The enigma of Neoproterozoic giant ooids-Fingerprints of extreme climate?

Trower, Elizabeth J.

doi:10.1002/essoar.10501113.1

Cited by 7 publications

(15 citation statements)

References 50 publications

(58 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example Trower et al. (2017), developed an Ω proxy for carbonate minerals based on the size of coated grains such as ooids, which has subsequently been applied to questions about Neoproterozoic climate (Trower, 2020). Other approaches have been developed based on carbonate textures and accessory minerals in large evaporite basins (Pope et al., 2000); however, a drawback of this approach is that large evaporite basins are unevenly distributed in the rock record (Babel & Schreiber, 2014).…”

Section: Introductionmentioning

confidence: 99%

Arid Coastal Carbonates and the Phanerozoic Record of Carbonate Chemistry

et al. 2021

View full text Add to dashboard Cite

Ocean chemistry and carbonate sedimentation link Earth's climate, carbon cycle, and marine pH. The carbonate system in seawater is complex and there are large uncertainties in key parameters in deep time. Here, we link sedimentary textures formed in arid coastal environments and preserved in the rock record to past seawater carbonate chemistry. Prior to the mid‐Mesozoic, tepee structures and pisoids – features associated with peritidal environments – co‐vary with available shelf area during cycles of supercontinent formation and rifting. In contrast, tepees and pisoids are consistently scarce after the mid‐Mesozoic, which coincides with a radiation in pelagic calcifiers as well as the breakup of Pangea. Numerical models suggest that the global and temporal abundances of tepee structures and pisoids are correlated with secular shifts in seawater chemistry, and that trends likely reflect the underlying influence of tectonics and biotic innovation on marine alkalinity and the saturation states of carbonate minerals. As independent sedimentary proxies, tepees and pisoids serve as benchmarks for global carbon cycle models and provide a new proxy record of seawater chemistry that can help discern links among tectonics, biotic innovation, and seawater chemistry.

show abstract

Section: Introductionmentioning

confidence: 99%

Arid Coastal Carbonates and the Phanerozoic Record of Carbonate Chemistry

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Cathodoluminescence (CL) characteristics of a subset of thin sections were analyzed using a Technosyn (Cambridge Image Technology Limited, Cambridge, UK) cold cathodoluminescence unit with beam settings of ca 14 KV and a gun current of ca 400 mA. Exposure times for CL images varied with most exposures lasting 1 to 5 s. Trower et al (2017Trower et al ( , 2018Trower et al ( , 2020 demonstrated that ooid size reflects an equilibrium between precipitation and abrasion rates, which supports the application of ooid size measurements in the rock record to reconstruct Ω of ancient seawater or lake water (Li et al, 2020;Trower, 2020). Ooid diameters were measured from thin sections using JMicrovision (Roduit, 2020); when possible, 400 grains were measured per sample, but some samples contained <400 usable grains.…”

Section: Field Geology Sedimentology and Petrographymentioning

confidence: 84%

“…Trower et al . (2017, 2018, 2020) demonstrated that ooid size reflects an equilibrium between precipitation and abrasion rates, which supports the application of ooid size measurements in the rock record to reconstruct Ω of ancient seawater or lake water (Li et al ., 2020; Trower, 2020). Ooid diameters were measured from thin sections using JMicrovision (Roduit, 2020); when possible, 400 grains were measured per sample, but some samples contained <400 usable grains.…”

Section: Methodsmentioning

confidence: 99%

Lake level controls the recurrence of giant stromatolite facies

et al. 2022

View full text Add to dashboard Cite

Stromatolites have often served as a diagnostic carbonate facies for deep-time palaeoclimatic and geobiological studies because they may form under favourable environmental conditions for microbially mediated carbonate production. 'Giant' (<5 m) stromatolites occur in the Laney Member of the Eocene Green River Formation in the Vermillion Creek section of the Sand Wash Basin (northwest Colorado, USA). Giant stromatolite growth was hypothesized to have been promoted by both availability of large substrates as nucleation sites and physicochemical factors, including increased calcium carbonate mineral saturation states due to the generally warmer Eocene climate and a dynamic period in Lake Gosiute's hydrological balance. Depositional horizons of giant stromatolites were observed at two distinct stratigraphic levels, which demonstrated that the formation of the giant morphotype was not a unique occurrence, and provided an opportunity to examine both onset and cessation of stromatolite development. Coincident increases in carbonate clumped isotope-derived Accepted ArticleThis article is protected by copyright. All rights reserved temperatures, the carbon and oxygen isotopic compositions of lake water (δ 18 O w ), carbonate mineral saturation states (Ω) estimated by ooid size, and salinity estimated by ostracod assemblages demonstrated that formation of giant stromatolites was facilitated by lake level drawdown. Decreased lake levels: (i) promoted carbonate precipitation; and (ii) positioned benthic microbial communities within the photic zone. Field and petrographic analyses revealed that the giants preserved micritic laminations, 'trapped and bound' grains, and aragonite fans, interpreted as reflecting contributions from both microbially mediated and abiotic carbonate mineral precipitation. Field and microscopic sedimentological and stable isotope data indicated that giant stromatolite growth ceased as a result of subaerial exposure of mounds during lake level lows. Although microbial mediation of carbonate chemistry was seemingly important for initiation of stromatolite growth, this work demonstrated that stromatolite macromorphology was dominantly controlled by availability of large substrates, lake level and resultant solute chemistry, i.e. increased Ω.

show abstract

“…The combination of abundant marine cementation, early lithification of oolitic sediment, the growth of giant ooids at the platform margins, and ample carbonate production rates to produce exceedingly thick, high‐relief platforms, points to elevated sea water calcium carbonate saturation during the Early Triassic. The modelling of ooids in Neoproterozoic platforms (Sumner & Grotzinger, 1993; Trower, 2020) and the Early Triassic GBG (Li et al, 2020b) suggest that the genesis of giant ooids requires elevated sea water carbonate saturation. A factor common to both Neoproterozoic and Early Triassic systems is the absence of or greatly reduced skeletal calcium carbonate precipitation that would have resulted in high sea water carbonate saturation and a shift to precipitation of abiotic and microbial components (cf.…”

Section: Interpretation and Discussionmentioning

confidence: 99%

The role of carbonate factories and sea water chemistry on basin‐wide ramp to high‐relief carbonate platform evolution: Triassic, Nanpanjiang Basin, South China

Lehrmann

Stepchinski

Wolf

et al. 2021

The Depositional Record

View full text Add to dashboard Cite

The end-Permian extinction and its aftermath altered carbonate factories globally for millions of years, but its impact on platform geometries remains poorly understood. Here, the evolution in architecture and composition of two exceptionally exposed platforms in the Nanpanjiang Basin are constrained and compared with geochemical proxies to evaluate controls on platform geometries. Geochemical proxies indicate elevated siliciclastic and nutrient fluxes in the basal Triassic, at the Induan-Olenekian boundary and in the uppermost Olenekian. Cerium/Ce* shifts from high Ce/Ce* values and a lack of Ce anomaly indicating anoxia during the Lower Triassic to a negative Ce anomaly indicating oxygenation in the latest Olenekian and Anisian. Uranium and Mo depletion represents widespread anoxia in the world's oceans in the Early Triassic with progressive oxygenation in the Anisian. Carbonate factories shifted from skeletal in the Late Permian to abiotic and microbial in the Early Triassic before returning to skeletal systems in the Middle Triassic, Anisian coincident with declining anoxia. Margin facies shifted to oolitic grainstone in the Early Triassic with development of giant ooids and extensive marine cements. Anisian margins, in contrast, are boundstone with a diverse skeletal component. The shift in platform architecture from ramp to steep, high-relief, flat-topped profiles is decoupled from carbonate compositions having occurred in the Olenekian prior to the onset of basin oxygenation and biotic stabilisation of the margins. A basin-wide synchronous shift from ramp to high-relief platforms points to a combination of high subsidence rate and basin starvation coupled with high rates of abiotic and microbial carbonate accumulation and marine cement stabilisation of oolitic margins as the primary causes for margin up-building. High sea water carbonate saturation resulting from a lack of skeletal sinks for precipitation, and basin anoxia promoting an expanded depth of carbonate supersaturation, probably contributed to marine

show abstract

The enigma of Neoproterozoic giant ooids-Fingerprints of extreme climate?

Cited by 7 publications

References 50 publications

Arid Coastal Carbonates and the Phanerozoic Record of Carbonate Chemistry

Arid Coastal Carbonates and the Phanerozoic Record of Carbonate Chemistry

Lake level controls the recurrence of giant stromatolite facies

The role of carbonate factories and sea water chemistry on basin‐wide ramp to high‐relief carbonate platform evolution: Triassic, Nanpanjiang Basin, South China

Contact Info

Product

Resources

About