于都 赣县矿集区科学钻探NLSD 1孔超声波成像 测井响应特征及其深部找矿意义

NLSD-1孔是南岭地区第一口科学钻探孔,也是目前我国金属矿区最深的科学钻探工程之一,终孔深度达到2967.83m。为了精细刻画矿集区深部结构框架、揭示深部矿化带分布特征和建立深部找矿地球物理解释标尺,提高对深部成矿规律的认识,该孔在钻进过程中实施了连续取芯,并且进行了多种地球物理测井和井中物探方法的测量。超声波成像测井是一种先进的测井技术,包含丰富的原位地质特征信息,在油气勘探中常用于井旁地质构造和地应力分析。本文将超声波成像测井应用于金属矿区科学钻探中,对NLSD-1孔采集到的超声波成像测井资料进行了研究,认为成像测井图像能够精细刻画孔壁裂缝、破碎带等地质特征,同样适合于金属矿勘查中的井旁构造解释;主要矿化层(409~429m、430~446m、621~641m、655~666m、679~691m、696~706m、744~759m、776~788m、907~921m、1031~1042m、1081~1090m、1430~1439m、1440~1448m等)均发育裂缝或破碎带,表明测井结果对矿化层埋深具有指示作用,并且揭示钻孔附近矿化层具有西浅东深的空间展布特征;根据裂缝产状的垂向变化,推断F1断层过NLSD-1孔深度范围为1375.32~1380.79m;此外,裂缝与孔斜关系的研究对钻孔纠斜具有指导意义。研究结果表明超声波成像测井在深部找矿中能够发挥重要作用。     

南岭地区多金属矿NLSD-2孔综合地球物理测井研究

NLSD-2孔是在南岭东段于都赣县矿集区盘古山示范区部署的南岭地区第二口科学钻孔———金属异常验证孔,终孔深度2012.12m,全井段实施了连续取芯和综合地球物理测井作业,测井项目包括自然电位、自然伽马、电阻率、声波速度、密度、井径、井斜、井温、超声波成像、极化率、磁化率和井中三分量磁测等,原位获取了钻孔剖面的各种物理化学参数、钻孔几何形态及井壁图像。综合利用各种测井资料,并结合岩芯编录资料,对全井段岩性、金属矿化带和断裂破碎带进行了细致分析。结果表明,自然伽马、声波速度和密度测井对该钻孔的岩性响应明显,通过制作岩性识别交会图,可识别出钻孔剖面的主要岩性;该钻孔的多金属矿化主要有白钨矿化、黑钨矿化、黄铁矿化、闪锌矿化、辉钼矿化等,在测井图中表现为高极化率、低电阻率、磁异常垂直分量ΔZ及水平分量模差ΔH’异常的组合特征,据此能够有效地划分和评价矿化带;断裂破碎带的测井响应特征为井径扩大,电阻率、声波速度、密度减小,超声成像呈暗色条带,这些特征可作为找矿辅助标志。实践证明综合测井资料在深部找矿方面能够发挥重要的作用。     

不确定性引导下的地形简化方法研究

提出一种不确定性引导下的地形简化方法。该方法利用地统计方法中特有的方差统计量对简化结果的不确定性进行量化评估,并以此作为优化目标进行地形简化操作。实验部分,从高程精度、地表基本形态以及骨架保留度三方面对新方法的有效性进行验证。结果表明:与传统的特征简化方法相比,新方法在控制地形简化的不确定性的前提下很好地保持了地形简化精度以及原始地表的骨架结构。     

基于CiteSpace的热浪研究知识图谱分析

近年来,全球热浪事件频发,对环境、生态系统以及人体健康造成了重大影响。对热浪研究发展历程和研究热点与前沿进行梳理有助于为研究学者提供一些有益的启示。文中以热浪为主题词,从Web of Science核心数据库中检索出1975—2019年文献2237篇,运用CiteSpace知识图谱分析工具,对热浪的研究进展及演变趋势进行了图谱解读和分析。结果表明:(1)国外对于热浪的研究起步较早,在该领域拥有较多的高影响力学者以及科研机构,如美国国家大气研究中心;中国在热浪领域起步较晚,但是发展速度很快,代表机构为中国科学院。(2)热浪研究涉及的学科广泛,如气象与大气科学、环境科学、环境科学与生态学等,其中与环境相关的学科占主要。(3)热浪研究热点可概括为4个方向,包括热浪对健康的影响、热浪热点事件、热浪的影响因素以及热浪研究方法。(4)热浪的研究发展过程可分为3个阶段:起始阶段,研究重点在极端气候现象导致的热浪和热浪的时间变化特征领域;发展阶段,研究内容为1995年芝加哥热浪事件与2003年欧洲热浪事件,并关注了热浪与城市热岛的关系及热浪对健康的影响;当前研究阶段,减少城市热浪风险和海洋热浪是热浪研究领域的前沿。     

Jurassic Black Shales Facies from Qiangtang Basin (Northern Tibet):Rare Earth and Trace Elements for Paleoceanographic Implications

The Biluo Co and Amdo 114 station, northern Tibet, cropping out the Early Toarcian and Middle-Late Tithonian (Jurassic) organic-rich black shales, have been a focus to petroleum geologists in discussing their oil-producing potential. This paper first reports the trace elements and rare earth elements to discuss the paleoenvironments, redox conditions and sedimentary mechanisms of those black shales. Both sections exhibit variation in trace element abundances with concentrations <0.1 ppm to 760 ppm, mostly enriched in V, Cr, Ni, Cu, Zn, Mo, Ba and U. Element ratios of Ni/Co, V/Cr, U/Th and V/(V+Ni) plus U were used to identify redox conditions. The shale-normalized rare earth element (REE) patterns are characterized by the flat-shale type with instable Ce anomalies and very weekly positive Eu anomalies. Positive Ceanom values are significant with values varying between –0.064 and 0.029 in Biluo Co, which may be interpreted as release of REE and input of riverine terrestrial matter with rich Ce (resulting in pH change) during the anoxic conditions. In the middle parts of Amdo 114 station, distinct negative Ceanom values are observed (?0.238 to ?0.111) and associated surface water warming were interpreted as being related to a major sea level rise. In contrast, the formation of the black shales in the lower and upper part of the studied succession took place during a cooler (Ceanom values >–0.10), lower surface water productivity, and lower sea-level stage. Thus, we emphasize the role of different factors that control the formation of local and regional black shales. The most important factors are sea-level fluctuations and increasing productivity.     

西沙北部海域海洋环境噪声频谱特性

Ambient noise is very important in the prediction system of a sonar performance, because it determines the detection ranges always in a passive sonar and usually in an active sonar. In the uncertainty issue for the so-nar performance, it is necessary to know this factor＇s statistical characteristics that are only obtained by data processing from the underwater ambient noise measurements. Broad-band ambient noise signals from 16 hydrophones were amplified and recorded for 2 min every 1 h. The results show that the ambient noise is essentially depth independent. The cross correlation of the ambient noise levels （1, 6 and 12 h average） with a wind speed is presented. It was found that the correlation is excellent on the upper frequency band and the noise levels correlate better with high wind speed than with low wind speed.     

Latest update of tests and improvements to US Coast Guard viscous oil pumping system

Over the past nine years, the US Coast Guard has incorporated the prevention through people (PTP) philosophy as a “human factors” approach to learn how maritime operations can be regulated safer and be more efficient by evaluating training, management policies, operational procedures, and establishing partnerships with the maritime industry. One of the key elements of applying a PTP approach is identifying and incorporating lessons learned from major marine casualties and pollution incidents. Since 1997, the US Coast Guard National Strike Force has responded to three major oil spills involving foreign freight vessels grounding, which included the removal of highly viscous oil using various lightering equipment and systems. An informal workgroup consisting of the US Coast Guard, US Navy Supervisor of Salvage (NAVSUPSALV), and various representatives from oil pollution clean-up companies met at the following facilities: the Chevron Asphalt Facility in Edmonds, WA (September 1999), the Oil and Hazardous Materials Simulated Environmental Test Tank (OHMSETT) testing facility in Leonardo, New Jersey (November 1999 and March 2000), the Alaska Clean Seas (ACS) warehouse annex in Prudhoe Bay, AK (October 2000), and Cenac Towing Company facility in Houma, LA (May 2002). The group shared ideas and techniques, and tested different pumps and hose lengths with viscous oil. It was during the early tests that the first quantitative results showed just how efficient lubricated transport of heavy oil product could be, and broadened the knowledge of such methods to the entire industry. Although this technology had existed for many years in the oil production and handling industry, its use had never been investigated in a laboratory setting with regard to salvage response lightering systems.     

Coral skeletal delta(15)N reveals isotopic traces of an agricultural revolution

This study introduces a new method of tracing the history of nutrient loading in coastal oceans via delta(15)N analysis of organic nitrogen preserved in the skeleton of the massive Porites coral. Four coral cores were collected in Bali, Indonesia, from reefs exposed to high levels of fertilizers in agricultural run-off, from lagoonal corals impacted by sewage, and from a reef located 30 km offshore. Skeletal delta(15)N in the agriculturally exposed coral declined from 10.7+/-0.4 per thousand in 1970-1971, when synthetic fertilizers (-0.8 per thousand+/-0.2 per thousand) were introduced to Bali, to a depleted "anthropogenic" baseline of 3.5 per thousand+/-0.4% in the mid-1990s. delta(15)N values were negatively correlated with rainfall, suggesting that marine delta(15)N lowers during flood-bourn influxes of waste fertilizers. Reef cores exposed to untreated sewage in terrestrial discharge were enriched (7.8 and 7.3+/-0.4 per thousand), while the offshore core reflected background oceanic signals (6.2+/-0.4 per thousand). delta(15)N, N concentration, and C:N systematics indicate that the N isotopic composition of skeletal organic matter was generally well preserved over 30 years. We suggest that skeletal organic delta(15)N can serve as a recorder of past nitrogen sources. In Bali, this tracer suggests that the intensification of Western style agricultural practices since 1970 are contributing to the degradation of coastal coral reefs.