The carbon isotopic composition of CO2 inclusions trapped in minerals reflects the origin and evolution of CO2-bearing fluids and melts, and records the multiple-stages carbon geodynamic cycle, as CO2 took part in various geological processes widely. However, the practical method for determination isotope composition of individual CO2 inclusion is still lacking. Developing a microanalytical technique with spatial resolution in micrometers to precisely determinate the δ13C value of individual CO2 inclusion, will make it possible to analyze a tiny portion of a zoning mineral crystal, distinguish the differences in micro-scale, and possible to find many useful information that could not be obtained with the bulk extraction and analysis techniques. In this study, we systematically collected Raman spectra of CO2 standards with different δ13C values (?34.9 ‰ to 3.58 ‰) at 32.0 °C and from ~7.0 MPa to 120.0 MPa, and developed a new procedure to precisely determinate the δ13C value of individual CO2 inclusion. We investigated the relationship among the Raman peak intensity ratio, δ13C value, and CO2 density, and established a calibration model with high accuracy (0.5 ‰?1.5 ‰), sufficient for geological application to distinguish different source of CO2 with varying δ13CO2. As a demonstration, we measured the δ13C values and the density of CO2 inclusions in the growth zones of alkali basalt-hosted corundum megacrysts from Changle, Shandong Province. We found the significant differences of density and δ13C between the CO2 inclusions in the core of corundum and those inclusions in the outer growth zones, the δ13C value decreases from core to rim with decreasing density: δ13C values are from ?7.5 ‰ to ?9.2 ‰ for the inclusions in the core, indicating the corundum core was crystallized from mantle-derived magmas; from ?13.5 ‰ to ?18.5 ‰ for CO2 inclusions in zone 1 and from ?16.5 ‰ to –22.0 ‰ for inclusions in zone 2, indicating the outer zones of corundum grew in a low δ13C value environment, resulted from an infilling of low δ13C value fluid and/or degassing of the ascending basaltic magma. 相似文献
A large amount of deep oil has been discovered in the Tazhong Uplift, Tarim Basin whereas the oil source is still controversial. An integrated geochemical approach was utilized to unravel the characteristics, origin and alteration of the deep oils. This study showed that the Lower Cambrian oil from well ZS1C (1x) was featured by small or trace amounts of biomarkers, unusually high concentration of dibenzothiophenes (DBTs), high δ34S of DBTs and high δ13C value of n-alkanes. These suggest a close genetic relationship with the Cambrian source rocks and TSR alteration. On the contrary, the Middle Cambrian oils from well ZS1 (2a) were characterized by low δ13C of n-alkanes and relatively high δ34S of individual sulfur compounds and a general “V” shape of steranes, indicating a good genetic affinity with the Middle–Upper Ordovician source rocks. The middle Cambrian salt rock separating the oils was suggested to be one of the factors responsible for the differentiation. It was suggested that most of the deep oils in the Tazhong Uplift were mixed source based on biomarkers and carbon isotope, which contain TSR altered oil in varied degree. The percentage of the oils contributed by the Cambrian–Lower Ordovician was in the range of 19–100% (average 57%) controlled by several geological and geochemical events. Significant variations in the δ34S values for individual compounds in the oils were observed suggesting a combination of different extent of TSR and thermal maturation alterations. The unusually high DBTs concentrations in the Tazhong-4 oilfield suggested as a result of mixing with the ZS1C oil (1x) and Lower Ordovician oils based on δ34S values of DBT. This study will enhance our understanding of both deep and shallow oil sources in the Tazhong Uplift and clarify the formation mechanisms of the unusually high DBTs oils in the region. 相似文献
Abstract The objective of this paper is to show that the investments through the clean development mechanism (CDM) can exert a leverage effect to (i) make attractive to developing countries non-binding commitments and the adoption of national policies and measures; this comes as a guarantee of non-conditionally of the mechanism to strictly environmental concerns and (ii) create a flow of additional investments and technological transfer from Annex B countries to non-Annex B countries. The Indian power sector has been chosen as an example of a sector where institutional barriers, market imperfections, and tariff distortions create a great space for Pareto improvements and leave an important potential for no-regret measures: technological transfer, air conditioned systems, transport infrastructures and removal of subsidies on consumption. This paper presents a micro-economic formalisation on (i) the evolution of profitability of current emitting technologies used in the power sector under the adoption of national policies and measures and (ii) the impact on renewable energy technologies competitiveness of emission credits in the context of CDM. This formalisation has been developed to enable quantitative simulation. A first exercise using the Markal model (used in 77 countries) on the electric sector in India enabled us to simulate the leverage effect of emission credits on additional incomes taken as a proxy for development. 相似文献
The Free-Wilson paradigm is an established and powerful tool for quantitatively relating activity withchemical structure.Current implementations of the paradigm,however,are flawed both conceptually andin execution.As part of an attempt to more fully realize the promise of the paradigm,it was necessaryto examine these limitations in detail.This report introduces a robust,theory-founded Free-Wilson implementation:stepwise principalcomponents regression analysis(SPCRA).SPCRA is computationally superior to previousimplementations but does not in itself correct their conceptual flaws.The development of SPCRA did,however,facilitate derivation of a simple and chemically significantinterpretation of the Free-Wilson structure-activity model.A number of statistical aspects of this modelcommonly misused in previous applications are discussed at length.These discussions provide criticalbackground for the development of an alternative implementation of the Free-Wilson paradigm. 相似文献