Global iridium anomaly, mass extinction, and redox change at the Devonian-Carboniferous boundary

Wang, K.; Attrep, Moses; Orth, C. J.

doi:10.1130/0091-7613(1993)021<1071:giamea>2.3.co;2

Cited by 52 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, an Ir anomaly by itself is not suffi cient evidence to identify the KTB because multiple Ir enrichments are common in late Maastrichtian and early Danian sediments and may be due to a variety of factors, including multiple impacts, volcanism and redox conditions (Graup and Spettel 1989;Grachev et al 2005;Stüben et al 2005;Keller 2008a). Moreover, Ir anomalies typically occur in organicrich shales or clays, which serve as low-permeability redox boundaries where Ir can move both upward and downward (Tredoux et al 1988;Sawlowicz 1993;Wang et al 1993).…”

Section: High Resolution K-t Biostratigraphymentioning

confidence: 99%

Deccan volcanism, the KT mass extinction and dinosaurs

2009

View full text Add to dashboard Cite

Recent advances in Deccan volcanic studies indicate three volcanic phases with the phase-1 at 67.5 Ma followed by a 2 m.y. period of quiescence. Phase-2 marks the main Deccan volcanic eruptions in Chron 29r near the end of the Maastrichtian and accounts for approximately 80% of the entire 3500 m thick Deccan lava pile. At least four of the world's longest lava flows spanning 1000 km across India and out into the Gulf of Bengal mark phase-2. The final phase-3 was smaller, coincided with the early Danian Chron 29n and also witnessed several of the longest lava flows. The KT boundary and mass extinction was first discovered based on planktic foraminifera from shallow marine intertrappean sediments exposed in Rajahmundry quarries between the longest lava flows of the main volcanic phase-2 and smaller phase-3. At this locality early Danian (zone P1a) planktic foraminiferal assemblages directly overlie the top of phase-2 eruptions and indicate that the masse extinction coincided with the end of this volcanic phase. Planktic foraminiferal assemblages also mark the KT boundary in intertrappean sediments at Jhilmili, Chhindwara, where freshwater to estuarine conditions prevailed during the early Danian and indicate the presence of a marine seaway across India at KT time. Dinosaur bones, nesting sites with complete eggs and abundant eggshells are known from central India surrounding the hypothesized seaway through the Narmada-Tapti rift zone. A Maastrichtian age is generally assigned to these dinosaur remains. Age control may now be improved based on marine microfossils from sequences deposited in the seaway and correlating these strata to nearby terrestrial sequences with dinosaur remains.

show abstract

Section: High Resolution K-t Biostratigraphymentioning

confidence: 99%

Deccan volcanism, the KT mass extinction and dinosaurs

2009

View full text Add to dashboard Cite

show abstract

“…There are no observed structural differences between the sections underlying the paraconformity and the sections overlying it, implying that the depositional hiatus was not associated with tectonic movement. The possible correlation of the black mudstone facies of the Chepor Formation, which lies just below the paraconformity surface, with the global Hangenberg Anoxic Event indicates that the cause of the depositional hiatus is most probably the global regression occurring near the end of the Famennian, just after the transgressive episode which marked the Hangenberg Anoxic Event (Schonlaub, 1986;Xu et al, 1986;Bai and Ning, 1988;Chlupac, 1988;Krstic et al, 1988;Ulmishek, 1988;Feist, 1990;Klemme and Ulmishek, 1991;Paproth et al, 1991;Wang et al, 1993).…”

Section: Implications Of a Mid-palaeozoic Paraconformity In Northwestmentioning

confidence: 96%

The Devonian–Lower Carboniferous succession in Northwest Peninsular Malaysia

Meor

Lee

2005

Journal of Asian Earth Sciences

View full text Add to dashboard Cite

“…The goal is to elucidate the long-term behavior of the redox-sensitive element enrichments as they encounter the increasingly anoxic conditions of deeper burial in sediments. Knowledge of the behavior of these elements at sedimentological discontinuities is vital for the correct interpretation of paleoenvironmental changes in the geological record, such as those identified at the Cretaceous/Tertiary (K/T) and other geologically important boundaries (Lowrie et al, 1990;Wallace et al, 1990;Wang et al, 1993). An improved knowledge of the comparative behavior of different elements during burial is required to distinguish primary from diagenetic signals in such studies.…”

mentioning

confidence: 99%

Oxidation fronts in Madeira Abyssal Plain turbidites: persistence of early diagenetic trace-element enrichments during burial, Site 950

Thomson¹,

Jarvis²,

Green³

et al. 1998

Proceedings of the Ocean Drilling Program, 157 Scientific Results

View full text Add to dashboard Cite

The emplacement of organic-rich turbidite units on abyssal plains is commonly followed by the early diagenetic redistribution of redox-sensitive elements. This occurs only at the summit of the turbidite unit, where it is caused by the downward diffusion of seawater oxygen, which continues for as long as each turbidite is in diffusive contact with bottom waters. The duration of this process is generally a few tens of thousands of years on the Madeira Abyssal Plain (MAP), where turbidite emplacement occurs at frequent intervals. The known sequence of redox-sensitive element redistribution peaks around oxidation fronts in turbidites, derived from studies of conventional piston core material sampling the upper few tens of meters of Quaternary sediments on the MAP, is compared here with that in a single turbidite recovered at Site 950, and now buried to 230 mbsf. This unit was deposited during the late Miocene (~7.6 Ma) and has experienced consecutively post-oxic and sulfate-reducing conditions during burial. The organic carbon (C org ) profile and C org /S ratio are remarkably similar to those in more recent examples. The labile (nondetrital) fractions of many redox-sensitive elements remain concentrated around a sharp color change from dark green (below) to greenish gray (above), which marks the limit of penetration of oxygen when the turbidite top was exposed on the seafloor. The elements Cd, Sb, Se, Tl, and V are all still found in peaks immediately below the original oxic/post-oxic boundary although, as in the younger turbidites, the peak maxima are not exactly coincident. Cobalt, Cu, Ni, and Zn have apparently moved upward in chromatographic-like fronts, which are seen as thin dark-purple or gray bands in the core. Labile As, S, and U, which were selectively removed from sediment above the color change by the bacterially driven redox processes that accompanied the oxic decomposition of C org in the turbidite, have retained their characteristic stepped-concentration profiles. The successive passage through ~130 m of post-oxic and ~100 m of sulfate-reducing conditions (each lasting ~3.8 m.y.) has had remarkably little effect on trace-metal distributions.

show abstract

Global iridium anomaly, mass extinction, and redox change at the Devonian-Carboniferous boundary

Cited by 52 publications

References 0 publications

Deccan volcanism, the KT mass extinction and dinosaurs

Deccan volcanism, the KT mass extinction and dinosaurs

The Devonian–Lower Carboniferous succession in Northwest Peninsular Malaysia

Oxidation fronts in Madeira Abyssal Plain turbidites: persistence of early diagenetic trace-element enrichments during burial, Site 950

Contact Info

Product

Resources

About