摘要
本文对丹霞群砂岩中的石英、长石、电气石、锆石４种碎屑矿物的表面结构特征作了初步研究，并与现代河流和海岸砂质沉积物中的同类矿物的表面结构特征进行类比。文章指出，由于成岩作用的影响，古代砂岩中的碎屑矿物比现代砂的同类矿物具有更为复杂的表面结构，原因在于成岩环境下，溶解、溶蚀和压溶作用对古代砂岩的矿物表面有更深刻的改造。
he Danxia Group in Jinjiling area of north Guangdong is mainly composed of fluvial facies calciferous sandstone,On the basis of grain size analysis and artificial placer mineral analysis,four detrital minerals,i.e.,quartz,feldspar,tourmaline and zircon were studied under a scanning electron microscope,and it is thus discovered that their surface textures are much more complex than the surface textures of similar minerals from any modern coastal and fluvial arenaceous sediments the authors have ever studied.The reason is that the surface of detrital minerals in ancient sandstone not only underwent transformation in the process of weathering,transportation and sedimentation like what detrital minerals are experiencing in modern riversor coastal areas,but also suffered superimposition of further transformation during diagenesis.The composition of intergranular liquid and the change intemperature and in pH value under the diagenetic conditions played animportant role in the formation of surface textures of minerals.It is thereforeobvious that the various characteristics of surface textures of minerals arerelated not only to mineral behaviors but also to the action and influence of the media in the diagenetic environment.A comparison of surface textures of various minerals shows that,in addi-tion to the physical and chemical properties of minerals,the temperaturesand pH values of the media in the diagenetic environment are also importantfactors affecting the formation of surface textures of minerals,with the mainreaction being dissolution.The degree of transformation of the four mineralsis in decreasing order of tourmaline→feldspar→quartz→zircon,which is notquite consistent with the sequence of stability of these minerals.
出处
《岩石矿物学杂志》
CAS
CSCD
1994年第1期90-94,T002,共6页
Acta Petrologica et Mineralogica
基金
国家自然科学基金
关键词
沉积环境
成岩作用
砂岩
矿物结构
Danxia Group
surface texture of mineral
sedimentary environment
diagenesis
