Fig 9 - uploaded by Sixto Rafael Fernández-López
Content may be subject to copyright.
- Zonal diagram showing the maximum thickness, the stratigraphic and registratic gaps, condensed sections, expanded sections, condensed associations, types of taphonic populations, taphorecords, taphocycles and megataphosequences of ammonites identified in the Middle Jurassic of the Iberian Basin (Castilian, Aragonese and Tortosa platforms). SM = shallowing megataphosequence. DM = deepening megataphosequence. TP-l = taphonic population of type l. TP-2 = taphonic population of type 2. TP-3 = taphonic population of type 3. IDT = incipient-deepening taphorecord. MDT = median-deepening taphorecord. ADT = advanced-deepening taphorecord. IST = incipient-shallowing taphorecord. MST = median-shallowing taphorecord. AST = advanced-shallowing taphorecord. 2nd PT = peak transgression of second order. 2nd PR = peak regression of second order. - Esquema zonal de las potencias, lagunas, secciones condensadas, secciones expandidas, asociaciones condensadas, tipos de poblaciones tafónicas, taforregistros, tafociclos y megatafosecuencias de ammonites identificadas en el Jurásico Medio de las plataformas Castellana, Aragonesa y de Tortosa. SM= megatafosecuencia de somerización. DM = megatafosecuencia de profundización. TP-1 = población tafónica de tipo l. TP-2 = población tafónica de tipo 2. TP-3 = población tafónica de tipo 3. IDT = taforregistro de profundización incipiente. MDT= taforregistro de profundización media. ADT = taforregistro de profundización avanzada. IST = taforregistro de somerización incipiente. MST = taforregistro de somerización media. AST = taforregistro de somerización avanzada. 2nd PT = pico transgresivo de segundo orden. 2nd PR = pico regresivo de segundo orden.
Source publication
[ES] Algunas variaciones de los caracteres tafonómicos y la distribución de las asoctactones registradas de ammonites en las plataformas epicontinentales carbonáticas permiten distinguir secuencias tafonómicas elementales, tafosecuencias, taforregi stros, tafociclos, megatafosecuencías y supertafociclos que son el resultado de cambios relativos del...
Citations
... The species Garantiana subgaranti Wetzel was proposed as an index species of the middle subzone of the Garantiana Zone of the standard Western European scale (Pavia and Sturani, 1968). At present, the Subgaranti Subzone is recognized by most researchers of the Bajocian of various regions of Europe (Fernández-López, 1997;Rioult et al., 1997;O'Dogherty et al., 2006;Chandler et al., 2014;Fernández-López, Pavia, 2016, etc.), although some biostratigraphers prefer using the index species Garantiana garantiana (d'Orbigny) (Gauthier et al., 1996;Dietze et al., 2002, etc.). The boundary of the Alanica and Subgaranti subzones in an outcrop on the Kyafar River is conventionally drawn along the boundary of Beds 1 and 2, due to the absence of finds of ammonites in the boundary interval. ...
New finds of ammonites in the Upper Bajocian Garantiana garantiana Zone in the interfluve of the Kuban and Urup rivers (Karachay-Cherkessia) allow their identifications and the rank of infrazonal subdivisions to be clarified. Djanaliparkinsonia egori sp. nov. from the upper part of the Garantiana Zone is described. The zone includes three subzones (from bottom to top): Alanica, Subgaranti, and Egori; each subzone contains a faunal horizon of the same name. The data on taxonomic composition and stratigraphic distribution of species of the subfamily Garantianinae in the Upper Bajocian of the Kuban River basin are summarized, and index-species of the subzones (and faunal horizons) of the Garantiana Zone are illustrated.
... Павиа и К. Стурани (Pavia, Sturani, 1968). В настоящее время подзона Subgaranti признается большинством исследователей байоса различных регионов Европы (Fernández-López, 1997;Rioult et al., 1997;O'Dogherty et al., 2006;Chandler et al., 2014;Fernández-López, Pavia, 2016 и др.), хотя часть биостратиграфов предпочитает использовать в качестве ее индекса вид Garantiana garantiana (d'Orbigny) (Gauthier et al., 1996;Dietze et al., 2002 и др.). Граница подзон Alanica и Subgaranti в обнажении на р. ...
New finds of ammonites in the Upper Bajocian Garantiana garantiana Zone in the interfluve of the Kuban and Urup rivers (Karachay-Cherkessia) allow their identifications and the rank of infrazonal subdivisions to be clarified. Djanaliparkinsonia egori sp. nov. from the upper part of the Garantiana Zone is described. The zone includes three subzones (from bottom to top): Alanica, Subgaranti, and Egori; each subzone contains a faunal horizon of the same name. The data on taxonomic composition and stratigraphic distribution of species of the subfamily Garantianinae in the Upper Bajocian of the Kuban River basin are summarized, and index-species of the subzones (and faunal horizons) of the Garantiana Zone are illustrated.
... The chronostratigraphic position of the volcanic level V 11 has been linked with an Aalenian (intra-Murchisonae Zone) regional unconformity [Cortés, 2018[Cortés, , 2021. This unconformity separates the Casinos and El Pedregal formations and corresponds to the boundary between the LJ-4 and MJ-1 second-order transgressive-regressive cycles [Fernández-López, 1997. The shallow marine conditions of that time are compatible with the water-depth conditions going along welding or above the water-air interface eruptions. ...
Volcaniclastic accumulations in shallow marine environments are prone to be eroded and transported by sedimentary agents and then resedimented either on contemporaneous or younger substrates. Therefore, dating of the volcanic events through the sediments containing interbedded volcanic layers can lead to errors. A case study of volcanism in the southeastern Iberian Range during the Early and Middle Jurassic is presented. Precise dating of hosting carbonate sediments based on ammonite and brachiopod biochronostratigraphic method has allowed distinguishing 13 volcanic levels of different ages ranging from the early Pliensbachian to the early Bajocian. A set of petrological, geomorphological, sedimentological, and paleontological criteria are applied in order to discriminate primary from secondary (epiclastic) volcaniclastic deposits and thus make it possible to match the ages of primary volcaniclastic deposits with volcanic eruptions. Implementation of such criteria has confirmed that the early Pliensbachian-early Bajocian interval (ca. 20 Ma) corresponds with the actual period of volcanic activity.
... Although due to diagenetic compaction, the ventral view is rarely visible and the suture lines are hardly observable. This taphorecord is characteristic of sediments from deep subtidal environment (Fernández-López 1997). ...
This research is focused on the ammonoids of Oxynotum Zone and Raricostatum Zone (Densinodulum Subzone) from Asturian (Spain) and Lusitanian (Portugal) basins. They come from expanded sections from where 216 specimens have been collected. These have been classified in eight genera and 15 species that belong to families Echioceratidae, Oxynoticeratidae and Eoderoceratidae. Most of the ammonoids are typical of the Northwest European Province. Echioceratidae is the most frequent in the Asturian Basin, whereas Oxynoticeratidae is the predominant in the Lusitanian Basin. Eoderoceratidae specimens are scarcer, and they are registered only between the middle part of Oxynotum Subzone and the lower part of Densinodulum Subzone. A new species is proposed for the upper part of Oxynotum Subzone of the Lusitanian Basin, Plesechioceras rochai sp. nov., which is relatively frequent. As well, also in Portugal, Cheltonia sp. is registered in Densinodulum Subzone, which is a form different from Cheltonia accipitris. This provides new evidence to support the hypothesis of the relation micro-macroconch between the genera Oxynoticeras (M) and Cheltonia (m). Remarkable differences in the studied area are the presence of Paroxynoticeras salisburgense and Plesechioceras cf. delicatum in the Asturias Basin, and Crucilobiceras densinodulum, associated to Oxynoticeras lymense, in the Lusitanian Basin.
https://zoobank.org/NomenclaturalActs/FEF11B83-03CA-4BD6-BB15-F3E9926B7C4F
... Identifying major discontinuities of regional extent which represent noteworthy time gaps combined with facies stacking pattern analyses may allow the recognition of high-rank cycles (firstand second-order cycles). Two regionally extensive gaps in the stratigraphic record occurred at the scale of the whole iberian platform system, one during the lower part of the Aalenian murchisonae Zone (Fernández-lópez 1997;Fernández-lópez & Gómez 2004;Gómez & Fernández-lópez 2004, 2006Gómez et al. 2004) and the other at the middle-Upper Jurassic boundary (e.g., Bulard 1971;Fernández-lópez & Gómez 2004). Thus, except for the earliest Aalenian deposits, the rest of the middle Jurassic succession (from the middle murchisonae Aalenian Zone until the upper Callovian) represents a first-order cycle, the Middle Jurassic major T-R Four second-order transgressive-regressive cycles, named mJ-1, mJ-2, mJ-3, and mJ-4, have been identified within the Middle Jurassic first-order cycle. ...
... The sediments were deposited below the fair-weather wave base, but above the storm-wave base (Gómez et al. 2003Gómez & Fernández-lópez 2006). A regionally extensive gap in the stratigraphic record occurred during the Aalenian murchisonae Zone (Fernández-lópez 1997;Fernández-lópez & Gómez 2004;Gómez & Fernández-lópez 2004, 2006Gómez et al. 2004), separating the Casinos and the El Pedregal formations. ...
... biochronostratigraphic framework PV.4-3 log (Fig. 3) -The murchisonae discontinuity marks the contact between the Casinos and El Pedregal formations, underlines the boundary between the second-order lJ-4 and mJ-1 cycles, and implies the establishment of very shallow-water sedimentary conditions, even including, at least, intermittent subaerial exposures (Fernández-lópez 1997). This means that the immediately previous and subsequent sedimentary successions were deposited under a high degree of turbulence. ...
To cite this article: Cortés J.E. (2021)-Using high-resolution ammonite biochronostratigraphy to date volcanogenic deposits preserved in Middle Jurassic carbonate platforms successions of the westernmost Tethys (southeastern Iberian Range, Spain). Riv. It. Paleontol. Strat., 127(3): 557-583.
Abstract. The Middle Jurassic successions that are currently exposed in eastern Spain (southeastern Iberian Range) were deposited in a system of shallow carbonate platforms, constituting the western margin of the Alpine Ocean, and display a series of successively interbedded volcaniclastic rocks and minor lava flows. The large-scale mapping reveals that Middle Jurassic volcanic rocks crop out along NW-SE pathways, highlighting the importance of the role played by tectonics in controlling the spatial distribution of volcanic outcrops. The progressive dismemberment of Pangea impelled a geographic provinciality increase and, thus, might have contributed to a growing speciation rate of marine invertebrate organisms, notably ammonites. The present study provides new data constraining in detail the age of the Middle Jurassic volcanic deposits. The biochronostratigraphic calibrations of the sedimentary host rocks encasing the volcanics have been obtained from the study of the fossil content (mainly ammonites) from16 well-exposed stratigraphic sections. The study of the fossils from these sections has enabled the identification of three volcanic episodes during the Murchisonae Zone (Aalenian), the Concavum-Discites zonal boundary (Aalenian-Bajocian), and the late Laeviuscula Zone or Laeviuscula-Propinquans zonal boundary (Bajocian). Precise age constraints for volcanic accumulations can be a significant contribution in reconstructing the geodynamic history of the Iberian Basin.
... En estos ejemplares, la parte aplastada siempre se sitúa en el lóbulo más grande, mientras que el lóbulo más corto mantiene su volumen original. El relleno generalmente presenta diferencias granulométricas y texturales con respecto a los materiales de la matriz, de acuerdo con las diferentes condiciones de las cavidades rellenas (Fernández-López, 1997). En los especímenes estudiados, el relleno es siempre de grano muy fino, y el aplastamiento del lóbulo más largo indica que esa parte de la concha no se rellenó por completo (Figura 31). ...
... In summary, the eastern platforms of Iberia underwent a long-term progressive deepening from peritidal carbonate coastal environments (Cuevas Labradas Formation) in the Pliensbachian to open-marine settings (Turmiel Formation) throughout the early-middle Toarcian. This deepening was followed by a gradual shallowing interval including condensed sections in the late stages (upper part of the Casinos Formation) to culminate with a gap in the stratigraphic record on a regional scale in Aalenian (Murchisonae Zone) times (Fernández-López 1997;Fernández-López and Gómez 2004;Gómez andFernández-López 2004, 2006;. From the intra-Murchisonae discontinuity, a progressive deepening began to develop with condensed sections throughout the late Aalenian and early Bajocian, which culminated in the Bajocian Humphriesianum Zone . ...
The Ligurian Tethys began to open in a roughly NE–SW direction in Pliensbachian times. West of the Ligurian oceanic crust, a carbonate-platform system constituted the eastern Iberian paleomargin. Lower and Middle Jurassic marine sediments deposited in these shallow platforms are well exposed today in the southeastern Iberian Range and host multiple volcanogenic deposits, mainly volcaniclastic in nature. Regional mapping reveals that volcanic outcrops show NW and NE (or NNE) oriented lineaments following tracks of cortical weakness. Volcanic ages were estimated by using biochronostratigraphic methods and sequence-stratigraphic correlations. As a result, ten Lower Jurassic volcanic episodes have been identified. The chronostratigraphic positions of the volcanic deposits span from the early Pliensbachian (Jamesoni Zone or later) to the late Toarcian (Thouarsense Zone). The extension-dominated regime of the eastern Iberian paleomargin also affected the southern Iberian paleomargin (Betic Cordillera) as a result of the eastward prolongation of the central Pangea fragmentation. The break-up of wide platforms and the first volcanic emissions seem to be roughly coeval in the Betic and Iberian domains and synchronous with the onset of rifting and spreading events of the Ligurian Tethys Ocean.
... For the taphonomic analysis, the acceptable terminologies applied by Fernández-López (1991, 1997a, 1997b, 2011 and Fernández-López et al. (2002) were used. The term "accumulated assemblage" represents shells remain at the place of their paleobiological production. ...
... Taphonomic analyses of the studied Callovian-Oxfordian macrofossil assemblages contained some preservational features related to biostratinomic and synsedimentary modifications (Fernández-López, 1997a, 1997b. These taphonomic analyses are described in terms of preservation state of fossil specimens, taphonic populations and fossil assemblages, specifically the degree and nature of mechanisms of alteration such as disarticulation, fragmentation, bioerosion, encrustation, sorting and abrasion (Table 3). ...
... For the taphonomic analysis, the acceptable terminologies applied by Fernández-López (1991, 1997a, 1997b, 2011 and Fernández-López et al. (2002) were used. The term "accumulated assemblage" represents shells remain at the place of their paleobiological production. ...
... Taphonomic analyses of the studied Callovian-Oxfordian macrofossil assemblages contained some preservational features related to biostratinomic and synsedimentary modifications (Fernández-López, 1997a, 1997b. These taphonomic analyses are described in terms of preservation state of fossil specimens, taphonic populations and fossil assemblages, specifically the degree and nature of mechanisms of alteration such as disarticulation, fragmentation, bioerosion, encrustation, sorting and abrasion (Table 3). ...
Four Middle‒Upper Jurassic sections from central Saudi Arabia have been investigated to evaluate microfacies types and macro-invertebrate paleocommunities and to interpret their paleoecology and paleoenvironments. The studied Jurassic successions are part of the Middle‒Upper Callovian Tuwaiq Mountain Limestone and the Middle‒?Upper Oxfordian Hanifa Formation. Three main facies were recorded, including mud-supported microfacies, grain-supported microfacies and boundstones. A data matrix comprising 48 macrobenthic species in 35 samples collected from four sections were grouped into fifteen assemblages and one poorly fossiliferous interval by means of a Q-mode cluster analysis. The recorded macrofaunal assemblages have been subdivided into low-stress and high-stress on the basis of hydrodynamic conditions, substrate type, nutrient supply and hypoxia. The low-stress assemblages occur in (a) high-energy paleoenvironments with firm substrates; (b) high-energy shoals with unstable substrates of low cohesion and in (c) low-energy open marine environments with soft-substrates. The moderate- to high-stress assemblages occur in (a) oligotrophic environments with reduced terrigenous input in shelf lagoonal or in restricted inner ramp settings; (b) low-energy, soft substrate environments with hypoxia below the sediment‒water interface; and, in (c) high-energy shoals and shelf lagoonal environments. The temporal distribution patterns of epifaunal and infaunal bivalve taxa are controlled by variations in water energy, substrate characteristics and productivity level. The reported litho- and biofacies confirmed that the Callovian Tuwaiq Mountain Limestone and the Oxfordian Hanifa Formation were deposited across wide spectrum of depositional environments, ranging from restricted lagoon to moderately deeper open marine basin, and providing the perfect conditions for macrofossils.
... Ribbing is sharp, simple to triplicate, mainly biplicate and interrupted on the venter by a smooth band or groove. Tubercles can be developed at the furcation points 1995FernánDez-lóPez 1997;rioult et al. 1997;o'DoGherty et al. 2006;Dietze et al. 2011;chanDler et al. 2014;SanDoval 2016). ...
Two genera and six species of ammonites belonging to the subfamily Garantianinae are described from the Upper Bajocian of the Maizet-Bretteville-Sully area of Calvados (North-West France). A revision of the genus Paragarantiana proposed by Gauthier (2003) is presented. Paragarantiana alticosta (Wetzel), P. longidoides (Gauthier et al.), P. ipfensis (Dietze et al.) and P. sullyensis sp. nov. are heterochronic components of a lineage characterizing the Parkinsoni Zone. Another lineage is identified as a new genus Metagarantiana composed at least by the following species: M. occidentalis (Gauthier), M. media sp. nov. and M. magna sp. nov., recorded from the Tetragona Subzone to the Densicosta Subzone of the Garantiana and Parkinsoni zones. The taphonomic, palaeobiological and biochronological information on Paragarantiana and Metagarantiana suggest that representatives of these two Submediterranean-NW European genera inhabited the central part of the Anglo-Paris Basin (in the sector of the present day area of Maizet-Bretteville-Sully), at least with six miodemic species showing intraspecific dimorphism. The Late Bajocian species of Metagarantiana and Paragarantiana herein identified in the western Neotethys, as members of the Mediterranean-Caucasian Subrealm, formed separate gradational series of morphological change or peramorphoclines, undergoing greater ontogenic variation and development by hypermorphosis and acceleration respectively, during the Subgaranti-Bomfordi subzonal interval of the Garantiana and Parkinsoni zones. In contrast, rapid proterogenesis undergoing smaller ontogenic variation originated and diversified some garantianin lineages, giving paedomorphic members of neotenic type, such as Paragarantiana sullyensis sp. nov. These two Submediterranean-NW European genera represent diverse and lasting anagenetic lineages initially branched off from Garantiana/Pseudogarantiana, in turn, a direct derivative of Strenoceras/Orthogarantiana.
