CAJ | 학술논문

二叠纪-三叠纪之交是古生界向中生界过渡的重要地质历史转折时期，发生了地史时期规模最大的生物灭绝事件。石千峰组作为华北地台二叠系-三叠系过渡阶段沉积，其时代归属对二叠系-三叠系界线的准确划分至关重要。本文应用LA-MC-ICPMS对华北中部太原西山晚二叠世-早三叠世上石盒子组、石千峰组、刘家沟组中4件砂岩样品进行碎屑锆石U-Pb定年，4件砂岩样品（SNF、XM、K8、LJG）分别给出了最年轻锆石峰值年龄270Ma、296Ma、250Ma、262Ma，表明太原西山上石盒子组师脑峰砂岩（SNF）的沉积时间不早于270Ma，石千峰组底部K8砂岩（K8）沉积时间不早于250Ma。因此，太原西山地区石千峰组应归属于早三叠世，二叠系-三叠系的界线应位于石千峰组K8砂岩之下。
이첩기-삼첩기지교시고생계향중생계과도적중요지질역사전절시기，발생료지사시기규모최대적생물멸절사건。석천봉조작위화북지태이첩계-삼첩계과도계단침적，기시대귀속대이첩계-삼첩계계선적준학화분지관중요。본문응용LA-MC-ICPMS대화북중부태원서산만이첩세-조삼첩세상석합자조、석천봉조、류가구조중4건사암양품진행쇄설고석U-Pb정년，4건사암양품（SNF、XM、K8、LJG）분별급출료최년경고석봉치년령270Ma、296Ma、250Ma、262Ma，표명태원서산상석합자조사뇌봉사암（SNF）적침적시간불조우270Ma，석천봉조저부K8사암（K8）침적시간불조우250Ma。인차，태원서산지구석천봉조응귀속우조삼첩세，이첩계-삼첩계적계선응위우석천봉조K8사암지하。
Permian to Triassicis an important turning point of geological history during the transition period of Paleozoic to Mesozoic,in which the largest mass extinction events in geological history happened.As the transition stage of Permian to Triassic,the era of Shiqianfeng Formation is crucial to define the boundary of Permian to Triassic.In order to determine the era of Shiqianfeng Formation in Xishan,Taiyuan,North China,the laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) was applied to date the U-Pb age of detrital zircon.Four sandstone samples (SNF,XM,K8 ,LJG)from the marker layers of strata division and correlation from the Xiashihezi Formation,Shiqianfeng Formation and Liujiagou Formation were analyzed.Four sandstone samples SNF,XM,K8,LJG obtained youngest graphical detrital zircon age were 270 Ma,296 Ma,250 Ma,262 Ma,respectively.The results show that the deposition time of Shinaofeng sandstone(SNF)was not earlier than 270Ma,the deposition time of K8 sandstone(K8)was not earlier than 250Ma.Therefore,Shiqianfeng Formation of Xishan,Taiyuan should belong to the Lower Triassic,and the boundary of Permian to Triassic lied under the K8 sandstone.