摘要
朝阳磷矿的磷块岩有五种类型,即泥晶磷块岩、球粒磷块岩、鲕粒磷块岩、内碎屑磷块岩和细晶磷块岩。其中内碎屑磷块岩占优势。磷酸盐岩沉积在海退旋回中,是处于深水向浅水过渡的层位。磷块岩的沉积环境主要是隆起附近的浅水带。
There are five types of phosphorite in Chaoyang phosphorus deposit, i.e. micritic, pelletal, oolitic, intraclastic and finecrystal phosphorite. The intraclastic phosphorite is a main type of phosphorite in this area. The phosphate minerals in the deposit are micritic, sparry and fine-crystal apatite. The micritic apatite was directly precipitated from sea water and formed the(?)critic phosphorites or pellets. The sparry apatite was precipitated from pore water as cements filling interstitial spaces among pelletes or intraclaste grains. The fine-crystal phosphorites were composed of fine-crystal apatite. It was resulted from recrystallizadon, phos-phatization and siliceous solution replacement.The phosphate-bearing sequence consists of five cyclothems. These rocks were mainly deposited in transitional horizon from deep water to shallow water during the regressive cyclo-them. The phosphorites were mainly deposited in shallow-water sedimentary environment around a high-land in sea water.
出处
《地质科学》
CAS
CSCD
北大核心
1989年第3期274-287,共14页
Chinese Journal of Geology(Scientia Geologica Sinica)
关键词
磷矿
磷块岩
类型
成因
Phosphorite, phosphate-bearing sedimentary cyclothem, pericontimental sea.
