山东枣庄市曹庄找煤区中新生代地层划分与对比

Mesozoic and Cenozoic Strata Division and Correlation in Caozhuang Coal Looking Area,Zaozhuang City,Shandong

枣庄市曹庄找煤区为中新生界掩盖的含煤区,盖层为侏罗—白垩系和古近系,因其颜色多以紫红、褐红色为主,故统称为"红层"。根据区内验1孔获得的孢粉资料,1-7层中孢粉组合以裸子植物花粉为主,蕨类植物孢子数量较少,其中裸子植物花粉中的松柏类花粉Monosulcites自下而上均有分布,Classopollis分子普遍发育,没有发现被子植物花粉,从第3层底部开始出现Aequitriradites、Pilosisporites,它们是早白垩世的典型分子,而1-2层孢粉组合中没有发现这些分子,由于上侏罗统与下白垩统为连续沉积,生物群面貌有很多相似之处,根据周边侏罗系发育特征,认为此段地层时代定为晚侏罗世?-早白垩世早中期;从8-12层孢粉组合面貌看,出现了相当数量的Ulmns和被子植物花粉如Rhus、Quercus、Loncera、Zelkova、Cedrus,特别是该组合中出现的古近纪中期—晚期的常见分子Rhus和Taxodiaceaepollenites,反映出古近纪中期—晚期孢粉组合面貌,符合Ulmns-Pteris孢粉组合面貌特征,由此推断此段地层时代应属古近纪始新世—渐新世。根据岩性特征及孢粉组合特征综合分析,红层自下而上主要由下白垩统青山组及古近系官庄群组成,钻孔揭露地层与周边地区地层岩性基本一致,可以进行对比。此结果对该区及相邻区域开展深部找煤工作具有一定的实际意义。

The Caozhuang coal looking area in the Zaozhuang City is a coal-bearing area covered by Mesozoic and Cenozoic strata.Cap rocks belong to Jurassic,Cretaceous and Paleogene systems,with colors mostly purplish red,brownish red,thus go by the general name of ＂red beds＂.Based on sporo-pollen data from borehole Jian No.1,sporo-pollen complex in Nos.1 ~7 beds is mainly gymnosperm pollens,lesser fern spores;in which,Coniferales pollen Monosulcites has distributed from bottom to top,Classopollis is generally developed,no angiosperm pollens have found.From the bottom of bed No.3,Aequitriradites and Pilosisporites were emerged and they are typical elements of early Cretaceous,while no same elements have found in sporo-pollen complex in beds Nos.1 and 2.Since the upper Jurassic and lower Cretaceous strata have deposited continuously,biota features are similar,based on peripheral Jurassic System development features,and considered that the age of the strata in this sector belongs to Late Jurassic Epoch to the earlier middle Early Cretaceous Epoch.From sporo-pollen complex features in beds Nos.8~12,quite a bit Ulmns and angiosperm pollens such as Rhus,Quercus,Loncera,Zelkova and Cedrus have appeared,especially middle to late Paleogene Period common elements of Rhus and Taxodiaceaepollenites,reflected sporo-pollen complex features of middle to late Paleogene Period and agreed with Ulmns--Pteris sporo-pollen complex features,thus deduced that the age of the strata in this sector belongs to Eocene Epoch to Oligocene Epoch,Paleogene Period.Based on comprehensive analysis of lithologic features and sporo-pollen complex features,the red beds from bottom to top are mainly composed of Lower Cretaceous Qingshan Formation and Paleogene Guanzhuang Group,boreholes revealed and peripheral area strata lithology are basically identical,can be correlated each other.The result has certain practical significance in deep part coal looking in the area and neighboring areas.