Sedimentary lithofacies, petrography and diagenesis of the Kapuni group in the Kapuni Field, Taranaki Basin, New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science with Honours in Earth Science at Massey University, Palmerston North, New Zealand

The reservoir architecture and quality of the Kapuni Group sandstones in seven wells (Kapuni−1, −3, −8, −12, Deep−1, 14 and −15) in the Kapuni Field are characterised using available core and digital geophysical log data. The study focused primarily on the Eocene Mangahewa Formation, but where limited core permits the older Kaimiro and Farewell formations are also examined. Eleven lithofacies in the Kapuni Group, identified and defined in core on the basis of colour, lithology, bedding, texture and sedimentary structures, are interpreted to represent tidal sand bar, tidal-inlet channel, fluvial-tidal channel, spit platform, sand flat, shallow marine, tidal channel, meandering tidal channel, mud flat, swamp and marsh environments. Correlation of core lithofacies with geophysical log motifs enabled lithofacies identification where core data are not available. Log motifs representing each of the lithofacies were then extrapolated to uncored sections of the Mangahewa Formation in the Kapuni Field wells. Interpretation of lithofacies in core and geophysical log motifs indicate that the Mangahewa Formation was deposited in an estuarine setting. During initial deposition of the Mangahewa Formation tide-dominated estuarine lithofacies were deposited. A major coal horizon, the K20 coal, in the field represents a period of maximum infilling. Above this coal core and log data indicate a wave-dominated estuary exhibiting a clearly- defined, "tripartite" (coarse-fine-coarse) distribution of lithofacies. Provenance studies suggest that low-grade metamorphic and granitic rocks are the dominant source for the Kapuni Group sandstones. Minor input from sedimentary and acid volcanic source rocks are also identified. A volcanic source, however, is more important in sandstones from the Farewell Formation, than in the younger Kapuni Group formations. Probable sources include the low-grade metamorphic rocks of Lower Cambrian to Permian age, Permian to Carboniferous Karamea Granite, Triassic and Jurassic greywacke-argillite sediments. Upper Cretaceous Pakawau Group sediments and Pre Cambrian to Upper Cretaceous acid volcanics. Reservoir quality variations in the Kapuni Group sandstones are directly related to environmental and diagenetic processes that have controlled porosity reduction and enhancement. Porosity has been reduced mainly by mechanical and chemical compaction, clay formation (predominantly kaolinite and illite in the Mangahewa and Kaimiro formations and smectite in the Farewell Formation), carbonate precipitation (primarily siderite and calcite), quartz and feldspar overgrowths and pyrite precipitation. While, porosity has been enhanced primarily by carbonate dissolution and subordinately by grain and clay dissolution and minor grain fracturing. The Mangahewa Formation sandstone lithofacies of tidal sand bar and tidal channel environments exhibit the best reservoir characteristics. Future reservoir development in the Kapuni Field and exploration in the Kapuni Field should focus on identifying and exploiting these lithofacies

Partial mirror symmetry, lattice presentations and algebraic monoids

This is the second in a series of papers that develops the theory of reflection monoids, motivated by the theory of reflection groups. Reflection monoids were first introduced in arXiv:0812.2789. In this paper we study their presentations as abstract monoids. Along the way we also find general presentations for certain join-semilattices (as monoids under join) which we interpret for two special classes of examples: the face lattices of convex polytopes and the geometric lattices, particularly the intersection lattices of hyperplane arrangements. Another spin-off is a general presentation for the Renner monoid of an algebraic monoid, which we illustrate in the special case of the "classical" algebraic monoids.Comment: 41 page

Growth accounting with misallocation: Or, doing less with more in Singapore

We derive aggregate growth-accounting implications for a two-sector economy with heterogeneous capital subsidies and monopoly power. In this economy, measures of total factor productivity (TFP) growth in terms of quantities (the primal) and real factor prices (the dual) can diverge from each other as well as from true technology growth. These distortions potentially give rise to dynamic reallocation effects that imply that change in technology needs to be measured from the bottom up rather than the top down. We show an example, for Singapore, of how incomplete data can be used to obtain estimates of aggregate and sectoral technology growth as well as reallocation effects. We also apply our framework to reconcile divergent TFP estimates in Singapore and to resolve other empirical puzzles regarding Asian development.Industrial productivity ; Productivity ; Technology ; Singapore

Measuring productivity growth in Asia: do market imperfections matter?

Recent research reports contradictory estimates of productivity growth for the newly industrialized economies (NIEs) of Asia. In particular, estimates using real factor prices find relatively rapid TFP growth; estimates using quantities of inputs and output find relatively low TFP growth. The difference is particularly notable for Singapore, where the difference is about 2-1/4 percentage-points per year. We show that about 2/3 of that difference reflects differences in estimated capital payments. We argue that these differences reflect economically interesting imperfections in output and capital markets, including sizeable economic profits in Singapore and government-directed credit. We derive a measure of technology growth, corrected for the imperfections that we quantify.Asia ; Economic conditions ; Productivity

Measuring the miracle: market imperfections and Asia's growth experience

The newly industrialized economies (NIEs) of Asia are the fastest-growing economies in the world since 1960. A clear understanding of their rapid development remains elusive, with continuing disputes over the roles of technology growth, capital accumulation, and international trade and investment. We reconcile seemingly contradictory explanations by accounting for imperfections in output and capital markets. For instance, in Singapore, growth-accounting studies using quantities (the primal approach) find rising capital-output ratios and a constant labor share; but studies using real factor prices (the dual approach) find a constant user cost. We provide evidence that "favored" firms reaped economic profits and received preferential tax treatment, subsidies, and access to capital-- market imperfections that are difficult to capture when implementing the dual approach. Further, declining pure profits can reconcile the constant or rising labor shares in revenue in the NIEs with theories of international trade that predict falling labor shares in cost. We provide empirical support for the quantitative importance of profits and heterogeneous user costs, describe the two-sector dynamics, and derive measures of technology growth, corrected for the imperfections that we quantify. We then discuss implications for broader disputes about Asian development.Asia ; Economic conditions ; Productivity

Identification of Expected Outcomes in a Data Error Mixing Model with Multiplicative Mean Independence

We consider the problem of identifying a mean outcome in corrupt sampling where the observed outcome is a mixture of the distribution of interest and some other distribution. We make two contributions to this literature. First, the statistical independence assumption maintained under contaminated sampling is relaxed to the weaker assumption that the outcome is mean independent of the mixing process. We then generalize this restriction to allow the two conditional means to differ by a known or bounded factor of proportionality. Second, in the special case of a binary outcome, we consider the possibility that draws from the alternative distribution are known to be erroneous, as might be the case in a mixture model of response error. We illustrate how these assumptions can be used to inform researchers about the population's use of illicit drugs in the presence of nonrandom reporting errors. In this application, we find that a response error model with multiplicative mean independence is easy to motivate and can have substantial identifying power.

Disability and Employment: Reevaluating the Evidence in Light of Reporting Errors

Measurement error in health and disability status has been widely accepted as a central problem for social science research. Long-standing debates about the prevalence of disability, the role of health in labor market outcomes, and the influence of federal disability policy on declining employment rates have all emphasized issues regarding the reliability of self-reported disability. In addition to random error, inaccuracy in survey datasets may be produced by a host of economic, social, and psychological factors that can lead respondents to misreport work capacity. We develop a nonparametric foundation for assessing how assumptions on the reporting error process affect inferences on the employment gap between the disabled and nondisabled. Rather than imposing the strong assumptions required to obtain point identification, we derive sets of bounds that formalize the identifying power of primitive nonparametric assumptions that appear to share broad consensus in the literature. Within this framework, we introduce a finite-sample correction for the analog estimator of the monotone instrumental variable (MIV) bound. Our empirical results suggest that conclusions derived from conventional latent variable reporting error models may be driven largely by ad hoc distributional and functional form restrictions. Under relatively weak nonparametric assumptions, nonworkers appear to systematically overreport disability.

Inferring Disability Status from Corrupt Data

In light of widespread concerns about the reliability of self-reported disability, we investigate what can be learned about the prevalence of work disability under various assumptions on the reporting error process. Developing a nonparametric bounding framework, we provide tight inferences under our strongest assumptions but then find that identification deteriorates rapidly as the assumptions are relaxed. For example, we find that inferences are highly sensitive to how one models potential inconsistencies between subjective self-assessments of work limitation and more objective measures of functional limitation. These two indicators appear to measure markedly different aspects of health status.