Abstract NEGSA.docx

AAPG Bulletin, 1967

Study of the Lower Devonian Manlius Formation along iSO miles of outcrop in New York State indicates that, by analogy with Recent carbonate environments, it was deposited in an environment very near mean sea-level, and having great lateral extent with very low relief. Three facies can be recognized within the Manlius: supratidal, intertidal, and subtidal, representing carbonate environments slightly above, at, and just below, mean sea-level, respectively. Small fluctuations in water level, caused by lunar tides, storms, or seasonal climatic variations, as well as local differences in sediment accumulation and erosion, resulted in sharp lateral and vertical facies changes with the result that the Manlius today has a complex internal stratigraphy and fossil distribution. The supratidal facies is characterized by non-fossiliferous, laminated, mudcracked, dolomitic, pelletal carbonate mudstone. Mudcracks and spar-filled vugs ("bird's-eye" structure) indicate frequent subaerial exposure; thin bituminous films separating individual carbonate laminae suggest the presence of algal mats. Dolomitization was penecontemporaneous and is inferred to have been similar to presentday supratidal dolomite formation in Florida and the Bahamas. The intertidal facies is composed of alternating thin beds of sparsely fossiliferous, pelletal, carbonate mudstone and skeletal calcarenite; individual beds commonly lie uncomformably on those below. Many primary structures are evident, especially scour-and-fill, cross-stratification, and limestone-pebble conglomerate. Many fossil occurrences have abundant individuals but only a few tax a are represented. Algal stromatolites and oncolites also are common. A few mudcracks and minor prosir)nal relief on carbonate mudstone beds indicate intermittent subaerial exposure. The subtidal facies is a skeletal, pelletal, carbonate mudstone commonly with well-developed, tabular masses of stromatoporoids. The relatively diverse biota of this facies required continuous marine submergence; its close association and juxtaposition with rocks that clearly indicate periodic subaerial emergence further suggest that water depths were very shallow. The stromatoporoids are interpreted as having grown either as encrusting masses within tidal creeks or channels, or else a» closely crowded, individual heads in front of the tidal flats of the intertidal facies. The three facies of the Manlius existed contemporaneously, retreating and advancing continuously with the result that, today, they form a complex facies mosaic. Manlius deposition as a whole took place within and marginal to a broad and shallow, though somewhat restricted, lagoon that developed on the landward side of a wide belt of crinoid meadows, represented by the laterally equivalent Coeymans Formation, which is a brachiopod-rich crinoidal calcarenite. During the Early Devonian marine transgression in the northern part of the Appalachian basin, these environments represent>>(l liv the Manlius and Coeymans migrated westward with time across New 'S'ork State. PART I: DESCRIPTION AND and clay, The scquen,T ranges in thickne.'^s ENVIRONMENTAL INTERPRETATION from a feather etfee to more than 300 feet CFig. OF MANLIUS FACIES 1). The Helderberg unit.-, i rop out for several 'Manuscript received, August 6, 196.';; accepted, buff-weathiTiiiEr, argiiku i-()u= dolomite (Rondoul March 2, 1966. Published by permission of the Assistant Commissioner, New York State Museum and-Science Service. ^,gy ^jj^ shared his extensive knowledge of the Lower ^ Department of Geological Sciences, Brown Univer-Devonian of New 'Vork and who reviewed the final sity. The writer acknowledges the financial supi)ort manuscript; Eugene Shinn of Shell Development Comgiven by The American Association of Petroleum Ge-pany, who showed the writer the supratidal environologists, Brown University, The Geological Society of ments of Florida Bay and explained the critical features America, and the New York State Museum and Sci-of supratidal deposition; Robert N. Ginsburg of The ence Service in underwriting the costs of this study. Johns Hopkins University and John Imbrie of Colum-Also, he expresses his thanks to those people who gave bia University, both of whom, through clever "devil's a variety of ideas, criticisms, and encouragements; advocacy," clarified main' of the writer's ideas and particularly L. V. Rickard of the N.Y. Geological Sur-generously provided ^t \ er i! of their own,

AAPG Bulletin, 1987

Petrographic and geochemical studies of pore-filhng cements and replacement products in the Helderberg Group (Upper Silurian-Lower Devonian, central Appalachians) document the diagenetic history of these rocks. Shallow-ramp skeletal limestones and buildups were partially lithified by marine cements. However, most porefilling cement formed under shallow (<300 m) to deep burial (300-4,000 m) conditions. Regional cathodoluminescent zonation patterns in early, calcite cements indicate meteoric ground waters were involved in shallow burial cementation. Early zoned calcite cements consist of updip nonluminescent cements with thin luminescent laminae in limestone or sandstone, that pass downdip into subzoned dull cements (interiayered bright and dull laminae), and then into nonzoned dull cement in basinward limestone. The regional distribution, stable isotopic compositions, and timing of early zoned cements relative to other diagenetic events suggest that all of the early cements formed synchronously from meteoric ground waters that became progressively more reducing as they flowed downdip (at least 150 km). Helderberg sandstone tongues probably were preferential conduits for meteoric ground waters because early calcite cements formed only on scattered skeletal grains in sandstones. Late, void-filling dull cement formed from deep burial pore fluids at burial depths of 300 to 4,000 m. Deep burial

Journal of Sedimentary Research, 1999

Upper Devonian (Frasnian) terrestrial strata of south-central New York contain palustrine and lacustrine carbonate deposited within the well-developed Catskill clastic wedge succession. These nonmarine limestone beds (8-50 cm thick) were repeatedly subaerially exposed and subjected to pedogenic processes. Palustrine features include subaerial exposure surfaces with soil crusts, pseudo-microkarst and microkarst, brecciation, desiccation cracks, horizontal, planar, and circumgranular cracks, and rhizoliths. Lacustrine carbonate sedimentation was derived primarily from biogenically induced precipitation and from degradation of calcified charophyte stems and ostracodes. These deposits accumulated in relatively shallow water depths, probably Ͻ 10 m. The results of stable isotope analyses (␦ 13 C ‫؍‬ Ϫ4.0 to Ϫ4.7‰ PDB; ␦ 18 O from Ϫ6.8 to Ϫ8.7‰ PDB) reveal covariance between ␦ 13 C and ␦ 18 O values. The high degree of covariance (r ‫؍‬ 0.75) suggests that these Late Devonian carbonate lakes were hydrologically closed; high rates of surface-water productivity resulted in the heavier ␦ 13 C values.

Sedimentology, 1993

The morphology and geochemistry of pedogenic carbonate found in vertic claystone palaeosols in the Devonian Catskill Formation in central Pennsylvania preserve a record of the physical and chemical environment of carbonate precipitation. The carbonate is characterized by three distinct petrographic generations. Pedogenic rhizoliths and nodules are the earliest precipitated generation, and typically consist of dull red-brown luminescent micrite. Clear, equant calcite spar cement fills voids in the centres of rhizoliths, as well as circumgranular cracks and septarian voids in nodules. Early spar cements are nonluminescent to dull luminescent, whereas later spar cements exhibit bright yellow-orange luminescence. Late stage pedogenic fractures are always occluded with very bright yellow-orange luminescent spar cements. The incorporation of progressively higher concentrations of Mn (up to 34 000 ppm) into successively younger calcite spar cements, without concomitant increases in Fe, suggests carbonate precipitation from an evolving meteoric water in which Mn2+ became increasingly mobile over time. The increased mobility is possibly due to decreasing Eh, resulting from oxidation of organic matter after rapid soil burial on the floodplain. The amount of Fe2+ available for incorporation into calcite was limited because most iron was immobile, having been earlier oxidized and bound to the palaeosol clay matrix as a poorly crystallized ferric oxide or oxyhydroxide mineral. Carbon isotope compositions of pedogenic carbonate correlate with the inferred depth of carbonate precipitation. Rhizoliths preserved below the lowest stratigraphic occurrences of pedogenic slickensides are consistently depleted in 3C relative to nodules, which formed stratigraphically higher, within the zone of active soil shrink and swell processes. Nodular carbonate, precipitated in proximity to deep cracks in the soil, is enriched due to increased gas exchange with isotopically heavy atmospheric C 0 2 . Accordingly, rhizolith compositions will most accurately estimate palaeoatmospheric levels of C 0 2 ; the use of nodule compositions may result in overestimation of Pco, by as much as 30%.

The morphology and geochemistry of pedogenic carbonate found in vertic claystone palaeosols in the Devonian Catskill Formation in central Pennsylvania preserve a record of the physical and chemical environment of carbonate precipitation. The carbonate is characterized by three distinct petrographic generations. Pedogenic rhizoliths and nodules are the earliest precipitated generation, and typically consist of dull red-brown luminescent micrite. Clear, equant calcite spar cement fills voids in the centres of rhizoliths, as well as circumgranular cracks and septarian voids in nodules. Early spar cements are nonluminescent to dull luminescent, whereas later spar cements exhibit bright yellow-orange luminescence. Late stage pedogenic fractures are always occluded with very bright yellow-orange luminescent spar cements. The incorporation of progressively higher concentrations of Mn (up to 34 000 ppm) into successively younger calcite spar cements, without concomitant increases in Fe, suggests carbonate precipitation from an evolving meteoric water in which Mn2+ became increasingly mobile over time. The increased mobility is possibly due to decreasing Eh, resulting from oxidation of organic matter after rapid soil burial on the floodplain. The amount of Fe2+ available for incorporation into calcite was limited because most iron was immobile, having been earlier oxidized and bound to the palaeosol clay matrix as a poorly crystallized ferric oxide or oxyhydroxide mineral. Carbon isotope compositions of pedogenic carbonate correlate with the inferred depth of carbonate precipitation. Rhizoliths preserved below the lowest stratigraphic occurrences of pedogenic slickensides are consistently depleted in 3C relative to nodules, which formed stratigraphically higher, within the zone of active soil shrink and swell processes. Nodular carbonate, precipitated in proximity to deep cracks in the soil, is enriched due to increased gas exchange with isotopically heavy atmospheric C 0 2 . Accordingly, rhizolith compositions will most accurately estimate palaeoatmospheric levels of C 0 2 ; the use of nodule compositions may result in overestimation of Pco, by as much as 30%.

The Appalachian Geology of John M. Dennison: Rocks, People, and a Few Good Restaurants along the Way, 2020

A 3 ton (2.7 metric tonnes [t]), granitoid lonestone with Appalachian provenance was found in situ in offshore Devonian black shale in northeastern Kentucky, United States, and is denoted herein as the Robinson boulder, or lonestone, after its discoverer, Michael J. Robinson. This large boulder appears to have been displaced nearly 500 km from its source on the opposite margin of the Acadian/Neoacadian Appalachian foreland basin. While previous identifications of possible lonestones have been attributed to Pleistocene glacial events, scrutiny of this lonestone’s origin suggests that the boulder, which was embedded in the Upper Devonian Cleveland Shale Member of the Ohio Shale in northeastern Kentucky, is most likely a Devonian ice-rafted glacial dropstone. Notably, palynologic correlation with reported glacial diamictites elsewhere in the basin indicates such a source. Together, the dropstone and diamictites, separated by ~500 km, provide evidence for alpine glaciation in the ancient Acadian/Neoacadian orogen and for tidewater glaciers in the adjacent, eastern margin of the foreland basin. The latest Devonian marine transgression and Neoacadian foreland subsidence are interpreted to have been associated with tidewater glacial connections to the open sea. Importantly, the existence of this dropstone and its likely glacial precursor events require new considerations about contemporary black-shale sedimentation and the influence of tectonics on the delivery of glacial sediments to foreland basins.

Palaeogeography, …, 2002

Phosphatic microspherules (6 1 mm diameter) recovered from the Upper Devonian (uppermost Frasnian) Guilmette Limestone in eastern Nevada are interpreted here to be fish otoliths and thus provide insight into ocean water chemistry just prior to the Frasnian^Famennian mass extinction boundary. Analysis by scanning electron microscope (SEM) and electron microprobe indicates that they are apatite (francolite) and consist of radially aligned, concentrically banded crystals around a central nucleus. This type of microspherule, previously interpreted to be conodont pearls, has compositions more similar to fish teeth derived from the same unit than to conodonts. Microspherules and fish teeth have consistently lower concentrations in wt% of P 2 O 5 (31.88^36.32), F (3.05^5.12), SrO (0.15^0.34), and analysis totals (indicating higher concentrations of OH and/or CO 3 ; 90.66^96.09) and higher CaO (51.67^55.15), SO 2 (0.50^0.90), MgO (0.09^0.15), and Fe 2 O 3 (0.11^0.21) than the associated conodonts (P 2 O 5 : 37.

Sumber daya manusia memiliki peran penting dalam perusahaan, namun sumber daya manusia juga harus sesuai dengan kebutuhan. Sumber daya manusia yang berlebih dapat berdampak tingginya biaya operasional, menurunnya produktivitas dan berpengaruh pada kepuasan karyawan. Manajemen sumber daya manusia diperlukan disetiap perusahaan agar perusahaan mencapai tujuan dengan efektif dan efisien. PT. ABC memiliki lebih dari 10.000 karyawan, dari observasi dan wawancara dengan beberapa narasumber didapat hasil bahwa di divisi Procurement dan Logistik terdapat sumber daya manusia yang berlebih ini berdampak pada biaya operasional yang tinggi, produktivitas yang menurun karena turunya semangat kerja dan berdampak kepuasan karyawan karena seringnya memiliki waktu luang. PT. ABC dapat merekrut team proyek dalam penanganan manajemen sumber daya manusia agar PT. ABC dapat mencapai kestabilan dan dapat bersaing di masa mendatang.

Ilustração da Capa: "Despedindo-se da Terra" -Salvador Dali Pintura mediúnica realizada na Sociedade Bezerra de Menezes Campinas -SP.

This paper looks at the global, regional and bilateral actors involved in mass atrocities in Africa and in the Sudan, including the impact of their policy formulations in regard to humanitarian interventions and civilian protection duties in the Sudan. Particularly, it underscores the discrepancies between the findings of international commission of inquiries, the failure of law enforcement and civilian protection duties, including the accountability mechanisms against the criminal leadership in the Sudan, which regrettably is still in power.