Evidence for Cretaceous-Paleogene boundary bolide “impact winter” conditions from New Jersey, USA Johan Vellekoop1*, Selen Esmeray-Senlet2§, Kenneth G. Miller2, James V. Browning2, Appy Sluijs1, Bas van de Schootbrugge1, Jaap S. Sinninghe Damsté3,4, and Henk Brinkhuis1,3 1Marine Palynology and Paleoceanography, Department of Earth Sciences, Faculty of Geosciences, and Laboratory of Palaeobotany and Palynology, Utrecht University, Budapestlaan 4, 3584CD Utrecht, Netherlands 2Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, New Jersey 08854, USA 3NIOZ Royal Netherlands Institute for Sea Research, 1790 AB Den Burg, Texel, Netherlands 4Geochemistry, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Budapestlaan 4, 3584CD Utrecht, Netherlands ABSTRACT sulfate aerosols generated by the impact (10–200 Abrupt and short-lived “impact winter” conditions have commonly been implicated as the Gt; Pope et al., 1997; Gupta et al., 2001). main mechanism leading to the mass extinction at the Cretaceous-Paleogene (K-Pg) bound- However, so far, unequivocal evidence for ary (ca. 66 Ma), marking the end of the reign of the non-avian dinosaurs. However, so far the hypothesized impact winter is still lacking, only limited evidence has been available for such a climatic perturbation. Here we perform as the cooling signal has only been recorded at high-resolution TEX86 organic paleothermometry on three shallow cores from the New Jer- Brazos River, where it consists of multiple peaks, sey paleoshelf, (northeastern USA) to assess the impact-provoked climatic perturbations spread out over inferred post-impact storm immediately following the K-Pg impact and to place these short-term events in the context of deposits. Moreover, it is unknown how this cool- long-term climate evolution. We provide evidence of impact-provoked, severe climatic cool- ing signal is related to long-term climatic trends ing immediately following the K-Pg impact. This so-called “impact winter” occurred super- unrelated to the impact. Distinguishing short- imposed on a long-term cooling trend that followed a warm phase in the latest Cretaceous. term changes directly following the K-Pg bound- ary impact is complicated by a lack of records of INTRODUCTION used across the K-Pg boundary (Vellekoop et al., sufficient temporal resolution. Testing the K-Pg The Cretaceous-Paleogene (K-Pg) boundary 2014), potentially providing insight into climate boundary impact-winter hypothesis requires the mass extinction (ca. 66 Ma) is one of the most changes across this interval. examination of additional stratigraphically com- devastating events in the history of life, mark- In a recent study we documented the first plete marine records that are characterized by ing the end of the dinosaur era (Bambach, 2006). indications of rapid short-term cooling following a good preservation of organic matter and are Although Deccan Traps volcanism may have the Chicxulub impact, based on the TEX86-based sufficiently expanded to allow for the detection contributed to environmental perturbations, the SST record of Brazos River (Texas, USA; Velle- of relatively fast, transient changes. mass extinction at the K-Pg boundary is widely koop et al., 2014). This record provided the first The New Jersey paleoshelf K-Pg succession, acknowledged to be related to the global envi- evidence for cold conditions, from sediments characterized by clayey glauconitic sands and ronmental consequences of the impact of an directly overlying the impact and tsunami lay- glauconite clays deposited in a shallow marine asteroid with a diameter of ~10 km at Chicxulub, ers, that are possibly linked to the remnant of the setting (Miller et al., 2010; Esmeray-Senlet et Mexico (Alvarez et al., 1980). The impact likely commonly assumed “impact winter” (Alvarez et al., 2015), may provide suitable sites. In A.D. caused rapid and profound global climate change al., 1980). This dark and cold phase is proposed 2008 and 2009, three new shallow (<25 m) (e.g., Kring, 2007) that was superimposed on to have caused a global collapse of terrestrial and cores were drilled across the K-Pg boundary in long-term environmental trends unrelated to the marine food webs, ultimately leading to the K-Pg New Jersey (Miller et al., 2010)—Meirs Farm impact. Unraveling climate changes across the boundary mass extinction (Alvarez et al., 1980; (40°06′15.48″N, 74°31′37.48″W), Search Farm K-Pg boundary interval is nevertheless compli- Schulte et al., 2010; Vellekoop et al., 2014). (40°05′29.20″N, 74°32′16.10″W), and Fort cated because many biotic environmental proxy Theory suggests that the impact winter was Monmouth 3 (40°18′37.18″N, 74°02′46.25″W) carriers, such as planktic foraminifera and cal- caused by sulfate aerosols, dust, and soot par- (Fig. 1)—providing records that may be used careous nannoplankton, experienced major ticles ejected into the atmosphere by the impact to unravel both impact-related perturbations as extinctions and are rare to absent in the earli- (Pope et al., 1994). Examples of sulfate aero- well as the long-term climate changes in the lat- est Paleocene (e.g., Huber et al., 2002). In con- sol injections into the stratosphere by volcanic est Cretaceous–earliest Paleogene interval. Here trast, the sea-surface temperature (SST) proxy eruptions during past millennia confirm that even we provide a biostratigraphic framework for TEX86, based on fossilized membrane lipids of relatively small injections of sulfate aerosols these three cores and present a TEX86 analyses pelagic archaea (Schouten et al., 2002), can be (100–500 Mt; Legrand and Delmas, 1987; Wit- to assess the impact-provoked climatic pertur- ter and Self, 2006; Oman et al., 2006) can lead bations immediately following the K-Pg impact *Current address: Division of Geology, Depart- to short-term cooling at regional to global scales, and to place these short-term events in a context ment of Earth and Environmental Sciences, KU Leu- persisting for up to ten years after some of the of a long-term climatic background. ven, Celestijnenlaan 200E, 3001 Leuven, Belgium; largest eruptive episodes (Oppenheimer, 2002; E-mail: [email protected]. §Current address: Chevron Energy Technology Sigl et al., 2015). This argues for a very strong MATERIALS AND METHODS Company, 1500 Louisiana St., Houston, Texas 77002, cooling effect resulting from the K-Pg boundary The three cores are characterized by Maas- USA. impact, considering the much larger volume of trichtian, grayish, bioturbated clayey glauconitic GEOLOGY, August 2016; v. 44; no. 8; p. 1–4 | Data Repository item 2016201 | doi:10.1130/G37961.1 | Published online XX Month 2016 GEOLOGY© 2016 Geological | Volume Society 44 | ofNumber America. 8 For| www.gsapubs.org permission to copy, contact [email protected]. 1 N Meirs Farm n ) s Fort Monmouth Ma Age Sample events Lithology Meirs Farm Iridium Formatio Depth (m Dinocyst zonation 40º Dinocyst Search Farm Search Farm Fort Monmouth 3 ) n n 8 ) s s 9 m Bass River events BARREN events Sample Iridiu (ODP Leg 174AX) Dinocyst Dinocyst Formatio Sample Depth (m Lithology Lithology Iridium 10 Formatio Depth (m Foram zon. 11 (Vincentown Fm) Hornerstown Upper Paleocene BARREN 6 α Paleogene 15 Lower Paleocene (Hornerstown Fm) 8 4 12 10 11 2 Maastrichtian (Tinton, New Egypt & 8 4 5 7 P0/P 9 16 39º Navesink Fms) 13 10 2 Upper Campanian/Lower 66.04 6 7 8 3 8 Maastrichtian (Mt. Laurel & 0 20 km 14 17 Wenonah Fms) 0 5 00.4 9 0 0.4 * 3 ppb 3 4 1 18 75º 74º Zone 15 ppb r ppb New Egypt New Egypt pelagica 19 T. 16 1 Palynodinium grallator Figure 1. Geological map of part of New Jersey, 1 2 Disphaerogena carposphaeropsis USA, showing outcropping Maastrichtian and 17 2 3 Disphaerogena carposphaeropsis var. “cornuta” Paleocene formations and locations of Bass m 4 New Egypt Thalassiphora pelagica 18 * Pg. hariaensis/Pl. hantk. equivalent River, Meirs Farm, Search Farm, and Fort Mon- 5 Manumiella seelandica Cretaceous mouth cores. ODP—Ocean Drilling Program. 19 6 Senoniasphaera cf. inornata Green clayey glauconitic sand 7 Membranilarnacia? tenella Whitish clay clasts magdaliu 20 Palynodinium grallato 8 Grey sandy, glauconitic clay T. Senoniasphaera inornata 9 21 Damassadinium cf. californicum sands to glauconite clays of the New Egypt For- ca.67 10 1 Damassadinium californicum mation, overlain by heavily bioturbated clayey 11 Carpatella cornuta glauconitic sands of the Danian Hornerstown Figure 2. Stratigraphic correlation between Meirs Farm, Search Farm, and Fort Monmouth 3 Formation, deposited at an inner neritic set- cores (New Jersey, USA), with ranges of dinocyst marker taxa. Dinocyst zonation is based on ting (water depth of <35 m; Miller et al., 2010; Hansen (1977). Iridium records of Meirs Farm and Search Farm are from Miller et al. (2010); Esmeray-Senlet et al., 2015). that of Fort Monmouth 3 is from this study. T. magdalium—Tanyosphaeridium magdalium; Organic-walled dinoflagellate cysts (dino- T. pelagica—Thalassiphora pelagica; Pg. hariaensis—Pseudoguembelina hariaensis; Pl. cysts), abundantly present in these deposits hantk.—Plummerita hantkeninoides; zon.—zonation. (Habib and Saeedi, 2007), serve as reliable chro- nobiostratigraphic tools (Williams et al., 2004), RESULTS AND DISCUSSION shift in osmium isotope records near the base of especially at shallow marine sites (Brinkhuis Our age model (Fig. 2; Figs. DR1–DR3 in subchron C29R (Robinson et al., 2009), it has and Schiøler, 1996; Vellekoop et al., 2014). By the Data Repository) shows that our combined been suggested that the warming phase in the combining high-resolution dinocyst and plank- record ranges from ~1.1 m.y. before the K-Pg latest Maastrichtian is related to a significant tic foraminiferal biostratigraphy with the analy- boundary to >100 k.y. after the boundary, based outpouring phase of the Deccan Traps large ses of iridium using high-sensitivity sector field– on the biochronology of Gradstein et al.