@article{oai:nipr.repo.nii.ac.jp:00010745,
 author = {E.A. Melnik and V.D. Suvorov and E.V. Pavlov and Z.R. Mishenkina and E.A. Melnik and V.D. Suvorov and E.V. Pavlov and Z.R. Mishenkina},
 issue = {1},
 journal = {Polar Science, Polar Science},
 month = {Mar},
 note = {The estimate of seismic lithosphere thickness in Siberia remains controversial in spite of long-range controlled–source data available from peaceful nuclear explosions (PNE). Published models of layered upper mantle based on this evidence fail to unambiguously constrain the asthenospheric depth. The observed velocity changes may be due either to vertical layering or to lateral heterogeneity, which are difficult to discriminate because of large (1000 km) PNE spacing. Among the upper mantle models, obtained with reference to Moho velocities derived from higher-resolution chemical explosion data, we focus especially on lateral density heterogeneity. The model reveals three velocity layers, with velocities 8.0–8.5 km/s in Layer 1, 8.6–8.7 km/s in Layer 2, and ∼8.5 km/s in Layer 3. Layers 2, which varies strongly in thickness, may consist of dense eclogite, judging by the high velocities. Its base may correspond to the base of the lithosphere underlain by the lower-velocity asthenospheric material of Layer 3.

The lateral variations in velocity within Layer 1 and in thickness of Layer 2 correlate with major tectonic units: the West Siberian basin, the Tunguska basin with the Permian–Triassic continental flood basalts (the large igneous province of Siberian Traps), as well as the Vilyui basin and the Yakutian kimberlite province. Isostasy in the West Siberian and Vilyui basins results in thick sediments and thin crust, while the large depths of the basement and the intra–crustal discontinuity in the Tunguska basin isostatically compensate the elevated surface topography due to voluminous lavas. The magmatism left its imprint in the mantle as an attenuated “eclogitic layer” beneath the Tunguska basin. However, the available data are still insufficient to understand the exact causes of this attenuation, because mantle conditions may have changed during the elapsed 250 m.y. since then., シベリア地域で爆薬を用いた人工地震実験データにより推定された上部マントル構造は、8.0?8.5km/sの第１層、8.6?8.7 km/sの第２層、及び~8.5 km/sの第３層をもつ。第２層はその高速度から判断し、高密度のエクロジャイトから成ると思われる。第２層は厚さの変化が顕著でその底はリソスフェア底部に対応し、第3層はアセノスフェアに対応する。水平方向の速度・層厚の違いは、主要なテクトニクス単位である西シベリア盆地、ツングースカ盆地とP-T境界における大陸洪水玄武岩、さらにビルユイ盆地やヤクート･キンバーライト地域、等と対応している。西シベリア盆地とビルユイ盆地では、アイソスタシーを示す厚い堆積層及び薄い地殻が存在し、ツングースカ盆地の深い基盤岩と地殻内部の不連続面は、大量の溶岩により盛り上がった基盤地形をアイソスタシー補正している。ツングースカ盆地下のマントル内マグマ活動の履歴として、「エクロジャイト層」が残っていると解釈できるが、既存データだけでこの減衰領域の成因を解明することは出来ない。},
 pages = {119--129},
 title = {Seismic and density heterogeneities of lithosphere beneath Siberia: Evidence from the Craton long-range seismic profile},
 volume = {9},
 year = {2015}
}