Pangaean climate during the Early Jurassic: GCM simulations and the sedimentary record of paleoclimate

Chandler, Mark A.; Rind, David; Ruedy, R.

doi:10.1130/0016-7606(1992)104<0543:pcdtej>2.3.co;2

Cited by 171 publications

(116 citation statements)

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“…5. Average calculated temperature for the studied interval is 18.3 cC, which is compatible with the temperature values measured in current oceans by the National Oceanic and Atmospheric Agency (NOM, 2007), taking into account that the palaeolatitude calculated for Madrid during the Toarcian was about 35-36cN (Osete et al, 2000), around 4_5c south of its current position, and that thejurassic climate has been assumed to be warmer than present (Chandler et al, 1992;Bailey et al, 2003;Sellwood and Valdes, 2006). …”

Section: Stable Isotope Record and Seawater Temperaturesupporting

confidence: 62%

Palaeoclimatic and biotic changes during the Aalenian (Middle Jurassic) at the southern Laurasian Seaway (Basque–Cantabrian Basin, northern Spain)

Gómez

Canales

Ureta

et al. 2009

Palaeogeography, Palaeoclimatology, Palaeoecology

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The uppermost Toarcian-lowermost 8ajocian deposits have been studied in 10 sections located in the western part of the Basque-Cantabrian Basin (northern Spain). The studied 276 successive recorded ammonite assemblages allowed detailed biostratigraphical subdivision and the correlation of the sections at the ammonite zone and subzone scale. The foraminifers were studied in 96 samples and 55 diagenetically screened belemnite rostra were analyzed for C and 0 isotope.Facies and thickness distribution of the Aalenian sediments suggest that deposition took place in a nearly symmetrical sub-basin included into an intra plate shallow platform, developed over continental crust, on which flexure was the main control responsible for subsidence and basin evolution.Noteworthy negative 613Cb�1 excursions, coinciding with seawater temperature changes, were recorded during the Bradfordensis Biochron, around the Concavum-Limitatum biochron boundary, and around the Aalenian-Bajocian boundary. A close relationship between the changes in seawater temperature and the biotic changes observed in the foraminiferal and in the ammonoids assemblages has been evidenced. During the Comptum Biochron, the 6180�1-based palaeotemperature shows a remarkable cooling interval with an average seawater temperature of 15.7 QC. This cooling favoured the immigration of species of foraminifers that thrived in platforms with colder seawater temperatures located north of the Basque-Cantabrian Basin.As a consequence, a strong increase in the diversity of the foraminiferal assemblages (28.5% of first appearances) occurred. This interval also coincides with the highest ammonoid abundance recorded during the Aalenian. A notable increase in temperature with peak values up to 24.3 QC, was measured during the Bradfordensis Biochron. This warming marks the beginning of progressive loss of foraminifer diversity and the decrease in the abundance of ammonoids. However, the increase in the relative abundances of some foraminiferal taxa such as the genus Spirillina during the warming phase is remarkable. Some of the foraminiferal species that had their last occurrence during this interval seem to be immigrants from NW Europe that arrived during the Comptum cooling interval, and that did not survive to rise of the seawater temperature.Another drop in temperature was recorded during the late Gigantea and the early Concavum biochrons.Coinciding with this cooling interval nearly 20% of the foraminiferal species disappeared while the ammonoid abundance increased. A new and significant warming episode occurred during the latest Aalenian (Limitatum Biochron), extending to the earliest Bajocian (Discites Biochron). Biotic response to this new bT of 2.5 QC is remarkable, marking one of the most important crises of the Aalenian. More than 30% of the foraminiferal species disappeared and no new appearances were recorded. Ammonoids show a decrease in the specimen abundance during the Limitatum-Discites warming, preceding a drastic decrease in the species abundance.The rem...

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Section: Stable Isotope Record and Seawater Temperaturesupporting

confidence: 62%

Palaeoclimatic and biotic changes during the Aalenian (Middle Jurassic) at the southern Laurasian Seaway (Basque–Cantabrian Basin, northern Spain)

Gómez

Canales

Ureta

et al. 2009

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…The progressive warming provoked the gradual disappearance of numerous taxa of ostracods and many other faunistic groups. The prevalence of southwards winds and currents in the Laurasian seaway (Chandler et al, 1992;Bj errum et al, 2001;Arias, 2007) may have impeded the migration of the ostracods towards cooler waters located north of the Iberian platform system, as indicated by the predominant southwards migration routes detected in this area for the Early Toarcian ostracods (Arias, 2006(Arias, ,2007.…”

Section: Discussionmentioning

confidence: 99%

“…13 a, b), average palaeotemperatures reached during this warming interval were in the order of 5-8 cC higher than in the present-day oceans at a similar latitude (NOAA) but lower than the palaeotemperatures calculated for the Early jurassic from climate modelling (Chandler et al, 1992).…”

Section: Comparison Of the 0180 Records And Palaeotemperature Calculamentioning

confidence: 99%

Rapid warming and ostracods mass extinction at the Lower Toarcian (Jurassic) of central Spain

Gómez

Arias

2010

Marine Micropaleontology

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“…Westem Pangaea (the area closest to the Iberian Range) would be arid excluding the Tethys coast (Chanctler et aL, 1992), Arias anct Whatley (2004) proposed that the earlyToarcian ostracod tumover could be a consequence of a gradual climate change during the Pliensbachian-Toarcian boundary from cold to warrn seas. Early Toarcian climate models (Chandler et al, 1992) seem to indicate that tropical sea surface temperatures were higher than today (from 25 cC in the East Panthalassa Ocean to 32 cC in the West Tethys Ocean). High-latitude sea surface temperatures were much lower (seasonal range from 3.5 cC to 9.5 ce) and the equator-to-pole temperature gradient was much lower than today (Chandler et al, 1992 ).…”

Section: The Effect Oiseawater Temperature Change On the Extinction Omentioning

confidence: 99%

“…11 c), that could have favoured a significant stratification and the forrnation of low oxygen levels in bottom waters below the mixed layer under several palaeoceanographic conditions, for example the sapropel formation under anti-estuarine circulation conditions in the Mediterranean Sea (Struck et al, 2001;Casford et al, 2003 ). At the beginning of the Toarcian the climatic conditions changed (Chandler et al, 1992) and new warrning conditions dominated the Iberian Range seas (Arias, 2oo6a, 2007(Arias, 2oo6a, , 2008bCómez and Arias, 2010), generating: (i) a weaker anti-estuarine circulation driven by intense buoyancy loss at the surface (by the strong evaporation), (ii) an important deep water forrnation, (iii) an inflow of relatively freshwater surface water with low nutrient content (Eg. 11), (iv) the reduced deep ventilation, and (v) low oxygen conditions (Struck et al, 2001;Casford et al, 2003).…”

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confidence: 99%

The early Toarcian (early Jurassic) ostracod extinction events in the Iberian Range: The effect of temperature changes and prolonged exposure to low dissolved oxygen concentrations

Arias

2013

Palaeogeography, Palaeoclimatology, Palaeoecology

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ABSTRAeT Keywords:Early Jurassic Metacopine Mass extinctions OstracodaThe early Toarcian extinction event, once regarded as spanning in the late Pliensbachian-early Toarcian boundary period, actually occurred in two distinct phases in the early Toarcian of the Iberian Range. The first episode occurred in the Mirabile Subzone, Tenuicostatum Zone and is characterised by the disappearance of abaut 12% of ostracod species and one suborder, the Metacopina (Superfamily Healdioidea). Ihis study shows that this suborder disappears during stratigraphical intervals that are considered to be representative of low oxygen conditions in the Iberian Range. The collapse of marine ecosystems (affecting up to 40% of ostracod species) in the Elegantulum Subzone, Serpentinum Zone was most likely triggered by a sudden and widespread lethal increase in seawater temperature. These combined processes of oxygenation and temperature change are considered to be responsible for the profound changes in marine environments that resulted in the early Toarcian ostracod extinction in the Iberian Range.Low oxygen episodes Water temperature

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Pangaean climate during the Early Jurassic: GCM simulations and the sedimentary record of paleoclimate

Cited by 171 publications

References 0 publications

Palaeoclimatic and biotic changes during the Aalenian (Middle Jurassic) at the southern Laurasian Seaway (Basque–Cantabrian Basin, northern Spain)

Palaeoclimatic and biotic changes during the Aalenian (Middle Jurassic) at the southern Laurasian Seaway (Basque–Cantabrian Basin, northern Spain)

Rapid warming and ostracods mass extinction at the Lower Toarcian (Jurassic) of central Spain

The early Toarcian (early Jurassic) ostracod extinction events in the Iberian Range: The effect of temperature changes and prolonged exposure to low dissolved oxygen concentrations

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