广东省粤西北地区晚泥盆世融县组岩性组合及分布规律

Lithology Assemblage and Distribution Law of the Rong County Group in Late Devonian in Northwest of Guangdong Province

摘要: 广东连州地区晚泥盆世融县组主要以灰色、浅灰色厚层块状砂屑灰岩、含鲕粒灰岩、砾屑灰岩、白云质灰岩为主。通过对野外剖面测制及前人研究成果的收集，探讨连州地区融县组岩性组合特征，并根据岩性、厚度对区域空间分布规律做了详细分析，得出：纵向上，融县组岩性由浅灰色带浅肉红色厚层状白云质灰岩、浅灰色厚层泥晶灰岩或灰色厚层状含砂屑鲕粒灰岩、泥晶灰岩及泥质灰岩组成，泥质灰岩中常含炭质，自底而上，岩层单层厚度有先变薄而后又加厚的趋势，组成的矿物颗粒由细到粗再到细。横向上岩性岩相变化较为显著，中西部岩性由浅灰色带浅肉红色厚层状白云质灰岩与浅灰色厚层泥晶灰岩组成；东部岩性主要由灰色厚层状含砂屑泥晶灰岩、含鲕粒泥晶灰岩、泥晶灰岩、薄层泥质灰岩组成，沉积厚度总体有自南西连南经星子至北东大路边有逐渐增大的趋势，为邻区开展野外调查及地层对比打下了坚实基础。

Abstract: The Late Devonian group in the Lianzhou area of Guangdong province is mainly composed of gray, light gray thick-layer blocky sand-dust, oolitic limestone, gravel limestone and dolomite limestone. Through the collection of field profile measurement system and previous research results, this paper discusses the lithology assemblage characteristics of the Lianzhou area, and makes a detailed analysis according to the lithology and thickness of the regional spatial distribution, and concludes that: vertically, the lithology of the Rong County group is composed of shallow-gray red thick-layered dolomite limestone, shallow gray thick layer mud-crystal limestone or gray thick layer of sand debris oolitic limestone, the clay-crystal limestone and the muddy limestone. The muddy limestone is often carbonaceous, from the bottom, the single layer thickness of the forma-tion of the first thinning and then thickened, the composition of the mineral particles from thin to coarse and fine. The variation of lithologic facies is more obvious. The lithology of Middle and West is composed of shallow grey red thick layer dolomite limestone and shallow gray thick layer mud-crystal limestone; The eastern lithology is mainly composed of grey thick layer-like limestone, including oolitic mud-crystal limestone, mud-crystal limestone and thin-layer argillaceous limestone, The deposition thickness has a tendency to increase gradually from the South West Liannan to the North East roadside, which lays a solid foundation for the field investigation and stratigraphic correlation.