甘肃走廊南山朱龙关群的时代及其火山岩的岩石化学特征

甘肃走廊南山朱龙关群是一套以发育大量基性火山岩为特征的浅变质火山沉积岩系，分布于托来山北坡刘口峡山至热水大坂一带以及朱龙关河北侧小柳沟和古浪峡等地。本文在前人工作的基础上，对区内地层的分布提出了新的见解，认为沙龙地区和北过龙至金龙河地区出露的一套浅变质火山－沉积岩石应划归来龙关群，并运用同位素年代学方法测定了该地层中火山岩的成岩时代，首次较确切地给出了这套浅变质岩系的时代归属，从而进一步确定了朱龙关群的时空分布。同时根据火山岩岩石化学特征研究，认为朱龙关群火山岩的成岩大地构造背景为陆内裂谷。     

香炉碗子金矿床稳定同位素研究及矿床成因探讨

香炉碗子金矿床产于脆一韧性剪切带内，控矿围岩为火山隐爆角砾岩体，通过硫，铅，氢，氧，碳，锶等同位素及稀土元素的研究可以看出，该矿床是一个中，低温有大气水参与火山热液型金矿床，其火山岩岩浆属太古宙结晶基底重熔再造，壳幔混合型。     

陆相火山岩铜矿床成矿条件研究

研究陆相火山岩铜矿床的成矿条件，对于多发现新的铜矿资源有着重要的意义。本文就陆相火山岩型铜矿床的实际存在，大陆玄武岩型铜矿的成矿系列，大陆裂谷的成矿环境和热液成矿作用等方面进行讨论。     

NW断裂构造──鹅公山火山盆地铀矿成矿的关键要素

鹅公山火山盆地受郯庐断裂系影响，ＮＷ断裂构造尤为特色：张扭性，倾向ＮＥ，右行下滑，对盆地中３个铀矿床及绝大多数铀矿（化）点具明显控制作用，是铀矿成矿的关键要素。研究ＮＷ断裂对在鹅公山火山盆地及其它地区找矿都具有实际意义。     

石源龙地区岩浆岩的稀土元素和同位素地球化学

本章系统研究石源龙地区流纹质熔结凝灰岩、粒状碎斑熔岩、英安岩、星村中细粒黑云母花岗岩的铷锶同位素地质年龄，并根据锶、氧同位素和稀土元素含量讨论其地质意义     

A model study on the decay of volcanic aerosol layer and verification with Pinatubo and El Chichon data

The time evolution of stratospheric aerosol layer formed after a volcanic eruption is studied taking into account the aerosol microphysical processes of growth, coagulation and sedimentation. Using a simple model we could explain the observed evolution of the Pinatubo volcanic layer which decayed in about 3 years. The experimental data obtained by Nd:YAG backscatter lidar over Ahmedabad further supports this finding. The data obtained after the El Chichon volcanic eruption also showed that the El Chichon aerosol layer decayed in about 3 years time. Thus, though the amount of SO₂ injected has been higher, in the case of Pinatubo, about two to three times more than El Chichon, it has resulted in the production of larger aerosol particles due to faster growth and coagulation processes, and subsequently a faster removal rate, to give more or less a similar background aerosol amount at the stratosphere in about 3 years time.     

The color of pumice: case study on a trachytic fall deposit, Meidob volcanic field, Sudan

 This paper examines the cause of color variations of trachytic pumices which are essentially uniform in chemical composition and proposes a geological model for their formation. A pyroclastic sequence of distinct subunits with brown, buff, and black pumices was deposited during the 5000-B.P. eruption of a tuff ring in the central Meidob volcanic field (Sudan). Subunits of buff pumices locally contain minor amounts of streaky pumice with pale-gray and dark-gray domains. The combined evidence of petrographic studies, chemical analyses of whole pumices and groundmass separates, electron microprobe analyses, optical spectroscopy, transmission electron microscopy, and magnetic susceptibility measurements show that color variations of the pumice clasts are related to the size and distribution of Fe³⁺-rich oxide microcrysts. Buff pumice and light-gray domains of streaky pumice have a colorless, transparent groundmass with very few microcrysts. Dark-gray domains of streaky pumice contain abundant hematite and/or magnetite microcrysts visible in thin section within a transparent, colorless glass groundmass. The groundmass of the black pumice clasts is brown in thin section which is most likely caused by submicroscopic magnetite microcrysts. Brown pumice clasts have a mixed groundmass consisting of brown domains and domains with opaque microcrysts in transparent glass. Variations in the eruption dynamics have been inferred from lithological observations. Subunits of black pumices are related to eruption pulses with low magma discharge and high water/magma mass ratio, whereas subunits of buff pumice were deposited during eruption pulses with high magma discharge and low water/magma mass ratio. Brown pumices represent the top part of the magma body, and the initial stage of the eruption probably had a low magma discharge. Streaky pumices are interpreted as the product of syn-eruptive mixing of Fe³⁺-rich oxide microcryst-bearing magma and microcryst-free magma. Received: 3 February 1997 / Accepted: 28 July 1997     

陆相渐新统划分中的问题及新进展

近年来国际上关于始新世－渐新世界线的研究取得了重大进展，其同位素年龄被确认为３４Ｍａ，北美哺乳动物年代表已据此重新厘定。通过对哺乳动物群的分析和对比，论证了我国原认为是早渐新世的乌兰戈楚期和呼尔井期的时代应改归晚始新世，原认为是中渐新世的三达河期的时代应为早渐新世。在亚洲始新世－渐新世的界线不是在乌兰戈楚期之末，而是在呼尔井期与三达河期之间。     

福建沙县地区早白垩世火山岩成因及构造环境分析

本文着重阐述了沙县地区早白垩世火山岩地球化学特征，论证了中性与酸性火山岩的成因及物质来源，认为二者为不同源岩浆演化的产物，其岩浆物质来源于壳幔混源区，为省内双峰式火两端员岩石间成因关系的分析研究提供了新的例征。     

太白维山中生代火山岩特征及其与成矿的关系

晋北太白维山火山岩属钾质碱性玄武岩系列,产于板块内部活化带,来源于上地幔或下部地壳,被上部地壳物质混染,为壳幔源型或同熔型火山岩.火山岩与Ag(Pb、Zn)矿化关系密切,是成矿热液和矿质的主要来源之一.