高校地质学报
高校地質學報
고교지질학보
GEOLOGICAL JOURNAL OF CHINA UNIVERSITIES
2014年
2期
268-276
,共9页
区域重力异常分离%松辽盆地%盆地基底%Moho面%小波多尺度分解%对数功率谱
區域重力異常分離%鬆遼盆地%盆地基底%Moho麵%小波多呎度分解%對數功率譜
구역중력이상분리%송료분지%분지기저%Moho면%소파다척도분해%대수공솔보
regional gravity anomaly separation%Songliao Basin%Basin basement%Moho depth%wavelet multi-scale decomposition%power spectrum analysis
松辽盆地是中国东北盆地群的代表性盆地之一。松辽盆地及其邻区的布格重力异常分布特征以北东-北北东向为主,其次为东西向,重力场分区分块特征明显,显示了明显的拼贴构造背景,依据布格重力异常特征对研究区构造单元进行分区,共分成松辽盆地异常区、大兴安岭重力梯级带等5个特征区。利用小波多尺度分解方法对松辽盆地重力场进行分离,选择最佳的分离阶数(4阶),随后利用对数功率谱确定每阶异常的视深度,提取区域异常,分层研究地壳顶部(D1G)、基底(D2G,D3G)及深部密度界面(A4G)的起伏特征,共圈定基底凹陷14个,并绘制了研究区的Moho面埋深图。地球物理特征揭示了松辽盆地的深部构造,为研究盆地油气勘探及构造演化提供了重要依据。
鬆遼盆地是中國東北盆地群的代錶性盆地之一。鬆遼盆地及其鄰區的佈格重力異常分佈特徵以北東-北北東嚮為主,其次為東西嚮,重力場分區分塊特徵明顯,顯示瞭明顯的拼貼構造揹景,依據佈格重力異常特徵對研究區構造單元進行分區,共分成鬆遼盆地異常區、大興安嶺重力梯級帶等5箇特徵區。利用小波多呎度分解方法對鬆遼盆地重力場進行分離,選擇最佳的分離階數(4階),隨後利用對數功率譜確定每階異常的視深度,提取區域異常,分層研究地殼頂部(D1G)、基底(D2G,D3G)及深部密度界麵(A4G)的起伏特徵,共圈定基底凹陷14箇,併繪製瞭研究區的Moho麵埋深圖。地毬物理特徵揭示瞭鬆遼盆地的深部構造,為研究盆地油氣勘探及構造縯化提供瞭重要依據。
송료분지시중국동북분지군적대표성분지지일。송료분지급기린구적포격중력이상분포특정이북동-북북동향위주,기차위동서향,중력장분구분괴특정명현,현시료명현적병첩구조배경,의거포격중력이상특정대연구구구조단원진행분구,공분성송료분지이상구、대흥안령중력제급대등5개특정구。이용소파다척도분해방법대송료분지중력장진행분리,선택최가적분리계수(4계),수후이용대수공솔보학정매계이상적시심도,제취구역이상,분층연구지각정부(D1G)、기저(D2G,D3G)급심부밀도계면(A4G)적기복특정,공권정기저요함14개,병회제료연구구적Moho면매심도。지구물리특정게시료송료분지적심부구조,위연구분지유기감탐급구조연화제공료중요의거。
The Songliao Basin is one of the typical basins among the NE China Basin Groups. The main structural trending of gravity anomaly field is NNE to NE, and the study area shows a significant feature of deep collage-type pattern. Accordingly, the region is divided into five subregions with different features of gravity anomalies. The gravity field of NE China Songliao Basin is separated, using the WMD method with the 4th separation order, the apparent depth of the anomalies in each order is determined using the Logarithmic PSA. The shallow high-frequency anomalies are then removed to obtain the regional gravity anomalies. Through the hierarchical analyses, we learned the characters of the irregularity of the shallow crust, basement, and the crustal deep interfaces, and identified 14 depressions of the basement while drawing a depth map of Moho discontinuity. The geophysical characteristics of Songliao Basin reveal its deep structures, which provide an important basis for oil-gas exploration and studying tectonic evolution.