Paleomagnetism and Cyclostratigraphy of the Permian-Triassic Boundary Interval of the Staroe Slukino Section, Vladimir Region

Abstract

The paper presents the results of paleomagnetic, rock magnetic, and cyclostratigraphic studies of continental red beds that compose the Permian-Triassic boundary interval of the Staroe Slukino section in the Vladimir Region, Russia. Based on the directions of the characteristic components of the natural remanent magnetization of the studied rocks in the sampled stratum, the intervals of normal and reverse polarity related to the regional magnetozones r2RnP, r3RnP, and N3P-T were identified. Within the r3RnP zone, there is an interval of anomalous paleomagnetic directions, which has similar characteristics to those identified earlier in the coeval intervals of the Nedubrovo, Zhukov Ravine, and Okskiy Siyezd sections. Revising the biostratigraphy allows us to assume that the two zones of anomalous paleomagnetic directions in the composite magnetic polarity scale of the upper Permian of the Russian Platform are a reflection of the same epoch of an anomalous geomagnetic field configuration. It is estimated by the cyclostratigraphic method that the studied 16 m interval of the Staroe Slukino section took 900±20 thousand years to accumulate, which limits the duration of the geomagnetic field anomalous state near the Permian-Triassic boundary to ~110 000 years. A new Permian-Triassic (~252 Ma) paleomagnetic pole of the East European Platform is calculated: plat = 36.3°; plong = = 155.0°; dp/dm = 2.8°/4.8°.