發(fā)布時間：2018-09-03 20:59

【摘要】：本論文對遼西興城曹莊地區(qū)的早白堊世火山巖地層進行研究,通過野外區(qū)域地質(zhì)調(diào)查和實測剖面工作以及室內(nèi)的綜合地層學分析,厘定了巖石地層序列,針對研究區(qū)典型的巖石樣品進行鋯石U-Pb年齡及地球化學測定,并結(jié)合老爺廟南溝地區(qū)剖面,與義縣組層型(阜新-義縣盆地馬神廟-宋八戶剖面)進行區(qū)域地層對比。論文的研究內(nèi)容及成果包括以下幾個方面:1.野外工作對研究區(qū)進行了大比例尺區(qū)域地質(zhì)調(diào)查,通過對SⅠ興城地區(qū)尖山-老灘早白堊世剖面的實測,厘定了研究區(qū)早白堊世火山巖的巖石地層序列,通過對其巖石組合特征的分析和整理,將該套地層劃分為兩個段級巖石地層單元。2.對研究區(qū)內(nèi)的5個典型巖石樣品進行鋯石U-Pb年齡測定,獲得年齡分別為131.5±1.4Ma、126.0±1.2Ma、129.2±1.0Ma、113.3±1.6Ma和112.7±2.6Ma。結(jié)果顯示,尖山-五里橋采石場一帶的巖石樣品年齡介于135~120Ma之間,應(yīng)屬義縣組;老灘一帶的巖石樣品年齡較年輕,或為九佛堂組頂部或阜新組同時期的熔巖相。二者呈平行不整合接觸,為遼西南部地區(qū)早白堊世兩期火山活動形成的產(chǎn)物。3.通過對SⅡ新臺門盆地白馬石地區(qū)老爺廟南溝義縣組剖面和義縣組層型(阜新-義縣盆地馬神廟-宋八戶剖面)的觀測,將研究區(qū)SⅠ興城地區(qū)尖山-老灘早白堊世剖面(義縣組部分)與二者進行對比,結(jié)果顯示曹莊地區(qū)義縣組與義縣組層型中、下部可對比,白馬石地區(qū)義縣組與研究區(qū)義縣組下段可對比。4.分別對尖山地區(qū)和老灘地區(qū)的火山巖樣品進行主量元素、微量元素和稀土元素的地球化學測定,結(jié)果顯示尖山地區(qū)巖石樣品屬高鉀鈣堿性系列,老灘地區(qū)義縣組屬鉀玄巖系列,這與巖漿噴發(fā)時的動力條件強弱有關(guān),二者巖漿源區(qū)相同,均為殼幔混源形成的產(chǎn)物,形成于板塊碰撞后的板內(nèi)伸展背景下。
[Abstract]:In this paper, the early Cretaceous volcanic strata in Caozhuang area, Xingcheng area, western Liaoning Province, are studied. The sequence of rock and strata is determined through field regional geological survey, measured section work and laboratory comprehensive stratigraphic analysis. Zircon U-Pb age and geochemistry were measured for typical rock samples in the study area and regional stratigraphic correlation was carried out with the stratigraphic type of Yixian formation (Mashenmiao-Songbahu section of Fuxin-Yixian basin) combined with the section of Nangou area of Laoyamiao. The research contents and results of this paper include the following aspects: 1. A large scale regional geological survey was carried out in the study area by field work. The lithostratigraphic sequence of the early Cretaceous volcanic rocks in the study area was determined by measuring the early Cretaceous section of the Jianshan-Laotan area in the S 鈪，

本文編號：2221147