We report the Narmada Seaway began in India during the largest global sea-level transgression and Oceanic Anoxic Event 2 (OAE2) δ13C excursion during the late Cenomanian to early…

Early Eocene rift basins sediments in western and northwestern India contain deposits including lignite. These rift basins were formed during the early stage of the India - Eurasia collision. The Sedimentary successions in the studied five lignite mines are stratigraphically similar. In these successions, there are two thick lignite units,…

Mercury (Hg) anomalies linked to Large Igneous Provinces (LIP) volcanism have been identified in sediments across all five major mass extinctions in Earth's history. This study tests whether Hg in marine sediments is a reliable proxy linking Deccan Traps volcanic eruptions to late Maastrichtian global climate warming and the mass extinction at…

This volume covers new developments and research on mass extinctions, volcanism, and impacts, ranging from the ancient Central Iapetus magmatic province linked with the Gaskiers glaciation to thermogenic degassing in large igneous provinces, the global mercury enrichment in Valanginian sediments, and the Guerrero-Morelos carbonate platform…

The end-Cretaceous mass extinction (66 Ma) has long been associated with the Chicxulub impact on the Yucatan Peninsula. However, consensus on the age of this impact has remained controversial because of differing interpretations on the stratigraphic position of Chicxulub impact spherules relative to the mass extinction horizon. One side argues…

The Cretaceous-Paleocene (K/P) boundary intervals are rarely preserved in successions of shallow-water limestones. Here, we describe a shallow rocky shore on the active orogenic wedge of the eastern Alps (Austria) fringed by a carbonate platform that was largely cannibalized by erosion. We compared this succession with similar nearshore…

Temporal correlation between some continental flood basalt eruptions and mass extinctions has been proposed to indicate causality, with eruptive volatile release driving environmental degradation and extinction. We tested this model for the Deccan Traps flood basalt province, which, along with the Chicxulub bolide impact, is implicated in the…

We conducted detailed rock magnetic, mineralogical and geochemical (mercury) analyses spanning the Cretaceous–Paleogene boundary (KPB) at Zumaia, Spain, to unravel the signature of Deccan-induced climate and environmental changes in the marine sedimentary record. Our biostratigraphic results show that Zumaia is not complete, and lacks the…

The Cenomanian–Turonian Oceanic Anoxic Event (OAE2; ~94.5 million years ago) represents an episode of global-scale marine anoxia and biotic turnover, which corresponds to one of the warmest time intervals in the Phanerozoic. Despite its global significance, information on continental ecosystem response to this greenhouse episode is lacking…

The Cretaceous-Paleogene boundary (KPB) mass extinction (~66.02 Ma) and the Paleocene-Eocene Thermal Maximum( PETM)(~55.8Ma) are two remarkable climatic and faunal events in Earth's history that have implications for the current Anthropocene global warming and rapid diversity loss. Here we evaluate these two events at the stratotype localities…

We conducted detailed rock magnetic, mineralogical and geochemical (mercury) analyses spanning the Cretaceous–Paleogene boundary (KPB) at Zumaia, Spain, to unravel the signature of Deccan-induced climate and environmental changes in the marine sedimentary record. Our biostratigraphic results show that Zumaia is not complete, and lacks the…

Korbar, McDonald, Fućek, Fuček, and Posilović (2017) report a tsunamite, triggered by the Chicxulub impact on Yucatan, from the Likva Cove carbonate platform of the Island of Brač, Croatia, which is similar to that in an earlier report from the nearby Island of Hvar (Korbar et al., 2015). If true, such deposits in the Adriatic Sea would be…

Mercury is a very toxic element, with a long residence time (1-2 years) and wide distribution by aerosols. Volcanic emissions and coal combustion are the two main natural sources of mercury. Several studies [1-4] evaluated the relationship between Hg anomalies in sediments and LIP activity across mass extinction horizons. The bulk (80%) of…

Recent studies indicate that the bulk (80%) of Deccan trap eruptions occurred over a relatively short time interval in magnetic polarity C29r. U-Pb zircon geochronology shows that the main phase-2 began 250 ky before the Cretaceous-Tertiary (KT) mass extinction and continued into the early Danian suggesting a cause-and-effect relationship…

The Deccan Traps Magmatic Province coincides with the Cretaceous-Paleogene (KPg) boundary and probably contributed to the associated mass extinctions by inducing rapid and abrupt climate changes, including continental and superficial seawater acidification. However, how such environmental acidification is expressed in the marine sedimentary…

The Cretaceous-Paleogene boundary (KPB) mass extinction (~ 66.02 Ma) and the Paleocene-Eocene Thermal Maximum (PETM) (~ 55.8 Ma) are two remarkable climatic and faunal events in Earth's history that have implications for the current Anthropocene global warming and rapid diversity loss. Here we evaluate these two events at…

The Cenomanian-Turonian boundary witnessed major perturbations in global biogeochemical cycling, oceanography and climate expressed in the widespread deposition of organic-rich marine shales (OAE2) and a pronounced positive carbon isotope excursion (CIE). Despite the global significance of this event, information on the dynamics of continental…

Planktic foraminiferal analysis, including species populations, diversity trends, high-stress indices and stable isotopes of the latest Campanian through Maastrichtian in the South Atlantic, Tethys and Indian oceans reveal four major climate and faunal events that ended with the Cretaceous-Paleogene (K/Pg), formerly Cretaceous-Tertiary (K/T),…

The Paleocene-Eocene Thermal Maximum (PETM, ≈55.8±0.2 Ma) is marked by a global change in carbon cycle and rapid warming. Climate warming persisted for several tens of thousands of years and resulted in rapid diversification in terrestrial mammals and marine planktic foraminifera.

Deep-water benthic foraminifera suffered a mass…

Mercury (Hg) as indicator of large-scale volcanism in marine sediments provides new insights into relative timing between biological and environmental changes, mass extinctions and delayed recovery. We analyzed Hg concentrations linked to Deccan volcanism, TOC, δ13C, δ18O and faunal changes for C29r that spans 250 ky below the Cretaceous…

The discovery of a new Cretaceous/Palaeogene (K/Pg) bathyal marine sequence on Gorgonilla Island, SW Colombia, extends the presence of Chicxulub impact spherule deposits to the Pacific region of northern South America and to the Eastern Pacific Ocean. The Gorgonilla spherule layer is approximately 20 mm thick and consists of extraordinarily…

The contribution of the Deccan Traps (west-central India) volcanism in the Cretaceous-Paleogene (KPg) crisis is still a matter of debate. Recent U-Pb dating of zircons interbedded within the Deccan lava flows indicate that the main eruptive phase (>1.1 × 106 km3 of basalts) initiated ∼250 k.y. before and ended ∼500 k.y. after the…

The late Maastrichtian was a time of major climate, evolution and extinction extremes. Rapid climate warming of 2–3 °C in intermediate waters between 69.5 and 68 Ma (top C31r to base C30n) accompanied maximum evolutionary diversification (43% increase, zone CF5 to low CF4) in planktic foraminiferal history, followed immediately by a…

We thank Jan Smit and colleagues (Smit et al., 2016) for giving us the opportunity to clarify some important points in our original manuscript (Font et al., 2016a) and to discuss the issues raised in their Comment. Their main critique centers on the origin of the mercury anomalies, which they argue are post-depositional and cannot be assigned…

Late Maastrichtian through middle Eocene planktic foraminiferal biostratigraphy and erosion patterns from three Cauvery basin wells are compared with the Krishna-Godavari basin, Madagascar and South Atlantic Site 525A. Maastrichtian sedimentation appears continuous at DSDP site 525A and substantially complete in the Cauvery basin and Madagascar…

The age of the Chicxulub impact is still controversial. Impact spherules found at or near the Cretaceous-Paleogene boundary (KPB) in the North Atlantic, Caribbean, Belize and Guatemala are reworked in early Danian sediments above a KP hiatus [1-3]. But, in NE Mexico and Texas where impact spherules are beyond erosion by the Gulf Stream, they…

Glass spherules are a common occurrence around the Cretaceous-Paleogene (KPG) boundary in the stratigraphic record throughout the Caribbean and North Atlantic and are widely thought to represent tektites produced by the Chicxulub impact [1,2]. A new example, which contains some of the largest individual spherules yet found (typically 0.5–1.5 mm…

Preliminary results show poor planktic foraminifer test preservation in the top ~1 m (zone CF1) at Agost, correlative with high-stress conditions preceding the mass extinction horizon at Bidart, Gamsbach and Elles (Tunisia). Correlative zone CF1 sediments in the eastern Tethys (Egypt, Israel) show inverse correlation between carbonate…

Deccan Volcanic Province erupted ~80% of the total volume during C29r flooding the Indian continent with ~1.5 million km3 of lava that forms >3000 m high mountains. The base of C29r was recently dated (U-Pb) at ~66.250 Ma [1] and the Cretaceous-Paleogene boundary (KPB) at 66.043 Ma [2]. Volcanic eruptions released tens of thousands of…

Mercury is a very toxic element, with a long residence time (1-2 years) and wide distribution by aerosols. Volcanic emissions and coal combustion are the two main natural sources of mercury. Several studies [1-4] evaluated the relationship between Hg anomalies in sediments and LIP activity across mass extinction horizons. The bulk (80%) of…

The Paleocene-Eocene Thermal Maximum (PETM, ~55.8±0.2 Ma) is marked by a global drop of 2-6‰ in δ13C values and rapid warming of 4-5°C in tropical surface waters and 4-8°C in high latitudes. Climate warming persisted for several tens of thousands of years and resulted in rapid diversification in terrestrial mammals…

Recent studies indicate that ~80% of Deccan Traps erupted over ~750 ky in magnetic polarity C29r. U-Pb zircon geochronology shows that the main phase began 250 ky before the Cretaceous-Tertiary (KT) mass extinction and continued for 500 ky into the early Danian, suggesting played a role in the mass extinction. Many lava flows are separated by…

Today it is virtually unthinkable to solve complex geologic problems without biostratigraphy based on microfossils, whether for relative age control or environmental proxies. This is amply demonstrated for the end-Cretaceous (KTB) mass extinction where radiometric dating cannot decipher the order of events because they fall within dating error…

The discovery of a new Cretaceous/Palaeogene (K/Pg) bathyal marine sequence on Gorgonilla Island, SW Colombia, extends the presence of Chicxulub impact spherule deposits to the Pacific region of northern South America and to the Eastern Pacific Ocean. The Gorgonilla spherule layer is approximately 20 mm thick and consists of extraordinarily…

Mass extinctions generally involve a complex array of interrelated causes and are best evaluated by a multi-proxy approach as applied here for the end-Cretaceous mass extinction. This study documents and compares the planktic foraminiferal records, carbonate dissolution effects, stable isotopes, and magnetic susceptibility in France (Bidart),…

Deep-sea sections in the North Atlantic are claimed to contain the most complete sedimentary records and ultimate proof that the Chicxulub impact is Cretaceous-Tertiary boundary (KTB) in age and caused the mass extinction. A multi-disciplinary study of North Atlantic DSDP Sites 384, 386 and 398, based on high-resolution planktonic foraminiferal…

Deccan Traps erupted in three main phases with 6% total Deccan volume in phase-1 (C30n), 80% in phase-2 (C29r) and 14% in phase-3 (C29n). Recent studies indicate that the bulk (80%) of Deccan trap eruptions (Phase-2) occurred over a relatively short time interval in magnetic polarity C29r. U-Pb zircon geochronology shows that the main Phase 2…

The discovery of a new Cretaceous/Paleogene (K/Pg) bathyal marine sequence on Gorgonilla Island, SW Colombia, extends the presence of Chicxulub spherule deposits to northern South America and to the Eastern Pacific Ocean. At the time of the Chicxulub impact, Gorgonilla was located approximately 2700-3000 km SW of the impact site.

The…

The Paleocene-Eocene Thermal Maximum (PETM) shows an extraordinary drop in the δ13C of carbonate and organic matter across the globe, suggesting massive release of 13C-depleted carbon dioxide into the ocean and atmosphere over a very short time interval (probably < 20ky). We report a geochemical and mineralogical study of 106…

Highly diversified planktic foraminiferal assemblages (~65 species) prevailed in the early late Maastrichtian (mid C31n, ~68.8 Ma) at the South Atlantic DSDP Site 525A. A rapid warming (~2°C deep water) at the base CF4/ top C31n is associated with carbonate dissolution and enhanced planktic test-fragmentation indicative of ocean acidification…

The cause for the end-Cretaceous mass extinction (KTB) has long been attributed solely to the Chicxulub impact based on two major assumptions: (1) the Chicxulub impact trumped any earth-derived potential cause, and (2) Deccan volcanism played no significant role. Both of these assumptions have been challenged in recent years based on evidence…

The Maastrichtian (C31-C30n) was a time of major environmental changes that record evolutionary diversification in planktic foraminifera as well as a minor extinction associated with climate change and high carbonate dissolution. Although these changes have been observed worldwide, their cause(s) remain speculative. Here we report on these…