First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells
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The stable isotope (δ13C, δ18O) composition of a collection of Lower Jurassic brachiopods and oysters from the Andean Basin of northern Chile was analyzed. The results allow the first reconstruction of absolute water temperatures for several ammonite zones in the Lower Jurassic of South America. The temperature record starts with comparatively high values in the Late Sinemurian (average: 27.0 °C; Raricostatum Zone). Just before the Sinemurian–Pliensbachian transition, temperatures dropped to an average of 24.3 °C. The lowest temperature value in the dataset was recorded for a brachiopod shell of the latest Pliensbachian Spinatum Zone (19.6 °C). No data are available for the Early Toarcian, but results for the late Toarcian show again comparatively warm conditions (average: 24.4 °C; Thouarsense–Levesquei zones). Even though more material and analyses are necessary to corroborate the recorded temperatures, the present dataset seems to indicate the global nature of the Late Pliensbachian Cooling Event. In contrast, the global warming during the Toarcian Oceanic Anoxic Event has not been recorded due to a lack of Early Toarcian material. The δ13C record of brachiopods and oysters documents a gradual increase in values representing background conditions. Oyster shells were used for high-resolution stable isotope analyses and show seasonal temperature fluctuations over a period of around 3 years in the life time of the bivalves. If explained only by temperatures, the δ18O values point to a minimum estimate for the seasonality in the late Toarcian of slightly more than 3 °C.
KeywordsEarly Jurassic Chile Stable isotopes Palaeoclimate Water temperatures Seasonality
Late pliensbachian cooling event
Toarcian oceanic anoxic event
Vienna pee dee belemnite
Vienna standard mean ocean water
The climate conditions of the Jurassic world have traditionally been described as warmer than today, relatively stable through time, and with weak latitudinal temperature gradients leading to a lack of polar glaciations (e.g., Chandler et al. 1992; Valdes and Sellwood 1992; Rees et al. 2000; Hallam 2001; Bailey et al. 2003; Sellwood and Valdes 2006). In the last few decades, this simple view has been challenged by a series of articles, suggesting polar ice caps for at least short intervals in the Jurassic (e.g., Price 1999; Dromart et al. 2003; Suan et al. 2008, 2010) and larger temperature fluctuations (e.g., Dera et al. 2011; Korte et al. 2015; Martinez and Dera 2015; Silva and Duarte 2015; Price et al. 2016). Only recently, Alberti et al. (2017, 2019) presented data pointing to latitudinal temperature gradients in the Middle and Late Jurassic as steep as today. Much of our knowledge on the Jurassic climate is based on seawater temperature reconstructions using stable isotope (δ18O) analyses of fossil hard parts. This methodology has been fundamental in improving our understanding of the climate throughout the history of Earth (e.g., Epstein et al. 1951; Urey et al. 1951). During the last decades a large amount of data has been assembled by analyzing mainly calcitic fossils such as belemnite rostra and bivalve or brachiopod shells. However, research on temperature reconstructions has concentrated largely on European localities with data from other regions of the Earth being relatively scarce and scattered. Consequently, it seems beneficial to gather more information from non-European sections in order to fully understand global climate conditions in the Jurassic. The present study is part of a series of articles trying to improve our knowledge of the seawater temperature conditions of Gondwanan localities (Alberti et al. 2012a, 2012b, 2013, 2017, 2019).
The Early Jurassic was an epoch which experienced several events with a global impact. Most of these have been identified via geochemical analyses of sedimentary rocks or their fossil content (e.g., Jenkyns 1988; Hesselbo et al. 2000a; Jenkyns et al. 2002; Korte et al. 2009; Bodin et al. 2016) and could be connected to pulses in the volcanic activity of the Karoo-Ferrar large igneous province influencing the atmospheric composition and thus the global climate. The strongest of these events was the Toarcian Oceanic Anoxic Event (TOAE) which is evident in the geological record by a prominent carbon isotope excursion and has been studied thoroughly over the last decades (e.g., Jenkyns 1988; Mettraux et al. 1989; Hesselbo et al. 2000a, 2007; McArthur et al. 2000; Schmid-Röhl et al. 2002; van de Schootbrugge et al. 2005a; Metodiev and Koleva-Rekalova 2008; Suan et al. 2008; Rodríguez-Tovar and Reolid 2013; Huang and Hesselbo 2014; Ullmann et al. 2014; Ruhl et al. 2016; Bougeault et al. 2017). Following a phase of very low temperatures during the Late Pliensbachian, increased volcanic activity in the Early Toarcian in combination with other factors (such as the release of methane hydrates from continental shelfs; Hesselbo et al. 2000a) seems to have caused perturbations in the carbon cycle, intense global warming, ocean acidification, and ultimately mass extinctions (e.g., Aberhan and Fürsich 1996; Pálfy and Smith 2000; Aberhan and Baumiller 2003; Cecca and Macchioni 2004; Gómez et al. 2008; Dera et al. 2010; Dera and Donnadieu 2012; Danise et al. 2013; Huang and Hesselbo 2014; Krencker et al. 2014). While the global nature of many of the Early Jurassic events (particularly the TOAE) has been illustrated by geochemical analyses of rocks outside Europe (e.g., Al-Suwaidi et al. 2010, 2014, 2016; Mazzini et al. 2010; Caruthers et al. 2011; Gröcke et al. 2011; Suan et al. 2011; Yi et al. 2013; Kemp and Izumi 2014; Ros-Franch et al. 2019), reconstructions of absolute water temperatures for the Early Jurassic are almost completely restricted to the northwestern Tethys. In the present study, a collection of Sinemurian to Toarcian oyster and brachiopod shells from the Andean Basin of Chile has been analyzed for their stable isotope (δ13C, δ18O) content in a first step to remedy this lack of data.
2 Geological overview
During the Mesozoic, a narrow but long back-arc basin existed along the South American Pacific margin more or less parallel to the modern-day Andes (e.g., Gröschke et al. 1988). This Andean Basin in present-day Chile and Argentina was divided into subbasins by several ridges and separated from the open ocean by volcanic arcs, but connections allowing the exchange of water masses existed most of the time (e.g., Gröschke et al. 1988; Aberhan 1992; Vicente 2006). A marine transgression reached the basin in the Late Triassic and marine conditions prevailed throughout the Jurassic (Aberhan 1992) with sea-level maxima in the Toarcian and Bajocian (Fantasia et al. 2018). The study area was inundated in the Early Sinemurian (von Hillebrandt 1971, 1973). The thickness of the Lower and Middle Jurassic successions (up to the basal Callovian) is more than 1000 m in the west, but only 30–40 m in the east (Aberhan 1992; von Hillebrandt 2002). The sampled Lower Jurassic strata belong to the Montandón Formation (Pérez 1982).
As in other regions, the Jurassic biostratigraphy of South America relies heavily on ammonites, but age assignments and correlations based on these index fossils are still continuously improved and have not been finalized for all localities and/or time intervals (compare von Hillebrandt 1987; Riccardi 2008). The fossils used in the current study have been assigned to ammonite zones based on results of previous studies (von Hillebrandt 1973, 1987, 2002; von Hillebrandt and Schmidt-Effing 1981; Aberhan and von Hillebrandt 1996; Pérez et al. 2008; Fantasia et al. 2018).
Sinemurian ammonites of Chile were discussed in detail by von Hillebrandt (2002). The lower part of the Jurassic succession near El Transito contains only few ammonites, but von Hillebrandt (2002) described some specimens, which he could assign to the Raricostatum Zone. Even though the Sinemurian at these localities has a thickness of more than 200 m, it seems to belong entirely to this ammonite zone indicating a late Sinemurian age (von Hillebrandt 2002).
Section 2 is a classic locality in the lower Quebrada El Asiento near Potrerillos examined or mentioned by numerous previous researchers (e.g., von Hillebrandt and Schmidt-Effing 1981; Pérez 1982; Aberhan 1992; von Hillebrandt 2006; Pérez et al. 2008; Fantasia et al. 2018). Shells used in the present study were collected from the Pliensbachian part of the succession, which was divided into three ammonite zones by von Hillebrandt and Schmidt-Effing (1981): Fig. 3): the Davoei, Margaritatus, and Spinatum zones. This scheme was also adopted by Fantasia et al. (2018), who additionally studied the nannofossil biostratigraphy of the same section. These studies were the foundation to assign Bed 2-1 to the upper Davoei to lower Margaritatus Zone and Bed 2-2 to the Margaritatus Zone (for sections with bed numbers see chapter 5). Based on the stratigraphic correlation by Aberhan (1992), Beds 6-7, 6-8, and 6-9 should be slightly younger than Beds 2-1 and 2-2. Consequently, they can be assigned to the Spinatum Zone.
Toarcian oyster shells and one brachiopod were available from sections 4, 5, and 6 near El Transito. Beds 4-1, 5-7, and 6-10 correspond to a conspicuous oolitic ironstone to bioclastic limestone unit almost directly above a thick package of sandstones. This stratigraphic interval has been assigned to the Upper Toarcian Copiapense and Tenuicostatum zones (not to be confused with the European Lower Toarcian Tenuicostatum Zone; compare von Hillebrandt 1973, 1987; Aberhan and von Hillebrandt 1996), which are equivalent to the Thouarsense and lowermost Levesquei zones of Europe (e.g., Pérez et al. 2008). The overlying marly limestones with Beds 4-2 and 4-3 have been assigned to the Lotharingica and Fluitans zones (compare Aberhan and von Hillebrandt 1996), which are equivalent to the middle and upper Levesquei Zone of Europe (e.g., Pérez et al. 2008).
3 Material and methods
Fifty-nine shells of oysters and brachiopods from the Lower Jurassic strata of northern Chile were used in the current study. The fossil material was originally collected by Martin Aberhan for a palaeoecological study (Aberhan 1992, 1993) and is now stored in the collections of the Bayerische Staatssammlung für Paläontologie und Geologie in Munich, Germany. The diverse benthic fauna has been identified and described in detail by Aberhan (1992) and contains a number of species with an original calcitic shell enabling stable isotope analyses. Taxa used in the present study include oysters of the genera Gryphaea and Actinostreon as well as rhynchonellid brachiopods of the genera Gibbirhynchia, Tetrarhynchia, Quadratirhynchia, Rudirhynchia, and Rhynchonelloidea. One specimen of the spiriferid brachiopod Spiriferina chilensis was analyzed as well. Illustrations of these taxa can be found in taxonomic studies (e.g., Manceñido 1981; Manceñido and Dagys 1992; Aberhan 1994; Baeza-Carratalá 2013).
4 Preservation of the fossil material
Another possible indicator for alteration is a correlation between the δ18O and δ13C values of the analyzed shells. Sedimentary rocks are commonly characterized by lower δ18O and δ13C values than fossil shells, especially after diagenetic alteration or influence by meteoric waters (e.g., Hodgson 1966; Hudson 1977; Nelson and Smith 1996). Similarly, stable isotope ratios of fossil shells shift towards lower values with increasing alteration leading to a correlation between both values in the dataset. Such a correlation should therefore be treated with caution, although in some cases it can be primary in origin, for example, because of an increase in primary productivity with higher water temperatures.
Three oysters were selected for high-resolution stable isotope analyses (Fig. 2c–e). The data of specimen CH18–006 show a strong correlation between δ18O and δ13C values (Fig. 4b; rs = 0.89; p < 0.05), which is believed to be due to the influence of diagenetic alteration. Results of this specimen were therefore not used for temperature reconstructions. Stable isotope data of the other two specimens CH18-017 and CH18-030 show no significant correlation (Fig. 4c, d) and are therefore believed to represent original conditions.
In summary, cathodoluminescence microscopy and the evaluation of a potential correlation between δ18O and δ13C values indicate a good preservation of the shells used for temperature reconstructions (except for specimen CH18-006).
5 Results of the stable isotope analyses
Results of the stable isotope (δ13C, δ18O) analyses of oysters and brachiopods from the Lower Jurassic of northern Chile. In addition to well-preserved shells, some luminescent and altered oyster shells as well as sediment and cement samples were analyzed. Please note that the high-resolution analysis of specimen CH18-006 indicated a diagenetic alteration of this shell, which has consequently not been used for further interpretations
δ13C (‰ VPDB)
δ18O (‰ VPDB)
Oysters and brachiopods
Middle to upper Levesquei
Middle to upper Levesquei
Middle to upper Levesquei
Middle to upper Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Thouarsense – lower Levesquei
Rudirhynchia aff. rudis
Rudirhynchia aff. rudis
Upper Davoei – lower Margaritatus
Gibbirhynchia cf. curviceps
Luminescent, altered shells
Sediment and cement samples
Thouarsense – lower Levesquei
Results of the high-resolution stable isotope (δ13C, δ18O) analyses of three oysters with a late Toarcian age
δ13C (‰ VPDB)
δ18O (‰ VPDB)
Gryphaea sp. (CH18-006; late Toarcian; Bed 6-10)
Gryphaea sp. (CH18-017; late Toarcian; Bed 5-7)
Gryphaea sp. (CH18-030; late Toarcian; Bed 4-1)
The δ18O values show some fluctuations through time. In the late Sinemurian, the values range around an average of -3.22‰ (range: -4.09‰ to -2.31‰) with the highest values close to the Sinemurian–Pliensbachian boundary (Fig. 5). In the Pliensbachian, there are two outliers with comparatively low values (CH18-032: -4.88‰; CH18-034: -3.86‰). These two shells (which show δ13C values similar to the other shells) are from section 2 near Potrerillos around 280 km north of all other analyzed shells (Fig. 1). The other two Pliensbachian shells from a higher stratigraphic interval near the boundary to the Toarcian show comparatively high δ18O values around an average of -2.46‰ (CH18-001: -3.07‰; CH18-002: -1.85‰). In the late Toarcian, the data fluctuate around an average of -2.92‰ (range: -3.69‰ to -2.46‰). This interval also contains specimen CH18-006, which has been excluded from interpretation, as it has shown signs of diagenetic alteration during high-resolution analysis (see above).
In summary, the δ13C and δ18O values show differing trends through time. While the δ13C values show an overall steady increase through time, the changes in the δ18O values are somewhat more complex. Over most of the late Sinemurian, the δ18O values are below -3‰. Just below the Sinemurian–Pliensbachian boundary, the average δ18O value rises above -3‰. The highest δ18O value in the entire dataset is reached at the end of the Pliensbachian. The δ18O values in the late Toarcian are again lower but not as low as in the late Sinemurian (Fig. 5).
Aberhan (1992) assigned three different depositional environments to the Lower Jurassic strata of the study area: (1) a coastal zone dominated by siliciclastic sediments with sedimentary structures pointing to a setting above or just below the fair-weather wave-base (mainly sand- or siltstones), (2) an intermediate zone dominated by carbonates, but still showing a considerable clay and silt content (mainly bioclastic wacke- to packstones), and (3) a distal zone with low sedimentation rates characterized by very fine-grained terrigenous siliciclastics and carbonate mud (mainly mud- to wackestones and marl). While zones 1 and 2 have comparatively high faunal diversities, zone 3 is characterized by very low diversities (possibly caused by low oxygen availability and soupy substrates; Aberhan 1992).
Shells used in the present study are from the deeper part of zone 1 and zone 2 (compare Fig. 5). Some shells come from siltstones or mixed carbonate–siliciclastics (partly with ferruginous ooids), which represent somewhat deeper water around or just below the fair-weather wave-base (zone 1 of Aberhan 1992). Most fossils come from carbonates (zone 2 of Aberhan 1992), which are occasionally marly or are developed as shell beds possibly formed by storm action (the repeated occurrence of higher energy conditions such as storms has also been suggested by Fantasia et al. 2018). No direct correlation between the results of the stable isotope analyses and the facies types (= water depth) can be seen (Fig. 5) and it can be assumed that the analyzed shells were formed above the thermocline and therefore represent sea-surface water conditions.
Apart from the water temperature, the stable isotope (δ18O) composition of shells in marine environments can be influenced by salinity fluctuations. A deviation from the normal marine salinity due to freshwater influx (rain fall or river discharge) or strong evaporation (e.g., in an enclosed lagoon) can considerably alter the oxygen isotope composition of the ocean water and consequently of the shells. As described above, the fossil material used in the present study represents a shallow water depth slightly above the fair-weather wave-base or just below, but still above the thermocline and within reach of occasional stronger storms. No fossils have been used from the cross-bedded sandstones which formed in a very shallow setting. Freshwater influx via stronger rain fall affecting the uppermost water layers can therefore be excluded. Strong deviations from normal marine salinity are also unlikely considering that the fossils collected in the stratigraphic interval studied include stenohaline forms such as corals, brachiopods, crinoids, and ammonites (Fig. 5; Aberhan 1992; compare also Fantasia et al. 2018).
6.2 Carbon isotope record
The δ13C data (Fig. 5) indicate a trend towards higher values, however, it should be noted that the Sinemurian and Pliensbachian samples are represented by brachiopods, while the Toarcian data come mainly from oysters. The δ13C values of oysters are consistently higher than those of the brachiopods (Fig. 4a), even though the δ18O values are comparable. Vital effects causing higher δ13C values of oysters might therefore explain the recorded “trend” from the Sinemurian to the Toarcian at least in parts. This is in broad agreement with the dataset of Korte et al. (2015) for the Early Jurassic, which shows mostly higher δ13C values in bivalves than in brachiopods of the same age. Other studies, however, show that co-occurring bivalves and brachiopods have very similar δ13C values (e.g., Alberti et al. 2017, 2019). Further data of different faunal groups is therefore necessary to judge whether there actually is a trend in the δ13C values through time or whether the difference is merely caused by vital effects. Apart from this problem, the absolute δ13C values are comparable to those of shells from Europe (e.g., Korte et al. 2015).
Lower Jurassic rocks include a number of prominent carbon isotope excursions including one during the Toarcian Oceanic Anoxic Event (e.g., Jenkyns 1988; Hesselbo et al. 2000a, 2007; Pálfy and Smith 2000; van de Schootbrugge et al. 2005a; Gómez et al. 2008; Suan et al. 2008, 2011; Littler et al. 2010; Korte and Hesselbo 2011; Silva et al. 2011; Caswell and Coe 2012; Riding et al. 2013; Kemp and Izumi 2014; Krencker et al. 2014; Ait-Itto et al. 2017; Arabas et al. 2017; Bougeault et al. 2017; Menini et al. 2019; Mercuzot et al. 2019). The TOAE has also been reported from Argentina (Al-Suwaidi et al. 2010, 2014, 2016; Mazzini et al. 2010) and Chile (Fantasia et al. 2018). Fantasia et al. (2018) reported several negative carbon isotope excursions based on analyses of whole-rock samples (i.e. within the Margaritatus Zone, at the Pliensbachian–Toarcian boundary, and during the TOAE). These excursions are not visible in the present δ13C values of fossil shells (Fig. 5), because they were of relatively short duration and/or the stratigraphic intervals where they are most pronounced are not represented by fossils (compare Boulila and Hinnov 2017). The variation in the δ13C values of fossil shells is relatively small compared to that recorded by Fantasia et al. (2018) from whole-rock analyses. The only exception is specimen CH18-046 from the upper Toarcian, which shows a much lower δ13C value than all other shells analyzed. However, this shell has a considerably younger age than the previously reported negative carbon isotope excursions, and since other shells from the same horizon show higher values, it might be less reliable. It can be therefore presumed that the presented dataset represents background conditions prevalent over most of the Early Jurassic and not exceptional events.
6.3 Water temperatures
Considering that the shells formed above the thermocline and in normal marine salinity conditions, the recorded δ18O values can be translated into sea-surface water-temperatures. In accordance with the majority of other studies on Jurassic stable isotopes, the equation of Anderson and Arthur (1983) with a δ18O value of -1‰ VSMOW for seawater during shell precipitation (as suggested for an ice-free Jurassic world; Shackleton and Kennett 1975) was used. The reconstructed water temperatures show several fluctuations through time (Fig. 5). During most of the late Sinemurian, temperatures were relatively high (average: 27.0 °C). Just before the Sinemurian–Pliensbachian transition, temperatures dropped to an average of 24.3 °C. At the Quebrada El Asiento (section 2) near Potrerillos, the results point to very warm conditions during the Pliensbachian (average: 31.4 °C). Further south near El Transito (sections 4, 5, 6) temperatures were much lower (average: 22.3 °C). The lowest temperature in the entire dataset was recorded for the latest Pliensbachian (specimen CH18-002: 19.6 °C). No data is available for the early Toarcian, but results indicate again higher temperatures for the late Toarcian (average: 24.4 °C) comparable to those of the late Sinemurian.
The data retrieved by high-resolution stable isotope (δ18O) analyses of the two oysters CH18-017 and CH18-030 can be translated into seasonal temperature fluctuations (Fig. 6b, c). Both shells show similar conditions in the late Toarcian reflecting temperature cycles during a period of around 3 years in the life time of the oysters. If explained only by temperature, the δ18O values of specimen CH18-017 record an average temperature of 23.9 °C with a minimum of 22.4 °C and a maximum of 25.6 °C. The δ18O values of specimen CH18-030 record a slightly lower average temperature of 21.5 °C with a minimum of 19.7 °C and a maximum of 22.8 °C. Since the oyster shells are not very large (Fig. 2d, e), the temporal resolution of samples is not very high for both shells with a year being represented by less than ten samples. Therefore true temperature maxima and minima occurring over the life time of the oysters are not recorded. Each value instead represents an average temperature of a period of one to 2 months. The reconstructed seasonality of slightly more than 3 °C for both shells is therefore only a minimum estimate.
6.4 Comparisons with previously published data
So far, reconstructions of absolute seawater temperatures for the Early Jurassic using the stable isotope (δ18O) composition of fossil hard parts are almost completely restricted to European and neighboring localities (e.g., Sælen et al. 1996; Hesselbo et al. 2000b; McArthur et al. 2000, 2007; Bailey et al. 2003; Nori and Lathuilière 2003; Rosales et al. 2004a, 2004b, 2018; van de Schootbrugge et al. 2005b; Gómez et al. 2008, 2016; Metodiev and Koleva-Rekalova 2008; Suan et al. 2008, 2010; Dera et al. 2009a, 2009b, 2011; Gómez and Arias 2010; Price 2010; Korte and Hesselbo 2011; Armendáriz et al. 2012; Li et al. 2012; Harazim et al. 2013; Teichert and Luppold 2013; Krencker et al. 2014, 2015; Metodiev et al. 2014; Korte et al. 2015; Martinez and Dera 2015; Price et al. 2016; Arabas et al. 2017). In these regions of the northwestern Tethys, previously published results show decreasing temperatures from the late Sinemurian throughout the Pliensbachian with a temperature minimum in the late Pliensbachian and around the Pliensbachian–Toarcian boundary. Temperatures then strongly increased in the early Toarcian with the development of the Toarcian Oceanic Anoxic Event, but remained relatively high throughout the Toarcian until they again decreased strongly into the Aalenian (Korte et al. 2015). Even though most authors agree that temperatures increased dramatically throughout the early Toarcian, some authors have questioned the reconstructed amplitude of this change and attributed at least part of it to a parallel change in the δ18O values of the seawater (e.g., by the disappearance of polar ice shields or an increased freshwater runoff in the Toarcian; Sælen et al. 1996; Rosales et al. 2004b; Suan et al. 2008; Dera et al. 2009b, 2011; Dera and Donnadieu 2012; Korte et al. 2015).
Temperature reconstructions for regions outside Europe especially those based on stable isotope (δ18O) analyses are very scarce (Volkheimer et al. 2008). Bowen (1963) analyzed eight poorly dated belemnites from the Lower Jurassic of Argentina. After dismissing one specimen due to unlikely analytical results, his δ18O results vary between -0.1‰ and -2.9‰ (equivalent to temperatures of 12.4 °C to 24.3 °C using a δ18O for seawater of -1‰ and the equation of Anderson and Arthur 1983). Interestingly, Bowen (1963) reconstructed a seasonality of 3.3 °C to 3.7 °C based on his belemnites, which is quite comparable to the results of the present study. However, since his data is only known to be Lower Jurassic, it can hardly be compared to the current dataset considering the likelihood of prominent climate changes during this time interval.
On average, the reconstructed absolute water temperatures in Chile are slightly higher than those of the northwestern Tethys (Fig. 7). This can be attributed to a higher palaeolatitude of the European localities in the northern hemisphere compared to Chile in the southern hemisphere. At the same time, it has to be noted that the majority of data from Europe is based on belemnites, which are known to commonly record lower temperatures than co-occurring brachiopods and bivalves (e.g., Dera et al. 2011; Alberti et al. 2012a, 2019). The cause of this difference might include different life habits between the faunal groups, but is still strongly debated in literature (Fürsich et al. 2005; Mutterlose et al. 2010; Alberti et al. 2012a, 2012b; Price et al. 2015; Dera et al. 2016; Hoffmann et al. 2016).
The dataset from the Andean Basin in northern Chile is the first stable isotope record of well-dated brachiopod and oyster shells from the Lower Jurassic of South America. The recorded δ18O values point to warm conditions in the late Sinemurian (average: 27.0 °C), a slight cooling just before the Sinemurian–Pliensbachian transition (average: 24.3 °C), lowest temperatures in the latest Pliensbachian (19.6 °C), and again warmer temperatures in the late Toarcian (average: 24.4 °C). Thereby, the dataset supports the global nature of the Late Pliensbachian Cooling Event. More material is necessary to detect the presumed global warming during the early Toarcian Oceanic Anoxic Event, which was not represented by material in the collection analyzed. The recorded δ13C values represent background conditions prevalent over most of the Early Jurassic instead of short-term intervals of carbon-cycle perturbations. High-resolution stable isotope (δ18O) analyses of oyster shells point to a seasonality in northern Chile of more than 3 °C in the late Toarcian.
The authors thank Winfried Werner for enabling access to the collections of the Bayerische Staatssammlung für Paläontologie und Geologie in Munich, Germany. Birgit Leipner-Mata and Michael Joachimski allowed the use of laboratories at the University of Erlangen-Nürnberg, Germany. Horacio Parent (Rosario, Argentina) and Axel von Hillebrandt (Berlin, Germany) provided copies of scientific articles. The authors thank the Editor-in-Chief Zengzhao Feng and three anonymous reviewers for their support and constructive comments.
MA designed research, performed research, acquired data, and analyzed data. NA performed the stable isotope analyses. MA, FTF, and NA drafted the manuscript. All authors read and approved the final manuscript.
The study was supported financially by the German Research Foundation (DFG; project AL 1740/3–1).
The authors declare that they have no competing interests.
- Aberhan, M. 1992. Palökologie und zeitliche Verbreitung benthischer Faunengemeinschaften im Unterjura von Chile. Beringeria 5: 3–174.Google Scholar
- Aberhan, M. 1994. Early Jurassic Bivalvia of northern Chile. Part I. subclasses Palaeotaxodonta, Pteriomorpha, and Isofilibranchia. Beringeria 13: 3–115.Google Scholar
- Ait-Itto, F.-Z., G.D. Price, A.A. Addi, D. Chafiki, and I. Mannani. 2017. Bulk-carbonate and belemnite carbon-isotope records across the Pliensbachian-Toarcian boundary on the northern margin of Gondwana (Issouka, middle atlas, Morocco). Palaeogeography Palaeoclimatology Palaeoecology 466: 128–136.CrossRefGoogle Scholar
- Alberti, M., F.T. Fürsich, A.A. Abdelhady, and N. Andersen. 2017. Middle to late Jurassic equatorial seawater temperatures and latitudinal temperature gradients based on stable isotopes of brachiopods and oysters from Gebel Maghara, Egypt. Palaeogeography Palaeoclimatology Palaeoecology 468: 301–313.CrossRefGoogle Scholar
- Alberti, M., F.T. Fürsich, and D.K. Pandey. 2012a. The Oxfordian stable isotope record (δ18O, δ13C) of belemnites, brachiopods, and oysters from the Kachchh Basin (western India) and its potential for palaeoecologic, palaeoclimatic, and palaeogeographic reconstructions. Palaeogeography Palaeoclimatology Palaeoecology 344–345: 49–68.CrossRefGoogle Scholar
- Alberti, M., F.T. Fürsich, and D.K. Pandey. 2013. Seasonality in low latitudes during the Oxfordian (late Jurassic) reconstructed via high-resolution stable isotope analysis of the oyster Actinostreon marshi (J. Sowerby, 1814) from the Kachchh Basin, western India. International Journal of Earth Sciences 102: 1321–1336.CrossRefGoogle Scholar
- Al-Suwaidi, A.H., G.N. Angelozzi, F. Baudin, D. Condon, S.E. Damborenea, S.P. Hesselbo, H.C. Jenkyns, M. Manceñido, and A. Riccardi. 2014. Re-evaluating the Toarcian oceanic anoxic event from the southern hemisphere, Neuquén Basin, Argentina. Beringeria Special Issue 8: 17–18.Google Scholar
- Al-Suwaidi, A.H., G.N. Angelozzi, F. Baudin, S.E. Damborenea, S.P. Hesselbo, H.C. Jenkyns, M.O. Manceñido, and A.C. Riccardi. 2010. First record of the early Toarcian oceanic anoxic event from the southern hemisphere, Neuquén Basin, Argentina. Journal of the Geological Society London 167: 633–636.CrossRefGoogle Scholar
- Al-Suwaidi, A.H., S.P. Hesselbo, S.E. Damborenea, M.O. Manceñido, H.C. Jenkyns, A.C. Riccardi, G.N. Angelozzi, and F. Baudin. 2016. The Toarcian oceanic anoxic event (early Jurassic) in the Neuquén Basin, Argentina: A reassessment of age and carbon isotope stratigraphy. The Journal of Geology 124: 171–193.CrossRefGoogle Scholar
- Anderson, T.F., and M.A. Arthur. 1983. Stable isotopes of oxygen and carbon and their application to sedimentological and paleoenvironmental problems. In Stable isotopes in sedimentary geology. SEPM Short Course, ed. M.A. Arthur, T.F. Anderson, I.R. Kaplan, J. Veizer, and L. Land, vol. 10, 1–151.Google Scholar
- Arabas, A., J. Schlögl, and C. Meister. 2017. Early Jurassic carbon and oxygen isotope records and seawater temperature variations: Insights from marine carbonate and belemnite rostra (Pieniny Klippen Belt, Carpathians). Palaeogeography Palaeoclimatology Palaeoecology 485: 119–135.CrossRefGoogle Scholar
- Armendáriz, M., I. Rosales, B. Bádenas, M. Aurell, J.C. García-Ramos, and L. Piñuela. 2012. High-resolution chemostratigraphic records from lower Pliensbachian belemnites: Palaeoclimatic perturbations, organic facies and water mass exchange (Asturian basin, northern Spain). Palaeogeography Palaeoclimatology Palaeoecology 333–334: 178–191.CrossRefGoogle Scholar
- Bailey, T.R., Y. Rosenthal, J.M. McArthur, B. van de Schootbrugge, and M.F. Thirlwall. 2003. Paleoceanographic changes of the late Pliensbachian-early Toarcian interval: A possible link to the genesis of an oceanic anoxic event. Earth and Planetary Science Letters 212: 307–320.CrossRefGoogle Scholar
- Bodin, S., F.-N. Krencker, T. Kothe, R. Hoffmann, E. Mattioli, U. Heimhofer, and L. Kabiri. 2016. Perturbation of the carbon cycle during the late Pliensbachian – Early Toarcian: New insight from high-resolution carbon isotope records in Morocco. Journal of African Earth Sciences 116: 89–104.CrossRefGoogle Scholar
- Bougeault, C., P. Pellenard, J.-F. Deconinck, S.P. Hesselbo, J.-L. Dommergues, L. Bruneau, T. Cocquerez, R. Laffont, E. Huret, and N. Thibault. 2017. Climatic and palaeoceanographic changes during the Pliensbachian (early Jurassic) inferred from clay mineralogy and stable isotope (C-O) geochemistry (NW Europe). Global and Planetary Change 149: 139–152.CrossRefGoogle Scholar
- Bowen, R. 1963. O18/O16 paleotemperature measurements on Mesozoic Belemnoidea from Neuquen and Santa Cruz provinces, Argentina. Journal of Paleontology 37: 714–718.Google Scholar
- Cresta, S., A. Goy, S. Ureta, C. Arias, E. Barrón, J. Bernad, M.L. Canales, F. García-Joral, E. García-Romero, P.R. Gialanella, J.J. Gómez, J.A. González, C. Herrero, G. Martínez, M.L. Osete, N. Perilli, and J.J. Villalaín. 2001. The global boundary Stratotype section and point (GSSP) of the Toarcian-Aalenian boundary (lower-middle Jurassic). Episodes 24: 166–175.CrossRefGoogle Scholar
- Dera, G., P. Pellenard, P. Neige, J.-F. Deconinck, E. Pucéat, and J.-L. Dommergues. 2009a. Distribution of clay minerals in early Jurassic Peritethyan seas: Palaeoclimatic significance inferred from multiproxy comparisons. Palaeogeography Palaeoclimatology Palaeoecology 271: 39–51.CrossRefGoogle Scholar
- Dera, G., E. Pucéat, P. Pellenard, P. Neige, D. Delsate, M.M. Joachimski, L. Reisberg, and M. Martinez. 2009b. Water mass exchange and variations in seawater temperature in the NW Tethys during the early Jurassic: Evidence from neodymium and oxygen isotopes of fish teeth and belemnites. Earth and Planetary Science Letters 286: 198–207.CrossRefGoogle Scholar
- Fürsich, F.T., I.B. Singh, M. Joachimski, S. Krumm, M. Schlirf, and S. Schlirf. 2005. Palaeoclimatic reconstructions of the middle Jurassic of Kachchh (western India): An integrated approach based on palaeoecological, oxygen isotopic, and clay mineralogical data. Palaeogeography Palaeoclimatology Palaeoecology 217: 289–309.CrossRefGoogle Scholar
- Gómez, J.J., A. Goy, and M.L. Canales. 2008. Seawater temperature and carbon isotope variations in belemnites linked to mass extinction during the Toarcian (early Jurassic) in central and northern Spain. Comparison with other European sections. Palaeogeography, Palaeoclimatology, Palaeoecology 258: 28–58.CrossRefGoogle Scholar
- Gröschke, M., A. von Hillebrandt, P. Prinz, L.A. Quinzio, and H.-G. Wilke. 1988. Marine Mesozoic paleogeography in northern Chile between 21°-26°S. In The Southern Central Andes. Lecture Notes in Earth Sciences, ed. H. Bahlburg, C. Breitkreuz, and P. Giese, vol. 17, 105–117.Google Scholar
- Hoffmann, R., D.K. Richter, R.D. Neuser, N. Jöns, B.J. Linzmeier, R.E. Lemanis, F. Fusseis, X. Xiao, and A. Immenhauser. 2016. Evidence for a composite organic-inorganic fabric of belemnite rostra: Implications for palaeoceanography and palaeoecology. Sedimentary Geology 341: 203–215.CrossRefGoogle Scholar
- Manceñido, M.O. 1981. A revision of early Jurassic Spiriferinidae (Brachiopoda, Spiriferida) from Argentina. In Cuencas sedimentarias del Jurásico y Cretácico de América del Sur, ed. W. Volkheimer and E. Musacchio, vol. 2, 625–660.Google Scholar
- Manceñido, M.O., and A.S. Dagys. 1992. Brachiopods of the circum-Pacific region. In The Jurassic of the Circum-Pacific, ed. G.E.G. Westermann, 328–333.Google Scholar
- McArthur, J.M., D.T. Donovan, M.F. Thirlwall, B.W. Fouke, and D. Mattey. 2000. Strontium isotope profile of the early Toarcian (Jurassic) oceanic anoxic event, the duration of ammonite biozones, and belemnite palaeotemperatures. Earth and Planetary Science Letters 179: 269–285.CrossRefGoogle Scholar
- Menini, A., E. Mattioli, J.E. Spangenberg, B. Pittet, and G. Suan. 2019. New calcareous nannofossil and carbon isotope data for the Pliensbachian/Toarcian boundary (early Jurassic) in the western Tethys and their paleoenvironmental implications. Newsletters on Stratigraphy 52: 173–196.CrossRefGoogle Scholar
- Mercuzot, M., P. Pellenard, C. Durlet, C. Bougeault, C. Meister, J.-L. Dommergues, N. Thibault, F. Baudin, O. Mathieu, L. Bruneau, E. Huret, and K. El Hmidi. 2019. Carbon-isotope events during the Pliensbachian (lower Jurassic) on the African and European margins of the NW Tethyan realm. Newsletters on Stratigraphy, in press. Google Scholar
- Metodiev, L.S., I.P. Savov, D.R. Gröcke, P.B. Wignall, R.J. Newton, P.V. Andreeva, and E.K. Koleva-Rekalova. 2014. Paleoenvironmental conditions recorded by 87Sr/86Sr, δ13C, and δ18O in late Pliensbachian-Toarcian (Jurassic) belemnites from Bulgaria. Palaeogeography Palaeoclimatology Palaeoecology 409: 98–113.CrossRefGoogle Scholar
- Mutterlose, J., M. Malkoc, S. Schouten, J.S. Sinninghe Damsté, and A. Forster. 2010. TEX86 and stable δ18O paleothermometry of early cretaceous sediments: Implications for belemnite ecology and paleotemperature proxy application. Earth and Planetary Science Letters 298: 286–298.CrossRefGoogle Scholar
- Nelson, C.S., and A.M. Smith. 1996. Stable oxygen and carbon isotope compositional fields for skeletal and diagenetic components in New Zealand Cenozoic nontropical carbonate sediments and limestones: A synthesis and review. New Zealand Journal of Geology and Geophysics 39: 93–107.CrossRefGoogle Scholar
- Pérez, E. 1982. Bioestratigrafía del Jurásico de Quebrada Asientos, Norte de Potrerillos, Región de Atacama. Servicio Nacional de Geología y Minería Boletin 37: 1–149.Google Scholar
- Pérez, E., M. Aberhan, R. Reyes, and A. von Hillebrandt. 2008. Early Jurassic Bivalvia of northern Chile. Part III. Order Trigonioida. Beringeria 39: 51–102.Google Scholar
- Rees, P.M., A.M. Ziegler, and P.J. Valdes. 2000. Jurassic phytogeography and climates: New data and model comparisons. In Warm climates in earth history, ed. B.T. Huber, K.G. Macleod, and S.L. Wing, 297–318.Google Scholar
- Rosales, I., A. Barnolas, A. Goy, A. Sevillano, M. Armendáriz, and J.M. López-García. 2018. Isotope records (C-O-Sr) of late Pliensbachian-early Toarcian environmental perturbations in the westernmost Tethys (Majorca Island, Spain). Palaeogeography, Palaeoclimatology, Palaeoecology 497: 168–185.CrossRefGoogle Scholar
- Ros-Franch, S., J. Echevarría, S.E. Damborenea, M.O. Manceñido, H.C. Jenkyns, A. Al-Suwaidi, S.P. Hesselbo, and A.C. Riccardi. 2019. Population response during an oceanic anoxic event: The case of Posidonotis (Bivalvia) from the lower Jurassic of Neuquén Basin, Argentina. Palaeogeography Palaeoclimatology Palaeoecology 525: 57–67.CrossRefGoogle Scholar
- Ruhl, M., S.P. Hesselbo, L. Hinnov, H.C. Jenkyns, W. Xu, J.B. Riding, M. Storm, D. Minisini, C.V. Ullmann, and M.J. Leng. 2016. Astronomical constraints on the duration of the early Jurassic Pliensbachian stage and global climatic fluctuations. Earth and Planetary Science Letters 455: 149–165.CrossRefGoogle Scholar
- Shackleton, N.J., and J.P. Kennett. 1975. Paleotemperature history of the Cenozoic and the initiation of Antarctic glaciation: Oxygen and carbon isotope analyses in DSDP sites 277, 279, and 281. Initial Reports of the Deep Sea Drilling Project 29: 743–755.Google Scholar
- Silva, R.L., L.V. Duarte, M.J. Comas-Rengifo, J.G. Mendonça Filho, and A.C. Azerêdo. 2011. Update of the carbon and oxygen isotopic records of the early-late Pliensbachian (early Jurassic, ~187Ma): Insights from the organic-rich hemipelagic series of the Lusitanian Basin (Portugal). Chemical Geology 283: 177–184.CrossRefGoogle Scholar
- Suan, G., B.L. Nikitenko, M.A. Rogov, F. Baudin, J.E. Spangenberg, V.G. Knyazev, L.A. Glinskikh, A.A. Goryacheva, T. Adatte, J.B. Riding, K.B. Föllmi, B. Pittet, E. Mattioli, and C. Lécuyer. 2011. Polar record of early Jurassic massive carbon injection. Earth and Planetary Science Letters 312: 102–113.CrossRefGoogle Scholar
- Ullmann, C.V., and C. Korte. 2015. Diagenetic alteration in low-mg calcite from macrofossils: A review. Geological Quarterly 59: 3–20.Google Scholar
- van de Schootbrugge, B., J.M. McArthur, T.R. Bailey, Y. Rosenthal, J.D. Wright, and K.G. Miller. 2005a. Toarcian oceanic anoxic event: An assessment of global causes using belemnite C isotope records. Paleoceanography 20: PA3008.Google Scholar
- Vicente, J.-C. 2006. Dynamic paleogeography of the Jurassic Andean basin: Pattern of regression and general considerations on main features. Revista de la Asociación Geológica Argentina 61: 408–437.Google Scholar
- Volkheimer, W., O.W.M. Rauhut, M.E. Quattrocchio, and M.A. Martinez. 2008. Jurassic paleoclimates in Argentina, a review. Revista de la Asociación Geológica Argentina 63: 549–556.Google Scholar
- von Hillebrandt, A. 1971. Der Jura in der chilenisch-argentinischen Hochkordillere (25° bis 32°30′ S). Münstersche Forschungen zur Geologie und Paläontologie 20 (21): 63–87.Google Scholar
- von Hillebrandt, A. 1973. Neue Ergebnisse über den Jura in Chile und Argentinien. Münstersche Forschungen zur Geologie und Paläontologie 31 (32): 167–199.Google Scholar
- von Hillebrandt, A. 1987. Liassic ammonite zones of South America and correlations with other provinces. With description of new genera and species of ammonites. In Bioestratigrafia de los Sistemas Regionales del Jurásico y Cretácico de América del Sur, ed. W. Volkheimer, vol. 1, 111–157.Google Scholar
- von Hillebrandt, A. 2002. Ammoniten aus dem oberen Sinemurium von Südamerika. Revue de Paléobiologie 21: 35–147.Google Scholar
- von Hillebrandt, A. 2006. Ammoniten aus dem Pliensbachium (Carixium und Domerium) von Südamerika. Revue de Paléobiologie 25: 1–403.Google Scholar
- von Hillebrandt, A., and R. Schmidt-Effing. 1981. Ammoniten aus dem Toarcium (Jura) von Chile (Südamerika). Zitteliana 6: 3–74.Google Scholar
- Wierzbowski, H., K. Dembicz, and T. Praszkier. 2009. Oxygen and carbon isotope composition of Callovian-lower Oxfordian (middle-upper Jurassic) belemnite rostra from Central Poland: A record of a late Callovian global sea-level rise? Palaeogeography, Palaeoclimatology, Palaeoecology 283: 182–194.CrossRefGoogle Scholar
- Wierzbowski, H., and M. Joachimski. 2007. Reconstruction of late Bajocian-Bathonian marine palaeoenvironments using carbon and oxygen isotope ratios of calcareous fossils from the polish Jura chain (Central Poland). Palaeogeography, Palaeoclimatology, Palaeoecology 254: 523–540.CrossRefGoogle Scholar
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