碎屑岩层序地层与成岩作用时空关系研究新进展

成岩作用与层序地层学在沉积地质学内是两个分支学科.文章叙述了碎屑岩层序地层与成岩作用关系,指出层序、准层序界面、海(湖)侵和最大湖泛面附近,及在低位体系域、海(湖)侵体系域、高位体系域等地层层序条件下,成岩作用包括成岩自生矿物的形成组合(如方解石、白云石、菱铁矿、黄铁矿、高岭石、海绿石、磁绿泥石)、假基质形成、机械粘土充填、粒间孔隙演变等均有明显差异.原因主要是由于层序地层控制成岩作用的类型与时空分布:①碎屑组分.包括沉积盆地内外碎屑组分类型与比例;②孔隙水化学条件;③有机质存在与作用;④特定地球化学条件下沉积物存在的时间;⑤古气候条件.层序地层与成岩作用时空关系模式,将层序地层界面、体系域与成岩作用、储层性质的演化有机地结合在一起,扩大了预测砂岩储层能力,使储层预测更具准确性和实用性.

TIME-SPACE RELATION STUDY OF DIAGENESIS AND SEQUENCE STRATIGRAPHY FOR CLASTIC ROCK

Diagenesis and sequence stratigraphy have been formally treated as two separate disciplines in sedimentary petrology.This thesis has discussed that integration of diagenesis and sequence stratigraphy,and has a beRer prediction of the spatial and temporal distribution of diagenetic alterations in siliciclastic sequences,and contraining of reservoir quality evolution of sandstones.Diagenetic minerals such as calcite,dolomite,siderite,pyrite,kaolinite,glaucony,and berthierine,and formation of pseudomatrix,mechanical clay infiltration,and intragranular porosity,which showed a distribution in sandstones lying in the vicinity of sequence and parasequence boundaries,transgressive and maximum flooding surfaces,and in sandstones of the lowstand,transgressive,and highstand system tracts.The main sequence stratigraphic controls on the distribution and type of diagenetic alteration.