Variation in Pore Space and Structure of Organic-rich Oil-prone Shales from a Non-marine Basin: Constraints from Organic Matter and Minerals

Organic matter (OM) and minerals are major particle components of lacustrine shales. The influence of OM and minerals on pore space and structure in organic-rich oil-prone shales containing a large range of total organic carbon (TOC) contents is poorly understood. In this study, we investigated the variation in pore space and structure of low mature lacustrine shales in the Songliao Basin (NE China), based on a study of the mineralogy, petrography, geochemistry, and geophysical properties of shales. Different pore types make markedly different contributions to the mineral surface area (MSA) and pore volume (PV) of the shales. There exists a negative correlation between MSA/PV and TOC in mesopores (r2 = 0.75/0.65) and macropores (r2 = 0.74/0.68), and a positive correlation in micropores (r2 = 0.59/0.64), which are associated with the variation of mineral and TOC contents. A positive relationship between the throat/pore ratio and TOC (r2 = 0.82) shows an increase in throat radius and decrease in pore radius with increasing TOC content. This relationship is supported by the reduction in mean pore diameter (MPD) for large pores and increase in MPD for small pores. These variations are related to the decreased pores by quartz plus feldspar (Q + F) content, increased throats by clay minerals, and enhanced pore-fill by OM. We propose that the variation of OM and minerals is a key control on the pore space and structure of low mature organic-rich oil-prone shales.     

Issues at the fore in the land of Magnuson and Stevens: A summary of the 14th Bevan Series on Sustainable Fisheries

The Magnuson–Stevens Act is the United States׳ premier law governing fisheries conservation and management. Congress has revisited the Act multiple times since its inception in 1976—most recently in 1996 with the Sustainable Fisheries Act and in 2006 with the Magnuson Stevens Act—and is currently in the process of reauthorizing the Act. The University of Washington focused the 14th annual Bevan Series on Sustainable Fisheries on issues surrounding reauthorization. The symposium featured a diversity of stakeholders, including fisheries scientists, managers, policy analysts, students, non-governmental organizations, Tribes, and industry. The symposium explored the Act׳s history, means of ending overfishing and ensuring accountability, lessons from U.S. West Coast and North Pacific fisheries, and challenges and solutions to ecosystem-based fisheries management.     

Human dignity: A fundamental guiding value for a human rights approach to fisheries?

Recently, a human rights approach has been center-staged within fisheries governance as a response to the limits of private property rights in reducing insecurity and vulnerability among fishers and fishing communities. Despite its growing adoption in international legal frameworks and among civil society organizations, the conceptual pitfalls of the human rights approach to fisheries (i.e., its neoliberal tendencies and the neglect of collective rights and social duties) raised by critical scholarship remain largely unsettled, leading to practical concerns about whether such a framework will ultimately benefit fishers on the ground. To further contribute to the debate, this article presents a nuanced discussion of the human rights perspective by introducing the concept of human dignity. Specifically, it argues that human dignity, with its greater conceptual scope and depth, could act as a foundational value with which to mitigate some of the shortcomings of the human rights approach. The purpose here is suggestive rather than definitive and is aimed at highlighting the link that has not been clearly made between human rights and human dignity. I argue that heightened attention to human dignity has the potential to create wider support for the human rights approach and ultimately help facilitate its efficacy in fisheries.     

Into the scrap iron business: Transaction costs for fleet sustainability in Norway

For decades the need to reduce surplus fishing capacity has been a fisheries political priority. While decommissioning schemes (buyback programs) usually is a publicly financed measure to reduce capacity, the Norwegian decommissioning scheme is privately financed. Whereas market-based transactions are assumed to lead to cost free adaptations, the Norwegian version reflects public policy aims which impose severe transaction costs on private actors. This article examines the use of market mechanisms for fleet capacity reduction, how private actors adapted to the new order, and the transfer of quota transaction costs from the public to the private sphere.     

A multi-channel approach for automatic microseismic event association using RANSAC-based Arrival Time Event Clustering (RATEC)

In the presence of background noise, arrival times picked from a surface microseismic data set usually include a number of false picks that can lead to uncertainty in location estimation. To eliminate false picks and improve the accuracy of location estimates, we develop an association algorithm termed RANSAC-based Arrival Time Event Clustering (RATEC) that clusters picked arrival times into event groups based on random sampling and fitting moveout curves that approximate hyperbolas. Arrival times far from the fitted hyperbolas are classified as false picks and removed from the data set prior to location estimation. Simulations of synthetic data for a 1-D linear array show that RATEC is robust under different noise conditions and generally applicable to various types of subsurface structures. By generalizing the underlying moveout model, RATEC is extended to the case of a 2-D surface monitoring array. The effectiveness of event location for the 2-D case is demonstrated using a data set collected by the 5200-element dense Long Beach array. The obtained results suggest that RATEC is effective in removing false picks and hence can be used for phase association before location estimates.     

The Digital Versatile Disc as a Learning Support Medium in the Teaching and Learning of Map Work

Abstract

This article describes the results of a study where the digital versatile disc (DVD) was used as a variant of Information and Communication Technology (ICT) in order to aid in the teaching and learning of map work in geography at secondary school level. A group of grade 10 learners of a previously disadvantaged school in South Africa comprised the target group for the project. A case study was conducted and data was gathered on the implementation of the DVD and the learners' perceptions thereof. Qualitative analysis techniques such as field notes, observation, interviews with the learners, and questionnaires were used to analyze the effectiveness of the implementation of the DVD as well as the learners' perceptions regarding the use of the DVD in geography education. The results of the study indicated that the geography learners demonstrated positive attitudes towards the implementation of the DVD as a learning support medium. To determine the contribution of the DVD project towards the achieved results of the learners in map work, both the experimental and control groups participated in a pre- and post-test at the beginning and conclusion of the project. Effect size was used to determine the significance of the differences between the two groups and indicates a strong practical significance regarding the contribution of the DVD project towards the achieved test results of the learners.     

浙江南部近海主要鱼类的时空生态位及种间联结性

基于2016年8月(夏季)、11月(秋季)、2017年3月(冬季)、5月(春季)浙江南部近海的鱼类调查数据,利用生态位宽度、生态位重叠、聚类分析、方差比率法、卡方检验、联结系数以及种对共同出现百分率对主要鱼类种间关系进行研究.结果表明:(1)调查共采集鱼类169种,主要鱼类共有26种;(2)在空间维度上,日本鲭(Sco...     

四川名山建山大邑砾岩沉积特征及地层时代

详细描述了四川名山建山大邑砾岩实测剖面,讨论了大邑砾岩的岩性组合特征及沉积环境。认为大邑砾岩主要为一套位于风化壳之上的河流-冲积扇沉积,自下而上由细变粗,属于物源区总体不断上升过程中的近源沉积。通过大邑砾岩中的孢粉组合,讨论了其地质时代。该剖面孢粉组合以水龙骨科孢子为主,年代地层归属于新近系上新统。     

东坪金矿矿石碲、金分布及其相关性

用原子吸收，原子荧光法分别系统测定矿石Au,Te含量表明，东坪金矿具有典型的Au-Te元素组合，Te/Au比值平均为0．71，且随矿石Au丰度的加富而增加，它们的相关系数增大，Au,Te含量对数值的统计分布和矿物组合，元素赋存状态的微束分析结果表明，Au,Te均以独立矿物为主要赋存状态，但Aud的矿化表现出多期次特征，而Te主要在硅化－硫化物阶段，二可能具有不同的母源，上述结论对提高金的回收率，碲的综合利用和事矿体的追索提供一定的依据。     

板桥凹陷沙三段沉积体系与物源分析

板桥凹陷位于黄骅坳陷中北部，沙三段是区内的主要生储油岩系。根据沉积环境、沉积特征及重矿物组合分布特征分析，板桥凹陷沙三段沉积期在湖盆的陡岸发育冲积扇-扇三角洲-深水浊积扇-深湖沉积体系以及近岸水下扇-深湖沉积体系，不同的物源区通过边界断层的运动控制着沉积体系的发育。在盆地的裂陷兴盛期，北部燕山褶皱带物源经过北唐凹陷和海河断层，于长芦一带形成扇三角洲，并进一步向板桥凹陷中央推进，形成板桥深水浊积扇沉积体；西北部的沧县隆起物源则沿着不同的入口，在沧东大断裂下降盘形成近岸水下扇和扇三角洲，它们也可进一步向凹陷深处推进而形成深水浊积体。应用沉积体系分布与油气聚集的规律，处于沉积体系的中间相带的扇三角洲和深水浊积扇，具有良好的油气生储组合，是断陷湖盆中有利的勘探目标。