Modern and Ancient Hiatuses in the Pelagic Caps of Pacific Guyots And
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9. Small-Scale Shallow-Water Carbonate Sequences of Resolution Guyot (Sites 866, 867, and 868)1
Winterer, E.L., Sager, W.W., Firth, J.V., and Sinton, J.M. (Eds.), 1995 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 143 9. SMALL-SCALE SHALLOW-WATER CARBONATE SEQUENCES OF RESOLUTION GUYOT (SITES 866, 867, AND 868)1 Andre Strasser,2 Hubert Arnaud,3 François Baudin,4 and Ursula Röhl5 ABSTRACT The Hauteri vian to upper Albian carbonate sediments drilled on Resolution Guyot are all of shallow-water origin. The volcanic basement is covered by dolomitized oolitic and oncolitic grainstones of an inner-ramp setting. At 1400 m below seafloor (mbsf), they pass into peritidal facies punctuated by small coral and mdist bioherms and by beach sediments. Oolites dominate between 790 and 680 mbsf. The upper part of the guyot (from 680 mbsf up to the phosphate-iron-manganese crust capping the Cretaceous platform) is composed of lagoonal carbonates exhibiting some calcrete horizons. The material collected from Holes 867B and 868A implies that the platform was rimmed by barrier islands and storm beaches, and that reefs (rudists and sponges) were of minor importance. This is in contrast to modern atolls, where reefs are the major rim builders. In the late Albian, the platform was subaerially exposed and karstified, then drowned. Although average recovery was low (15.4% for Hole 866A, 29.2% for 867B, 46.3% for 868A), the cored material clearly shows that the sedimentary record is composed of small, meter-scale sequences. They are especially well developed in platform- interior, lagoonal-peritidal settings, where facies evolution indicates cyclic deepening and shallowing of the depositional environ- ment. -
Curriculum Vitae
TIMOTHY JAMES BRALOWER Department of Geosciences Pennsylvania State University University Park, PA 16802 [email protected] www.globalnannoplankton.com Education: Ph.D. Earth Sciences, Scripps Institution of Oceanography, University of California, San Diego, 1986. M.S. Oceanography, Scripps Institution of Oceanography, University of California, San Diego, 1982. B.A. with Honours in Geology, Oxford University, England, 1980. Professional Experience: Professor, Department of Geosciences, Pennsylvania State University, 2003-. Head, Department of Geosciences, Pennsylvania State University, 2003-2011; 2017-2018. Chair, Department of Geological Sciences, University of North Carolina, Chapel Hill, 1998-2002. Joseph Sloane Professor of Geological and Marine Sciences, University of North Carolina, Chapel Hill, 1998-2002. Associate Professor of Geological and Marine Sciences, University of North Carolina, Chapel Hill, 1993-1998. Assistant Professor, Geological and Marine Sciences, University of North Carolina, Chapel Hill, 1990-1993. Assistant Professor, Florida International University, State University of Florida at Miami, 1987-1990. ODP/IODP: Shipboard biostratigrapher, Leg 122 (Indian Ocean, 1988), Leg 143 (Pacific Ocean, 1993), Leg 165 (Caribbean, 1995), Expedition 364 (Chicxulub, 2016). Co-chief scientist, ODP Leg 198 (Pacific, 2001). Honors: Hettelman Junior Faculty Research Prize, UNC-CH, 1995. Fulbright Senior Scholarship, University of New South Wales, 2011-12. Wilson Service Award, College of Earth and Mineral Sciences, PSU, 2015; G. Montgomery and Marion Mitchell Award for Innovative Teaching, College of Earth and Mineral Sciences, PSU, 2017; George W. Atherton Award for Excellence in Teaching, PSU Systemwide Highest Award 2020. Memberships: AGU, GSA, NAGT Publications: http://scholar.google.com/citations?user=q4WEgGYAAAAJ&hl=en&oi=ao Partial list of Professional Service (past 20 years) . -
Appendix 2. the Mystery of Guyot Formation and Sinking
Appendix 2 The Mystery of Guyot Formation and Sinking Origin of Guyots Unknown In 1946, geologist Harry Hess was the first geologist to describe guyots (flat-topped seamount).1 Since then, the number of guyots has become numerous. Resolution Guyot in the Mid-Pacific Mountains that was studied in the 1990s by the Deep Sea Drilling Project2 is a typical guyot. Figure A2.1 shows the silhouette. Ever since Hess’s time, the cause of the flat top has eluded explanation.3 Winterer and Met- Figure A2.1. Silhouette of Resolution Guyot zler maintain: “Since Hess first recognized them in the Mid-Pacific Mountains (drawn by Mrs. Melanie Richard). in 1946, the origin of flat-topped seamounts, or guyots, has remained one of the most persistent problems in marine geology.”4 Since guyots are believed to have been truncated near sea level, there are two suggested subsid- ence mechanisms used to explain why they are now found well below sea level. But some guyots must have become flat well below sea level. Not All Guyots Eroded At Sea Level Many scientists have simply assumed that the flat top of a guyot was eroded at or near sea level.5,6 ‘This has been challenged by a few marine geologists.’7,8 For instance, a number of guyots near the East Pacific Rise have been attributed to the infilling of calderas by small lava flows well below sea level.9,10,11,12 “But, these guyots are small 1 Hess, H.H., 1946. Drowned ancient islands of the Pacific Basin. American Journal of Science 244:772–791. -
1 John A. Tarduno
JOHN A. TARDUNO January, 2016 Professor of Geophysics Tel: 585-275-5713 Department of Earth and Environmental Sciences Fax: 585-244-5689 University of Rochester, Rochester, NY 14627 Email: [email protected] USA http://www.ees.rochester.edu/people/faculty/tarduno_john Academic Career: 2005-present Professor of Physics and Astronomy, University of Rochester, Rochester, NY. 2000-present Professor of Geophysics, University of Rochester, Rochester, NY. 1998-2006 Chair, Department of Earth and Environmental Sciences 1996 Associate Professor of Geophysics, University of Rochester, Rochester, NY. 1993 Assistant Professor of Geophysics, University of Rochester, Rochester, NY. 1990 Assistant Research Geophysicist, Scripps Institution of Oceanography, La Jolla, Ca. 1989 National Science Foundation Postdoctoral Fellow, ETH, Zürich, Switzerland 1988 JOI/USSAC Ocean Drilling Fellow, Stanford University, Stanford, Ca. 1987 Ph.D. (Geophysics), Stanford University, Stanford, Ca. 1987 M.S. (Geophysics) Stanford University, Stanford Ca. 1983 B.S. (Geophysics) Lehigh University, Bethlehem Pa. Honors and Awards: Phi Beta Kappa (1983) Fellow, Geological Society of America (1998) JOI/USSAC Distinguished Lecturer (2000-2001) Goergen Award for Distinguished Achievement and Artistry in Undergraduate Teaching (2001) Fellow, American Association for the Advancement of Science (2003) American Geophysical Union/Geomagnetism and Paleomagnetism Section Bullard Lecturer (2004) Fellow, John Simon Guggenheim Foundation (2006-2007) Edward Peck Curtis Award for -
Cenozoic Changes in Pacific Absolute Plate Motion A
CENOZOIC CHANGES IN PACIFIC ABSOLUTE PLATE MOTION A THESIS SUBMITTED TO THE GRADUATE DIVISION OF THE UNIVERSITY OF HAWAI`I IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN GEOLOGY AND GEOPHYSICS DECEMBER 2003 By Nile Akel Kevis Sterling Thesis Committee: Paul Wessel, Chairperson Loren Kroenke Fred Duennebier We certify that we have read this thesis and that, in our opinion, it is satisfactory in scope and quality as a thesis for the degree of Master of Science in Geology and Geophysics. THESIS COMMITTEE Chairperson ii Abstract Using the polygonal finite rotation method (PFRM) in conjunction with the hotspot- ting technique, a model of Pacific absolute plate motion (APM) from 65 Ma to the present has been created. This model is based primarily on the Hawaiian-Emperor and Louisville hotspot trails but also incorporates the Cobb, Bowie, Kodiak, Foundation, Caroline, Mar- quesas and Pitcairn hotspot trails. Using this model, distinct changes in Pacific APM have been identified at 48, 27, 23, 18, 12 and 6 Ma. These changes are reflected as kinks in the linear trends of Pacific hotspot trails. The sense of motion and timing of a number of circum-Pacific tectonic events appear to be correlated with these changes in Pacific APM. With the model and discussion presented here it is suggested that Pacific hotpots are fixed with respect to one another and with respect to the mantle. If they are moving as some paleomagnetic results suggest, they must be moving coherently in response to large-scale mantle flow. iii List of Tables 4.1 Initial hotspot locations . -
Constraining Basin Parameters Using a Known Subsidence History
geosciences Article Constraining Basin Parameters Using a Known Subsidence History Mohit Tunwal 1,2,* , Kieran F. Mulchrone 2 and Patrick A. Meere 1 1 School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, T23 TK30 Cork, Ireland; [email protected] 2 School of Mathematical Sciences, University College Cork, Western Gateway Building, Western Road, T12 XF62 Cork, Ireland; [email protected] * Correspondence: [email protected] or [email protected]; Tel.: +353-21-490-4580 Received: 5 June 2020; Accepted: 6 July 2020; Published: 9 July 2020 Abstract: Temperature history is one of the most important factors driving subsidence and the overall tectono-stratigraphic evolution of a sedimentary basin. The McKenzie model has been widely applied for subsidence modelling and stretching factor estimation for sedimentary basins formed in an extensional tectonic environment. Subsidence modelling requires values of physical parameters (e.g., crustal thickness, lithospheric thickness, stretching factor) that may not always be available. With a given subsidence history of a basin estimated using a stratigraphic backstripping method, these parameters can be estimated by quantitatively comparing the known subsidence curve with modelled subsidence curves. In this contribution, a method to compare known and modelled subsidence curves is presented, aiming to constrain valid combinations of the stretching factor, crustal thickness, and lithospheric thickness of a basin. Furthermore, a numerical model is presented that takes into account the effect of sedimentary cover on thermal history and subsidence modelling of a basin. The parameter fitting method presented here is first applied to synthetically generated subsidence curves. Next, a case study using a known subsidence curve from the Campos Basin, offshore Brazil, is considered. -
Ocean Drilling Program Scientific Results Volume
Haggerty, J.A., Premoli Suva, L, Rack, R, and McNutt, M.K. (Eds.), 1995 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 144 2. PLANKTONIC FORAMINIFER BIOSTRATIGRAPHY AND THE DEVELOPMENT OF PELAGIC CAPS ON GUYOTS IN THE MARSHALL ISLANDS GROUP1 Paul N. Pearson2 ABSTRACT Five guyots were drilled on Ocean Drilling Program Leg 144, three of which possess thick caps of pelagic sediment. These guyots (Limalok, Site 871; Lo-En, Site 872; and Wodejebato, Site 873) belong to the Marshall Islands group of seamounts. Pelagic sediments of late Oligocene to Holocene age were recovered from them. In each case, the sediment was found to be unconsolidated on recovery and contain very abundant planktonic foraminifers, particularly in the >150-µm size range. Preservation of tests is generally good, with most showing only minor signs of dissolution or recrystallization, although many samples have a high proportion of fragmented material in the fine fraction. Planktonic foraminifer faunas are diverse and consist predominantly of warm-water species. A typically western Pacific fauna occurs throughout the Miocene. Biostratigraphic assignment was generally straightforward except for the bottommost interval of the pelagic caps where severe reworking (sediment mixing) is a common feature. A significant hiatus was found at each site between drowning of the carbonate platform and the onset of pelagic sediment accumulation. Thus, the platforms were apparently swept clean of sediments, with the exception of isolated ponds, until subsidence took the guyots sufficiently deep for sediment to accumulate in large quantities. Backtracking of subsidence paths for each guyot suggests that pelagic cap formation began at depths of between 700 and 1000 mbsl. -
Influence of Sediment Transport on Short-Term Recolonization by Seamount Infauna
MARINE ECO'R'OGY PROGRESS SERIES Vol. 123: 163-175,1995 Mu Published July 20 Ecol Prog Ser / Influence of sediment transport on short-term recolonization by seamount infauna Lisa A. Levin, Claudio DiBacco Marine Life Research Group, Scripps Instituliar of Oceanography, La Jolla, California 92093-0218, USA ABSTRACT: Rates and mechanisms of mEa'nnal recolonization in contrasting sediment transport regimes were examined by deploying hydrodynamically unbiased colonization trays at 2 sites -2 km apart on the flat summit plain of Fieberhg Cplyot in the eastern Pacific Ocean. Both study sites expe- rienced strong bottom currents and high shear velocity (U. exceeding 1.0 cm S-' daily). Macrofaunal recolonization of defaunated sediments on Werling Guyot was slow relative to observations in shal- low-water sediments, but rapid compared l&other unennched deep-sea treatments. Microbial colo- nization was slower but macrofaunal colon~isnwas faster at White Sand Swale (WSS, 585 m),where rippled foraminiferal sands migrate daily, than at Sea Pen Rim (SPR, 635 m), where the basaltic sands move infrequently. Total densities of macroiannal colonizers at WSS were 31 and 75% of ambient after 7 wk and 6.4 mo, respectively; at SPR they were 6 and 49% of ambient, respectively. Over % of the colonists were polychaetes (predominantly ksionids and dorvilleids) and aplacophoran molluscs. Species richness of colonizers was comparab.lle at SPR and WSS and did not differ substantially from ambient. Most of the species (91%) and indmduals (95%) recovered in colonization trays were taxa present in background cores. However, only 25% of the taxa colonizing tray sediments occurred in trays at both WSS and SPR. -
32. Radiometric Ages of Basement Lavas Recovered at Loen, Wodejebato, Mit, and Takuyo-Daisan Guyots, Northwestern Pacific Ocean1
Haggerty, J.A., Premoli Silva, I., Rack, F., and McNutt, M.K. (Eds.), 1995 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 144 32. RADIOMETRIC AGES OF BASEMENT LAVAS RECOVERED AT LOEN, WODEJEBATO, MIT, AND TAKUYO-DAISAN GUYOTS, NORTHWESTERN PACIFIC OCEAN1 Malcolm S. Pringle2 and Robert A. Duncan3 ABSTRACT The best estimate for the age of the oldest volcanism recovered from the summits of Loen, Wodejebato, MIT, and Takuyo- Daisan guyots, northwestern Pacific Ocean, is 113, 83, 123, and 118 Ma, respectively. All of these sites originated in the central and western regions of the South Pacific Isotopic and Thermal Anomaly (SOPITA). The 113-Ma age for Loen Guyot is signifi- cantly different from the 76-Ma age of volcanism under the carbonate platform of its neighbor, the living Anewetak Atoll, and suggests that drowned guyot/living atoll seamount pairs may have no genetically significant relationship other than geographic proximity. Although all of the basalts recovered from the top of Wodejebato Guyot were erupted during polarity Chron 33R (ca. 79-85 Ma), both the occurrence of reworked Cenomanian calcareous nannofossils in one of the summit cores and the existence of a thick Cenomanian volcaniclastic sequence, including 94-Ma basaltic clasts, in the archipelagic apron indicate that there must have been a Cenomanian or older edifice beneath the drilled summit volcanics. AT MIT Guyot, two late-stage periods of volcanism can be recognized: late Aptian (ca. 115 Ma) phreatomagmatic eruptions through the existing volcanic and carbonate platform, and 120-Ma hawaiites seen both as exotic clasts in the 115-Ma tuffs and as lava flows at the top of the basement sequence. -
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. -
Depositional Patterns Constrained by Slope Topography Changes On
www.nature.com/scientificreports OPEN Depositional patterns constrained by slope topography changes on seamounts Dewen Du1,2,3*, Shijuan Yan1, Gang Yang1, Fengdeng Shi1, Zhiwei Zhu1, Qinglei Song1, Fengli Yang1, Yingchun Cui1 & Xuefa Shi1 Slope topography is known to control the spatial distribution of deposits on intraplate seamounts; however, relatively little is known about how slope topography changes constrain those depositional patterns. In this study, we analyse data on four lithotypes found on seamount slopes, including colloidal chemical deposits comprising mainly cobalt-rich crusts, and examine the relationships between the spatial distribution of these lithotypes and current slope topography. We use these relationships to discuss depositional patterns constrained by slope topography changes. Some depositional units in drill core samples are interpreted to have resulted from past topographic changes that created the current slope topography. Two or more types of deposits that accumulated at the same location implies that the slope topography changed over time and that the depositional patterns on seamount slopes are constrained by changes in slope topography. Seamounts are frst-order deep-sea morphological elements 1 and have important oceanographic research value. Cobalt-rich crust deposits that may contain several strategic metals and thus be considered mineral resources are widely distributed on seamount slopes2–5. Terefore, many scientists have surveyed and explored seamounts since the 1980s6–9, acquiring a large amount of data and knowledge on seamounts. However, some questions, such as how topographical changes to seamounts constrain depositional patterns on their slopes and how to interpret depositional sequences in sections of shallow drill samples taken from seamount slopes, remain unanswered. -
Volume 144 Index
Index to Volume 144 INDEX TO VOLUME 144 This index provides coverage for both the Initial Reports and Scientific Results portions of Volume 144 of the Proceedings of the Ocean Drilling Program. Refer- ences to page numbers in the Initial Reports are preceded by “A” with a colon (A:), and to those in the Scientific Results (this book), by “B” with a colon (B:). In addi- tion, reference to material on CD-ROM is shown as “bp:CD-ROM.” The index was prepared by Earth Systems, under subcontract to the Ocean Drill- ing Program. The index contains two hierarchies of entries: (1) a main entry, defined as a keyword or concept followed by a reference to the page on which that word or concept appears, and (2) a subentry, defined as an elaboration on the main entry fol- lowed by a page reference. The index is presented in two parts: (1) a Subject Index and (2) a Taxonomic Index. Both parts cover text, figures, and tables but not core-description forms (“barrel sheets”), core photographs, smear-slide data, or thin-section descriptions; these are given in the Initial Reports. Also excluded from the index are biblio- graphic references, names of individuals, and routine front and back matter. The Subject Index follows a standard format. Geographic, geologic, and other terms are referenced only if they are subjects of discussion. This index also includes broad fossil groups such as nannofossils and radiolarians. A site chapter in the Ini- tial Reports is considered the principal reference for that site and is indicated on the first line of the site’s listing in the index.