We strive to keep our communications relevant and timely so we can collectively succeed by staying informed, without the fluff. (2005) contended that the Burns spherules are iron condensation spherulesnot diagenetic concretions. This great event seems to have ended the period of banded iron formation. The ejecta-bearing sediments exposed in the drill hole at site #3B are massive, except for parallel lamination in the uppermost fine-grained sandstones. environmental science and urban planning have all In addition, there are other, more specific factors that are inconsistent with these models. 2. Lets get started. We petrographically and geochemically examined lapilli from five sites (McClure, Connors Creek, Hwy 588, Pine River, and Grand Trunk Pacific, approximately 480750km from the center of the Sudbury structure). Iridium anomaly but no shocked quartz from Late Archean microkrystite layer: Oceanic impact ejecta? 2007), subaerial reworking, and diagenesis (Fralick and Burton 2008), and, 15 million years later, it was buried by marine sediments (Addison et al. (e.g., Kissin et al., 2000). and River Valley intrusives (Easton, 2003; Easton et al., 2010). Here, we specifically consider the possibility that the Burns formation spherules formed as impact-induced accretionary lapilli, or from condensation. Depositional model for units associated with accretionary lapilli deposited by the Sudbury impact event. Image of the Day for September 20, 2021 Landsat 8 OLI Space Shuttle SRTM B3. Formations. vol.59 part 1, 83pp., 43-44, Houghton, MI. layer have now been recognized in and near the city of Thunder Comparison of their size and spacing has been presented by McLennan et al. Given the preceeding context for interpretation, it is an interesting footnote that the entire layer of breccia and ejecta very likely represents the catastrophic events of a single day; caught during the 48 million years that separate the deposition of Gunflint Iron Formation below from Rove Formation above (Fig. Strengthen your cybersecurity and invest in your people. Increase sales and refine your marketing strategy. 2005, Edgar et al., this volume): Facies A is composed of large-scale cross-bedded well-sorted sandstones. event occurred 18501 Ma, 650 to 875 km to the east Continuously improve your operations from the warehouse to the production line. It is derived in large part from the professional colleagues who joined them on their quest Notice in Figure 5 that the lapilli contain concentric rings that formed by repeated layering of ash and melt droplets onto the hail-stone like projectiles. cm- to m-scale 7) generally support a model whereby eolian and locally subaqueous processes deposited these sediments (Fig. The Sudbury impact layer in the Paleoproterozoic iron ranges of northern Michigan, USA 50 ABSTRACT A layer of breccia that contains fragments of impact ejecta has been found at 10 sites in the Paleoproterozoic iron ranges of north- ern Michigan, in the Lake Superior region of the United States. quartz and feldspar. (2007), from two drill holes very near some of the lo-, calities described here. (Cannon et al., 2013). Keays,RR and Lightfoot,PC (1999) At Endurance and Eagle craters, this facies is found in the upper part of the upper unit of the Burns formation and marks where the groundwater table breached the surface and wind-driven subaqueous currents transported the sediment. but since the 1960s the city of Sudbury has seen great progress Weston High School was the first expansion school of impaCT. Completed over 1,000 projects with Utah-based companies since 1995. northwestern Ontario. Dated at 1,850 million years ago, the impact occurred long after the majority of Clearly, criteria are necessary for evaluating the genesis of specific deposits in order to determine if occurrences of spherules similar to those found at Meridiani were formed by impact-related processes, or if they are of another origin. Areas further than approximately 800 km from the impact site commonly do not contain accretionary lapilli. Over time, this material is buried by younger sediments, cemented together, and fused by molten rock to form a solid layer. The highly cratered surface of Mars leads to the prediction that impact ejecta deposits, possibly containing accretionary lapilli, should be part of the sediment record. (2) Dietz, R.S., 1964, Sudbury structure as an astrobleme: Journal of Geology, v. 72, pp. vesicular glass clasts, which formed from molten rock. site (Cannon, 2008). The main exposure consists of lithified carbonate grainstones and stromatolites that were erosively planed off and are overlain by impact-derived material (Fig. 3. (Kring et al., 2006; Cannon et al., 2006). Sedimentologic observations that constrain the environment of deposition for the Burns formation. The accretionary lapillirich units overlying the upper-flow-regime, parallel to undulatory beds of sand- to granule-sized material possess many of the attributes of the sandy succession. The layer at the sites in Michigan exhibits a range of thicknesses, lithologic characters, and sedimentary settings. This assemblage of bed forms is somewhat similar to the progression of upper-flow-regime, parallel-lamination to type V and type III dunes described by Schmincke et al. Why do we ask for your zip code? volume 58 part 2, 219pp., trip 1&13, 2-26, Thunder Bay, ON. OGS Spec.Vol.1, 603pp. Past production and resources in the camp Webster,CL, Vega,FJ, Smit,J, Fritsche,AE and Claeys,P (1999) The layer formed by the impact occurs at the contact between the iron formation, in black, and a thick succession of overlying shales and turbiditic sandstones (small dots). 2007). Well-documented examples occur in the Ordovician volcanics of the English Lake District Anonymous Coach Compares Michigan To Elite Ohio State, SEC Teams Of The Where road closures will impact weekend travel throughout Michigan Published: Jul. Though direct observation of the events triggered by a large impact on a terrestrial planet has never been made, insight into the sediment dispersal dynamics can be gained from the literature on explosive volcanic eruptions and nuclear tests. in 1973), at Songaksan mount (Chough and Sohn 1990), and at Cora Maar volcano (Gencalioglu-Kuscu et al. 11). Further Finds in the Great Lakes States (Moseley, 1983). 2. In northern Michigan the Sudbury impact, some 550 km to the east, produced a modelled magnitude 10.5 earthquake, about 30 times stronger than any recently recorded earthquake. Based on the Thunder Bay area, But, what happened after the dust settled? When you're ready to transform, grow, and pivot your business, we'll show you where to start and how to keep going. Addison,WD, Brumpton,GR, Vallini,DA, McNaughton,NJ, "re-greening" blackened, deforested hillsides, 59th Annual Meeting, Institute on Lake Superior Geology, By using our site, you agree to our collection of information through the use of cookies. Meridiani Planum, Mars, Sulfate-rich eolian and wet interdune deposits, Erebus Crater, Meridiani Planum, Mars, Crater geometry and ejecta thickness of the Martian impact crater Tooting, Alluvial and coastal conglomerates: their significant features and some comments on gravelly mass-flow deposits, Sedimentology of Gravels and Conglomerates, The formation of the Reis Crater, West Germany: evidence of atmospheric interactions during a large cratering event, Global Catastrophies in Earth History: An Interdisciplinary Conference on Impacts, Volcanism and Mass Mortality, Sedimentary Environments: Processes, Facies and Stratigraphy, Effects of volatiles and target lithology on the generation and emplacement of impact crater fill and ejecta deposits on Mars, Chicxulub impact ejecta from Albion Island, Belize, Chicxulub impact ejecta deposits in southern Quintana Roo, Mexico, and central Belize, Physical and chemical evidence for the 1850 Ma Sudbury impact event in the Baraga Group, Michigan, Density segregation of minerals during high-velocity transport over a rough bed: implications for the formation of placers, Antidune and chute and pool structures in base surge deposits of the Laacher see area, Germany, Discrimination of eolian and pyroclastic-surge processes in the generation of cross-bedded tuffs, Jemez Mountains volcanic field, New Mexico, The initial giant umbrella cloud of the May 18, 1980, explosive eruption of Mount St Helens, Journal of Volcanological and Geothermal Research, Tectonic influences on the morphometry of the Sudbury impact structure: implications for terrestrial cratering and modeling, Planetary science: bedrock formation at Meridiani Planum, The Opportunity rovers Athena science investigation at Meridiani Planum, Mars, In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars, Sedimentary rocks at Meridiani Planum: origin, diagenesis and implications for life on Mars, Two years at Meridiani Planum: results from the Opportunity rover, Impact generated carbonate accretionary lapilli in the Late Devonian Alamo Breccia, Catastrophic Events and Mass Extinctions; Impacts and Beyond, Ignimbrite depositional facies: the anatomy of a pyroclastic flow, Journal of the Geological Society of London, Hydrodynamic aspects of caldera-forming eruptions: numerical models, This site uses cookies. A curving outcrop here allowed a series of sections to be compiled from the underlying basement to the top of the accretionary lapillirich layer (Fig. clasts; 4) bedded lapilli above accretionary lapilli and This strongly indicates that the spherules must have developed in situ, after deposition of the sediments, favoring an origin as depicted in this third scenario. ballistic trajectory to about 5 times the estimated 130 km crater of rock, at a temperature approaching 2000C. Accretionary lapilli beds are laterally transitional into very coarse-grained sandstone layers, and sand stringers and lenses exist in some lapilli beds (Fig. solar system history. The Burns formation does not show evidence for concentration of the spherules as this scenario would predict. hundreds of km away, in northwest Ontario and in northern reaches of the water sediments, which do not readily Weston. These alternative models have not been widely accepted in part because they are inconsistent with the regional geological context, which provides no evidence for contemporaneous sources of volcanism or age-appropriate impacts of sufficient size (see McLennan and Grotzinger 2008). 2002; Masaitis 2003; Koeberl et al. 2.7Ga) pillow basalts to a Paleoproterozoic (ca. Visit the Turnstone Its importance lies in the record of global catastrophe that occurred in a moment of the planets long geologic history and it is remarkable that such a thin layer has survived weathering and erosion for nearly 2 billion years. 1). 5) devitrified Deccan volcanism, the Chicxulub impact, and the end-Cretaceous mass extinction: Coincidence? This debris was entrained by the leading edge of the base surge and swept into topographic lows. Coarse lapilli and related impact-derived ash-fall ejecta, northwest Ontario The thickness of the lower sandstones is probably controlled by fluctuations in velocity and concentration of sediment in the highly turbulent flow. The Michigan sites described here, along with previously described sites in Minnesota and Ontario, define an extensive ejecta-bearing deposit throughout the Paleoproterozoic iron ranges of the Lake Superior region that we refer to as the Sudbury impact layer. Thus, deposits progress from massive to well stratified, both outward from the ventthough local topography complicates this (Schmincke et al. The boulder breccia is commonly overlain by a 10 to 20-cm-thick, matrix-supported pebble breccia to massive, pebbly sandstone. veins in the footwall of the igneous complex. as the southernmost and deepest-water known occurrence of the The layer at the sites in Michigan exhibits a range of thicknesses, lithologic characters, and sedimentary settings. million tonnes of ore grading on average 1.2% Ni, Chicxulub Mexico 180 __65 Backfilling strata fill scours, building in an upstream direction, and extend laterally outside the scour on the downstream side to drape the underlying scoured beds (Fig. At all outcrops observed to date, the spherules do not disrupt lamination and are highly dispersed relative to bedding, so they are not observed to concentrate along bedding planes or scour surfaces (Fig. Explore recent publications by USGS authors, Browse all of Pubs Warehouse by publication type and year, Descriptions of US Geological Survey Report Series, The Sudbury impact layer in the paleoproterozoiciron ranges of northern Michigan, USA, Eastern Mineral and Environmental Resources Science Center. overlain by the detritus of the `debrisites'. The Sudbury impact deposit was first discovered and documented in Ontario and Minnesota by Addison et al. Sorry, preview is currently unavailable. discoveries in both pure and applied science. The coarser sandstone beds are, in places, laterally discontinuous, lensing out into the surrounding medium-grained sandstone. The Sudbury impact deposits also provide clues as to what a spherule deposit on Mars, which is related to an impact, may look like. Across more than 130 years, Sudbury Canada 300 1850 Curiously, the western Marquette Range contains the only BIF above the The breccias commonly are coarse-tail graded upward (Addison et al. there is a thick sequence of sandstones and breccia, Formations. Michigan-- Sudbury Meteorite Impact Breccia - YouTube He's currently finding great success leading the Impact United Premier 1 U13 Boys team. Please check your email address / username and password and try again. ) or https:// means youve safely connected to the .gov website. Earned a spot at Regionals this June and a spot in Next Pro League next season. "Rock of the Month #159, posted for September 2014" --- In the second scenario (Fig. In places, 10- to 40-cm-thick, festoon (trough) cross-stratified sandstones fill erosive cuts into the lapilli-bearing units (Fig. The U16 girls Impact team coached by Aaron Gabbart dominated the competition to win the Rage Showcase Gold Division. The third photo shows, on its left side, irregular fragments of chert, Fralick,P, Brumpton,GR, Jirsa,MA, Kissin,SA and Severson,MJ (2010) Rocks. about 300-330 km in diameter. This important stratigraphic boundary, termed the Wellington contact, is interpreted to be a deflation surface formed where the groundwater capillary fringe limited erosion of previously deposited dune sediments. a black silica-rich sediment. 52nd Annual Meeting, Institute on Lake Superior Geology, These massive beds with scattered accretionary lapilli probably formed as a result of an increase in the rainout of material from suspension, which will suppress the formation of parallel lamination (Arnott and Hand 1989). The stratification and sorting characteristics of volcanic base surge deposits are largely determined by the particle concentration and velocity profiles across the flow-boundary zone from which the lithofacies aggrades (Branney and Kokelaar 2003). metal-enriched rock that was sampled and concentrated by the vol.53 part 1, 89pp., 20-21, Lutsen, MN. In the third scenario, spherules are dispersed across all strata and show no concentration, even at obvious erosional surfaces, such as the lowermiddle unit boundary (Wellington contact) at Burns cliff (Grotzinger et al.