Paleomagnetism of Upper Vendian sediments from the Winter Coast, White Sea region, Russia: Implications for the paleogeography of Baltica during Neoproterozoic times
Paleomagnetism of Upper Vendian sediments from the Winter Coast, White Sea region, Russia: Implications for the paleogeography of Baltica during Neoproterozoic times
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DOI：
10.1029/2001jb001607
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发表时间：
2002-11
影响因子：
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通讯作者：
V. Popov;A. Iosifidi;A. Khramov;J. Tait;V. Bachtadse
中科院分区：
文献类型：
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作者：
V. Popov;A. Iosifidi;A. Khramov;J. Tait;V. Bachtadse
[1]描述了俄罗斯西北部白海海岸线上文迪甸沉积序列的古地磁结果。由于其保存完好的埃迪卡拉动物群，这些经典的暴露一直是密集的古生物调查的主题，但到目前为止还没有公布任何古地磁结果。在(65.5°，40.0°E)火山灰层同源岩浆锆石U-Pb年龄为555 Ma±3 Ma的地区，共采集了3个剖面(35个测点)的337个手样和210个定向钻芯。标准的古地磁程序产生两个主要的自然剩余磁化分量：中温(15 0°-35 0°C)，单极性分量(D=12 1°，I=72°，n=2 32个样品，k=46.0，α95=1.3°，磁极位置在40.0°N，79.0°E，dp=2.0°，dm=2.3°)和高温(5 5 0°-6 80°C)双极性分量(正常极性：D=2 78°，I=43°，n=54个样品，k=2 5.2，α95=3.9°，反极性：D=10 1°，I=−39°n=40，K=23.3，α95=4.8°，南极位置24°S，132°E，dp=2.3°，dm=3.8°)。后者被称为Z，通过了反转、地层和一致性测试，并被解释为反映了文迪亚晚期地球磁场的方向。这些结果使波罗的海处于北纬低纬度(10°至35°之间)，由此产生的极点位置需要对波罗的海最新的视极游路径(APWP)进行修正。
[1] Paleomagnetic results from an Upper Vendian sedimentary sequence exposed along the White Sea shoreline, NW Russia are described. These classical exposures have been the subject of intense paleontological investigations due to their well-preserved Ediacara fauna, but no paleomagnetic results have as yet been published. A total of 337 hand samples and 210 oriented drill cores (35 sites) along three profiles have been collected at the locality (65.5°, 40.0°E) where a 555 ± 3 Ma U–Pb age of comagmatic zircons from volcanic ash layers has been recently obtained. Standard paleomagnetic procedures yield two main natural remanent magnetization (NRM) components: an intermediate-temperature (150°–350°C), single-polarity component (D = 121°, I = 72°, n = 232 samples, k = 46.0, α95 = 1.3°, pole position at 40.0°N, 79.0°E, dp = 2.0°, dm = 2.3°) and a high-temperature (550°–680°C) dual-polarity component (normal polarity: D = 278°, I = 43°, n = 54 samples, k = 25.2, α95 = 3.9°, reversed polarity: D = 101°, I = −39° n = 40, K = 23.3, α95 = 4.8°, south pole position at 24°S, 132°E, dp = 2.3°, dm = 3.8°). This latter component, termed Z, passes reversal, stratigraphic, and consistency tests and is interpreted to reflect the direction of the Earth's magnetic field during Late Vendian times. These results put Baltica into low northern latitudes (between 10° and 35°) and the resulting pole position requires modification of the most recent Apparent Polar Wander Paths (APWP) for Baltica.