105958","DOIUrl":null,"url":null,"abstract":"<div><p>The Tolmin Basin constitutes the western part of the Slovenian Basin, a large Mesozoic interplatform basin that was bounded to the north by the Julian Carbonate Platform and to the south by the Dinaric Carbonate Platform. Today, it is found along the structural boundary between the Southern Alps and the External Dinarides in northwestern Slovenia. After the drowning of the Julian Carbonate Platform, the Tolmin Basin was dominated by pelagic deposits, namely the Toarcian marlstones (Perbla Formation), the Aalenian to lower Tithonian siliceous limestones and radiolarites (Tolmin Formation), and the upper Tithonian to the Berriasian Biancone Limestone Formation. In this study, a basin-scale sedimentary evolution and calpionellid biostratigraphy of the latter is presented. The Biancone Limestone Formation is a calpionellid-bearing pelagic limestone typical of all deepened segments of the Adria microplate in this time interval. It is generally monotonous but shows considerable vertical and lateral variations. The lower boundary with radiolarites is sharp, revealing a pronounced and rapid overturn in pelagic sedimentation. The lower Berriasian slumps indicate a tectonic pulse. Rare beds of resedimented limestones, assigned to the middle Berriasian, are similar in composition to those intercalated in the underlying radiolarites. They thus show that the factors that led to a significant shift in pelagic sedimentation had little or no effect on shallow-marine carbonate production. In the upper Berriasian, an increase in clay content is evident in the formation, which is explained by the uplift and erosion of the propagating thrust belt in the Neotethys area, superimposed by humidification.</p></div>","PeriodicalId":55207,"journal":{"name":"Cretaceous Research","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0195667124001319/pdfft?md5=62778eda84f01db4f5b81e61a398b1ae&pid=1-s2.0-S0195667124001319-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cretaceous Research","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0195667124001319","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"GEOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The Tolmin Basin constitutes the western part of the Slovenian Basin, a large Mesozoic interplatform basin that was bounded to the north by the Julian Carbonate Platform and to the south by the Dinaric Carbonate Platform. Today, it is found along the structural boundary between the Southern Alps and the External Dinarides in northwestern Slovenia. After the drowning of the Julian Carbonate Platform, the Tolmin Basin was dominated by pelagic deposits, namely the Toarcian marlstones (Perbla Formation), the Aalenian to lower Tithonian siliceous limestones and radiolarites (Tolmin Formation), and the upper Tithonian to the Berriasian Biancone Limestone Formation. In this study, a basin-scale sedimentary evolution and calpionellid biostratigraphy of the latter is presented. The Biancone Limestone Formation is a calpionellid-bearing pelagic limestone typical of all deepened segments of the Adria microplate in this time interval. It is generally monotonous but shows considerable vertical and lateral variations. The lower boundary with radiolarites is sharp, revealing a pronounced and rapid overturn in pelagic sedimentation. The lower Berriasian slumps indicate a tectonic pulse. Rare beds of resedimented limestones, assigned to the middle Berriasian, are similar in composition to those intercalated in the underlying radiolarites. They thus show that the factors that led to a significant shift in pelagic sedimentation had little or no effect on shallow-marine carbonate production. In the upper Berriasian, an increase in clay content is evident in the formation, which is explained by the uplift and erosion of the propagating thrust belt in the Neotethys area, superimposed by humidification.
期刊介绍:
Cretaceous Research provides a forum for the rapid publication of research on all aspects of the Cretaceous Period, including its boundaries with the Jurassic and Palaeogene. Authoritative papers reporting detailed investigations of Cretaceous stratigraphy and palaeontology, studies of regional geology, and reviews of recently published books are complemented by short communications of significant new findings.
Papers submitted to Cretaceous Research should place the research in a broad context, with emphasis placed towards our better understanding of the Cretaceous, that are therefore of interest to the diverse, international readership of the journal. Full length papers that focus solely on a local theme or area will not be accepted for publication; authors of short communications are encouraged to discuss how their findings are of relevance to the Cretaceous on a broad scale.
Research Areas include:
• Regional geology
• Stratigraphy and palaeontology
• Palaeobiology
• Palaeobiogeography
• Palaeoceanography
• Palaeoclimatology
• Evolutionary Palaeoecology
• Geochronology
• Global events.