Age of the Tokkalehto metagabbro and its significance to the lithostratigraphy of the early Proterozoic Kuusamo supracrustal belt, northern Finland
9
Citation
12
Reference
10
Related Paper
Citation Trend
Abstract:
Age of the Tokkalehto metagabbro and its significance to the lithostratigraphy of the early Proterozoic Kuusamo supracrustal belt, northern Finland.Bulletin of the Geological Society of Finland 73Keywords:
Lithostratigraphy
High-resolution lithostratigraphy has been attempted here to provide a detailed stratigraphic sequence of the Changhsingian Stage and the Lower Triassic in Meishan Section D. Previous stratigraphic data from Yin et al. (1996), Sheng et al. (1987) and Zhao et al. (1981) were compiled and revised with numerous errors in stratigraphic descriptions and thickness measurements corrected. Most importantly, the stratigraphic positions of the ash-beds and carbonatized tuff beds have been precisely measured. New microstratigraphic observation suggests that the Permian-Triassic transitional sequence at Meishan is a rather condensed or discontinuous at the uppermost part of Bed 24e and within Bed 27. Together with precise biostratigraphic data high-resolution lithostratigraphy will help us to improve our knowledge about the Permian-Triassic transition and the Permian-Triassic GSSP.
Lithostratigraphy
Chronostratigraphy
Sequence (biology)
Section (typography)
Early Triassic
Stratigraphic unit
Cite
Citations (12)
This study focuses on the lithostratigraphy and paleoenvironment reconstruction of the Upper Cretaceous in the Junggar Basin, which is characterized by a succession of red beds. The Upper Cretaceous in the Junggar Basin is regionally variable in thickness and poor in fossils. However, ostracod fossils from these rocks are characteristic of Late Cretaceous. Three ostracod assemblage zones have been recognized. These assemblage zones offer a biostratigraphic tool to correlation of Upper Cretaceous successions in the Junggar Basin.
Ostracod
Lithostratigraphy
Red beds
Assemblage (archaeology)
Stratigraphic unit
Cite
Citations (1)
The paleo-middle Proterozoic strata are both best exposed in the eastern Liaoning and southern Jilin Provinces. However, their correlation is very difficult for different classification schemes used by the two provinces. By comparison of the magnesium marble of the Zhenzhumen Formation in rock association, tectonic sequence, REE geochimestry, chronostratigraphy and paleo-biology in both Ⅰand Ⅱareas, it is concluded that these marbles were formed in different geologic periods and different tectonic settings. The marbles in Ⅰarea were formed in middle Proterozoic while the marbles in Ⅱarea were formed in palaeo-Proterozoic. A new classification scheme is proposed for the palaeo-middle Proterozoic strata in southern Jilin Province by the present authors, in which the middle Proterozoic strata contain two formations:Dahongyu and Gaoyuzhuang Formations while the palaeo Proterozoic strata include Ji'an, Linjang, and Dalizi Groups.
Chronostratigraphy
Sequence (biology)
Cite
Citations (0)
Thrust fault
Cite
Citations (24)
Abstract The Fenland basin is filled with unconsolidated Holocene marine and freshwater deposits. Stratigraphic studies of the basin date back to 1877. This paper reviews the various lithostratigraphic schemes which have been proposed. Particular attention is paid to the presently accepted lithostratigraphy. Examples and a case study of a newly surveyed area are used to highlight its failings. Many of the difficulties experienced in Fenland are common to problems of lithostratigraphic classification in coastal lowland environments, as is demonstrated by reference to recent debate in the southeastern North Sea. In Fenland, as a result of the shortcomings of the various schemes, it is proposed that a new lithostratigraphy with formal stratotypes is devised. Suggestions are made as to the form this new stratigraphy could take. In the meantime, an informal lithostratigraphy should be adopted which has no regional or chronostratigraphic connotations.
Lithostratigraphy
Cite
Citations (13)
Geochronology
Lithostratigraphy
Stratotype
Cite
Citations (2)
The Middle and Upper Jurassic sedimentary successions of Alborz in northern Iran and Koppeh Dagh in northeastern Iran comprise four formations; Dalichai, Lar (Alborz) and Chaman Bid, Mozduran (Koppeh Dagh). In this thesis, the biostratigraphy, lithostratigraphy, microfacies, depositional environments and palaeobiogeography of these rocks are discussed with special emphasis on the abundant ammonite fauna. They constitute a more or less continuous sequence, being confined by two tectonic events, one at the base, in the uppermost part of the Shemshak Formation (Bajocian), the so-called Mid-Cimmerian Event, the other one at the top (early Cretaceous), the so-called Late-Cimmerian Event. The lowermost unit constitutes the uppermost member of a siliciclastic and partly continental depositional sequence known as Shemshak Formation. It contains a fairly abundant ammonite fauna ranging in age from Aalenian to early Bajocian. The following unit (Dalichai Formation) begins everywhere with a significant marine transgression of late Bajocian age. The following four sections were measured: The Dalichai section (97 m) with three members; the Golbini-Jorbat composite section (449 m) with three members of the Dalichai Formation (414 m) and two members of the Lar Formation (414 m); the Chaman Bid section (1556 m) with seven members, and the Tooy-Takhtehbashgheh composite section (567 m) with three members of the Chaman Bid Formation (567 m) and four members of the Mozduran Formation (1092 m). Altogether, 80 species of ammonites from the Dalichai and Chaman Bid formations belonging to 30 genera and 16 families are described. Among the taxa Phylloceratidae are most abundant, followed by Ataxioceratidae, Perisphinctidae, and Cardioceratidae. Pachyceratidae are the least common family. The ammonite fauna is of low diversity and is concentrated in several levels. Some of the ammonite genera and species are recorded from Iran for the first time. These include Pachyceras lalandei, Cardioceras praecordatum, Microbajocisphinctes sp., Geyssantia geyssanti, Larcheria schilli, Passendorferia sp., Sequeirosia sp., Phanerostephanus subsenex, Nothostephanus sp., Nannostephanus cf. subcomutus, Parawedekindia callomoni, Physodoceras sp., Extrenodites sp.. Biostratigraphically, thirty ammonite zones have been recognized for the Middle and Upper Jurassic successions at the four studied sections. Based on ammonites, the Dalichai Formation ranges from the Upper Bajocian to Callovian (Dalichai section) and from the Upper Bajocian to Lower Tithonian (Golbini-Jorbat section), the Chaman Bid Formation ranges from the ?Bathonian to Lower Tithonian (Chaman Bid section) and from the Upper Bajocian to Middle Kimmeridgian (Tooy-Takhtehbashgheh section), the Lar Formation ranges from the Middle to Upper Tithonian (Golbini-Jorbat section), and the Mozduran Formation from the Upper Kimmeridgian to ?Tithonian. Forty-four Microfacies types are briefly described. They were grouped into 16 facies associations, which then were interpreted in terms of their palaeoenvironments. They are part of a carbonate system consisting of a platform and adjacent slope to basin. Five major environments are represented: Tidal flat, shelf lagoon, and platform margin barrier as parts of the carbonate platform, and slope to basin representing open marine conditions. The sediments of the Dalichai and Chaman Bid formations are the slope and basinal sediments of the diachronous Lar and Mozduran formations, which formed an extensive carbonate platform in the Middle and Upper Jurassic.
Ammonite
Lithostratigraphy
Siliciclastic
Marine transgression
Magnetostratigraphy
Cite
Citations (21)
The non-marine Cretaceous-Palaeogene boundary Datang section is located in the northeasetern Nanxiong Basin, northern Guangdong Province. The red beds seccession has been subdivided into three formations, i.e. in ascending order: the Zhutian, Zhenshui and Shanghu formations. The Cretaceous-Palaeogene boundary sequence contains abundant fossils, such as dinosaurian eggs, mammals, ostracodes, gastropods, conchostracans, bivalves, palynomorph and charaphytes. The paper introduces the recent progresses in the study of lithostratigraphy, biostratigraphy, magnetostratigraphy, chronostratigraphy on the Cretaceous-Paleogene boundary Datang section.
Lithostratigraphy
Paleogene
Magnetostratigraphy
Chronostratigraphy
Red beds
Cite
Citations (10)