摘要
浙江省白垩系由下而上新建立三个岩石地层单位：（１）小平田组以中酸性火山碎屑岩为主，夹中、酸性熔岩及紫红色砂岩，厚度３７０～１１００ｍ，测得Ｒｂ－Ｓｒ等时线年龄１０８Ｍａ，时代为早白垩中晚期）（２）两头塘组以紫红色泥宕、粉砂宕为主，局部夹砾岩及流纹质玻屑凝灰岩，厚度１７５～６９０ｍ，与上、下地层均为整合关系，产有恐龙蛋及甲龙等化石，时代属于晚白垩世；（３）赤城山组主要为紫红色砾岩、粉砂岩，偶夹凝灰岩层，厚度６００～１０００ｍ，整合于两头塘组之上，顶部出露不全，产恐龙蛋化石，时代为晚白垩世。第四系镇海组，据清水浦４１号钻孔资料，其岩性由灰黄一深灰色亚粘土、深灰一灰黑色亚砂土组成，出露厚度４０ｍ左右，含有孔虫、贝类等化石，并平行不整合于宁波组之上。其时代应为全新世。
Three new Lithostratigraphic units have been established for the Cretaceous of ZhejiangProvince;in ascending order they are Xiaopingtian Formation,Liangtoutang Formation andChichengshan Forrnation. The Xiaopingtian Formation, 370 1100m thick, consists mainly ofintermediate acid pyroclastic rocks with lava and purplish red sandstone; with a Rb-Srisochron age of 108 Ma,it is mid-late Early Cretaceous in age. The Liangtoutang Formation,175 690 m thick,is composed mainly of purplish red mudstone and siltstone, partly interca-lated with conglomerate and rhyolitic tuff, yielding fossils of dinosaur eggs and ankylosaurs;itsage is Late Cretaceous. The Chichengshan Formation,600 1000 m thick ,consists of purplishred conglomerate and siltstone with occasional tuffs,with its top being exposed incompletely;ityields egg fossils of dinosaurs.On the basis of the data from hole No. 41 in Qingshuipu,the Quaternary is composed ofgreyish yellow-dark grey clays, with an outcrop thickness of 40 m, containing fossils offoraminifers and mulluscs. It rests disconformably on the Ningbo Formation and its age shouldbeHolocene.
出处
《中国区域地质》
CSCD
1995年第2期125-130,共6页
Regional Geology of China
