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Tytuł:
Cephalopod fauna and stratigraphy of the Adnet type red deposits of the Krížna unit in the Western Tatra Mountains, Poland
Autorzy:
Myczyński, R.
Jach, R.
Powiązania:
https://bibliotekanauki.pl/articles/191903.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
ammonites
nautiloids
Toarcian
Western Tethys
Opis:
The Lower Jurassic Adnet type red limestones and marlstones (Kliny Limestone Member, Huciska Limestone Formation) of the Krížna unit in the Tatra Mountains comprise cephalopod fauna represented by ammonites, belemnites and rarely by nautiloids. Ammonites belong to the families Phyloceratidae, Lytoceratidae, Hildoceratidae and Dactylioceratidae and indicate Early Toarcian Serpentinum Zone, Middle Toarcian Bifrons Zone (most probably Sublevisoni and Bifrons Subzones) and Late Toarcian Pseudoradiosa Zone. Hence, the age of Adnet type deposits may be estimated as Early Toarcian-Late Toarcian. Relatively moderate diversity of ammonite assemblage is noticed. Ammonites and nautiloids are preserved mainly as internal moulds, only some specimens display preserved calcified shells. Part of this macrofauna has resedimented character. Studied ammonite assemblage is closely related to that of the Mediterranean Province.
Źródło:
Annales Societatis Geologorum Poloniae; 2009, 79, No 1; 27-39
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Turonian-Coniacian (Upper Cretaceous) of the Babadag Basin (North Dobrogea, Romania) : integrated biostratigraphy and microfacies succession
Autorzy:
Lodowski, Damian Gerard
Walaszczyk, Ireneusz Piotr
Grădinaru, Eugen
Powiązania:
https://bibliotekanauki.pl/articles/2058617.pdf
Data publikacji:
2019
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
microfacies
petrology
inoceramids
ammonites
foraminifera
palaeoenvironment
Opis:
The Upper Turonian to Middle Coniacian (Upper Cretaceous) succession of the Babadag Basin (North Dobrogea, Romania) constitutes an apparently continuous fossiliferous carbonate succession. The presence of moderately rich inoceramid, ammonite and foraminiferal assemblages allows for the application of a precise biostratigraphic subdivision. The palaeoenvironmental conditions and evolution of the Babadag Basin during the Late Turonian-Middle Coniacian are inferred using microfacies analysis and foraminiferal spectra. Together, these suggest the Turonian-Coniacian Badabag Basin reflects relatively shallow-water conditions in a near-shore environment, punctuated by two regression events in the Late Turonian and in the Middle Coniacian.
Źródło:
Geological Quarterly; 2019, 63, 1; 39--64
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pseudothurmanniid ammonites from quarries near Lietavská Lúčka and their stratigraphical significance (Late Hauterivian, Central Western Carpathians, Slovakia)
Autorzy:
Vašiček, Z.
Malek, O.
Powiązania:
https://bibliotekanauki.pl/articles/2060607.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
taxonomy
stratigraphy
Hauterivian
Western Carpathians
Opis:
Pseudothurmanniid ammonites within Upper Hauterivian calcareous deposits are present in quarries on Polomec Hill near the village of Lietavská Lúčka, Slovakia. These deposits belong to the Mráznica Formation of the Krížna Nappe that is a part of the Fatricum Unit in the Central Western Carpathians. Nine ammonite species are described in detail, one of which, Binellicerasmichalíki, is new. The species identified indicate the Upper Hauterivian Balearis and Ohmi ammonite zones. The zone of the uppermost Hauterivian, Catulloi Zone, is not documented as far as pseudothurmanniid ammonites are concerned. The lackof developmentally younger representatives of the pseudothurmanniid ammonites neitherin the studied locali ty, nor in other Slovak locali ties, is explained by marked changes in the northern Tethyan margin in Europe duri ng the latest Hauterivian.
Źródło:
Geological Quarterly; 2017, 61, 3; 613--631
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure of the calcitic layer of the aptychus of the ammonite genus Peltoceras
Autorzy:
Mironenko, Aleksandr A.
Powiązania:
https://bibliotekanauki.pl/articles/2055869.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Aspidoceratidae
Peltoceratinae
Peltoceras
aptychi
ammonites
Jurassic
Opis:
The aptychi of ammonites combined the functions of lower jaws and protective opercula. They consist of two parts: an inner organic layer and an outer calcitic lamella. In different evolutionary lineages of ammonites, the shape of aptychi, the sculpture of their surface and the microstructure of the calcitic layer vary greatly. However, the structure of the aptychi is not known for all evolutionary lineages of ammonites. Although numerous aptychi have been described for the Jurassic family Aspidoceratidae, almost all of them belong to only one evolutionary branch of this family – the Aspidoceratinae (sensu lato). For the second branch – the Peltoceratinae, only one aptychus had been described to date and the structure of its calcitic layer remained unknown. In this article, for the first time, the structure of the aptychus of the Peltoceratinae (upper Callovian Peltoceras) is described. The surface of this aptychus is covered with rough ribs and the calcitic part consists of only one layer of dense calcite. The thickness of the aptychus is much greater than that of the aptychi of supposed ancestors of the Peltoceratinae. The increase in the thickness of the aptychi in both the Aspidoceratinae and the Peltoceratinae, contemporaneously with the appearance of spines on their shells, is most likely related to increasing the protective function of the aptychi of these ammonites in the late Callovian.
Źródło:
Annales Societatis Geologorum Poloniae; 2021, 91, 4; 397--404
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the typological basis of Perisphinctes Waagen, 1869 and the leading modern ammonite superfamily Perisphinctoidea Steinmann, 1890
Autorzy:
Callomon, J. H.
Wright, J. K.
Powiązania:
https://bibliotekanauki.pl/articles/2060988.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
United Kingdom
Oxfordian
amonity
Wielka Brytania
Opis:
A re-examination of the type specimen of Ammonites biplex Sowerby, 1821 shows that the reasons previously given for rejecting this species as the type species of Perisphinctes, to be replaced by Amm. variocostatus Buckland, 1836 (Hemming, 1954), were unfounded. Fortunately, the replacement, based on a macroconch type, is a better representative of the genus than its originally validly designated microconch, Ammonites biplex. The decision in Opinion 303 (Hemming, 1954) is therefore a good one but arrived at for the wrong reasons. It should be left unchanged.
Źródło:
Volumina Jurassica; 2016, 14, 1; 1--14
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Indirect biostratigraphy in condensed successions: a case history from the Bajocian of Normandy (NW France)
Autorzy:
Pavia, G.
Martire, L.
Powiązania:
https://bibliotekanauki.pl/articles/2061355.pdf
Data publikacji:
2009
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
taphonomy
condensation
biostratigraphy
ammonites
Middle Jurassic
Normandy
Opis:
The fossil assemblages of the Bajocian of Normandy are affected by taphonomic condensation, and the use of these assemblages for biostratigraphy must be carried out with great care because of the taphonomic reworking (reelaboration) of most of them. Nevertheless such beautiful fossils, ammonites in particular, retain their value at least as taxonomic references if their relative stratigraphic position is recognized. Such a goal has been achieved in the Bretteville section, where the "Oolithe Ferrugineuse de Bayeux" Formation (OFB), consisting of 14 beds contained within 170 cm of strata, is exposed. Each bed contains a condensed ammonite assemblage in which the overall chronologic interval represented by fossils is longer than the time of sedimentation of the bed, and no ammonites can be defined as contemporaneous with the enclosing matrix, except for the topmost two beds. The timing of biologic and sedimentary events in this Fe-oolitic succession must thus be established in an indirect way, through a stratigraphy of fossils based on their taphonomically delayed first occurrence. In particular, we can only define the maximum age of each layer, constrained by the youngest recorded fossil. On the basis of this approach, the lower part of the OFB is shown to fall within the middle to upper part of the Bajocian Stage (Humphriesianum to Parkinsoni chrons), whereas the uppermost OFB can be referred to as the uppermost Bajocian (latest Parkinsoni Chron). We conclude that, at Bretteville and in general for the Fe-oolites of Normandy, fossiliferous horizons with condensed assemblages have no value for definition of the biostratigraphic standard scale, and that indirect biostratigraphy is useful to assign minimal chronologic values to taxa when (1) their stratigraphical range has not yet been established in expanded successions, (2) they are new taxa, and (3) they are present only in a condensed succession that suffered from the same taphonomic constraints as the Bajocian of Normandy.
Źródło:
Volumina Jurassica; 2009, 7, 1; 67-76
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Następstwo amonitów dolnego i środkowego oksfordu w profilu kamieniołomu w Ogrodzieńcu i ich znaczenie biogeograficzne
Autorzy:
Matyja, B.
Głowniak, E.
Powiązania:
https://bibliotekanauki.pl/articles/2061394.pdf
Data publikacji:
2003
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
amonity
środkowy oksford
Ogrodzieniec
ammonites
Middle Oxfordian
Źródło:
Volumina Jurassica; 2003, 1, 1; 53-58
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Early Berriasian ammonites from the Štramberk Limestone in the Kotouč Quarry (Outer Western Carpathians, Czech Republic)
Autorzy:
Vašíček, Z.
Skupien, P.
Powiązania:
https://bibliotekanauki.pl/articles/191726.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
ammonites
Berriasian
Štramberk area
Outer Western Carpathians
Opis:
Over 100 ammonites were collected from a block of bedded shallow-water Štramberk Limestone at a new location at the Kotouč Quarry, near Štramberk (Silesian Unit, Czech Republic). Berriaselline neocomitids, including Berriasella jacobi, B. oppeli, Tirnovella allobrogensis, T. cf. allobrogensis, Delphinella consanguinea, Pseudosubplanites cf. grandis and Malbosiceras cf. asper, are the most abundant species in this ammonite association. The olcostephanitid, Spiticeras blancheti, is rare. The index species for the Early Berriasian, B. jacobi, occurs in large numbers. On the basis of the present study, the upper boundary of the stratigraphic range of the Štramberk Limestone in the type area is dated as early Berriasian (ammonite Berriasella jacobi Zone). Ammonites with ages younger than early Berriasian have never been found in the Štramberk area. The deposition of the Štramberk Limestone in the Štramberk area came to an end during that period.
Źródło:
Annales Societatis Geologorum Poloniae; 2013, 83, 4; 329-342
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Albian ammonites from northern Pakistan
Autorzy:
Kennedy, W. J.
Fatmi, A. N.
Powiązania:
https://bibliotekanauki.pl/articles/138606.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ammonites
Cretaceous
Albian
Pakistan
amonity
kreda
alb
Opis:
The occurrence of rich Albian ammonite faunas in what is now northern Pakistan has been known for more than 80 years, but there has been no comprehensive account of the assemblages present. A total of 36 taxa are described below. The middle part of the Lumshiwal Formation yields Upper Aptian ammonites south of the Samana Range. Elsewhere, it yields Douvilleiceras leightonense Casey, 1962, of the lower Lower Albian Leymeriella regularis Zone and the Sonneratia perinflata and S. kitchini Subzones of the Sonneratia chalensis Zone of the northwest European sequence. The top one to two metres of the Lumshiwal yields an abundant fauna of rolled and phosphatised ammonites that includes elements from much of the Albian. Of these, Prolyelliceras gevreyi (Jacob, 1907) first appears in the lower Lower Albian Leymeriella tardefurcata Zone. The commonest ammonite is Douvilleiceras mammillatum (Schlotheim, 1813) sensu lato, which ranges from the perinflata Subzone of the chalensis Zone to the Otohoplites bulliensis Subzone of the O. auritiformis Zone of the Lower Albian. The presence of Lyelliceras pseudolyelli (Parona and Bonarelli, 1897) indicates the uppermost, pseudolyelli Subzone of the auritiformis Zone. The presence of Lyelliceras lyelli (d’Orbigny, 1841) indicates the basal Middle Albian lyelli Subzone of the Hoplites dentatus Zone. There is no evidence for the higher parts of the Middle Albian. Dipoloceras (Rhytidoceras ) sp. indicates the presence of lower Upper Albian, possibly the pricei Zone. There is evidence, in the form of specifically indeterminate Mortoniceras (Mortoniceras) sp., of a level within the inflatum to fallax Zone inteval from a single locality, but no evidence of the succeeding parts of the upper Upper Albian. The base of the Kawagarth Formation that succeeds the Lumshiwal yields lower Upper Albian Mortoniceras (M.) geometricum Spath, 1932 of the Mortoniceras pricei Zone, northwest of Darmasand in the Samana range.
Źródło:
Acta Geologica Polonica; 2014, 64, 1; 47-98
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two ammonites from the Early Cretaceous deep-sea sediments of the Silesian Nappe, Polish Carpathians, and stratigraphic problems resulted from micropalaeontological dating of their sites
Autorzy:
Vašíček, Z.
Gedl, E.
Kędzierski, M.
Uchman, A.
Powiązania:
https://bibliotekanauki.pl/articles/191914.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
ammonites
nannoplankton
dinocysts
biostratigraphy
Lower Cretaceous
flysch Carpathians
Opis:
Two ammonites Teschenites subflucticulus Reboulet and Criosarasinella mandovi Thieuloy have been found for the first time in the Flysch Carpathians. They occur in the so far poorly dated Early Cretaceous flysch deposits of the Silesian Nappe at Poznachowice Dolne, in the Upper Cieszyn Shale and the Hradiště (Grodziszcze) beds lithotypes, respectively. Teschenites subflucticulus points to Late Valanginian (Furcillata Zone), but nanno- plankton points to Late Hauterivian-Late Barremian and dinocysts to Late Hauterivian, all analyzed from the same sample. Criosarasinella mandovi points also to Late Valanginian (Furcillata Zone), what is not in contra-diction with the nannoplankton assemblage (Early Valanginian-Early Barremian) analyzed from the same bed, but dinocysts suggest Late Hauterivian. Preservation of the ammonites and sedimentary features of their host beds exclude redeposition. The difference in age by almost 3 Ma years between the ammonites and microfossils cannot be satisfactorily explained according to the current knowledge on their biostratigraphic meaning; it is left as it is as a dilemma.
Źródło:
Annales Societatis Geologorum Poloniae; 2010, 80, No 1; 25-37
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On some Turonian and Coniacian ammonites from central Colombia
Autorzy:
Kennedy, William James
Powiązania:
https://bibliotekanauki.pl/articles/1835595.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ammonites
Turonian
coniacian
Colombia
amonity
turon
koniak
Kolumbia
Opis:
The rich collections of Turonian and Coniacian ammonites from Colombia, housed in the University of California Museum of Paleontology, Berkeley, are described, with 20 species recognized, referred to the genera Reymenticoceras Kennedy, 2018, Vascoceras Choffat, 1898, Fagesia Pervinquière, 1907, Wrightoceras Reyment, 1954a, Subprionocyclus Shimizu, 1932, Subprionotropis Basse, 1951, Prionocycloceras Spath, 1926, Barroisiceras de Grossouvre, 1894, Forresteria Reeside, 1932, Niceforoceras Basse, 1948, Peroniceras de Grossouvre, 1894, Gauthiericeras de Grossouvre, 1894, Protexanites Matsumoto, 1955, and Metaptychoceras Spath, 1926. One species, Reymenticoceras ornatum, is new. Most of the species described can be assigned to the substages and ammonite zones recognized in Western Europe.
Źródło:
Acta Geologica Polonica; 2021, 71, 3; 259-285
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ammonites from the Oxfordian-Kimmeridgian boundary and the Lower–Upper Kimmeridgian of Kachchh, western India
Autorzy:
Pandey, D.
Alberti, M.
Fürsich, F.
Głowniak, E.
Olóriz, F.
Powiązania:
https://bibliotekanauki.pl/articles/2061026.pdf
Data publikacji:
2013
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
Kachchh
India
Oxfordian-Kimmeridgian boundary
amonity
Indie
Opis:
Several new specimens of ammonites from the Oxfordian and Kimmeridgian of Kachchh, western India, are described and illustrated. The Oxfordian ammonites ?Subdiscosphinctes Malinowska, Perisphinctes Waagen, Dichotomoceras Buckman, and ?Larcheria Tintant, all from Bharodia in the Wagad Uplift, enable tentative biochronostratigraphic correlations with the uppermost Middle Oxfordian up to the lower Upper Oxfordian of the unified Submediterranean zonation, whereas the Kimmeridgian ammonites Streblites Hyatt, “Orthosphinctes” Schindewolf, Torquatisphinctes Spath, Pachysphinctes Dietrich, Katroliceras Spath, Aspidoceras Zittel, and Schaireria Checa reconfirm a stratigraphic gap embracing incompletely known parts of the uppermost Oxfordian and the Lower Kimmeridgian as known from the ammonite records of the Kachchh Mainland of the Kachchh Basin.
Źródło:
Volumina Jurassica; 2013, 11, 1; 97--146
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ammonite assemblage and age of the hydrocarbon seep La Elina, Neuquén Basin, Argentina
Autorzy:
Parent, Horacio
Kaim, Andrzej
Garrido, Alberto C.
Powiązania:
https://bibliotekanauki.pl/articles/27311289.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
Neuquén Basin
hydrocarbon seep
ammonites
Early Jurassic
Toarcian
Opis:
The ancient hydrocarbon seep deposits at the La Elina Ranch, Neuquén Basin, northern Patagonia, Argentina, are the only Mesozoic seep site in South America yielding metazoan fossils. Apart from benthic mollusc shells and worm tubes, they yielded a number of nektonic ammonoids. Four species of ammonoids were identified: Hildaitoides retrocostatus, Hammatoceras ex gr. insigne, Calliphylloceras cf. nilssoni, and Phylloceras sp. The occurrences of three species (H. ex gr. insigne, C. cf. nilssoni, and Phylloceras sp.) probably are fortuitous, while H. retrocostatus might have actually thrived in, or around the seep, as indicated by numerous well-preserved juveniles, in addition to some adult specimens. The bathymetric estimates indicate a depth not greater than 200 m, while the benthic molluscs, typical of hydrocarbon seeps, indicate a much greater depth. It is hypothesized that the deep-water taxa might have occurred in a shallower setting, owing to rising anoxia and/or strong input of continental waters from the eastern and/or southeastern deltaic system. The ammonite assemblage indicates that the seep at La Elina is (Andean) Middle Toarcian, probably Chilensis Zone, in age.
Źródło:
Annales Societatis Geologorum Poloniae; 2023, 93, 4; 353--361
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New records of Tmaegoceras lacordarii (Michelin, 1835) from the Lower Jurassic Arietenkalk Formation of SW Germany and its systematic relationships
Autorzy:
Schweigert, Günter
Scherzinger, Armin
Gräbenstein, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/2060916.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
systematics
Pseudotropitinae
palaeobiogeography
Sinemurian
amonity
systematyka
paleobiogeografia
Opis:
New material of the enigmatic cosmopolitan ammonite genus Tmaegoceras Hyatt, 1889 is reported from the upper Lower Sinemurian (Bucklandi Zone, ‛cf. pinguisʼ Biohorizon) of SW Germany. It is better preserved than previously described material. All specimens are assigned to Tmaegoceras lacordarii (Michelin, 1835), an almost forgotten subjective senior synonym of Tmaegoceras crassiceps Pompeckj, 1901. The presence of an extreme rursiradiate ribbing style in some specimens allows a better understanding of this genus and provides a hint for its systematic affiliation. This diagnostic ribbing style is shared with some extremely rare Alpine taxa such as Ammonites salinarius Hauer, 1846 and “Arietites” subsalinarius Wähner, 1891. Tmaegoceras is included here in Pseudotropitinae Donovan, 1973. Pseudotropitinae are possibly an early offshoot of Arietitidae indigenous of the Panthalassa Realm that occasionally spread into the Tethys and its adjacent shelves. A phyletic relationship with Late Triassic Tropitidae Mojsisovics, 1875, however, cannot be excluded either.
Źródło:
Volumina Jurassica; 2021, 19, 1; 95--108
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Jurassic succession at Lisadele Lake (Tulsequah map area, British Columbia, Canada) and its bearing on the tectonic evolution of the Stikine terrane
Autorzy:
Shirmohammad, F.
Smith, P.
Anderson, R.
McNicoll, V.
Powiązania:
https://bibliotekanauki.pl/articles/2061004.pdf
Data publikacji:
2011
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonites
chronology
Stikinia
terranes
Middle Jurassic
Lower Jurassic
Opis:
Jurassic rocks in the central Tulsequah map area include conglomerates and interbedded fossiliferous finer clastics of the Takwahoni Formation (Laberge Group) which unconformably overlie Triassic rocks. Ammonite collections document the Pliensbachian, Toarcian and Bajocian stages. We refine the age and provenance of episodes of coarse clastic input and confirm the progressive change of dominant clast lithology from reworked sedimentary rocks above the Triassic-Jurassic unconformity to volcanic, plutonic and then metamorphic clasts in the Upper Toarcian. The uppermost coarse clastic unit is a Bajocian chert-pebble conglomerate which, along with the immediately underlying black mudstone, we include in the Bowser Lake Group. Together with regional correlations, this confirms that the age of the basal part of the Bowser Lake Group is diachronous, younging southwards into Stikinia. Sandstone petrofacies trends and changes in conglomerate clast composition indicate arc uplift and dissection followed by Middle Jurassic orogen recycling. The isotopic ages of detrital zircons and granite clasts compared with the biochronologically constrained ages of the enclosing strata suggests that processes of intrusion, arc uplift, unroofing, and clastic deposition during the Early Jurassic occurred over intervals of significantly less than five million years.
Źródło:
Volumina Jurassica; 2011, 9, 1; 43-60
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
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