岩性识别：方法、现状及智能化发展趋势

岩性识别是地质工作中一项基础而又重要的工作。传统的岩性识别方法过于依赖经验和地质专业知识积累,不仅耗时长、专业性强,还易受主观因素影响,导致准确率不理想。笔者等首先回顾了传统的岩性识别方法,之后总结了最新涌现的智能化识别方法,最后详细介绍了基于岩石图像、镜下图像、图像与元素信息融合等的智能识别方法。基于岩石图像的识别方法对于文中的岩石识别准确率可达90%以上,基于图像与元素融合的岩性识别方法可以缓解图像相似度高、风化破坏表观特征等因素对识别准确度的影响。笔者等认为当前岩性智能化识别研究仍处于初级阶段,无法满足工程需求。综合各类数据源的优势,利用机器学习深度挖掘岩石元素、矿物、光谱和表观特征间的内在关联性,有利于突破单源信息的局限性,实现岩性快速准确识别。     

岩性和种植年限对火龙果地土壤碳、氮、磷生态化学计量特征的影响

以石漠化问题突出区域——广西平果县太平镇耶圩火龙果种植园不同岩性背景(白云岩、碎屑岩)和不同种植年限(1、3、5a)土壤为研究对象,采用相关性分析和冗余分析方法探讨了不同岩性背景和火龙果种植年限下土壤碳、氮、磷生态化学计量特征及其影响因素。结果表明：①白云岩区土壤全磷含量显著高于碎屑岩区,而土壤有机碳含量、生态化学计量比(C/N、C/P和N/P)显著低于碎屑岩区;且白云岩和碎屑岩背景下的生态化学计量比(5.96、11.78、1.96和8.71、19.78、2.28)均远低于全国水平。②随着火龙果种植年限的增加,土壤有机碳、全氮含量和C/N、C/P、N/P呈现出逐渐增加的趋势,而土壤有效氮、全磷和有效磷含量无显著变化规律。随着土层深度增加,土壤有机碳、全氮、有效氮含量和C/N、C/P、N/P均增加,而土壤全磷含量无明显变化规律。③土壤C/N和C/P与有机碳、有效氮均呈显著正相关(P<0.01),而与土壤水分、容重呈显著负相关,土壤N/P与全磷呈显著负相关。④冗余分析表明不同岩性背景和火龙果种植年限下土壤有效氮含量是土壤碳、氮、磷及其生态化学计量比的重要影响因子,且呈显著正相关关系(P<0.01)。白云岩背景下火龙果的生长受到氮元素的影响更大,长期火龙果种植有利于碳、氮元素固存,土壤有效氮含量是影响土壤碳、氮、磷及其生态化学计量比的关键因子。     

Source Lithology and Magmatic Processes Recorded in the Mineral of Basalts from the Parece Vela Basin

Since the Early Cenozoic, the Philippine Sea Plate (PSP) has undergone a complex tectonic evolution. During this period the Parece Vela Basin (PVB) was formed by seafloor spreading in the back-arc region of the proto-Izu-Bonin-Mariana (IBM) arc. However, until now, studies of the geological, geophysical, and tectonic evolution of the PVB have been rare. In this study, we obtained in situ trace element and major element compositions of minerals in basalts collected from two sites in the southern part of the PVB. The results reveal that the basalts from site CJ09-63 were likely formed via ~10% partial melting of spinel-garnet lherzolite, while the basalts from site CJ09-64 were likely formed via 15%–25% partial melting of garnet lherzolite. The order of mineral crystallization for the basalts from site CJ09-64 was olivine, spinel, clinopyroxene, and plagioclase, while the plagioclase in the basalts from site CJ09-63 crystallized earlier than the clinopyroxene. Using a plagioclase-liquid hygrometer and an olivine-liquid oxybarometer, we determined that the basalts in this study have high H2O contents and oxygen fugacities, suggesting that the magma source of the Parece Vela basalts was affected by subduction components, which is consistent with the trace element composition of whole rock.     

松辽盆地龙西地区泉四段砂岩岩石学特征及其对储层物性的影响

松辽盆地龙西地区泉四段主要为岩屑长石砂岩和长石岩屑砂岩,成份成熟度较低,粒度较细,分选中等偏差,填隙物主要为粘土矿物和方解石。研究表明,储层物性随着石英含量的增加而变好,而随着岩屑含量的增加而变差,说明成份成熟度影响岩石的抗压性,进而影响储层的物性。泉四段砂岩中的长石主要通过钾长石的溶蚀作用改善储层物性。粒度大小和均匀程度与储层物性呈正相关关系,砂岩粒度的均匀程度也是形成低孔低渗储层的内在因素之一。     

扬州市地质构造背景与氡浓度之间关系分析

本文通过对扬州市区地层岩性、地质构造、断裂及放射性元素氡的特性分析,阐明了地区地层岩性、地质构造、断裂与放射性元素氡的形成和运移之间存在的关系,为地区建设工程氡浓度检测与控制提供依据。     

State of in-situ stress in different rocks

Ｓｔａｔｅｏｆｉｎ－ｓｉｔｕｓｔｒｅｓｓｉｎｄｉｆｆｅｒｅｎｔｒｏｃｋｓ（朱焕春，陶振宇）Ｈｕａｎ－Ｃｈｕｎ；ＺＨＵａｎｄＺｈｅｎ－ＹｕＴＡＯ（ＷｕｈａｎＵｎｉｖｅｒｓｉｔｙｏｆＨｙｄｒａｕｌｉｃａｎｄＥｌｅｃｔｒｉｃＥｎｇｉｎｅｅｒｉｎｇ，Ｗｕｈａ...     

Bedrock lithology control on contemporaneous alluvial fan facies, Oligo-Miocene, southern Pyrenees, Spain

Climate and tectonics play important roles in controlling processes of transport and deposition on alluvial fans, but the bedrock lithology in the fan catchment area is also a significant, independent factor. Adjacent Oligo-Miocene alluvial fan deposits on the northern margin of the Ebro Basin display contrasting depositional characteristics with one dominated by the deposits of debris flows and the other by deposition from flows of water. A difference in clast compositions indicates that the two studied fans (the Nueno and San Julián fans) had contrasting bedrock lithology in their drainage basins. The proximal facies of the Nueno fan body contains matrix-supported conglomerate beds with up to 80% pebble clasts of gypsum in a matrix of gypsiferous sand, interbedded with gypsarenite beds. The drainage basin of this fan was dominated by Triassic bedrock consisting of beds of gypsum, marl and micritic limestone. The San Julián fan body comprises clast-supported, polymict conglomerate beds containing pebbles from Triassic, Cretaceous and Palaeogene limestone units that are exposed in the adjacent part of the basin margin. The interfingering of the deposits of these two fans demonstrates that they were contemporaneous. Given the consistent climate, the differences in fan depositional processes must therefore be attributed to the contrasting bedrock lithology in their drainage basins. A drainage basin consisting mainly of marl and gypsum bedrock provided sufficient fine-grained material to generate debris flows, whereas more dilute, water-lain processes dominated where the drainage basin was largely limestone strata.     

SPATIAL CORRELATION ANALYSIS BETWEEN KARST ROCKY DESERTIFICATION AND LITHOLOGY IN DU''AN YAO AUTONOMOUS COUNTY IN GUANGXI

Du'an Yao Autonomous County is a typical area for the distribution of karst rocky desertification in Guangxi.The indices for the grades of rocky desertification are selected according to the scientific meaning of karst rocky desertification and after the interpretative symbol system of rocky desertification. RS images are established by the landscape characteristics of Du'an karst and its TM image. Relying on RS & GIS means and taking land use map as base map, this paper conducts synthetic analysis on the 1999a TM image (126-043) and the correlation data involving landform, soil, geological map and GPS-database and photo on the spot, and brings forth a map showing the Du'an rocky desertification grades and a digital lithology map. As can be viewed from spatial correlation, the inherent connection is also illuminated between the various levels of rocky desertification and the carbonate lithology.     

AVO处理解释和岩性识别

从AVO技术最初用于识别“亮点”等振幅异常开始，特别是近几年来新科技的发展和应用，使该技术在油气勘探领域中具有不可替代的作用。用AVO拟合的纵横波、梯度、近道和远道迭加等剖面，结合AVOC、AVO偏振性分析、交汇图、流体替换、声阻抗、波阻抗、LMR等技术，可以从地震剖面中提取与地层直接相关的岩石物理参数，如λ、μ、K、σ等，进而预测储层的岩性和合流体性。在对这些技术进行了详细的研究后，用实际资料对每一种方法进行验证，总结了一套适用于碳酸岩储层的岩性识别处理解释流程。     

综合测井资料在研究新疆吐哈盆地十红滩铀矿区地层岩性及沉积环境中的应用

本文阐述了吐哈盆地十红滩铀矿区岩石地球物理参数特征，并利用综合测井资料深人研究了地层划分、岩性识别，进行了沉积环境分析，对可地浸砂岩型铀矿找矿具有重要的意义。