地质学报
地質學報
지질학보
Acta Geologica Sinica
2015年
11期
1945-1952
,共8页
四川盆地%三叠纪%盐盆%沉积中心
四川盆地%三疊紀%鹽盆%沉積中心
사천분지%삼첩기%염분%침적중심
Sichuan basin%Triassic%salt basin%depositional center
四川盆地早、中三叠世共有六次成盐期,形成二十多个大小不等的盐盆。通过统计大量含盐钻井的盐岩层位、厚度、分布及含钾情况,圈定了各成盐期次盐盆的分布范围和成盐中心。盐盆范围与成盐中心清晰地显示:四川盆地早三叠世嘉陵江期末至中三叠世雷口坡期初(T1 j 5~T2 l 1-1),和中三叠世雷口坡期末(T2 l 4),分别在盆地东北部和西部,进入高盐度化成盐环境,具备成钾条件。盐盆的这一时空格局是印支运动江南古陆和龙门山之间差异性推覆、挤压下,补偿盆地的轴线不断向西方向迁移的结果,同时表明盆地迁移演化过程中,成钾环境发生于盐化旋回中嘉四段、嘉五段和雷四段等时段持续干旱的“气候窗”与潮坪上一些小“盐盆窗”的耦合。
四川盆地早、中三疊世共有六次成鹽期,形成二十多箇大小不等的鹽盆。通過統計大量含鹽鑽井的鹽巖層位、厚度、分佈及含鉀情況,圈定瞭各成鹽期次鹽盆的分佈範圍和成鹽中心。鹽盆範圍與成鹽中心清晰地顯示:四川盆地早三疊世嘉陵江期末至中三疊世雷口坡期初(T1 j 5~T2 l 1-1),和中三疊世雷口坡期末(T2 l 4),分彆在盆地東北部和西部,進入高鹽度化成鹽環境,具備成鉀條件。鹽盆的這一時空格跼是印支運動江南古陸和龍門山之間差異性推覆、擠壓下,補償盆地的軸線不斷嚮西方嚮遷移的結果,同時錶明盆地遷移縯化過程中,成鉀環境髮生于鹽化鏇迴中嘉四段、嘉五段和雷四段等時段持續榦旱的“氣候窗”與潮坪上一些小“鹽盆窗”的耦閤。
사천분지조、중삼첩세공유륙차성염기,형성이십다개대소불등적염분。통과통계대량함염찬정적염암층위、후도、분포급함갑정황,권정료각성염기차염분적분포범위화성염중심。염분범위여성염중심청석지현시:사천분지조삼첩세가릉강기말지중삼첩세뢰구파기초(T1 j 5~T2 l 1-1),화중삼첩세뢰구파기말(T2 l 4),분별재분지동북부화서부,진입고염도화성염배경,구비성갑조건。염분적저일시공격국시인지운동강남고륙화룡문산지간차이성추복、제압하,보상분지적축선불단향서방향천이적결과,동시표명분지천이연화과정중,성갑배경발생우염화선회중가사단、가오단화뢰사단등시단지속간한적“기후창”여조평상일사소“염분창”적우합。
There were six salification periods,during which more than 20 salt basin with various were formed in the Sichuan Basin size in early Middle Triassic.Based on a large number of statictic on the horizon, thickness,distribution and contents of potassium of the salt boreholes, this paper delineates the distribution of salt basins and centers of salification in each period,which clearly displays eastern Sichuan might have been supersaline and potassium environment from early Triassic late Jialingjiang phase to middle Triassic early Leikoupo phase(T1j 5-T2 l 1 -1 ).Corresponding,western Sichuan also might have been that in middle Triassic late Leikoupo phase (T2 l 4 ).The Triassic space-time structure of salt basins in Sichuan was a resuct of migration of axis of the basin toward west under different overriding and compression coming from Jiangnan oldland and Longmengshan.Meanwhile,the potassium environment happened under the interconnection of continuous dry climate fragments (T1 j 4-5 、T1 j 5 -2 and T1 l 4-2 )in saline cycle the and salt basins window on the strandflat.