Stratigraphy Commons^™

New Hampshire And Vicinity Continental Shelf: Sand And Gravel Resources, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Center for Coastal and Ocean Mapping

The continental shelf off New Hampshire (NH) has extensive marine-modified glacial deposits and associated shoals. These features are potential targets for sand and gravel resources for beach nourishment and other efforts to build coastal resiliency. The distribution of sand and gravel deposits was evaluated based on the synthesis of relatively recent high-resolution bathymetry, new surficial sediment and geoform maps, and an extensive data archive that includes over ~1280 km of seismic profiles, ~750 grain size analyses, and 23 vibracores. This work heavily utilizes the results of previous research on mineral resources on the NH shelf by Birch (1984) …

New Hampshire Continental Shelf Geophysical Database: Vibracore Logs And Sediment Data, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Data Catalog

The "New Hampshire Continental Shelf Geophysical Database: Vibracore Logs and Sediment Data" contains complete core logs and sediment grain size data from twenty‐three vibracores taken on the New Hampshire shelf in 1984 and 1988. During the present program, the original core descriptions, data, and photographs were verified and significantly expanded, synthesized, and presented in uniform core logs.The vibracore logs, sediment data, and the depositional environments are discussed in detail in Ward et al., 2021 (https://dx.doi.org/10.34051/p/2021.26).

Analysis Of Vibracores From The New Hampshire Continental Shelf From 1984 And 1988, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Center for Coastal and Ocean Mapping

During this study, the twenty-three vibracores taken in 1984 and 1988 were reexamined, original descriptions verified and significantly expanded, and the cores sampled to provide complete grain size data (i.e. the original sediment grain size analyses were limited). The vibracores were grouped by location with respect to major physiographic features (geoforms) or surficial sediment type including Offshore Marine-Modified Glacial Features (Drumlins and Lodgement Till Deposits), Northern Sand Body, Isles of Shoals, Nearshore Marine-Modified Glacial Features (Eskers and Drumlins), Nearshore Sheet Sand, and Offshore Seafloor Plain.

The Northern Sand Body (NSB), located near the Isles of Shoals ~10 km from shore, …

Sediment Mixing In The Tropical Pacific And Radiolarian Stratigraphy, Ted C. Moore Jr, Larry A. Mayer, Mitchell Lyle

Center for Coastal and Ocean Mapping

The reworking of older radiolarian microfossils into near-surface sediments of the tropical Pacific has long been the source of confusion for the development of radiolarian stratigraphy and of puzzlement over the mechanism(s) that could effect such pervasive reworking. Widespread dissolution “pits” in the sediments of the tropical Pacific are believed to be associated with hydrothermal circulation cells in the older oceanic crust and are here linked to processes which expose older sections and inject older non-carbonate material into near-bottom waters. Discharging waters of these circulation cells tend to dissolve carbonate in near-surface sediments; thus, only the non-carbonate material (including radiolarians) …

Seismic Stratigraphy Of The Ontong Java Plateau, David Mosher, Larry A. Mayer, Tom H. Shipley, Edward L. Winterer, Rick A. Hagen, Janice C. Marsters, Frank Bassinot, Roy H. Wilkens, Mitchell Lyle

Affiliate Scholarship

The Ontong Java Plateau, a large, deep-water carbonate plateau in the western equatorial Pacific, is an ideal location for studying responses of carbonate sedimentation to the effects of changing paleoceanographic conditions. These carbonate responses are often reflected in the physical properties of the sediment, which in turn control the appearance of seismic reflection profiles. Seismic stratigraphy analyses, correlating eight reflector horizons to each drill site, have been conducted in an attempt to map stratigraphic data. Accurate correlation of seismic stratigraphic data to drilling results requires conversion of traveltime to depth in meters. Synthetic seismogram models, using shipboard physical properties data, …

Velocity Anisotropy In Calcareous Sediments From Leg 130, Ontong Java Plateau, Frank Bassinot, Janice C. Marsters, Larry A. Mayer, Roy H. Wilkens

Affiliate Scholarship

During Leg 130, an intensive program of P-wave velocity measurements was conducted on calcareous sediments of varying induration (ranging from ooze to limestone) that cover the Ontong Java Plateau (west equatorial Pacific). The high quantity and quality of shipboard acoustical property measurements seemed to be particularly appropriate for gaining a better understanding of acoustic anisotropy in calcareous sediments. Major results can be summarized as follows: 1. In calcareous oozes, acoustic anisotropy exists even at shallow depths of burial. Values are low, ranging from -0.5% to 3.5% and averaging 1.2%. Anisotropy profiles are affected by coring disturbances, but they still roughly …

Detailed Stratigraphic Correlation Of The Neogene Sedimentary Sequences On The Ontong Java Plateau By Well Logging; Odp Sites 803, 805, 806, 807, And Dsdp Site 586, Mitchell Lyle, Roy H. Wilkens, Larry A. Mayer

Affiliate Scholarship

We used well logs, in some cases combined with shipboard physical properties measurements to make more complete profiles and to correlate between sites on the Ontong Java Plateau. By comparing sediment bulk density, velocity, and resistivity logs from adjacent holes at the same site, we showed that even subtle features of the well logs are reproducible and are caused by variations in sedimentation. With only minor amounts of biostratigraphic information, we could readily correlate these sedimentary features across the entire top of the Ontong Java Plateau, demonstrating that for most of the Neogene the top of the plateau is a …

Seabeam And Seismic Reflection Surveys On The Ontong Java Plateau, Larry A. Mayer, Tom H. Shipley, Edward L. Winterer, David Mosher, Rick A. Hagen

Affiliate Scholarship

No abstract provided.

High-Resolution, Whole-Core Magnetic Susceptibility Data From Leg 130, Ontong Java Plateau, John A. Tarduno, Larry A. Mayer, Robert Musgrave

Affiliate Scholarship

High-resolution, whole-core magnetic susceptibility data, recorded at 3-cm intervals, were obtained for advanced hydraulic piston (APC) cores at Sites 805, 806, and 807 of Leg 130 on the Ontong Java Plateau. In this initial report, we present a preliminary evaluation of these data for their use in core correlations and paleoclimatic studies. The data allow detailed intrasite correlations between the offset APC cores and provide a means for intersite correlations of Pleistocene sediments. Variations in magnetic susceptibility values probably mirror variations in terrestrial influx and may act as proxy indicators of climate. Highly coherent cyclicity, representing Milankovitch orbital frequencies, is …

Ontong Java Plateau, Leg 130: Synopsis Of Major Drilling Results, W. H. Berger, Loren W. Kroenke, Larry A. Mayer, Shipboard Scientific Party

Affiliate Scholarship

Sixteen holes were drilled at five sites on the northeastern flank of Ontong Java Plateau during Leg 130 (Sites 803 through 807). All of these sites are near the equator, but are at different depths (803: 02°26.0'N, 3410 m; 804: 01°00.3'N, 3861 m; 805: 01°13.7'N, 3188 m; 806: 00°19.1'N, 2520 m; and 807: 03°36.4'N, 2805 m). One of our goals was to obtain a depth transect of Neogene carbonate deposition for reconstructing the history of ocean climate, chemistry, and productivity, and for understanding the origin of acoustic reflectors. Another goal was to achieve considerable penetration into basement for elucidating the …

Lithostratigraphy, Biostratigraphy, And Stable-Isotope Stratigraphy Of Cores From Odp Leg 105 Site Surveys, Labrador Sea And Baffin Bay, D. B. Scott, P. J. Mudie, A. De Vernal, C. Hillaire-Marcel, V. Baki, K. D. Mackinnon, F. S. Medioli, Larry A. Mayer

Affiliate Scholarship

Trigger weight (TWC) and piston (PC) cores obtained from surveys of the three sites drilled during Ocean Drilling Program (ODP) Leg 105 were studied in detail for benthic foraminiferal assemblages, total carbonate (all sites), planktonic foraminiferal abundances (Sites 645 and 647), and stable isotopes (Sites 646 and 647). These high-resolution data provide the link between modern environmental conditions represented by the sediment in the TWC and the uppermost cores of the ODP holes. This link provides essential control data for interpretating late Pleistocene paleoceanographic records from these core holes. At Site 645 in Baffin Bay, local correlation is difficult because …

The Origin Of Fine Scale Acoustic Stratigraphy In Deep-Sea Carbonates, Larry A. Mayer

Affiliate Scholarship

In this paper we investigate the origin and geologic significance of the closely spaced high-frequency subbottom acoustic reflectors characteristic of pelagic carbonates. A detailed survey was conducted of a small area in the equatorial Pacific with the Marine Physical Laboratory's Deep-Tow instrument package, providing high-resolution 4-kHz profiles and precise positioning of core samples. The cores were sampled at closely spaced intervals for sound velocity and saturated bulk density. Acoustic impedances were calculated, and a reflection coefficient log determined for the upper 10 m of the sediment column. The reflection coefficient log revealed no interfaces with large reflection coefficients that correlated …