The Pridoli (Silurian) Lithostratigraphy and Biostratigraphy of Gorny Altai

—The paper presents new data on the upper Silurian litho- and biostratigraphy of the Gorny Altai area. Sediments within this interval store a succession of taxonomically representative middle–upper Ludfordian, lower Pridoli, and Lower Devonian (Lochkovian–Pragian) conodont assemblages. The new fauna constraints made a basis for updated correlations of the local and regional stratigraphic units at the Silurian/Devonian boundary of Gorny Altai with the stages of the International Stratigraphic Chart. The correlation results reveal a mismatch between the boundaries of the local and regional Silurian units and the respective boundaries of stages in the International Stratigraphic Chart.

Middle–Upper Cambrian Trilobites of the Genus Nganasanella Rosova, 1963 and Their Stratigraphic Significance

—This paper presents a revision for the genus Nganasanella Rosova, 1963, first described in the stratotype of the Kulyumbean Regional Stage of the Kulyumbe River section (northwest of the Siberian Platform). This section is typical of the upper Cambrian sediments of the Kotuy–Igarka facies region, formed in a shallow marine shelf. As shown by the study, the genus comprises seven species. The species N. nganasanensis Rosova, 1963 (type species), N. tavgaensis Rosova, 1963, N. glabella (Kobayashi), 1943, N. granulosa Rosova et Makarova, 2009, and N. vernacula Rosova et Makarova, 2009 are found in the Siberian Platform. The species N. australica sp. nov. occurs in northeastern Australia. The species N. trisulcatus (Ergaliev), 1980 is widespread in southern Kazakhstan. Some species (N. granulosa and N. vernacula) are found in open marine facies sediments along with the cosmopolitan agnostid species Glyptagnostus reticulatus (Angelin), 1851, serving as a marker of the lower boundary of upper Cambrian strata in the International Chronostratigraphic Chart and the General Stratigraphic Chart of Russia. The species N. trisulcatus and N. australica are found slightly above Glyptagnostus reticulatus. Representatives of the genus Nganasanella are a link between strata of different facies containing different trilobite associations. Their stratigraphic position can serve as an argument for the correlation of the Kulyumbean Regional Stage with units containing Glyptagnostus reticulatus, i.e., the Omnian and Idamean regional stages, the lower parts of the Kutugunian Horizon and the Sakian Regional Stage, and the Paibian Stage of the International Chronostratigraphic Chart.

EVENT STRATIGRAPHY AND CORRELATION PROBLEMS OF THE ORDOVICIAN STRATA OF GORNY ALTAI AND SALAIR

Study of the Ordovician sedimentary sequences of Gorny Altai and Salair has revealed lithological and paleontological features correlating with global sedimentary events:(1) The Acerocare Regressive Event (an initial event in the Early Tremadocian);(2) Black Mountain Transgressive Event (Early Tremadocian);(3) Peltocare Regressive Event (Tremadocian);(4) Kelly Creek Regressive Event (Late Tremadocian);(5) Ceratopyge Regressive Event (Late Tremadocian);(6) Billingen Transgressive Event (Early Floian);(7) Stein Lowstand Event (Middle Darriwilian);(8) Vollen Lowstand Event (Sandbian);(9) Arestad Drowning Event (Middle Sandbian);(10) Frognerkilen Lowstand Event (Early Katian);(11) Linearis Drowning Events 1 and 2 (Middle Katian);(12) Terminal Husbergoya Lowstand Event (Hirnantian); and(13) Hirnantian Lowstand Event (HICE) (Late Ordovician).The chronostratigraphic levels with traces of the global sedimentary events in the Uymen-Lebed structural-facies zone (SFZ) (Gorny Altai) differ from those in the Charysh-Inya and Anui-Chuya SFZ (Altai). In the Ordovician, the Altai basin located in the Charysh-Inya and Anui-Chuya SFZ was a marine area separated from both the Uymen-Lebed basin and the coeval Salair basin. The traces of the global sedimentary and/or biotic events in the Altai and Salair sections can be used as a precise basis for direct correlation of the local stratigraphic units with the units of the International Stratigraphic Chart.

POSITION OF THE PALEOGENE STAGES BOUNDARIES IN THE SEDIMENTARY SECTION OF PLATFORM UKRAINE: CURRENT STATE, DETERMINATION CRITERIA

Data on the Global Stratotypes Sections and Points of the Paleogene Stages of the modern International Stratigraphic Scale, as well as the criteria for determining the boundaries of the Paleogene Stages in North-Western Europe are presented. The characteristics of the position of the stage boundaries in the sedimentary section of the platform Ukraine are given. In the Paleogene section of Southern Ukraine, the lower boundaries of the Ypresian and Priabonian were recognized by global correlation markers. According to the modern International Stratigraphic Scale, the position of the Lutetian / Bartonian and Rupelian / Chattian boundaries in the sedimentary sections of Southern and Northern Ukraine has been clarified in comparison with previous views. The position of most stage boundaries in the biostratigraphic (zonal) scheme of the Paleogene of Ukraine is more accurately determined. The criteria for identification for some of them in the section of the south and north of Ukraine are proposed. Most of the stage boundaries are represented by hiatus in the sedimentary cover of the platform Ukraine. Part of the boundaries of the Paleogene stages coincides with the boundaries of the regional stratigraphic units of Southern and Northern Ukraine, namely: – the Cretaceous / Paleogene boundary is at the base of the Belokamenskia and Pselian regional stages; – the Paleocene/Eocene boundary coincides with the boundary of the Merlian/Kanevian regional stages; – the Ypresian/Lutetian boundary coincides with the Kanevian/Buchakian regional stages; – the lower boundary of Priabonian is at the base of the Almian and Obukhovian regional stages; – the Eocene/Oligocene boundary passes on the limit of Almian/Planorbellian and Obukhovian/Mezhygorian regional stages; – the Rupelian/Chattian boundary is at the limit of the lower and upper regional substages of Kerleutian regional stage and at the limit of the lower and upper regional substages of the Berekian regional stage. The following stage boundaries are not coinciding with regional stage boundaries: – the Danian/Selandian boundary is within upper part of the Belokamenskian and Pselian regional stages; – the Selandian/Thanetian boundary is trassing in the lower part of the Kachian and Merlian regional stages; – the lower boundary of Ypresian is in the uppermost part of the Kachian regional stage; – the Ypresian/Lutetian boundary is within the Simferopolian regional stage; – the Lutetian/Bartonian boundary is in the lowest part of the Kumian regional stage and within the Kievian regional stage. Key words: International Stratigraphic Chart, Paleogene, stage, boundary, regional stage, Ukraine

THE REGIONAL STRATIGRAPHIC CHART FOR THE SILURIAN OF THE WESTERN SAYAN (NEW VERSION)

A new version of the Regional stratigraphic chart for the Silurian of the Western Sayan and explanatory note, compiled in accordance with the Russian Stratigraphic Code, introduce changes, additional and specified data in comparison with the previous (first edition) chart. The Interdepartmental stratigraphic meeting held at Novosibirsk in 1964 approved the old version of the chart and later it was validated by the USSR Interdepartmental Stratigraphic Committee as the official stratigraphic base for all types of the regional geologic activities. Since 1964 meeting, the stages of the Silurian chart were changed. Thus, former stages Llandovery, Wenlock, Ludlow and Pridoli become series. New stages Rhuddanian, Aeronian, Telychian, Sheinwoodian, Homerian, Gorstian and Ludfordian were adopted for the three former series. For the presented stratigraphic chart the new standard Silurian stages were used.

THE REGIONAL STRATIGRAPHIC CHART FOR THE ORDOVICIAN OF TYVA (NEW VERSION)

A new version of the Regional stratigraphic chart for the Ordovician of Tyva and explanatory note, compiled in accordance with the Russian Stratigraphic Code, introduce changes, additional and specified data in comparison with the previous (third edition) chart. The Interdepartmental stratigraphic meeting held at Novosibirsk in 1979 approved the old version of the chart and later it was validated by the USSR Interdepartmental Stratigraphic Committee as the official stratigraphic base for all types of the regional geologic activities. Since 1979 meeting, the stages of the Ordovician chart were changed. Volumes of the lower, middle and upper series were also changed. For the present version of the stratigraphic chart the new standard Ordovician stages were used.

THE REGIONAL STRATIGRAPHIC CHART FOR THE ORDOVICIAN OF THE WESTERN SAYAN (NEW VERSION)

A new version of the Regional stratigraphic chart for the Ordovician of the Western Sayan and explanatory note, compiled in accordance with the Russian Stratigraphic Code 2006, introduce changes, additional and specified data in comparison with the previous (first edition) chart. The Interdepartmental stratigraphic meeting held at Novosibirsk in 1964 approved the old version of the chart and later it was validated by the USSR Interdepartmental Stratigraphic Committee as the official stratigraphic base for all types of the regional geologic activities. Since 1964 meeting, the stages of the Ordovician chart were changed. Thus, instead of the traditional British stages (Tremadocian, Arenigian, Llanvirnian, Llandeilian, Caradocian, Ashgillian) the following units were adopted by the International Stratigraphic Chart – Tremadocian, Floian, Dapingian, Darriwilian, Sandbian, Katian, Hirnantian. Volumes of the lower, middle and upper series were also changed. For the present version of the stratigraphic chart the new standard Ordovician stages were used.

Chapter 2 Tectonostratigraphy of the eastern part of the Oman Mountains

This chapter provides comprehensive descriptions of 52 numbered formations/rock units of the Southeastern Oman Mountains, based on available literature. The oldest eight siliciclastic and carbonate formations are positioned below the ‘Hercynian’ Unconformity. The overlying formation (9–16) mostly represent carbonates which accumulated in a passive margin platform setting during or after the opening of the Neo-Tethys Ocean. The passive margin slope and platform collapsed during the late Cretaceous because of the obduction of the Semail Ophiolite along with the deep marine Hawasina sedimentary rocks. The collapsing passive margin interval was recorded within the syn-obductional Aruma Group (17; Muti Formation). Above this formation are the allochthonous units (18–42) of the tectonically lower Hawasina deep-sea basin and the structurally overlying Semail Ophiolite. The former contains Permian to Upper Cretaceous formations, while the latter is Cenomanian in age. Above the allochthonous rocks, the Neo-autochthonous formations were deposited, starting with the post-obductional uppermost Cretaceous Aruma Group (43; Al-Khod Formation) until the Quaternary deposits (52). All these formations/rock units are depicted on an accompanying map and stratigraphic chart.

New Early Devonian (late Emsian) placoderms from Belarus

Four placoderm fishes are described from the Lepel Beds of the Vitebsk Regional Stage of the Lower Devonian (upper Emsian) of Belarus. Two forms are new (Stipatosteus svidunovitchi new genus, new species and Actinolepis zaikai new species) and the other two taxa are left in open nomenclature (Coccosteidae gen. indet. sp. indet.; Placodermi indet. 1). Specimens of all four forms consist of disarticulated, mostly well-preserved plates (some are worn at the edges) originating from the cores of six boreholes. Additionally, the paper presents data on organic remains with the placoderms. A detailed lithological description of the enclosing rocks and a taphonomic description of the ichthyofauna are also provided. The 2010 Stratigraphic Chart of the Devonian deposits of Belarus was used as the stratigraphic basis. The presence of the genus Actinolepis Agassiz, 1844 in these deposits as well as in the Emsian of the Baltic region and Spitsbergen suggests a regional paleogeographic connection at this time.UUID: http://zoobank.org/368b44df-e9e9-417c-a0e0-f7e138b7f4ec