Palynofloral diversity and palaeoenvironments of early Eocene Akri lignite succession, Kutch Basin, western India

Verma, Poonam; Garg, Rahul; Rao, M. R.; Bajpai, Sunil

doi:10.1007/s12549-019-00388-1

Cited by 9 publications

(2 citation statements)

References 39 publications

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“…18.5 °C closely corroborate the brGDGT-biomarker reconstructions from the same site (Bijl et al, 2021), supporting the notion of a potential seasonal bias of this palaeothermometer (Contreras et al, 2014;Naafs et al, 2017). The warmth-loving taxa formed the main lowland forest components occupying sheltered areas and lowland subtropical coastal zones (Dowe, 2010;Carpenter et al, 2012;Tripathi and Srivastava, 2012;Verma et al, 2020) and swamps (Kershaw, 1988). Sporomorphbased temperature estimates yield cold month mean temperature (CMMT) well above freezing (11.2-12.5 ℃; Fig.…”

Section: Subtropical Vegetation and Early-late Eocene Cooling From 3797-3560 Masupporting

confidence: 71%

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>

Amoo

Salzmann

Pound

et al. 2021

Preprint

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Abstract. Considered as one of the most significant climate reorganisations of the Cenozoic period, the Eocene-Oligocene Transition (EOT; ca. 34.44–33.65) is characterised by global cooling and the first major glacial advance on Antarctica. While in the southern high-latitudes, the EOT cooling is primarily recorded in the marine realm, the extent and effect on terrestrial climate and vegetation is poorly documented. Here, we present a new, well-dated, continuous, high-resolution palynological (sporomorph) data and quantitative sporomorph-based climate estimates recovered from the East Tasman Plateau (ODP Site 1172) to reconstruct climate and vegetation dynamics from the late Eocene (37.97 Ma) to early Oligocene (33.06 Ma). Our results indicate three major climate transitions and four vegetation communities occupying Tasmania under different precipitation and temperature regimes: (i) a warm-temperate Nothofagus-Podocarpaceae dominated rainforest with paratropical elements from 37.97–37.52 Ma; (ii) cool-temperate Nothofagus dominated rainforest with secondary Podocarpaceae rapidly expanding and taking over regions previously occupied by the warmer taxa between 37.306–35.60 Ma; (iii) fluctuation between warm temperate – paratropical taxa and cool temperate forest from 35.50–34.49 Ma, followed by a cool phase across the EOT (34.30–33.82 Ma); (iv) post-EOT (earliest Oligocene) recovery characterised by a warm-temperate forest association from 33.55–33.06 Ma. Coincident with changes in stratification of water masses and sequestration of carbon from surface water in the Southern Ocean, our sporomorph-based temperature estimates between 37.52 Ma and 35.60 Ma (phase ii) showed 2–3 °C terrestrial cooling. The unusual fluctuation between warm and cold temperate forest between 35.50 to 34.59 Ma is suggested to be linked to the initial deepening of the Tasmanian Gateway allowing eastern Tasmania to come under the influence of warm water associated with the proto-Leeuwin Current (PLC). Further to the above, our terrestrial data show mean annual temperature declining by about 2 °C across the EOT before recovering in the earliest Oligocene. This phenomenon is synchronous with regional and global cooling during the EOT and linked to declining pCO2. However, the earliest Oligocene climate rebound along eastern Tasmania is linked to transient recovery of atmospheric pCO2 and sustained deepening of the Tasmanian Gateway, promoting PLC throughflow. The three main climate transitional events across the studied interval (late Eocene–earliest Oligocene) in the Tasmanian Gateway region suggest that changes in ocean circulation due to accelerated deepening of the Tasmanian Gateway may not have been solely responsible for the changes in terrestrial climate and vegetation dynamics, but a series of regional and global events, including a change in stratification of water masses, sequestration of carbon from surface waters, and changes in pCO2 may have played vital roles.

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Section: Subtropical Vegetation and Early-late Eocene Cooling From 3797-3560 Masupporting

confidence: 71%

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>

Amoo

Salzmann

Pound

et al. 2021

Preprint

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“…The new data in the compilation helps to improve geographical coverage in previously data‐poor regions, including central west coast and eastern Africa (e.g., Adeonipekun et al., 2012; Cantrill et al., 2013; Eisawi & Schrank, 2008) (also recently presented in Williams et al. (2022)); the coal and lignite bearing deposits of northeastern India and southern Pakistan (Frederiksen, 1994; Tripathi et al., 2000; Verma et al., 2019); the Tibetan plateau and sedimentary basins of southern China (e.g., Aleksandrova et al., 2015; Su et al., 2020; Xie et al., 2020); and the South American (e.g., Jaramillo et al., 2007; Pardo‐Trujillo et al., 2003; Quattrocchio & Volkheimer, 2000) and North American continent and Caribbean islands (e.g., Graham et al., 2000; Jarzen & Klug, 2010; Smith et al., 2020) (Figure 1; Supporting Information ). Most of these use the NLR approach based on palynological datasets, as plant macrofossils from the late Paleocene—early Eocene low latitudes are more rarely preserved, although some exceptions are known (Herman et al., 2017; Shukla et al., 2014; Wing et al., 2009).…”

Section: Methodsmentioning

confidence: 95%

Global and Zonal‐Mean Hydrological Response to Early Eocene Warmth

Cramwinckel

Burls

Fahad

et al. 2023

Paleoceanog and Paleoclimatol

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Earth's hydrological cycle is expected to intensify in response to global warming, with a "wet-gets-wetter, dry-gets-drier" response anticipated over the ocean. Subtropical regions (∼15°-30°N/S) are predicted to become drier, yet proxy evidence from past warm climates suggests these regions may be characterized by wetter conditions. Here we use an integrated data-modeling approach to reconstruct global and zonal-mean rainfall patterns during the early Eocene (∼56-48 million years ago). The Deep-Time Model Intercomparison Project (DeepMIP) model ensemble indicates that the mid-(30°-60°N/S) and high-latitudes (>60°N/S) are characterized by a thermodynamically dominated hydrological response to warming and overall wetter conditions. The tropical band (0°-15°N/S) is also characterized by wetter conditions, with several DeepMIP models simulating narrowing of the Inter-Tropical Convergence Zone. However, the latter is not evident from the proxy data. The subtropics are characterized by negative precipitation-evaporation anomalies (i.e., drier conditions) in the DeepMIP models, but there is surprisingly large inter-model variability in mean annual precipitation (MAP). Intriguingly, we find that models with weaker meridional temperature gradients (e.g., CESM, GFDL) are characterized by a reduction in subtropical moisture divergence, leading to an increase in MAP. These model simulations agree more closely with our new proxy-derived precipitation reconstructions and other key climate metrics and imply that the early Eocene was characterized by reduced subtropical moisture divergence. If the meridional temperature gradient was even weaker than suggested by those DeepMIP models, circulation-induced changes may have outcompeted thermodynamic changes, leading to wetter subtropics. This highlights the importance of accurately reconstructing zonal temperature gradients when reconstructing past rainfall patterns. Plain Language SummaryAs the world warms, the atmosphere is able to hold more moisturehowever, this moisture will not fall evenly across the globe. Some regions are expected to become wetter, whereas other regions will become drier. This is the basis of the familiar paradigm "wet-gets-wetter, dry-gets-drier" and is largely supported by future model projections. However, evidence from the geological record contradicts this hypothesis and suggests that a warmer world could be characterized by wetter (rather than drier) subtropics. Here, we use an integrated data-modeling approach to investigate the hydrological response to warming during an ancient warm interval (the early Eocene, 56-48 million years ago). We show that models with weaker latitudinal temperature gradients are characterized by a reduction in subtropical CRAMWINCKEL ET AL.

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Paleogene Indian Plate Dynamics and Palaeoclimate: A Review from Palynological Perspective

Verma,

Singh

2024

Society of Earth Scientists Series

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Palynofloral diversity and palaeoenvironments of early Eocene Akri lignite succession, Kutch Basin, western India

Cited by 9 publications

References 39 publications

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>

Global and Zonal‐Mean Hydrological Response to Early Eocene Warmth

Paleogene Indian Plate Dynamics and Palaeoclimate: A Review from Palynological Perspective

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Palynofloral diversity and palaeoenvironments of early Eocene Akri lignite succession, Kutch Basin, western India

Cited by 9 publications

References 39 publications

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO&lt;sub&gt;2&lt;/sub&gt;

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO&lt;sub&gt;2&lt;/sub&gt;

Global and Zonal‐Mean Hydrological Response to Early Eocene Warmth

Paleogene Indian Plate Dynamics and Palaeoclimate: A Review from Palynological Perspective

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Product

Resources

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Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>

Eocene to Oligocene vegetation and climate in the Tasmanian Gateway region controlled by changes in ocean currents and pCO<sub>2</sub>