基于沉积相变-粒度参数-旋回关系的第四纪河流相含水层精细对比

Heterogeneity and anisotropy of the aquifer is currently the core issues plaguing the hydrogeologists. The roots are lack of study on the deposition phase transition and its spatial and temporal distribution of aquifer, and the lack of high-precision formation grid basis. To this end, sendimentary theory and high-resolution sequence stratigraphy analysis method is applied to the study of Quaternary fluvial aquifer structure. A case study will be carried out at the middle reaches of Hutuo River of the North China Plain, which is not only based on the analysis of the datum about drill core, geophysical logging data, age and environment testing data, but also combined with previous research results related to sedimentary strata stratum, lithofacies and structure. On the basis of the regional stratigraphic framework established in the previously, we will carry out a fine comparative study of Quaternary fluvial aquifer based on the relationship between sedimentary facies change - grain size parameters - base level cycle. The detailed analysis of the single-hole sedimentary microfacies will be done. And through identifying the sequence boundary and base-level cycles of the borehole at the cross section, we will correlate the stratum of borehole based on the high-resolution sequence stratigraphy.And then a fine stratigraphic framework of Quaternary fluvial aquifer of the typical section will be established. On the basis, a method of fine compapative study on Quaternary fluvial aquifer will be explored and put forward. The results will provide a new idea for the technology of aquifer fine detection, and also be as a model for the regional aquifer fine detection. Research contents: 1. Sedimentary facies analysis of the key borehole and the relationship model between sedimentary facies and grain size parameter; 2. Recognition of base-level cycles of key borehole and comparision between the boreholes; 3. Fine structure of Quaternary fluvial aquifer at the typical section.

含水层的非均质性和各向异性是目前困扰水文地质学家的核心问题之一，其根源在于对含水砂层的沉积相变及其时空分布规律研究的不足，以及缺乏高精度的地层格架作为基础。为此，本申请将沉积学理论和高分辨率层序地层学分析方法应用于第四纪河流相含水层结构研究中，以华北平原滹沱河中游沿岸剖面为例，在前人建立的区域地层框架基础上，开展基于沉积相变-粒度参数-基准面旋回关系的第四纪河流相含水层精细对比研究。在详细划分单孔沉积微相、建立粒度参数与沉积微相间的关系模式、识别剖面上各钻孔不同级次基准面旋回的基础上，进行孔间多级次地层旋回等时对比，建立高精度等时地层格架；在等时地层格架内分析剖面上不同沉积微相在纵横方向上的组合特征、相序规律，准确认识河流相砂体空间展布特征，绘制典型剖面第四纪河流相含水层（组）精细结构图；为区域含水层（组）的进一步科学划分提供依据，也为地下水资源科学管理与可持续利用等提供工作基础。

含水层的非均质性和各向异性是目前困扰水文地质学家的核心问题之一，其根源在于对含水砂层的沉积相变及其时空分布规律研究的不足，以及缺乏高精度的地层格架作为基础。本文以河北省滹沱河山前平原为例，将沉积学理论和高分辨率层序地层学分析方法应用于平原区第四纪河流相含水层的划分与对比研究中。以钻孔岩芯、粒度分析、释光年龄等资料为基础，在详细划分单孔沉积相、识别各钻孔不同级次基准面旋回的基础上，进行孔间多级次地层旋回等时对比，建立了滹沱河山前平原沿河剖面第四系层序地层格架，理清了第四纪冲洪积-河流相砂体的分布规律，并对研究区含（隔）水层进行了合理划分。研究成果可为区域含水层（组）的进一步科学划分提供依据。取得的主要成果如下：.（1）建立了滹沱河山前平原重点钻孔ZD08-1第四纪年代地层格架。明确该孔第四纪以来主要包括冲洪积扇和辫状河流两种沉积相类型。.（2）建立了ZD08-1孔第四纪地层层序，识别出20个超短期旋回、6个短期基准面旋回、2个中期基准面旋回和1个长期基准面旋回。.（3）基于不同级次基准面旋回的孔间地层对比，建立了滹沱河山前平原沿河剖面（正定－藁城）第四系高分辨率层序地层格架。整个第四纪时期，研究区处于一个长期基准面旋回（LSC1）控制之下，以上升期为主，覆盖了约210万年的沉积地层，中更新世中期之后开始下降并延续至今。在长期基准面旋回框架内，各钻孔在中期、短期基准面旋回级次上均可进行逐一对比。.（4）探讨了沿河剖面第四纪以来砂体的空间分布规律。各短期基准面由下降到上升的转换面附近，砂体发育程度及透水性能相对较好。中期基准面上升半旋回砂体发育程度好，下降半旋回则相对较差。.（5）滹沱河山前平原在第四系深度范围内，由上到下可划分为5个含水层。其中，第Ⅰ、Ⅱ含水层对应于前人划分的第Ⅰ含水层组，第Ⅲ含水层对应于前人划分的第Ⅱ含水层组，第Ⅳ、Ⅴ含水层对应于前人划分的第Ⅲ含水层组，而前人确定的第Ⅳ含水层组在时限上应属于上新世。