鄂尔多斯盆地东南部延长组长7段陆相页岩气地质特征及勘探潜力评价

提要：鄂尔多斯盆地为大型富含油气盆地,发育本溪组、山西组、延长组长7段、长9段等多套页岩层系,具备页岩气形成的基本地质条件。为查明鄂尔多斯盆地东南部延长组长7段页岩气的勘探潜力,本文利用有机地球化学和岩石学分析、含气量测试、等温吸附曲线测定等多种手段,分析了延长组长7段页岩的基本地质、地化及含气性特征。在此基础上,对长7段页岩气勘探潜力进行了初步评价。结果表明,长7段陆相页岩埋深和厚度适中、有机质类型以Ⅰ、Ⅱ型为主,有机质丰度和脆性矿物含量高,含气量可达1.25~6.45 ml/g。与北美地区典型页岩相比,研究区长7段页岩有机质类型、有机碳含量类似,粘土矿物含量和长石含量偏高,碳酸盐和石英含量偏少,有机质成熟度偏低。研究区内延长组长7段页岩气资源勘探潜力巨大,资源量为1 528.409亿m3,可作为常规油气勘探的重要补充,志丹—甘泉一线西南部为页岩气勘探的有利目标。     

鄂尔多斯盆地陇东地区延长组长7段沉积微相及沉积演化特征

利用大量的岩芯、露头剖面观察和测井资料,在总结分析重力流沉积理论的基础上,系统研究了鄂尔多斯盆地陇东地区延长组长7段重力流沉积特征及沉积模式。研究认为陇东长7段主要发育砂质碎屑流和浊流沉积,局部发育滑动、滑塌岩;受多物源、湖盆底形、湖岸线迁移等因素的影响,研究区沉积砂体并未呈现出明显的扇形,受西南陡窄斜坡控制的泾川—华池一带砂体呈条带状分布,发育水道型重力流沉积,沉积微相可分为限制型水道、非限制型水道、侧翼溢漫、水道间、前缘朵体和深湖泥6种,在湖盆底庆城—华池一带多期水道交汇叠置,形成了大面积的连片砂体;受南部物源控制的宁县—合水地区,由于斜坡坡度相对较缓、物源供给充足,形成了以滑塌为主的斜坡沉积模式,根据滑动的距离可分为近源沉积和远源沉积2个亚相,沉积微相可分不规则滑塌体、砂质碎屑流舌状体、朵叶状浊流岩和深湖泥4种,研究区南部主要以砂质碎屑流舌状体为主,在斜坡处多期舌状体纵横叠置,形成了多期薄、厚砂体互层的连片砂体。通过对陇东长7段沉积模式的建立和沉积微相的识别与划分,为研究区砂体展布的精细刻画提供了重要指导,也为该区致密油水平井规模建产提供了依据。     

What happens after climate change adaptation projects end: A community-based approach to ex-post assessment of adaptation projects

Over the last decade, hundreds of climate change adaptation projects have been funded and implemented. Despite the importance of these first-generation adaptation projects for establishing funders and implementors’ “best practices,” very little is known about how early adaptation projects have endured, to what ends, and for whom. In this article, I propose a community-based methodology for ex-post assessment of climate change adaptation projects. This methodology contributes to recognitional justice by asking the individuals and collectives tasked with sustaining adaptation initiatives to define adaptation success and what criteria for success should be assessed. I apply this subjective assessment approach in 10 communities across Ecuador that participated in an internationally funded adaptation project that concluded in 2015. My analysis draws together participatory mapping, walking interviews with local leaders, participant observation, and surveys with former project participants. The results highlight that even adaptation projects that were deemed highly successful at their closure have uncertain futures. I find that the sustainability mechanisms that were envisioned by project implementors have not functioned, and communities are shouldering the burden of reviving failing adaptation interventions. These findings highlight that the current model of episodic funding for climate change adaptation projects and evaluation processes needs to be revisited to acknowledge the long-term challenges faced by communities. This analysis also calls attention to the importance of ex-post assessment for adaptation projects and the potential of subjective assessment approaches for building more ontological and epistemological pluralism in understandings of successful climate change adaptation.     

San Quirce (Palencia,Spain): new chronologies for the Lower to Middle Palaeolithic transition of south-west Europe

San Quirce is an open-air archaeological site situated on a fluvial terrace in the Duero basin (Palencia, northern Iberia). This paper presents new and consistent chronologies obtained for the sedimentary sequence using post-infrared infrared stimulated luminescence (pIR-IR) dating of K-feldspars and single-grain thermally transferred optically stimulated luminescence (TT-OSL) dating of quartz. The new dating results indicate that the sequence is older than ~200 000 years and place San Quirce Level III within marine isotope stages (MIS) 8 and 7, between 274
77; 13 ka and 238
77; 13 ka. The main lithic assemblage at San Quirce comes from Level III. The predominant tool types found in this level are hammerstones, manuports and flakes, with a small proportion of cores and a significant presence of denticulates. Adaptation to local environmental conditions resulted in distinctive cultural habits, which were embedded in the cultural tradition of hominins occupying the site during the final third of the Middle Pleistocene. San Quirce preserves a simple cultural tradition that was employed by local hominins to engage in a diverse array of activities, and highlights the cultural diversity that appears to have been a characteristic feature of the Lower to Middle Palaeolithic transition 300–200 ka.     

IPCC emission scenarios: How did critiques affect their quality and relevance 1990–2022?

Long-term global emission scenarios enable the analysis of future climate change, impacts, and response strategies by providing insight into possible future developments and linking these different climate research elements. Such scenarios play a crucial role in the climate change literature informing the Intergovernmental Panel on Climate Change’s (IPCC) Assessment Reports (ARs) and support policymakers. This article reviews the evolution of emission scenarios, since 1990, by focusing on scenario critiques and responses as published in the literature. We focus on the issues raised in the critiques and the possible impact on scenario development. The critique (280) focuses on four areas: 1) key scenario assumptions (40%), 2) the emissions range covered by the scenarios and missing scenarios (25%), 3) methodological issues (24%), and 4) the policy relevance and handling of uncertainty (11%). Scenario critiques have become increasingly influential since 2000. Some areas of critique have decreased or become less prominent (probability, development process, convergence assumptions, and economic metrics). Other areas have become more dominant over time (e.g., policy relevance & implications of scenarios, transparency, Negative Emissions Technologies (NETs) assumptions, missing scenarios). Several changes have been made in developing scenarios and their content that respond to the critique.     

Paleo- and Mesoarchean TTG-sanukitoid to high-K granite cycles in the southern São Francisco craton,SE Brazil

The generation of the continental crust is widely accepted to have taken place predominantly in the Archean, when TTG magmatism associated with greenstone-belt supracrustal succession development was typically followed by emplacement of high-K granites before crustal stabilization. This study focuses on the Campos Gerais complex (CGC), which is an Archean granite-greenstone belt lithological association in a tectonic window located in the southwesternmost portion of the S7;o Francisco craton (SFC). The CGC is an important segment of Paleo- to Mesoarchean continental crust to be integrated into paleogeographic reconstructions prior to the transition into the Paleoproterozoic. This investigation reports field relationships, 28 major and trace element compositions, U–Pb (zircon) geochronological results, and Hf and Sm–Nd isotope data for orthogneiss and amphibolite samples. The results indicate that the CGC records a complex Archean crustal evolution, where voluminous 2.97 Ga TTG tonalites and trondhjemites (ε_Nd(t) =  ? 4.7; T_DM = 3.24 Ga) were followed by 2.89 Ga sanukitoid tonalite production (ε_Nd(t) =  ? 1.9; T_DM = 3.02 Ga), broadly coeval with the development of the Fortaleza de Minas and Pitangui greenstone-belts. These events are interpreted to represent the initial stage of an important subduction-accretion tectonic cycle, which ended with the emplacement of 2.82–2.81 Ga high-K leucogranites and migmatization of the TTG-sanukitoid crust, with hybrid and two-mica, peraluminous compositions (ε_Nd(t) =  ? 8.0 to ? 8.6; T_DM = 3.57 – 3.34 Ga). The presence of inherited zircons with ²⁰⁷Pb/²⁰⁶Pb ages of 3.08 Ga, 3.29 Ga, 3.55 Ga and 3.62 Ga indicates that the Mesoarchean tectonic processes involved reworking of Meso- to Eo-archean crust. Renewed TTG magmatism took place at ca. 2.77 Ga represented by juvenile tonalite stocks (ε_Nd(t) = +1.0 to ? 1.5; T_DM = 2.80 – 2.88 Ga) which intrude the TTG-greenstone belt association. Crustal stabilization was attained by 2.67 Ga, allowing for the emplacement of within-plate tholeiitic amphibolites (ε_Nd(t) =  ? 3.1; T_DM = 2.87 Ga). The CGC shows important tectonic diachronism with respect to other Archean terrains in the southern S7;o Francisco craton, including an independent Meso- to Neoarchean crustal evolution.     

Exposure to extreme climate decreases self-rated health score: Large-scale survey evidence from China

High temperature is a growing threat and impacts public health through different exposure mechanisms. Our study constructs a comprehensive exposure measurement based on temperature variability, duration, and effective influence range. We investigate human responses to high temperatures through self-rated health scores based on individual-level data from China Labor-force Dynamic Survey (CLDS). Results show that higher temperature and temperature variability significantly decrease self-rated health scores. Subjective health risk is most significantly related to the cumulative temperature in the previous two weeks. We also find that the exposure effects at night and on weekdays are more severe. Workers who experience greater exposure from commuting and work environments are negatively impacted by high temperatures. In addition, men, the elderly, middle and low education groups, rural residents are more likely to be impacted by high temperatures.