山东省齐河—禹城地区“四维”地质过程及铁矿成矿模式

Four-dimensional Geological Processes and Iron Metallogenic Model in Qihe-Yucheng Area in Shandong Province

摘要:

山东省齐河禹城富铁矿重点勘查区是我国铁矿找矿热点地区，该区近年来发现了李屯、大张、郭店、叠道和丁寺铁矿床，同时科研工作也取得了较大进展，但对全区地质演化过程、总体成矿模式和矿床后期改造等方面间的耦合关系研究略显不足。本文通过对区域成矿背景、矿区地质—地球物理特征、铁矿床特征及各个时代的地质演化进行全过程总结分析，重点梳理该区铁矿体控矿要素特征，进而重塑研究区地质演化过程，并建立夕卡岩型铁矿成矿模式。本次研究首次系统构建了集前寒武纪、古生代、中生代和新生代时期“多角度、多层次、多时段”的“四维”地质演化过程和铁矿成矿模式。研究表明早白垩世前形成的奥陶系、石炭系和二叠系等为该区铁矿成矿提供了地质基础；早白垩世时期的大规模“构造—岩浆”事件为该区铁矿的形成提供动力来源和成矿物质，期间复杂的成矿过程中形成了规模不同、空间多样、形态各异的夕卡岩型铁矿体；早白垩世后期的地质构造运动和岩浆活动等对前期形成的铁矿体进行了较大规模的改造。本次研究较为清晰且直观地呈现了齐河禹城重点勘查区地质演化过程和铁矿成矿模式，为该区铁矿勘查研究提供了重要科研基础。

Abstract:

The key exploration area of Qihe-Yucheng rich iron deposit in Shandong province is a hot spot for iron ore exploration in China. In recent years, Litun iron deposit, Dazhang iron deposit, Guodian iron deposit, Diedao iron deposit and Dingsi iron deposit have been discovered in the area, and significant progress has been made in scientific research. However, there is a lack of research on the coupling relationship between geological evolution process, overall mineralization model and later transformation of the deposits. Through analysis on the background of regional mineralization, geological and geophysical characteristics of mining areas, characteristics of iron deposits, and geological evolution in various eras, ore controlling elements of iron ore bodies in the area have been sorted out significantly, geological evolution process has been reshaped, and a skarn type iron ore mineralization model has been established. A "four-dimensional" geological evolution process and iron ore mineralization model that integrates the pre-Cambrian, Paleozoic, Mesozoic and Cenozoic periods from multiple angles, levels and periods have been constructed systematically. It is showed that the Ordovician, Carboniferous and Permian systems formed before early Cretaceous can provide geological basis for iron mineralization in this area. The large scale "tectonicmagmatic" events during early Cretaceous period will provide the driving force and ore-forming materials for the formation of iron ore in this area. During the complex mineralization process, skarn type iron ore bodies with different scales, spatial diversity and shapes have been formed. Geological tectonic movements and magmatic activities in late early Cretaceous period have undergone significant modifications to the iron ore bodies formed in the early stage. This study has showed a clear and intuitive geological evolution process and iron ore mineralization model in Qihe Yucheng key exploration area. It will provide an important scientific foundation for iron ore exploration in this area.