铅—试铁灵络合物吸附波及溴化十六烷基三甲基铵增敏效应的研究

在０３０ｍｏｌ／ＬＨＡｃ介质中，Ｐｂ（Ⅱ）与７＿碘＿８＿羟基喹啉＿５＿磺酸（试铁灵，Ｆｅｒｏｎ）的络合物于－０５４Ｖ（ｖｓ．ＳＣＥ）产生一尖锐的极谱波，加入溴化十六烷基三甲基铵（ＣＴＭＡＢ）显著增敏，可使极谱波增高约４倍。峰电流与Ｐｂ（Ⅱ）浓度在９６×１０－９～４８×１０－６ｍｏｌ／Ｌ呈良好的线性关系，检出限为４８×１０－９ｍｏｌ／Ｌ。用多种电化学方法研究了该极谱波的性质及电极反应机理表明，络合物组成比为ｎＰｂ（Ⅱ）∶ｎＦｅｒｏｎ＝１∶１，极谱波为吸附波，峰电流由中心离子Ｐｂ（Ⅱ）还原产生，电子转移数为２。试验了多种离子对峰电流的影响，拟定的方法用于矿样分析，结果与原结果相符。     

Evaluating along‐strike variation using thin‐bedded facies analysis,Upper Cretaceous Ferron Notom Delta,Utah

Thin‐bedded delta‐front and prodelta facies of the Upper Cretaceous Ferron Notom Delta Complex near Hanksville in southern Utah, USA, show significant along‐strike facies variability. Primary initiation processes that form these thin beds include surge‐type turbidity currents, hyperpycnal flows and storm surges. The relative proportion of sedimentary structures generated by each of these depositional processes/events has been calculated from a series of measured sedimentological sections within a single parasequence (PS6–1) which is exposed continuously along depositional strike. For each measured section, sedimentological data including grain size, lithology, bedding thickness, sedimentary structures and ichnological suites have been documented. Parasequence 6–1 shows a strong along‐strike variation with a wave‐dominated environment in the north, passing abruptly into a fluvial‐dominated area, then to an environment with varying degrees of fluvial and wave influence southward, and back to a wave‐dominated environment further to the south‐east. The lateral facies variations integrated with palaeocurrent data indicate that parasequence 6–1 is deposited as a storm‐dominated symmetrical delta with a large river‐dominated bayhead system linked to an updip fluvial feeder valley. This article indicates that it is practical to quantify the relative importance of depositional processes and determine the along‐strike variation within an ancient delta system using thin‐bedded facies analysis. The wide range of vertical stratification and grading sequences present in these event beds also allows construction of conceptual models of deposition from turbidity currents (i.e. surge‐type turbidity currents and hyperpycnal flows) and storm surges, and shows that there are significant interactions and linkages of these often paired processes.     

Architecture of a forced regressive systems tract in the Turonian Ferron “Notom Delta”, southern Utah, U.S.A.

The large-scale stratigraphic architecture of forced regressive deposits has been documented in many previous studies. Bed-scale facies architectural analyses of these deposits, however, are still very limited. The Cretaceous Ferron “Notom Delta” in southern Utah, U.S.A. contains a 20 km dip-oriented exposure of a stepped, forced regressive systems tract. The main focus of this paper is to reconstruct the paleogeography and depositional history of the systems tract based on detailed stratigraphic and facies architectural analysis using 23 geological sections, photomosaics, and walking out of beds.Internally, the systems tract consists of 6 parasequences, 11f to 11a from the oldest to the youngest. During the progradation of parasequences 11f to 11b the paleoshorelines were wave-dominated, as indicated by the abundance of HCS and/or SCS beds, wave-ripple cross-laminated beds, and the occurrence of diverse and robust ichnological suites attributable to the Skolithos and Cruziana Ichnofacies. Progradation of the wave-dominated shorelines resulted in more homogeneous and laterally continuous sand bodies. From 11b to 11a, however, there is a distinct change in paleoshoreline regime from wave-dominated to tide-influenced as indicated by the common occurrence of tidal facies in 11a, including: (1) lenticular, wavy, and flaser bedding and bidirectional dipping cross strata; (2) reactivation surfaces, double-mud drapes, and ripple cross lamination with opposing dips at the toe of large dune-scale cross sets; (3) inclined heterolithic strata (IHS) and sigmoidal bedding with tidal rhythmites; and (4) cyclic vertical variation in facies and bed thickness and the common occurrence of sand-mud couplets. These tide-influenced facies show overall lower bioturbation intensity (BI 0-3). Progradation of the tide-influenced shoreline results in more heterolithic delta-front facies. Tidal and/or tidal-fluvial channels further dissect delta-front sandstones, forming more isolated sand bodies.Data from this study, as well as previous work, show that width and thickness of the forced regressive parasequences are small, typically less than 5 km and 20 m respectively. In subsurface studies, identifying and correlating such small-scale parasequences using sparse data involve significant uncertainties. A combination of the diagnostic features indicating forced regression and different data sets is essential to better constrain the geometry and architecture these small-scale bodies.     

Anatomy of falling‐stage deltas in the Turonian Ferron Sandstone of the western Henry Mountains Syncline,Utah: Growth faults,slope failures and mass transport complexes

Falling‐stage deltas are predicted by sequence stratigraphic models, yet few reliable criteria are available to diagnose falling‐stage deltaic systems in surface exposures. Recent work on the Upper Cretaceous (Turonian) Ferron Sandstone in the western Henry Mountains Syncline of south‐central Utah has established its environment of deposition as a series of modest‐sized (5 to 20 km wide), probably asymmetrical, mixed‐influence deltas (‘Ferron Notom Delta’) that dispersed sediment eastwards from the rising Sevier orogenic hinterland into the Western Cordilleran Foreland Basin. Analysis of sandstone body stacking patterns in a 67 km long, depositional strike‐parallel (north–south) transect indicates that the growth of successive deltas was strongly forced by synsedimentary growth of a long wavelength (ca 100 km), 50 m amplitude fold structure. Herein, two discrete areas within this transect, superbly exposed in three dimensions, are documented in order to determine the details of stratal stacking patterns in the depositional dip direction, and thereby to assess the stratigraphic context of the Ferron Notom Delta. In the two study areas, dip transects expose facies representing river mouth bar to distal delta front environments over distances of 2 to 4 km. Key stratal packages are clinothems that offlap, downlap, and describe descending regressive trajectories with respective to basal and top datums; they are interpreted as the product of relative sea‐level fall. The vertical extent of clinoforms suggests that deltas prograded into <30 m of water. Furthermore, these deltaic successions preserve abundant evidence of delta front slope failure, growth faulting, and incision and filling of deep (<15 m) slope gullies. Gully fills are composed of chaotic intraformational breccia and/or massive sandstone, and constitute linear, ‘shoestring’ sandbodies in the distal portions of individual palaeodelta systems. They are interpreted to have been cut and filled during the late falling‐stage and lowstand of relative sea‐level cycles. The north–south distribution of the stratal style described above seems to be focused on the flanks of the growth anticline, and so the numerous falling‐stage systems tracts preserved within the Ferron Notom Delta probably owe their origin to synsedimentary structural growth, and the unstable fluid pressure regime that this growth imposed on the sea floor and shallow subsurface.     

Facies architecture of asymmetrical branching distributary channels: Cretaceous Ferron Sandstone,Utah, USA

Distributary channel systems are an important component of deltaic systems, but details of their branching pattern, stream‐order, internal variability and relation with adjacent levée, bay and bayhead delta are rather poorly documented in ancient examples. Photomosaic and measured sections collected along a gooseneck‐shaped canyon in southern Utah allow direct mapping of the branching pattern of an ancient distributary system. The main channel belt is ca 250 m wide and narrows to ca 200 m downstream of the branching point. A subordinate channel belt, ca 80 m wide, branches off of the main channel, forming a distinctly asymmetrical branching pattern. Water discharge in the main channel is estimated to be 85 to 170 m³ sec^?1. Comparison with palaeodischarge estimates of trunk rivers mapped in previous studies suggests that the branching documented in this study probably is a fourth‐order split. The distributary channels are characterized by a U‐shaped geometry filled with medium‐grained, cross‐bedded sandstone, and are dominated by lateral accretion, suggesting limited lateral migration and moderate sinuosity. Tidally influenced facies and limited trace fossils indicate direct marine influence. The distributary channels erode into adjacent levée and underlying heterolithic bay‐fill deposits, and the marine influence suggests that they were deposited on a lower delta plain, rather than on a non‐marine floodplain. The subordinate channel fed a bayhead delta, suggesting that it was formed by a partial avulsion, rather than bifurcation around a mouth bar, as is more characteristic of terminal distributary channels. Channel‐floor drapes, bar‐accretion drapes and abandoned channel fills within the sandstone channel belts represent the most important heterogeneity from the perspective of reservoir characterization.     

Evaluating delta asymmetry using three‐dimensional facies architecture and ichnological analysis,Ferron ‘Notom Delta’, Capital Reef,Utah, USA

Delta asymmetry occurs where there is strong wave influence and net longshore transport. Differences in the morphology and facies architecture between updrift and downdrift sides of asymmetric deltas are potentially significant for exploration and exploitation of resources in this class of reservoirs. Although delta asymmetry has been recognized widely from modern wave‐influenced deltaic shorelines, there are few documented examples in the ancient record. Based on an integrated sedimentological and ichnological study, the along‐strike variability and delta asymmetry within a single parasequence (Ps 6) is documented in continuously exposed outcrops of the Cretaceous Ferron Sandstone Member of the Mancos Shale Formation near Hanksville in southern Utah. Two intra‐parasequence discontinuity surfaces are recognized which allow subdivision of the parasequence into three bedsets, marked as Ps 6‐1 to Ps 6‐3. Four facies successions are recognized: (i) wave/storm‐dominated shoreface; (ii) river‐dominated delta front; (iii) wave/storm‐reworked delta front; and (iv) distributary channel and mouth bar. Dips of cross‐strata within distributary‐mouth bars and shorefaces show a strong downdrift (southward) component. Ps 6‐3 predominantly consists of river‐dominated delta‐front deposits, whereas Ps 6‐1 and Ps 6‐2 show an along‐strike facies change with shoreface deposits in the north, passing into heterolithic, river‐dominated delta‐front successions south to south‐eastward, and wave/storm‐reworked delta‐front deposits further to the south‐east. Trace fossil suites correspondingly show distinct along‐strike changes from robust and diverse expressions of the archetypal Cruziana Ichnofacies and Skolithos Ichnofacies, into suites characterized by horizontal, morphologically simple, facies‐crossing ichnogenera, reflecting a more stressed, river‐dominated environment. Further south‐eastward, trace fossil abundance and diversity increase, reflecting a return to archetypal ichnofacies. The overall facies integrated with palaeocurrent data indicate delta asymmetry. The asymmetric delta consists of sandier shoreface deposits on the updrift side and mixed riverine and wave/storm‐reworked deposits on the downdrift side, similar to that observed in the modern examples. However, in contrast to the recent delta asymmetry models, significant paralic, lagoonal and bay‐fill facies are not documented in the downdrift regions of the asymmetric delta. This observation is attributed to a negative palaeoshoreline trajectory during delta progradation and subsequent transgressive erosion. The asymmetric delta was induced by net longshore transport from north to south. The forced regressive nature of the delta precludes significant preservation of topset mud.     

Charakterisierung von Al(III)-Spezies in basischen Aluminiumchlorid-Flockungsmitteln mittels Ferronreaktion bzw. 27Al-Kernresonanzspektroskopie Characterization of Al(III) Species in Basic Aluminium Chloride Flocculants by Means of Ferron Method and 27 Al Nuclear Magnetic Resonance

Flocculant processes as a treatment step in water and wastewater purification technology are of increasing importance. Partially neutralized aqueous aluminium chloride solutions — the basic aluminium chlorides — are often used as flocculants in water conditioning. The present paper describes the reactions which appear in these solutions by their dilution, the identification of occurring cationic aluminium species, and the relations between the composition of the solutions and their efficiency as flocculants. The solutions were quantitatively analyzed using ²⁷Al NMR and the ferron method; the latter method offers a simple and inexpensive alternative for identification and quantification of aluminium cations and can facilitate investigations of the Al speciation at concentrations too low for analysis by NMR. The distribution of aluminium cations in basic aluminium chloride solutions changes drastically by the dilution while applied as flocculants because the equilibrium strongly depends on the concentration. The dynamic changes following the dilution of partially neutralized solutions were investigated simply by mixing a solution with water and immediate analysis by the ferron method. It could be shown that rearrangement reactions occur in the system, partially overlapping each other, the oligomeric cations seem to be especially instable. Furthermore, a partial change from octahedral to tetrahedral coordination of the aluminium in the species can be observed. At extremely low aluminium concentration as in the case of application of the basic aluminium chloride solutions for flocculation, monomeric and especially transition polymeric and polymeric aluminium cations, respectively, appear. The ratio of these cations to each other also depends on the time up to the flocculation. Accordingly, these cations especially the different polymeric aluminium species seem to be important for the efficiency of the basic aluminium chlorides as flocculants in water conditioning.     

The Chemical Species Distribution of Aluminum in Composite Flocculants Prepared from Polyaluminum Chloride (PAC) and Polydimethyldiallylammonium Chloride (PDMDAAC)

In order to improve the coagulation/flocculation efficiency of polyaluminum chloride (PAC), a composite flocculant of PAC and polydimethyldiallylammonium chloride (PDMDAAC), or PAC‐PDMDAAC, was prepared. The chemical species distribution of aluminum in PAC and PAC‐PDMDAAC, which has a close relationship with their coagulation/flocculation performance, was investigated by Al‐Ferron complexation timed spectrophotometry and ²⁷Al‐NMR. The factors affecting the chemical species of aluminum in PAC‐PDMDAAC, such as the weight concentration of PDMDAAC (Wp), basicity (B) of PAC, and viscosity (η) of PDMDAAC, were studied. The flocculation efficiencies of PAC‐PDMDAAC, PAC and PDMDAAC were studied on a six‐spindle multiple stirrer unit. The results showed that the aluminum species distribution in PAC‐PDMDAAC depends on the Wp, B and η value. When the B value is 1.5 and η value is 1.22 dL/g, the composite flocculant with Wp = 15 % gives highest Al_b and Al₁₃ contents, and its flocculation efficiency is highest in the test flocculations.