bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Jurassic to recent chronology
Authors: Kent Dennis V. , Gradstein Felix M. 
Published: April 2015

Abstract
We present an integrated geomagnetic polarity and geologic time scale for the Jurassic to Recent interval, encompassing the age range of the modern ocean floor. The time scale is based on the most recent bio-, magneto-, and radiochronologic data available.
The biostratigraphic bases for Jurassic, Cretaceous, and Cenozoic time-scales are discussed extensively elsewhere (e.g., Gradstein, this volume; Van Hinte, 1976b; Hardenbol and Berggren, 1978; Berggren and Van Couvering, 1974; Van Couvering and Berggren, 1977). Emphasis is placed here on magnetochronology and its integration with biochronology in the derivation of an internally consistent geologic time scale. The binary signal of normal and reversed geomagnetic polarity has little intrinsic absolute time value (ordinal scale), but it can be used to measure time according to its radiochronologic calibration (cardinal scale). The standard magnetic reversal sequence has a correlatable, characteristic pattern and is demonstrated to be continuous from numerous marine magnetic anomaly profiles from the world ocean. The reversal sequence is recorded by lateral accretion in sea-floor spreading and vertical accumulation in sedimentary or lava sections, allowing independent checks on the completeness and relative spacing of the reversal sequence as well as the opportunity to apply an assortment of geochronologic data for calibration. Although different phenomena and assumptions are invoked in their derivation, both magneto- and bio- chronologic time estimates involve indirect assessment according to calculated rates of sea-floor spreading, sedimentation, and biotic evolution. These extend the application of the relatively few reliable radiometric dates available, so that a continuous
Oceanic particles and pelagic sedimentation in the western North Atlantic Ocean
Authors: Honjo Susumu 
Published: April 2015

Abstract
Deep-sea sediment is formed by the accumulation of oceanic particles originally generated elsewhere. A large part of oceanic sedimentation is due to biological activity in the oceanic surface layers. Some lithogenic particles, however, are transported long distances from interiors and edges of continents into the pelagic environment. Transportation pathways of oceanic particles usually are complex, involving biological, chemical, and physical processes. The time necessary to complete such pathways varies from instantaneous to hundreds of years. Not all oceanic particles settle as permanent members of the deep-sea sediment. Biogenic detritus in particular can be dissolved, decomposed, or changed in its properties. Refractory particles increase their relative proportions in pelagic sediments as a result of such alteration through time.
There are two major kinds of marine particles in oceans, lithogenic and biogenic. Lithogenic particles are mostly layered or framework aluminosilicate minerals such as clay, quartz, and plagioclase. Only fine particles—clay and silt-size—are transported to the pelagic ocean floor in quantity, except for some large ice-rafted boulders. Lithogenic particles are refractory and therefore become permanent constituents of the pelagic marine sediment without significant chemical alteration. They are transported from American, European, and African landmasses to the open North Atlantic Ocean by processes such as river outflow, coastline erosion, and glacial erosion. Significant amounts of fine refractory particles are transported from the continental shelves and slopes of both sides of the North Atlantic by advective processes to the interior of the ocean basins (e.g., McCave and Tucholke, this vol.). In boreal and Arctic latitudes,
Mass wasting in the western North Atlantic
Authors: Embley Robert M. , Jacobi Robert 
Published: April 2015

Abstract
The balance between processes of slope degradation and slope aggradation on the ocean floor is constantly shifting. Along “active” continental margins, tectonic effects can provide large amounts of sediments to submarine slopes and they also can trigger frequent large slope displacements. Along “passive” continental margins such as that of eastern North America, the aggradation and degradation processes probably operate at a slower rate; they are stimulated primarily by changes in sediment supply caused by climatic changes or by occasional intraplate earthquakes.
The North American continental margin has long been a “type area” for studies of submarine sedimentary features and the processes that formed them, including canyon incision (Veatch and Smith, 1939), turbidity currents (Heezen and Ewing, 1952), and contour currents (Heezen and others, 1966). Although slumping has always been considered an important process on the upper continental slope and in canyon heads, only within the past few years has it been recognized that slumps and slides are ubiquitous on the continental slope and upper rise and that mass- wasting products are an important component of the deep-water Pleistocene sedimentary sequence (Embley and Jacobi, 1977; Knebel and Carson, 1979; Embley, 1980). It also has only recently been appreciated how important such factors as jointing and biological erosion are to failure of consolidated sediments on steep slopes in the deep ocean. This chapter describes our present state of knowledge of mass-wasting processes in the provinces of the North American margin and basin.With increasing oil exploration in deeper water,
The crest of the Mid-Atlantic Ridge
Authors: Macdonald Ken C. 
Published: April 2015

Abstract
By 1854, there were enough deep ocean soundings to allow M. F. Maury to draw the first bathymetric chart of the North Atlantic Ocean in 1855. He defined the great shoaling “middle ground” of the Atlantic basin, later to be known as the Mid-Atlantic Ridge (MAR). It is interesting to note that during the Challenger expedition (1872–1876), Sir Wyville Thomson predicted, on the basis of water temperatures alone, that the MAR is a nearly continuous topographic barrier dividing the Atlantic Ocean. In the 1950s, continuous echogram profiles revealed the presence of a deep median valley along the axis of the MAR (Heezen and others, 1959; Hill 1960). Seismicity (Gutenburg and Richter, 1954) and the occurrence of youthful basaltic lavas on the MAR (Shand, 1949) indicated that the median valley was a geologically active rift zone. Heezen (1960) first suggested that extension across the rift valley might be responsible for accretion of basaltic oceanic crust and the drift of the continents, but his contention that this rifting resulted from expansion of the earth was incorrect. High heat flow measured on the MAR (Bullard and Day, 1961) and large axial magnetic anomalies (Heezen and others, 1959) were added to seismicity and recent volcanism as enigmas associated with the rift valley.
In his seafloor spreading hypothesis Hess (1962) elegantly explained these puzzling observations in a unified model, and the bilateral symmetry of magnetic anomalies found on other midocean ridges (Vine and Matthews, 1963; Vine, 1966)
Paleogene biofacies of the western North Atlantic Ocean
Authors: Premoli-Silva Isabella , Boersma Anne 
Published: April 2015

Abstract
This chapter presents an overview of the distributional patterns of the major calcareous and siliceous microfossil groups of the Paleogene in the western North Atlantic Ocean. From these patterns the evolution of open marine biofacies through space and time can be reconstructed. At first sight, this would seem to be an easy task, considering the large number of Deep Sea Drilling Project (DSDP) and commercial drill holes available, as well as the numerous piston cores which have retrieved pre-Quatemary sediments from the North Atlantic Basin in the last 25 years. However, two principal problems complicate detailed biofacies reconstructions. The first, and most frustrating, is the incompleteness of the Paleogene Stratigraphie record from the North Atlantic. Existing deep-sea cores are complicated by extensive drilling gaps, large sedimentary hiatuses, and/or the absence of age- diagnostic fossils. The second problem is the difficulty of intercorrelation of the many different Paleogene biostratigraphic zonations and time-scales.
Since about 1969, biostratigraphic schemes based on the major calcareous and siliceous fossil groups have been extensively refined or newly constructed. Because different biostratigraphic schemes and taxonomies have been used by different researchers in earlier studies of North Atlantic cores, the majority of Paleogene calcareous DSDP sections and many of the other boreholes from the western North Atlantic have been restudied and rezoned during preparation of this chapter. The sections have all been recalibrated according to the time scale and zonation shown on Plate 1. As a result, much of the early Paleogene can now be accurately correlated and
Paleogeographic and paleobathymetric evolution of the North Atlantic Ocean
Authors: Tucholke Brian E. , McCoy Floyd W. 
Published: April 2015

Abstract
The principles of plate tectonics developed over the past 25 years provide a conceptual and predictive framework that allows relatively detailed reconstruction of the geologic history of ocean basins. Excluding extra-terrestrial effects, tectonics of the earth’s crust is the primary mechanism controlling the evolution of the geologic record (Fig. 1). Secondary mechanisms related to tectonics through direct or indirect pathways create complicating and less easily predicted signals in the oceanic sedimentary record. In this paper we use plate-tectonic concepts to reconstruct the morphology and geologic conditions of the North Atlantic Ocean basin in twelve time slices from the Late Triassic (Atlantic closure) to the present. The specific time slices selected represent a balance between depiction of major tectonic/oceanographic “events” and portrayal of important, longer-term geologic episodes with relatively stable circulation and depositional patterns. Within each time-slice we have superimposed the major tectonic patterns, seamounts, oceanic circulation, and sedimentary lithofacies. While we have made this compilation as complete and coherent as possible within the time available, we point out that the synthesis is still a limited effort compared to the vast literature on the geology of the North Atlantic. Furthermore, because we have made the compilations at a small scale, many generalizations are necessary. Despite such deficiencies, these “first-generation” maps provide a good summary of our present knowledge of the geologic conditions in each time-slice.
Whole-earth wiring diagram summarizing the hierarchy and interaction of the most direct controls on sedimentation and erosion in the North Atlantic basins. Numerous less direct
Paleoceanography and evolution of the North Atlantic Ocean basin during the Jurassic
Authors: Jansa Lubomir F. 
Published: April 2015

Abstract
Jurassic paleoceanographic conditions in the Atlantic Ocean can be reconstructed from information derived from the preserved sediments and the biogeography of the fossil fauna, from reconstructed basin paleogeographies (shape, size, depth, and positions of landmasses and seaways), and from indications of paleotopography, paleobathymetry, and paleoclimate. An extensive literature exists about Mesozoic sediments and biota of the Teth- yan realm from Europe and parts of northwestern Africa. Such data, supplemented by my own field studies in central and southern Europe and Morocco, and by studies of oil exploratory wells on the eastern North American margin, were major sources of the Jurassic lithofacies data summarized in Plate 9. Additional data comes from Continental Offshore Stratigraphie Test (COST) wells drilled on the eastern North Atlantic U.S. shelf and summarized in U.S. Geological Survey reports. However, the most important information is derived from the Deep Sea Drilling Project (DSDP), which drilled numerous deep holes in the deep North Atlantic basin and its continental margins.
Greater insight into the early evolution of the North Atlantic basin was provided particularly by DSDP Leg 79, which drilled four holes on the deep-water Moroccan continental margin, at water depths of 3151 to 3992 m (Sites 554 to 547, Hinz and others, 1984; Plates 2, 9). These holes provide the only information about the Lower Jurassic in the central North Atlantic basin, and are used extensively in this chapter on the assumption that basin development was similar on both sides of the Atlantic. This assumption is supported
Cretaceous paleoceanography of the western North Atlantic Ocean
Authors: Arthur Michael A. , Dean Walter E. 
Published: April 2015

Abstract
In this paper we summarize available information on the Cretaceous lithostratigraphy and paleoceanography of the western North Atlantic. The data and some of our interpretations draw in large part on papers published in the Deep Sea Drilling Project (DSDP) volumes. We have attempted to cite relevant references when possible, but space limitations make it difficult to give proper credit to all sources; we apologize for any omissions.
Organic carbon (Corg) and carbonate (CaCO3) analyses were tabulated for each site from papers in the DSDP Initial Report volumes and other published works (e.g., Summerhayes,1981). Corg, CaCO3, and non-CaCO3 mass accumulation rates (MARS) were calculated using core by core averages of component percentages for the more continuously cored sites; core averages for wet bulk density and porosity (from DSDP data files); biostratigraphies of de Graciansky and others (1982), Roth and Bowdler (1981), and Cool (1982); and the time scales of the Decade of North American Geology (Palmer, 1983; Kent and Gradstein, this volume) or Harland and others (1982; see Plate 1).
Backtracked paleodepths for western North Atlantic DSDP Sites from Tucholke and Vogt (1979) with the revised stratigraphy of de Graciansky and others (1982) were used in plotting Corg and CaCO3 in Figures 2, 3,4 and 5 (see also Thierstein, 1979).
Backtracking curves of seafloor paleodepth versus age (Sclater and others, 1977; Tucholke and Vogt, 1979) for selected western North Atlantic DSDP sites. Average CaCO3 concentrations per core are shown by code number
Tertiary paleoceanography of the western North Atlantic Ocean
Authors: Tucholke Brian E. , Mountain Gregory S. 
Published: April 2015

Abstract
The Tertiary paleoceanography of the North Atlantic Ocean is known in greater detail than that of earlier periods because the upper part of the geologic record is more accessible to geologic sampling and geophysical observation. The Tertiary record also appears more complex, partially because of the greater data density. Nonetheless, there are large segments of this record about which we know relatively little. In particular, the Paleocene and Oligocene sedimentary records are not well represented on the shallow continental margin because erosion during sea-level low- stands removed much of the section. Equivalent records in the deep basin are poorly known because low sediment accumulation rates or erosion by abyssal currents resulted in preservation of abnormally thin sections. Many of these sections also are poorly sampled in existing Deep Sea Drilling Project (DSDP) drillsites.
In contrast to earlier periods, the Tertiary North Atlantic Ocean basin was strongly affected by the action of abyssal contour-following currents, particularly following Eocene time. The currents intermittently caused extensive seafloor erosion along the continental margins and they decorated the basin with large sediment drifts. The development and patterns of surface currents, and to some extent deep currents, are dealt with from a paleobiogeographic viewpoint by Berggren and Olsson (this volume). In this paper, we summarize the Tertiary paleoceanography based on other information from the geologic record, principally seismic Stratigraphic interpretations that are correlated with rock stratigraphy at DSDP and other boreholes. These data are interpreted within the framework of the plate-tectonic evolution of the North Atlantic
The juridical ocean basin
Authors: Knauss John A. 
Published: April 2015

Abstract
Since World War II, claims of national jurisdiction over areas of the ocean and its resources have been moving seaward in an irregular and often confusing way. The trend has been aptly described as “creeping jurisdiction.” A strong case can be made for the proposition that the fisheries and mineral resources of the ocean have been the primary driving force for these claims.
“Every nation is free to travel to every other nation and to trade with it,” wrote Hugo Grotius, often called the father of international law, in Mare Liberum published in 1609. He viewed the sea as res communis, a common possession for all and the private property of none. His views slowly gained international acceptance, in part because it was indeed in the general interest to encourage common use of the ocean for trade, and there was little in the ocean that could be subject to private property rights. Even fish were sufficiently abundant, given the crude methods of catching, so that whatever regulations were necessary could be con-trolled by local agreements.
The Grotius view was generally unchallenged for more than three centuries, a few international fisheries and whaling agreements notwithstanding. The first significant challenge came in 1945 when President Truman declared U.S. jurisdiction “with respect to the natural resources of the subsoil and seabed of [its] continental shelf’ and implied that other coastal nations should do likewise. The reason, of course, was oil. Although “under water”ï¿½ oil wells had been drilled from piers or slant drilled
The Arctic Region
Authors: Grantz Arthur , Johnson Leonard , Sweeney J. F. 
Published: April 2015

Abstract
The synthesis of the geology of the North American plate in the Arctic Ocean (Fig. 1) will cover the area between the Arctic (Nansen) Mid-Ocean Ridge and its extension into the Siberian continental shelf on the Eurasian side, and the Arctic continental margins of Greenland, Canada, Alaska, and Chukotka on the Amerasian side (Fig. 2). This predominantly oceanic region consists of a complex of ridges and plateaus of diverse and, in part, enigmatic origin, several oceanic deeps, and thick continental-rise sedimentary prisms. The margins of the region consist of an active spreading center along the Nansen Ridge, an active fracture zone off northern Greenland, and older passive margins off Canada, Alaska, and Chukotka.
The bathymetry and geography of all the world’s ocean basins and their borderlands are now known— except for the Arctic. Although apparently detailed maps of this region have been published, the soundings supporting the bathymetry shown are sparse, resulting in contours that only grossly reflect the true bottom physiography. In the Arctic, geologic knowledge is so limited that suggestions about the nature of the Alpha-Mendeleev Ridge, for example, range from continental crust to fossil subduction zone or extinct spreading ridge. The hostile environment over most of the Arctic Ocean has thus far prevented a systematic study of this important subbasin of the world ocean. Despite numerous expeditions into its marginal regions and repeated attempts to visit and probe its interior, the deep Arctic Ocean remains a frontier for geologic exploration.
Knowledge of the Arctic is important for more than just solving Arctic problems, and its plate tectonic evolution is closely linked to the evolution of the Atlantic and Pacific basins as well as to the continents that almost surround it.
The western North Atlantic
Authors: Vogt Peter R. , Tucholke Brian E. 
Published: April 2015

Abstract
Although available space strongly limits the scope of this essay, we want it to serve variously as a prospectus of subject matter to be covered; an informal “minisynthesis” that geographically and topically delimits synthesis contents; a guide for authors; a definition of synthesis problems as well as scientific problems; a philosophical perspective; identification of relationships with other volumes; and finally, if we are successful, a stimulus to new research.
Continental platforms and basins of Canada
Authors: Stott D. F. , Aitken J. D. 
Published: April 2015

Abstract
This chapter is an extended annotated outline of the planned contents for the volume Continental Platforms and Basins of Canada that will form a part of the sixth edition of the Geology and Economic Minerals of Canada as well as part of the series on The Geology of North America that is being prepared in connection with the Decade of North American Geology. Sections preceded by arabic numbers will be chapters in the synthesis volume. Information on the Hudson Platform was provided by A. W. Norris, and information on the St. Lawrence platform was provided by B. V. Sanford. Their assistance is gratefully acknowledged.
The Eastern Pacific and Hawaii
Authors: Hussong D. M. , Winterer E. L. , Decker R. W. 
Published: April 2015

Abstract
This volume will synthesize and describe the geology of the eastern northern Pacific Ocean Basin, a particularly large, variable, and dynamic region that is far less studied than most continental areas. Interpretation of the geology and geophysics of oceanic regions has been remarkably useful for elucidating the geometry and history of large-scale tectonics, especially lithospheric plate tectonics. Because it is accomplished by remote sensing techniques that generalize sea-floor structures and features, the structural complexities that are observed onshore at road-cut scales are smoothed out in marine studies. Thus, in many ways the success of marine studies is that they observe the forest without the confusion of looking at each tree, while on land the geologist must try to interpret the forest by the more difficult task of generalizing the study of features with the relative size of the trees.
In the past few years the scales of onshore and offshore geologic studies have been converging. Continental geologists are using more geophysics and remote sensing, while marine geologists have tried to conduct higher-resolution studies.
This volume will strive to provide a comprehensive description of our present state-of-knowledge of marine geology. At the same time, we will emphasize two general objectives in our field, as follows:
The Precambrian
Authors: Hoffman P. F. , Card K. D. , Davidson A. 
Published: April 2015

Abstract
Phanerozoic tectonics have not affected the basic integrity of the North American continent. From time to time, sialic crustal elements have been rifted off, accreted onto, and slipped along the continent’s margins, but the vast continental interior has remained intact. Furthermore, the dimensions of the continent are little different now than they were in early Paleozoic time.
No such assertions can be made for the Precambrian of North America. The structure of the shield (Fig. 1) and buried basement of the interior platform (Fig. 2) is part of a continent-wide “tectonic collage” (Helwig, 1974) consisting of (1) five or more old cratonic elements having crystalline basement rocks of Archean age (3.8 to 2.5 b.y.) and remnants of Early Proterozoic (2.5 to 1.6 b.y.) cratonic cover: (2) anastomosing Early Proterozoic orogenic belts, mostly culminating between 1.9 and 1.8 b.y., that enclose and marginally affect the Archean cratons; (3) intracratonic igneous and sedimentary rocks, mairtly of Middle Proterozoic age (1.6 to 0.9 b.y.), that document consolidation of the various Archean cratons and Early Proterozoic orogens to form a vast composite craton here called “Proto-Laurentia;” and (4) the Grenville Orogen, culminating at about 1.1 b.y., which developed along the presumed southeast margin of Proto-Laurentia and may contain elements exotic to it. In addition, the bounding Phanerozoic orogens contain Middle and Upper Proterozoic rocks deposited marginal to Proto-Laurentia, as well as Precambrian rocks outboard of Phanerozoic sutures that may not belong to Precambrian North America at all.