Ancient Bars Research Articles

Eloquor, Advocatus! Ancient Influences on Professional Responsibility

Law schools' professional responsibility courses cover ethical requirements of practicing attorneys and occasionally delve into moral obligations owed to the public. One topic not regularly studied is the profession itself as a profession, as opposed to a trade or other business. Professions have existed for much of human history in many ancient cultures. Much of modern European law is directly descended from the Roman legal system, and many elements of our own common law were developed in Ancient Rome. In many ways, Rome was the birthplace for jurisprudence as we know it. If Roman law laid the foundation for modern law, then how much did the ancient Roman bar contribute to the modern legal profession? This paper will argue that the ancient bar shared many of the same characteristics of professionalism as modern attorneys.

Beach orientation, bar morphology and the concentration of metalliferous placer deposits: a case study, Lake Turkana, N Kenya

The concentration of metalliferous particles in migrating swash bars is shown to depend upon processes controlled by the cross-sectional shape of the bar. A sand-spit provides two shorelines, each with a different pattern of wind-waves and each characterized consistently by bars of different shape. Where the wave period is low the bar is dune-like and its crest is set asymmetrically landward of the centre line. Where the wave period is high the bar is tabular, with a crest set just at the swash limit and on the lakeward side of the centre line. These differences in shape are important to the concentrating process. It is shown that swash-dominated dune-like forms produce concentrations of metalliferous grains that average only 13%. The tabular bar form, on the other hand, effects a significantly higher concentration of 21% through a hydrodynamic sorting process that is governed by limited swash overspill onto the landward slope. Concentrations of 90% are reached at specific positions. Confirmation of the concentrating process is obtained from detailed microstratigraphic interpretation of the contemporary bar, while the ancient bars of abandoned shorelines add supporting evidence. Clear-cut differences in placer concentration allow several diagnostic parameters to be identified for reconnaissance exploration. These include shore-line orientation, wave pattern, and bar cross-sectional morphology which can be combined with the reconstruction of abandoned shorelines using remote sensing imagery to provide a resource evaluation.

Sedimentary Structures and Discriminant Analysis of Textural Characteristics of Recent and Ancient Point Bars: ABSTRACT

Point-bar deposits of the Raton-Vermejo (Cretaceous) Sandstone are analogous to recent point-bar deposits of the Brazos River of Texas. Sedimentary structures in the two bars are similar; both contain abundant trough (festoon) crossbedding and climbing ripples. Avalanche foreset bedding is prominent at the maximum curvature of the meander in the Brazos River; reverse climbing ripples formed at the toe of the foresets. The upper and lower surfaces of the bars, measured perpendicular to flow direction at the maximum curvature of the meander, converge shoreward in both the Brazos and the Raton-Vermejo bars. Grain-size analyses of the Brazos River and Raton-Vermejo point bars are similar. In comparison with known suites of eolian, fluvial, and beach sands, all of 33 samples of Brazos River sands are classified as fluvial sands by multiple-group discriminant analysis. Ten of the initial 50 variables calculated for each sample were removed to decrease provenance effects. Classifications were performed from the remaining 40 by using the 16 most discriminating variables. Individual sedimentary structures in both the recent and ancient bars have similar grain-size distributions. Discriminant analysis indicates that grain-size variables alone are sufficient to separate the samples into 5 different sedimentary-structure groups (trough crossbedding, avalanche foresets, climbing ripples, reverse-climbing ripples, and horizontal laminations). End_of_Article - Last_Page 808------------

Evolution of Coastal Barriers in Japan during the Holocene

The coastal barriers in Japan are of three different types, formed at three different times (Fig. 4). 1) The oldest barriers, named as “Tsugaru-type”, form an extensive marine terrace having originated as ancient bar and lagoon, probably during the Shimosueyoshi (Riss-Wurm interglacial) stage. 2) “Akita-type” of the ancient barriers are believed to have been formed during some transgressional (interstadial) phases in Wurm stage. The top of the deposits is separated from the succeeding Holocene soft sediments. 3) The youngest barriers, called as “Kanazawa-type”, are of the Holocene transgression. All of those types is often developed along a same stretch of coastal area, where the ancient barriers are partly incised with numerous valleys, buried by the Holocene shallow marine, lagoon or fluviatile deposits.Based on the sedimentological analyses of subsurface data, it is generally established that the environment of deposition in the Japanese coastal area is changed from fresh or brackish to marine water during the early Holocene, in spite of the growth of sand spits or bars. Along the flanks of relatively large delta and fluvial fan, however, marine transgression was prevented its effect by the large supply of sediments.During the late Holocene, three series of beach ridges built by a prograding shoreline are developed on the coastal barriers. The environment in the landward area is generally changed from marine to brackish or fresh water. The cause is attributed to the intermittent emergences of shoreline. It is remarkable that these emergences can be recognized even on the relatively sinking coasts in Japan.

Petrology and Paleogeography of Greenbrier Formation

This paper describes the petrology and paleogeography of the Mississippian Greenbrier formation as determined from study of well samples, insoluble residues, heavy minerals, and thin sections. In the Greenbrier formation, clastic limestone beds composed of lime sand, oolites, and quartz sand alternate with beds of fine-grained limestone in which clastic texture is indistinct or can not be recognized. The clastic limestones appear to be nearshore sediments and in part are probably ancient bar, beach, channel, and dune deposits and have the shapes and trends characteristic of such deposits. Approximately half of the production of oil and gas from the Greenbrier formation is from clastic limestones; half from dolomite and dolomitic limestone, which are largely confined to th basal 20-30 feet of the Greenbrier formation. This basal zone appears to transgress both time units and structure. The dolomite clearly replaces limestone. Four methods by which magnesium-bearing waters could be introduced into the formation are suggested and the probable pattern of dolomitization resulting from each method is considered. The quartz sand in the Greenbrier was derived from two or more different sources on the north. Neither earlier Mississippian nor Upper Devonian sands of West Virginia and adjacent parts of Ohio and Pennsylvania were important sources of the quartz sand.

Petrology and Paleogeology of Greenbrier Limestone: ABSTRACT

This paper outlines the petrology and paleogeography of the Greenbrier formation of Mississippian age, as determined from study of well samples, insoluble residues, heavy minerals, and thin sections. In the Greenbrier, clastic limestone beds composed of calcareous sand, oolites, and quartz sand alternate with beds of fine-grained limestone in which clastic texture is indistinct or can not be recognized. The clastic limestones appear to be near-shore sediments and in part probably are ancient bar, beach, channel, and dune deposits and have the shapes and trends characteristic of such deposits. About half of the production of oil and gas from the Greenbrier is from clastic limestones; about half from dolomite and dolomitic limestone. Dolomite and dolomitic limestones are largely confined to the basal 20-30 feet of the formation. This basal zone appears to transgress both structure and time units. The dolomite clearly replaces limestone. Four methods by which magnesium-bearing waters could be introduced into the formation are suggested and the probable pattern of dolomitization resulting from each method is considered. The quartz sand in the Greenbrier was derived from two or more different sedimentary sources on the north. Earlier Mississippian and Upper Devonian sands of West Virginia, Ohio, and Pennsylvania were not important sources of the quartz sand. End_of_Article - Last_Page 2153------------

Original structures of beaches, bars, and dunes

Research Article| June 01, 1937 Original structures of beaches, bars, and dunes WARREN O. THOMPSON WARREN O. THOMPSON Search for other works by this author on: GSW Google Scholar GSA Bulletin (1937) 48 (6): 723–752. https://doi.org/10.1130/GSAB-48-723 Article history received: 07 May 1935 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation WARREN O. THOMPSON; Original structures of beaches, bars, and dunes. GSA Bulletin 1937;; 48 (6): 723–752. doi: https://doi.org/10.1130/GSAB-48-723 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract INTRODUCTIONGENERAL STATEMENTThis paper presents, in detail, facts about original structures of modern beaches, bars, and dunes, and stresses especially their stratification. It attempts also to formulate criteria for recognition of ancient bars, dunes, and stratified beaches that lack organic remains, which might reveal the origin of the deposits.For more than a century, the subject has been dealt with by numerous writers but little order has been brought out of the confusion. It is hoped that by very detailed studies of the formation of modern beaches, bars, and dunes a better means of interpreting these deposits may be worked out.The writer spent nearly a year along the coast of California, between San Francisco and San Diego, examining various deposits, some of which are modern beaches, and others contain fossils indicative of ancient beaches. In addition, beaches and bars of lakes, as well as eolian deposits, were examined . . . This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not currently have access to this article.

Progressive and Retrogressive Changes in the Plant Associations of the Delaware Coast

1. Ten years is too brief a period in which to show any considerable change in plant associations, even in so active a region as that of the dunes. 2. Progressive changes were observed: (a) advancement of the Hudsonia complex toward the heath; (b) advancement of the heath toward the thicket; (c) drying of isolated swamps and lakes; (d) fixation of the canal dune. 3. Retrogressive changes were noted: (a) recession of the coast, resulting in more frequent flooding of certain regions, thus continuing or increasing their hydrophytic character; (b) movement of active dunes over the forest. 4. The character and position of the sand-clay ledge suggests that it may have been an ancient sea-cliff. 5. The presence of a ledge of peat in the beach indicates the location of a former swamp. 6. This swamp was probably due to the presence of an ancient bar inclosing a lagoon. 7. The present erosion of the coast indicates that this bar with its dunes was moved inland over the swamp, while portions of the beach material ...