1. Objectives of Passive Margin Drilling1
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Preliminary Catalog of the Sedimentary Basins of the United States
Preliminary Catalog of the Sedimentary Basins of the United States By James L. Coleman, Jr., and Steven M. Cahan Open-File Report 2012–1111 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Coleman, J.L., Jr., and Cahan, S.M., 2012, Preliminary catalog of the sedimentary basins of the United States: U.S. Geological Survey Open-File Report 2012–1111, 27 p. (plus 4 figures and 1 table available as separate files) Available online at http://pubs.usgs.gov/of/2012/1111/. iii Contents Abstract ...........................................................................................................................................................1 -
Tsunami Risk Analysis of the East Coast of the United States
Tsunami Risk Analysis of the East Coast of the United States INTRODUCTION METHODOLOGY In the wake of the 2004 Indian Ocean tsunami and the 2011 Japan tsunami and Given the large area of the east coast, a rudimentary analysis was performed. corresponding nuclear disaster, much more attention has been focused on coastal Elevation is the most important factor in analyzing the risk of flooding in a coastal vulnerability to tsunamis. Areas near active tectonic margins have a much higher area; the lower the elevation, the greater the potential for damage. Elevation data risk of being hit by a tsunami, due to proximity. People who live in these areas are was reclassified into no risk, medium risk, and high risk zones. These zones were: more aware of the danger than their counterparts on passive tectonic margins. It is 25+ m above sea level, 10 to 25 m above sea level, and below 10 m above sea lev- generally a good assumption that the risk of a tsunami is low in places like the el. Essentially, most land adjacent to the coast that falls in the final category eastern seaboard of the United States. would be badly damaged by a 10m tsunami from the Canary Islands, unless buff- Despite the low risk, the east coast has been hit by tsunamis in the past. Ex- ered by another portion of land blocking the coast. If a larger tsunami were to oc- amples include the Newfoundland tsunami caused by the Grand Banks earth- cur, up to the max wave height predicted by Ward and Day of 25 m, any land ad- quake. -
Coupled Onshore Erosion and Offshore Sediment Loading As Causes of Lower Crust Flow on the Margins of South China Sea Peter D
Clift Geosci. Lett. (2015) 2:13 DOI 10.1186/s40562-015-0029-9 REVIEW Open Access Coupled onshore erosion and offshore sediment loading as causes of lower crust flow on the margins of South China Sea Peter D. Clift1,2* Abstract Hot, thick continental crust is susceptible to ductile flow within the middle and lower crust where quartz controls mechanical behavior. Reconstruction of subsidence in several sedimentary basins around the South China Sea, most notably the Baiyun Sag, suggests that accelerated phases of basement subsidence are associated with phases of fast erosion onshore and deposition of thick sediments offshore. Working together these two processes induce pressure gradients that drive flow of the ductile crust from offshore towards the continental interior after the end of active extension, partly reversing the flow that occurs during continental breakup. This has the effect of thinning the continental crust under super-deep basins along these continental margins after active extension has finished. This is a newly recognized form of climate-tectonic coupling, similar to that recognized in orogenic belts, especially the Himalaya. Climatically modulated surface processes, especially involving the monsoon in Southeast Asia, affects the crustal structure offshore passive margins, resulting in these “load-flow basins”. This further suggests that reorganiza- tion of continental drainage systems may also have a role in governing margin structure. If some crustal thinning occurs after the end of active extension this has implications for the thermal history of hydrocarbon-bearing basins throughout the area where application of classical models results in over predictions of heatflow based on observed accommodation space. -
Passive Margin Salt Tectonics: Effects of Margin Tilt, Sediment Progradation, and Regional Extension
Passive Margin Salt Tectonics: Effects of Margin Tilt, Sediment Progradation, and Regional Extension Steven J. Ings* Department of Earth Sciences, Dalhousie University, Halifax, NS, B3H 3J5 [email protected] and Lykke Gemmer and Chris Beaumont Department of Oceanography, Dalhousie University, Halifax, NS, B3H 4J1 ABSTRACT Deformation of many passive continental margin sedimentary packages is dominated by salt tectonics (e.g., offshore west Africa, east Brazil, eastern Canada). In many cases, salt became mobilized at an early stage of basin formation. In cases where salt deposition was syn-rift or immediately post-rift (e.g., Scotian margin, offshore eastern Canada), early salt mobilization may have been initiated by a combination of tilting and regional extension of the margin. On the Scotian margin, salt tectonics has been long-lived; once salt was initially mobilized, it continued to deform well into the Tertiary. Sediment progradation and aggradation into the Scotian Basin was likely the primary control on long- lived salt tectonics on the Nova Scotian margin. We analyze the driving mechanisms of passive margin salt tectonics using finite element numerical models of a viscous substratum (salt) overlain by a frictional- plastic overburden (sedimentary rocks), and present results of models incorporating margin tilting, regional extension, and sedimentation. The numerical models show that sediment progradation combined with basinward tilt destabilizes the salt-overburden system more than progradation alone. A basinward margin tilt of 1 degree accelerates the evolution of the system, and thereby produces landward extensional structures and basinward contractional salt structures earlier in the model evolution than with progradation alone, resulting in the formation of long allochthonous salt sheets extending greater lateral distances than in equivalent models without tilt. -
Structure and Distribution of Cold Seep Communities Along the Peruvian Active Margin: Relationship to Geological and Fluid Patterns
MARINE ECOLOGY PROGRESS SERIES Vol. 132: 109-125, 1996 Published February 29 Mar Ecol Prog Ser l Structure and distribution of cold seep communities along the Peruvian active margin: relationship to geological and fluid patterns 'Laboratoire Ecologie Abyssale, DROIEP, IFREMER Centre de Brest, BP 70, F-29280 Plouzane, France '~epartementdes Sciences de la Terre, UBO, 6 ave. Le Gorgeu, F-29287 Brest cedex, France 3~aboratoireEnvironnements Sedimentaires, DROIGM, IFREMER Centre de Brest, BP 70, F-29280 Plouzane, France "niversite P. et M. Curie, Observatoire Oceanologique de Banyuls, F-66650 Banyuls-sur-Mer, France ABSTRACT Exploration of the northern Peruvian subduction zone with the French submersible 'Nau- tile' has revealed benthlc communities dominated by new species of vesicomyid bivalves (Calyptogena spp and Ves~comyasp ) sustained by methane-nch fluid expulsion all along the continental margin, between depths of 5140 and 2630 m Videoscoplc studies of 25 dives ('Nautiperc cruise 1991) allowed us to describe the distribution of these biological conlnlunities at different spahal scales At large scale the communities are associated with fluid expuls~onalong the major tectonic features (scarps, canyons) of the margln At a smaller scale on the scarps, the distribuhon of the communities appears to be con- trolled by fluid expulsion along local fracturatlon features such as joints, faults and small-scale scars Elght dlves were made at one particular geological structure the Middle Slope Scarp (the scar of a large debns avalanche) where numerous -
Gas Seeps and Gas Hydrates in the Amazon Deep-Sea
Gas seeps and gas hydrates in the Amazon deep-sea fan Joao Marcelo Ketzer, Adolpho Augustin, Luiz Frederico Rodrigues, Rafael Oliveira, Daniel Praeg, Maria Alejandra Gomez Pivel, Antonio Tadeu dos Reis, Cleverson Silva, Bruno Leonel To cite this version: Joao Marcelo Ketzer, Adolpho Augustin, Luiz Frederico Rodrigues, Rafael Oliveira, Daniel Praeg, et al.. Gas seeps and gas hydrates in the Amazon deep-sea fan. Geo-Marine Letters, Springer Verlag, 2018, 38 (5), pp.429-438. 10.1007/s00367-018-0546-6. hal-02196115 HAL Id: hal-02196115 https://hal.archives-ouvertes.fr/hal-02196115 Submitted on 9 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Geo-Marine Letters (2018) 38:429–438 https://doi.org/10.1007/s00367-018-0546-6 ORIGINAL Gas seeps and gas hydrates in the Amazon deep-sea fan Joao Marcelo Ketzer1,2 & Adolpho Augustin1 & Luiz Frederico Rodrigues1 & Rafael Oliveira1 & Daniel Praeg1,3 & 4 Maria Alejandra Gomez Pivel & Antonio Tadeu dos Reis5 & Cleverson Silva6 & Bruno Leonel7 Received: 10 January 2018 /Accepted: 2 August 2018 /Published online: 17 August 2018 # The Author(s) 2018 Abstract Deep-sea fans have been proposed to act as carbon sinks, rapid deposition driving shallow methanogenesis to favor net storage within the gas hydrate stability zone (GHSZ). -
North America Free Download
NORTH AMERICA FREE DOWNLOAD Libby Koponen | 48 pages | 01 Mar 2009 | Children's Press(CT) | 9780531218303 | English | New York, NY, United States North America Plymouth remains the de jure capital. With soldiers in tow, his goal was to find gold for the Spanish Crown. United States of America Bureau of the Census. Nearly North America million immigrants have a four-year college degree or better. Retrieved 3 October This North America a list of North American countries and dependent territories by population. New Spain, a territory that stretched from the southwestern modern-day U. He explained the rationale for the name in the accompanying book Cosmographiae Introductio : [6]. This section needs expansion. Oceans portal Book Category. About ten years later another trading company, the West India Company, settled groups of colonists on Manhattan Island and at Fort Orange. North America has been historically referred to by other names. The first attempt by Europeans to colonize the New World occurred around A. Weishampel, David B. Demographics by North America. Other French-speaking locales include the Province of Ontario the official language is English, but there are an estimated North America, Franco-Ontariansthe Province of Manitoba co-official as de jure with Englishthe French West Indies and Saint-Pierre et Miquelonas well as North America US state of Louisiana, where French is also an official language. Canada shows significant growth in the sectors of services, mining and manufacturing. Inexplicably, Vineland was abandoned after only a few years. Between and Frobisher as well as John Davis explored along the Atlantic coast. Central Intelligence Agence. -
Carbon and Strontium Isotope Stratigraphy of the Permian from Nevada and China: Implications from an Icehouse to Greenhouse Transition
Carbon and strontium isotope stratigraphy of the Permian from Nevada and China: Implications from an icehouse to greenhouse transition Dissertation Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Kate E. Tierney, M.S. Graduate Program in the School of Earth Sciences The Ohio State University 2010 Dissertation Committee: Matthew R. Saltzman, Advisor William I. Ausich Loren Babcock Stig M. Bergström Ola Ahlqvist Copyright by Kate Elizabeth Tierney 2010 Abstract The Permian is one of the most important intervals of earth history to help us understand the way our climate system works. It is an analog to modern climate because during this interval climate transitioned from an icehouse state (when glaciers existed extending to middle latitudes), to a greenhouse state (when there were no glaciers). This climatic amelioration occurred under conditions very similar to those that exist in modern times, including atmospheric CO2 levels and the presence of plants thriving in the terrestrial system. This analog to the modern system allows us to investigate the mechanisms that cause global warming. Scientist have learned that the distribution of carbon between the oceans, atmosphere and lithosphere plays a large role in determining climate and changes in this distribution can be studied by chemical proxies preserved in the rock record. There are two main ways to change the distribution of carbon between these reservoirs. Organic carbon can be buried or silicate minerals in the terrestrial realm can be weathered. These two mechanisms account for the long term changes in carbon concentrations in the atmosphere, particularly important to climate. -
54. Mesozoic–Tertiary Tectonic Evolution of the Easternmost Mediterranean Area: Integration of Marine and Land Evidence1
Robertson, A.H.F., Emeis, K.-C., Richter, C., and Camerlenghi, A. (Eds.), 1998 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 160 54. MESOZOIC–TERTIARY TECTONIC EVOLUTION OF THE EASTERNMOST MEDITERRANEAN AREA: INTEGRATION OF MARINE AND LAND EVIDENCE1 Alastair H.F. Robertson2 ABSTRACT This paper presents a synthesis of Holocene to Late Paleozoic marine and land evidence from the easternmost Mediterra- nean area, in the light of recent ODP Leg 160 drilling results from the Eratosthenes Seamount. The synthesis is founded on three key conclusions derived from marine- and land-based study over the last decade. First, the North African and Levant coastal and offshore areas represent a Mesozoic rifted continental margin of Triassic age, with the Levantine Basin being under- lain by oceanic crust. Second, Mesozoic ophiolites and related continental margin units in southern Turkey and Cyprus repre- sent tectonically emplaced remnants of a southerly Neotethyan oceanic basin and are not far-travelled units derived from a single Neotethys far to the north. Third, the present boundary of the African and Eurasian plates runs approximately east-west across the easternmost Mediterranean and is located between Cyprus and the Eratosthenes Seamount. The marine and land geology of the easternmost Mediterranean is discussed utilizing four north-south segments, followed by presentation of a plate tectonic reconstruction for the Late Permian to Holocene time. INTRODUCTION ocean (Figs. 2, 3; Le Pichon, 1982). The easternmost Mediterranean is defined as that part of the Eastern Mediterranean Sea located east ° The objective here is to integrate marine- and land-based geolog- of the Aegean (east of 28 E longitude). -
Subduction Initiation at Passive Margins: Numerical Modeling K
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115, B03406, doi:10.1029/2009JB006549, 2010 Click Here for Full Article Subduction initiation at passive margins: Numerical modeling K. Nikolaeva,1 T. V. Gerya,1,2 and F. O. Marques1,3 Received 17 April 2009; revised 31 August 2009; accepted 21 October 2009; published 10 March 2010. [1] Subduction is a key process for terrestrial plate tectonics, but its initiation is still not entirely understood. In particular, despite the abundance of both passive and active continental margins on Earth, no obvious cases of transition between them have been identified so far. It has been shown that at most passive margins, elastic and frictional forces exceed gravitational instability and ridge‐push forces, which precludes subduction initiation. Therefore additional factors are needed to start subduction there. We investigated numerically in two dimensions factors controlling passive margins’ stability such as age of the oceanic plate, thickness of the continental lithosphere and crust, and density contrast between subcontinental and suboceanic lithospheric mantles. Our numerical experiments show that three subsequent tectonic regimes can develop at a passive margin: (1) stable margin, (2) overthrusting, and (3) subduction. Transition from stable margin to the overthrusting regime is mainly controlled by ductile strength of the lower continental crust. Further transition from overthrusting to the subduction regime is governed by the ductile strength of the subcontinental lithospheric mantle and its chemical density contrast with the suboceanic lithospheric mantle. Our experiments also demonstrate that the age of the oceanic plate is a factor of secondary importance for subduction initiation and only plays a role if other parameters are of critical values. -
Why Are Non-Volcanic Passive Margins Not Volcanic? Prof
Why are Non-Volcanic Passive Margins Not Volcanic? Prof. Tim Reston and Dr Stephen Jones Background Two important unsolved questions concerning non-volcanic passive margin evolution are how to avoid generating magma during plate separation and how to explain the transition from initial non-volcanic seafloor spreading to generation of 6–8 km thick oceanic crust by 10 million years after plate separation. The goal of this project is to investigate whether evolution from an initial broad, slow mode of mantle upwelling to a mature focussed, rapid upwelling mode can explain these questions. Divergence of two tectonic plates at a mid-ocean ridge draws the underlying mantle upward so that it melts by depressurisation to form new oceanic crust. The width of the melting region remains poorly known because traditional observations (the thickness, structure and chemical composition of oceanic crust) do not constrain the rate of upwelling in the mantle beneath. However, diachronous ridges of thickened oceanic crust, which form near hotspots when melting anomalies propagate along a mid-ocean ridge through time, provide a new direct constraint on the width of the melting region. Initial work on these ridges suggests that upwelling and melting are focussed within a narrow zone beneath mature mid-ocean ridges. In contrast, observations of rifting at non-volcanic passive margins suggest that mantle upwelling occurred at a lower rate over a much wider area. Work Plan The project will involve collating observations of crustal age, thickness, structure and chemical composition from mature mid-ocean ridges, and stratigraphy, crustal thickness and structure from non-volcanic passive margins. -
2 G322 Lab Exercise Neotectonic and Coastal Processes of Oregon Part I
G322 Lab Exercise Neotectonic and Coastal Processes of Oregon Part I. Pre-Lab Questions Use your notes, textbook, wall maps, and reading assignments to answer the following questions. A. Match the Following Coastal Locations with the terms on the Right. List all that apply. __________________ 1. Oregon Coast Passive Margin Tectonics (inactive) __________________ 2. Washington Coast Active Margin Tectonics - subduction __________________ 3. Southern California Coast Active Margin Tectonics - transform __________________ 4. Northern California Coast Active Margin Tectonics - rifting / spreading __________________ 5. Aleutian Islands of Alaska Emergent Coastline __________________ 6. Southeast Alaskan Coast Submergent Coastline __________________ 7. Gulf of Mexico - Texas Active Subsidence __________________ 8. Central Atlantic / U.S. Active Uplift B. Thinking Questions 9. The last major glaciation (i.e. a pervasive cold-wet climate regime) in the northern hemisphere was at it's peak 18,000 to 20,000 years ago. 100's to 1000' of feet of Ice covered much of Canada and the northern tier of the U.S. A. From what major hydrologic source does the precipitation that forms glacial ice originate? B. Describe how this moisture is cycled into glacial ice (what are the processes associated with this part of the hydrologic cycle). C. What happens to global sea level during a major glacial climate? What happens to global sea level during a major interglacial (i.e. warm / melting) climate? D. What happens to land surface elevation at convergent tectonic boundaries (i.e. subduction zones), especially where accretionary tectonics is prevalent? E. What happens to land surface elevation at passive tectonic boundaries, where sediment accumulates over time (think about what happens to water saturated sediment as it accumulates, becoming thicker over time, under increasing weight).