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葫芦岛市绥中县大河西村硫铁矿地质特征、成因类型及找矿标志
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作者 王萱 吴斌 《中国金属通报》 2023年第5期67-69,共3页
大河西村硫铁矿区地层出露齐全,断裂构造发育,中生代燕山期岩浆岩发育,矿产丰富,成矿条件十分有利。在矿区内,仅有混合花岗岩和燕山期花岗岩,其它地层不发育。在矿区的北部,仅有一条长约200m,走向北东的断裂构造,是硫铁矿的含矿断裂和... 大河西村硫铁矿区地层出露齐全,断裂构造发育,中生代燕山期岩浆岩发育,矿产丰富,成矿条件十分有利。在矿区内,仅有混合花岗岩和燕山期花岗岩,其它地层不发育。在矿区的北部,仅有一条长约200m,走向北东的断裂构造,是硫铁矿的含矿断裂和控矿断裂,围岩蚀变以褐铁矿化、赤铁矿化、绿泥石化和黏土矿化为主。矿区仅有一条硫铁矿体,走向北东、倾向南东,厚约1.13m~3.01m。矿石矿物成分仅有硫铁矿,而脉石矿物为长英质矿物,矿石具有全晶质和细粒结构,呈块状、条带状和网脉状构造,矿石属于黄铁矿矿石,易加工。通过研究大河西村硫铁矿床成矿地质背景、矿区地质特征、矿石特征,初步认为矿床成因类型属中-低温岩浆热液型硫铁矿;北东向断裂形成构造破碎蚀变带;绿泥石化、黏土矿化、赤铁矿化发育部位;地表形成的铁帽、节理裂隙均是重要找矿标志;矿区成矿条件有利,找矿标志明显,但矿区的深部及两端矿体受限工作量均未控制,因此可以利用电法中梯测量来寻找隐伏矿体。 展开更多
关键词 地质特征 成因类型 找矿标志 硫铁矿 大河西村
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Livelihood Strategy Change and Land Use Change——Case of Danzam Village in Upper Dadu River Watershed,Tibetan Plateau of China 被引量:3
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作者 YAN Jianzhong ZHANG Yili +1 位作者 ZHANG Liping WU Yingying 《Chinese Geographical Science》 SCIE CSCD 2009年第3期231-240,共10页
Land use change in rural China since the 1980s, induced by institution reforms, urbanization, industrialization and population increase, has received more attention. However, case studies on how institution reforms af... Land use change in rural China since the 1980s, induced by institution reforms, urbanization, industrialization and population increase, has received more attention. However, case studies on how institution reforms affect farmers' livelihood strategies and drive land use change are scarce. By means of cropland plots investigations and interviews with farmers, this study examines livelihood strategy change and land use change in Danzam Village of Jinchuan County in the upper Dadu River watershed, eastern Tibetan Plateau, China. The results show that, during the collective system period, as surplus labor forces could not be transferred to the secondary and tertiary industries, they had to choose agricultural involution as their livelihood strategy, then the farmers had to produce more grains by land reclamation, increasing multiple cropping index, improving input of labor, fertilizer, pesticide and adopting advanced agricultural techniques. During the household responsibility system period, as labors being transferred to the secondary and tertiary industries, farmers chose livelihood diversification strategy. Therefore, labor input to grain planting was greatly reduced, which drove the transformation of grain to horticulture, vegetable or wasteland and decrease of multiple cropping index. This study provides a new insight into understanding linkages among institution reforms, livelihood strategy of smallholders and land use change in rural China. 展开更多
关键词 livelihood strategy land use change agricultural involution upper Dadu River watershed Tibetan Plateau China
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