安徽休宁地区下震旦統休宁羣砂岩的交变場退磁研究

本文使用交变場退磁方法对安徽休宁地区下震旦统休宁羣砂岩定向标本进行了剩磁稳定性检验,结果表明该岩层的天然剩余磁性基本上是稳定的,并得出它们的平均剩余磁化强度方向D_r=311°,I_r=76°,相应时代的古地极位置λ=90°E,φ=45°N,标本产地在当时所处的古纬度是90°-p=63°。最后,文章肯定了交变場退磁方法对古地磁学研究的重要意义;根据实验结果,对研究地区在早震旦世时的古气候提出了看法。

ALTERNATING FIELD DEMAGNETIZATION STUDY ON LOWER SINIAN SANDSTONES IN HSIUNING DISTRICT,ANHWEI PROVINCE

This paper presents the results of the remanent magnetic stability test of some orientated Lower Sinian sandstone samples collected in Hsiuning district, Anhwei province. Demagnetization procedure has been carried out on all specimens by alternating magnetic field, and the results show that the natural remanent magnetism of the formation is stable. The direction of the intensity of the mean remanent magnetism is determined as D_r=311° and I_r=76°. Thus, the position of the palaeomagnetic north pole at this age is inferred to be 90°E and 45°N, and the former latitude of the sampling site is 90°-p=63°. On the basis of the results some suggestion on the climatic condition in Hsiuning district during early Sinian period is made.