Thickness Build-up Research Articles

Results of the Sea Ice Model Intercomparison Project: Evaluation of sea ice rheology schemes for use in climate simulations

A hierarchy of sea ice rheologies is evaluated on the basis of a comprehensive set of observational data. The investigations are part of the Sea Ice Model Intercomparison Project (SIMIP). Four different sea ice rheology schemes are compared: a viscous‐plastic rheology, a cavitating‐fluid model, a compressible Newtonian fluid, and a simple free drift approach with velocity correction. The same grid, land boundaries, and forcing fields are applied to all models. As verification data, there are (1) ice thickness data from upward looking sonars (ULS), (2) ice concentration data from the passive microwave radiometers SMMR and SSM/I, (3) daily buoy drift data obtained by the International Arctic Buoy Program (IABP), and (4) satellite‐derived ice drift fields based on the 85 GHz channel of SSM/I. All models are optimized individually with respect to mean drift speed and daily drift speed statistics. The impact of ice strength on the ice cover is best revealed by the spatial pattern of ice thickness, ice drift on different timescales, daily drift speed statistics, and the drift velocities in Fram Strait. Overall, the viscous‐plastic rheology yields the most realistic simulation. In contrast, the results of the very simple free‐drift model with velocity correction clearly show large errors in simulated ice drift as well as in ice thicknesses and ice export through Fram Strait compared to observation. The compressible Newtonian fluid cannot prevent excessive ice thickness buildup in the central Arctic and overestimates the internal forces in Fram Strait. Because of the lack of shear strength, the cavitating‐fluid model shows marked differences to the statistics of observed ice drift and the observed spatial pattern of ice thickness. Comparison of required computer resources demonstrates that the additional cost for the viscous‐plastic sea ice rheology is minor compared with the atmospheric and oceanic model components in global climate simulations.

Analysis of sidewall buildup during trilevel resist etching of metal

Sidewall buildup formed during trilevel resist etching of a layered metal was analyzed for individual etch steps using Auger electron and micro-Raman spectroscopy. Thick sidewall buildup was formed during the dry SOG strip in a fluorine-containing plasma and found to consist of the oxide forms of sputtered anti-reflective TiN, TiF x , and CF x polymers. From the sidewall buildup observed after the metal etch, resist strip, and wet cleaning, Ti, N, O, and Si AES peaks were identified and TiO and NO bonds were detected implying that this buildup is mainly composed of the oxide forms of TiN and sputtered BPSG during the metal overetch. We propose that the reduction of sidewall buildup can be achieved by maintaining the plasma self-DC bias as low as possible during the bottom resist etch, SOG strip, and metal overetch and employing a carbonless fluorine plasma during the SOG strip.

Arc spray process for the aircraft and stationary gas turbine industry

Technological advances in arc spray have produced a system that competes favorably with other thermal spray processes. In the past, arc spray was thought of as a process for very large parts that need thick buildups. However, an attachment device known as the arc jet system has been developed that focuses the pattern and accelerates the particles. This attachment device, coupled with the in-troduction of metal-cored wires that provide the same chemistries as plasma-sprayed powders, pro-vides application engineers with a viable economic alternative to existing spray methods. A comparative evaluation of a standard production plasma spray system was conducted with the arc spray process using the attachment device. This evaluation was conducted by an airline company on four major parts coated with nickel-aluminum. Results show that, for these applications, the arc spray process offers several benefits.

Composite and plain tubular synthetic graft conduits in right ventricle-pulmonary artery position: Fate in growing lambs

Our goal was to identify the most appropriate material for right ventricle-pulmonary artery conduits in growing animals. We used 100 lambs that were 3 to 4 weeks old (mean weight 11.7 kg). Follow-up was up to 24 months. Group I received plain tubular conduits: (1) Dacron knitted fabric, (2) collagen-coated knitted fabric, (3) Milliknit and Microknit material, (4) woven Dacron fabric, (5) three-dimensional Dacron fabric (crossweave 500 and 800), or (6) polytetrafluoroethylene. Group II received either a (1) woven Dacron fabric conduit with a built-in tissue valve or (2) polytetrafluoroethylene graft with a built-in St. Jude Medical valve. We did angiograms and catheterizations every 3 to 6 months and killed the lambs at 6, 12, 18, or 24 months. Tubular Dacron fabric woven or knitted grafts, regardless of matrix, pore size, thickness, or coating, caused formation of a thick acellular pseudointima buildup, which led to progressive obstruction starting as early as 3 months. Polytetrafluoroethylene grafts in groups I and II showed the formation of thin inner and outer capsules (0.5 mm) and none developed obstruction despite wall calcification. Conduits of woven Dacron fabric with a built-in tissue valve degenerated rapidly, leading to calcification thrombosis and obstruction within 3 months; no lamb survived 12 months. Polytetrafluoroethylene conduits with a St. Jude Medical valve in lambs receiving anticoagulants remained free of obstruction and continued to function well. It appears that synthetic conduits of polytetrafluoroethylene perform well in either of the situations here tested and may be the best choice at present. (J T HORAC C ARDIOVASC S URG 1995;110:427-35)

Depositional evolution of lower permian Palaeoaplysina build-ups, Kapp duner formation, Bjørnøya, Arctic Norway

The Lower Permian Kapp Duner Formation on Bjørnøya includes an approximately 45 m thick Palaeoaplysina build-up complex. This complex is composed of stacked cycles of thin (0–1 m thick) restricted shelf mudstones and thicker (< 10 m thick) build-ups of Palaeoaplysina wackestone to boundstone capped by subaerial exposure surfaces. In the lower part of the complex, the build-ups are tabular and laterally more widespread than the lenticular build-ups found in the upper part of the complex. The depositional cycles most likely formed in response to fourth-order glacio-eustatic fluctuations in sea level, while the history of the build-up complex is controlled by longer-term, third-order fluctuations in relative sea level. The position of the build-up complex is structurally controlled.

A newly discovered mid-Carboniferous - ?early Permian reef complex in the Wandel Sea Basin, eastern North Greenland

Three types of carbonate build-ups occur in the mid-Carboniferous – ?early Permian (Moscovian–?Asselian) succession at Kap Jungersen, southern Amdrup Land, North Greenland: (1) Palaeoaplysina-dominated build-ups; (2) AIgae-dominated build-ups; and (3) Bryozoan-dominated build-ups. The build-ups are less than 15 m thick and up to a few hundred metres wide. They often coalesce to form laterally widespread, build-up dominated units and are locally stacked to form up to 100 m thick build-up dominated sections along platform margins.

Electron Energy Constancy Check Using a Five-Chamber Detector Array

Two methods are shown here to determine the 50% depth ionization (d50) using buildup materials of different thickness placed on top of a five-chamber detector array. In the first method, two sets of different thickness buildup material are required to perform the check, one set for checking 6 and 9 MeV, while another set is used for 12, 16, and 20 MeV electron beam from a Varian Clinac 2100C. The second method only requires two data points to determine the d50 depth for each energy. The d50 depths determined were compared with the d50 depth obtained using a water phantom with ionization chamber measurements. The method is simple to use especially for departments that use a similar detector to perform quality assurance tests such as output/symmetry/flatness check.

Biostratigraphic Sequence Analysis of Two Lower Miocene to Pliocene Sections, Eastern Falcon, Northwestern Venezuela

The eastern region of the Falcon Basin in northwestern Venezuela comprises a thick sedimentary sequence deposited from a deep marine bathyal to neritic environment, ranging in age from the Middle Eocene to the Pliocene. A detailed biostratigraphic study (foraminifera and calcareous nannoplankton) was carried out in two sedimentary sequences outcropping in Cumarebo and Piritu, adjacent areas of eastern Falcon, representing: platform, slope and basinal settings. The Cumarebo section is continuous in the studied interval, from the Middle Miocene to the Pliocene. The Piritu section is continuous from the Lower to the lower Upper Miocene, terminating unconformably beneath a thin interval of middle Pliocene platform sediments, indicating tectonism during the latest Miocene. The sequence stratigraphical interpretation was based on the biostratigraphic analysis of the benthic and planktonic fossils, facies distribution and sedimentological data. Systems tracts, sequence boundaries and maximum flooding surfaces from cycles TB2.4 to TB3.5 of the cycle chart were identified. In the Cumarebo section, the upper Middle and Upper Miocene is mostly composed of shales, with some turbiditic sands belonging to a LSW system tract. The upper most Miocene contains a thick carbonate buildup (HST), and it is overlain by a Pliocene section that shallows upward from upper slopemore » to outer shelf depositional environments. In the basinal (Piritu) section, most of the sediments are deep-water shales belonging to a LSW system tract, with some turbiditic sands in the upper Lower Miocene. TST and HST sediments, with scattered carbonate buildups in the upper Middle Miocene were also identified.« less

On a Simple Sea-Ice Dynamics Model for Climate Studies

Sea-ice motion and dynamic thickness build-up play an important role in the transfer of heat between the ocean and the atmosphere and so must be included in large-scale climate studies. A “cavitating-fluid” approximation allows these dynamic processes to be parameterized in a simple way by ignoring shear and tensile strength yet retaining compressive strength. A simple procedure for approximating a cavitating fluid is presented here and is compared to the more complete viscous-plastic sea-ice model by performing several three year simulations with daily varying and monthly average wind forcing. Although differences exist on a monthly basis, the two models compare favourably over a seasonal cycle, particularly when compared to a thermodynamics only model in which ice motion is ignored. The lack of shear strength in a cavitating-fluid approximation makes it less sensitive to smoothing of the wind fields (as demonstrated by the monthly average wind simulations); however it also changes the detailed circulation and thickness build-up patterns somewhat. Overall, the cavitating-fluid approximation shows considerable promise for including sea-ice dynamics in large-scale climate models, especially where averaged wind fields are employed.

On a Simple Sea-Ice Dynamics Model for Climate Studies

Sea-ice motion and dynamic thickness build-up play an important role in the transfer of heat between the ocean and the atmosphere and so must be included in large-scale climate studies. A “cavitating-fluid” approximation allows these dynamic processes to be parameterized in a simple way by ignoring shear and tensile strength yet retaining compressive strength. A simple procedure for approximating a cavitating fluid is presented here and is compared to the more complete viscous-plastic sea-ice model by performing several three year simulations with daily varying and monthly average wind forcing. Although differences exist on a monthly basis, the two models compare favourably over a seasonal cycle, particularly when compared to a thermodynamics only model in which ice motion is ignored. The lack of shear strength in a cavitating-fluid approximation makes it less sensitive to smoothing of the wind fields (as demonstrated by the monthly average wind simulations); however it also changes the detailed circulation and thickness build-up patterns somewhat. Overall, the cavitating-fluid approximation shows considerable promise for including sea-ice dynamics in large-scale climate models, especially where averaged wind fields are employed.

The Effect Of Rheology On Seasonal Sea-Ice Simulations

On the seasonal time scales relevant to numerical investigations of climate, the rheology used in large-scale sea ice models significantly affects the ice thickness build-up and ice velocity fields. Plastic rheologies with a normal flow rule have been used to-date in seasonal dynamic thermodynamic simulations. These rheologies have proved useful in simulating discontinuous slip near the coast while still supplying relatively robust velocity fields in the central Arctic Basin. However, as indicated by limited numerical sensitivity studies with different types of elliptical yield curves, the amount of shear strength significantly affects the ice build-up and can possibly cause a stoppage of the ice outflow through Fram Strait. In addition to the shear strength issue, there is also the possibility that non-normal flow rule rheologies, such as the Mohr Coulomb failure criterion used in soil mechanics, may cause somewhat different types of flow patterns, especially in the Fram Strait region. However, to date no seasonal simulations with such non-normal flow rule rheologies have been carried out. In order to investigate the role of different rheologies on the large-scale flow patterns in the Arctic Basin, a more general numerical scheme than that of Hibler (1979) is developed, which allows the simulation of the dynamic thermodynamic behavior of sea ice with a wide variety of different non linear rheologies. Using this numerical scheme, comparative simulations are carried out to seasonal equilibrium with several variations of the Mohr Coulomb rheology and compared to the more standard Elliptical yield curve results. In particular, the main control Mohr Coulomb case is a capped rheology in which the shear strength is taken to be proportional to the compressive stress. In this capped case only shear flow is allowed until a maximum allowable compressive stress is reached. This cap strength is parameterized to be a function of the ice thickness and compactness. For comparison, a simulation with a very large cap strength is also carried out, and an experiment with a similar compressive cap but much lower shear strength. Overall the results are analyzed to determine the sensitivity of the ice build-up to flow rule and shear strength magnitude. In addition special attention is given to the character of the flow and stoppage (if any) through Fram Strait.

The Effect Of Rheology On Seasonal Sea-Ice Simulations

On the seasonal time scales relevant to numerical investigations of climate, the rheology used in large-scale sea ice models significantly affects the ice thickness build-up and ice velocity fields. Plastic rheologies with a normal flow rule have been used to-date in seasonal dynamic thermodynamic simulations. These rheologies have proved useful in simulating discontinuous slip near the coast while still supplying relatively robust velocity fields in the central Arctic Basin. However, as indicated by limited numerical sensitivity studies with different types of elliptical yield curves, the amount of shear strength significantly affects the ice build-up and can possibly cause a stoppage of the ice outflow through Fram Strait. In addition to the shear strength issue, there is also the possibility that non-normal flow rule rheologies, such as the Mohr Coulomb failure criterion used in soil mechanics, may cause somewhat different types of flow patterns, especially in the Fram Strait region. However, to date no seasonal simulations with such non-normal flow rule rheologies have been carried out.In order to investigate the role of different rheologies on the large-scale flow patterns in the Arctic Basin, a more general numerical scheme than that of Hibler (1979) is developed, which allows the simulation of the dynamic thermodynamic behavior of sea ice with a wide variety of different non linear rheologies. Using this numerical scheme, comparative simulations are carried out to seasonal equilibrium with several variations of the Mohr Coulomb rheology and compared to the more standard Elliptical yield curve results. In particular, the main control Mohr Coulomb case is a capped rheology in which the shear strength is taken to be proportional to the compressive stress. In this capped case only shear flow is allowed until a maximum allowable compressive stress is reached. This cap strength is parameterized to be a function of the ice thickness and compactness. For comparison, a simulation with a very large cap strength is also carried out, and an experiment with a similar compressive cap but much lower shear strength. Overall the results are analyzed to determine the sensitivity of the ice build-up to flow rule and shear strength magnitude. In addition special attention is given to the character of the flow and stoppage (if any) through Fram Strait.

Controls on Early Retention and Late Enhancement of Microporosity in Reefal Gas Reservoirs, Offshore North Sumatra Basin: ABSTRACT

Chalky lime-matrix texture is pervasive in 300 m of coralgal and skeletal carbonates in the NSB-A (North Sumatra basin-A) gas field (lower-middle Miocene), offshore northern Sumatra. Much of the reservoir quality can be attributed to matrix with abundant intercrystalline, vuggy, and channel-form micropores. Matrix is composed of calcite microrhombs which are interpreted to have developed during stabilization of the precursor mud. On the same shelf, the smaller NSB-H oil field is composed of more than 45-m thick buildup of similar lithofacies which lack abundant microporosity. In both fields, early diagenesis included dissolution of aragonitic skeletal material, matrix neomorphism, and precipitation of nonluminescent calcite followed by zoned, luminescent calcite cements. Stable isotopes from matrix reflect a more open or water-dominated matrix diagenesis at NSB-H field. More active flushing of oversaturated, organically charged meteoric waters was responsible for thorough matrix cementation and microporosity occlusion at NSB-H field. Calcite cements show progressive enrichment of iron and manganese and depletion of magnesium and strontium during growth. The matrix at NSB-H field contains iron-rich dolomite. At A field, remnant matrix microporosity and intraparticle microporosity in calcitic skeletal material were greatly enhanced after all phases of cementation. Some pore-rimming cements are partially dissolved. At NSB-H field,more » late-phase dissolution is limited to the vicinity of open fractures where matrix-calcite and dolomite crystals are leached. Reservoir brines have a limey marine origin but are depleted in Ca and Mg relative to seawater, and carbon dioxide accounts for 31% of reservoir gas. If present brines are carbonate undersaturated, they may be substantially enhanced microporosity at NSB-A field. Late-stage dissolution is insignificant at NSB-H field due to the lack of early formed matrix microporosity.« less

Determining optical properties of thin films by modified attenuated total reflection with a charge coupled device

Thin films of silver produced by vacuum deposition deteriorate and tarnish when exposed to the atmosphere. This aging is due to the gradual buildup of a layer of Ag2S. When the silver layer is the plasma in an attenuated total reflection (ATR) configured waveguide the buildup of this extra layer can be observed as a shift in the angle of the resonance‐type reflection minimum. Here a modified ATR configuration which utilizes a charge coupled device has been used for accurate measurement of the angle shift of the resonance minimum. Comparison of theoretical with experimental results for angle change leads to a value for thickness buildup of the Ag2S layer. Results are also given for the change in the refractive index with time of a MgF2 overcoat as atmospheric water is adsorbed into its columnar microstructure. This paper describes a simple, qualitative way for determining refractive index change in a freshly deposited thin film.

X-rays from an 241Am source and their relative intensities

We report on the L and M shell Np X-ray transitions which may occur during the decay of 241Am sources. The number of X-rays per decay for more than 20 X-ray peaks, over the energy range 2–25 keV are reported. Branching ratios for the 26 and 33 keV γ-rays are also given. A simple experiment to measure the 10–20 μm ice thickness buildup on modern Si(Li) detectors is also described. This is important because the presence of a thin absorbing layer on the front face of Si(Li) detectors is critical in the 0–5 keV energy region where the Np M lines occur.

Evolution of Permian Carbonate Shelf and Foreshelf Detrital Systems, Midland Basin, Texas: ABSTRACT

A major phase of shelf progradation and consequent filling of the Midland basin began in the Early Permian. Prior to this time, shelf carbonate systems were mostly ineffective in generating coarse detritus in quantities sufficient to infill adjoining basins. Beginning in the Early Permian (Wolfcampian), however, the character of shelf and basin deposition was abruptly modified, in part because of faunal changes - proliferation of rock-forming biotic communities and the consequent potential for rapid shelf-marginal oversteepening - and the effects of sea level fluctuations and periods of shale influx. Shelf systems in the northern Midland basin and Eastern shelf evolved from ramps in the lowermost Wolfcamp to steep rimmed platforms by the lower Leonard. Shelf progradation into the Midland basin was cyclic, with extensive carbonate shelves having developed during sea level highstands and massive shale wedges deposited during alternate lowstands. Coarse megabreccia with markedly little sand dominates in the lower to middle Wolfcamp systems, despite the occurrence of ramps in this section. Such an anomaly can be explained by invoking widespread shelf wastage caused by the inherent instability and failure of the shale slopes on which these ramps were deposited. In certain middle Wolfcamp zones, thin shelf-ramp sections may be more » recognized only because any thick shelf-marginal buildups that may have been present have been displaced into adjoining basinal tracts. The evolution to rimmed-platform shelves by the lower Leonard strata, foreshelf debris occurs mostly as complexes of megabreccia wedges and aprons, anastomosing megabreccia, and sand-channel and lobe deposits derived from adjoining rimmed-platforms. Major variations exist in the gross geometries of foreshelf units and component reservoirs even laterally within rocks of the same age. « less

Influence of Basement Islands and Ridges on Smackover Deposition, Southwest Alabama: ABSTRACT

Pre-Jurassic basement highs, composed of igneous and/or metamorphic rocks, have influenced the deposition of Jurassic Smackover sediments in Clarke, Monroe, Conecuh, and Escambia Counties, Alabama. These basement islands and ridges provided a structural fabric on which Smackover sediments were deposited. The following 3 basic structural settings illustrate the thickness variations and lithofacies distribution of Smackover sediments on the flanks and crests of these basement highs. Emergent features were never covered by Smackover seas, resulting in nondeposition of Smackover sediments over their crests. Flanking these features are finely crystalline and anhydritic dolomites capped by bedded nodular-mosaic anhydrite. The anhydrite grades upward into Haynesville continental sediments that also overlie the crests of these features. Semi-emergent features were above sea level for most of Smackover deposition. It was not until near the end of Smackover transgression that these islands and ridges were inundated. As the seas regressed, shoaling occurred on the flanks of these features deposi ing predominantly grain-supported limestones that were later dolomitized. The crests of these basement highs are covered by thin, low-porosity, grain- and mud-supported dolomites capped by bedded nodular-mosaic to distorted mosaic anhydrite. Nonemergent features were submerged through most of Smackover deposition. This enabled carbonates to accumulate as thick organic buildups and shoals over crestal portions of the basement highs. These thoroughly dolomitized and highly porous and permeable crestal sediments grade upward into nonporous, mud-supported dolomites capped by bedded nodular-mosaic anhydrite. End_of_Article - Last_Page 259------------

Smackover Platform Sand Bodies: A Bahamas Model: ABSTRACT

Stave Creek field, a potential multimillion-barrel Smackover oil field in Clarke County, Alabama, owes much of its prolific production to an extensive, 100 ft (30 m) thick buildup of porous ooid and peloid grainstones. Seismic profiles and residual gravity maps indicate the field is located on the edge of a large, Jurassic, northeast tilted block of approximately 12 mi2 (31 km2). The block, which formed a shallow platform for Late Jurassic deposition, is bounded on the west by an older component of the Jackson fault, and slopes eastward into the present graben complex of the Gilbertown and West Bend faults. This location placed the platform in a position between the mouth of the Manila embayment and the eastern edge of the Mississippi interior salt basin. Tidal fluctuation between basins and the open marine conditions to the west had a strong influence on sedimentation across the platform. Cores from the area indicate a pronounced westward trend in increased carbonate grain stability and sediment winnowing. Smackover sediments from the deeper east side of the platform are composed primarily of peloidal lime mudstones and wackestones. Those of the central platform are peloidal and onchoidal wackestones and packstones. Those of the western edge form a high-energy facies of well-sorted ooid and onchoidal grainstones, e.g., the Stave Creek field reservoir. A modern analog to the deposition on this Jurassic platform is found along the margins of the Great Bahama Bank, and specifically the north Andros-Joulters Cays area. End_of_Article - Last_Page 1461------------

Lime Peak--An Upper Triassic Reef Complex in Yukon: ABSTRACT

End_Page 621------------------------------Upper Triassic carbonates in the Whitehorse trough, Yukon, are lenticular bodies surrounded by Triassic graywacke and volcanic-clast conglomerate derived from an arc to the west. The carbonates at Lime Peak are unusually well exposed. They show multiple stages of reef growth and a complete facies zonation from massive reefal limestone to offlapping slope and basin. The massive reefal limestones have variable lithology from peloidal mudstones to organic framestones containing spongiomorphs, tabulozoans, and calcareous sponges, with lesser contributions from corals, brachiopods, mollusks, algae, and echinoderms. Figure Slope deposits are alternations of thick beds of reef-derived debris with thinner beds containing attached spongiomorphs, thick-shelled pelecypods, large gastropods, and corals which colonized the debris beds. Basinal sediments include thin-bedded limestones and shales consisting of muddy layers rich in sponge spicules and organic matter and graded packstones containing thin-shelled bivalves and skeletal debris. The stages of growth were (1) initial development of lensoid masses each about 25 m thick (1 on sketch), (2) growth of a much larger reefal mass about 150 m thick (2 on sketch) which shed an apron of debris to the west (2a on sketch), and (3) development of a second thick buildup (3 on sketch) on the underlying forereef debris (2a) as the whole system prograded to the west. The Lime Peak reef complex is not typical of other Triassic buildups in North America which are generally low-relief, thin accumulations (less than 10 m thick) dominated by corals and spongiomorphs. The buildups at Lime Peak are much thicker, and tabuloazons and sponges are more important builders than corals. End_of_Article - Last_Page 622------------

Pliocene-Pleistocene Carbonate Rocks of Bonaire, Netherlands Antilles

Research Article| August 01, 1974 Pliocene-Pleistocene Carbonate Rocks of Bonaire, Netherlands Antilles CHARLES A. BANDOIAN; CHARLES A. BANDOIAN 1Dames & Moore, 6 Commercial Drive, Cranford, New Jersey 07016 Search for other works by this author on: GSW Google Scholar RAYMOND C. MURRAY RAYMOND C. MURRAY 2Department of Geology, Rutgers University, New Brunswick, New Jersey 08903 Search for other works by this author on: GSW Google Scholar Author and Article Information CHARLES A. BANDOIAN 1Dames & Moore, 6 Commercial Drive, Cranford, New Jersey 07016 RAYMOND C. MURRAY 2Department of Geology, Rutgers University, New Brunswick, New Jersey 08903 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1974) 85 (8): 1243–1252. https://doi.org/10.1130/0016-7606(1974)85<1243:PCROBN>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation CHARLES A. BANDOIAN, RAYMOND C. MURRAY; Pliocene-Pleistocene Carbonate Rocks of Bonaire, Netherlands Antilles. GSA Bulletin 1974;; 85 (8): 1243–1252. doi: https://doi.org/10.1130/0016-7606(1974)85<1243:PCROBN>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A sequence of Pliocene-Pleistocene carbonate rocks preserved on the western side of the island of Bonaire, Netherlands Antilles, represents a thick build-up of sediment deposited mainly on the flanks of the Cretaceous volcanic core of the island. This sediment built up and developed a shallow-water shelf similar to the one that surrounds the island today. Sediments at the top of the section and the updip portions of beds lower in the section have been dolomitized in two episodes of dolomitization. Minor sea-level fluctuations occurred during deposition of this sequence, and a major lowering of sea level terminated sedimentation.Carbonate rocks and terraces were superimposed on Pliocene-Pleistocene rocks as the island was subjected to uplift and (or) sea-level fluctuation during Pleistocene time. Seven well-developed terraces are present and range from 5 to 90 m above present sea level. Two distinct episodes of terrace formation are represented. The two highest terraces at 90 and 70 m were formed during the earlier episode. Relative sea level was lowered at least 60 m, exposing Pliocene-Pleistocene dolomite and limestone to subaerial erosion. A rise in sea level to approximately 50 m was accompanied by deposition of carbonate sediment on the erosion surface. Marine sediment filtered down into fractures and solution cavities in the underlying rock. This cavity-filling sediment and the lowermost limestone deposited on the erosion surface have been dolomitized. Subsequent uplift of the island and (or) eustatic lowering of sea level were accompanied by extensive deposition of eolianite at elevations above 50 m. Terraces of erosional and depositional origin were formed during this regression at elevations of 50, 30, 20, 10, and 5 m. Deposition of sediments associated with the present 5-m terrace occurred during a high stand following a major lowering of sea level. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.