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REE and incompatible elements, which
helps to speculate that they originated
from the same mantle magma with rare
condemnation, and from basaltic explosive
eruption of Longgang volcano
group. The tephra, from peat with age
proved that the eruption possibly happened
in 15 BC-26 AD, is one of Longgang
volcano group eruption that was
not recorded and is earlier than that of
Jinglongdingzi about 1600 aBP eruption.
And the sedimentary time of tephra is
during the period of low temperature alteration,
which may be the influence of
eruption toward the local climate according
to the correlativity of eruption to
local temperature curve of peat cellulose
oxygen isotope.
2010010517
基 于 湖 泊 沉 积 的 西 伯 利 亚 东 北 部 气 候
和 植 被 重 建 = A reconstruction of the
climate and vegetation of northeastern
Siberia based on lake sediments. ( 英 文 ).
Lozhkin A V; Anderson P A. Paleontological
Journal, 2006, 40(Supplement
5): S622-S628 3 图 版 .
Detailed palynological analysis of
glacial, tectonic, and crater lakes of
northeastern Siberia reveals continuous
records of the changing vegetation during
one or several climatic cycles of the
Pleistocene and in the Holocene. The
most continuous records in the mountain
areas of the region are those of Lake
Elikchan-4 (northern Okhotsk Sea Region).
Pollen records of Lake
El’gygytgyn, which was formed by the
impact of a meteorite in the northern
Chukchi Peninsula, reflect the response
of land vegetation to the global climatic
impact during the last 300 ka.
前 古 生 界
2010010518
印 度 中 部 Chattisgarh 盆 地 最 上 部 凝
灰 岩 锆 石 的 SHRIMP 年 龄 指 示 印 度
元 古 代 地 层 学 500Ma 的 修 正 =
SHRIMP ages of zircon in the uppermost
tuff in Chattisgarh Basin in central
India require similar to 500-Ma adjustment
in Indian Proterozoic stratigraphy.
( 英 文 ). Patranabis-Deb S; Bickford M E;
Hill B; Chaudhuri A K; Basu A. Journal
of Geology, 2007, 115(4): 407-415
The Chattisgarh Basin of east central
India and many unmetamorphosed Proterozoic
sedimentary basins of Peninsular
India have been considered mostly
Neoproterozoic (1000-545 Ma) in age.
A newly recognized succession of rhyolitic
ignimbrite, ash beds, and volcaniclastic
sandstones near the top of the
similar to 2.2-km-thick sedimentary fill
of the Chattisgarh Basin is a
chronostratigraphic marker. Euhedral
igneous zircons from these units give U-
Pb SHRIMP ages of 990-1020 Ma, indicating
that the basin fill beneath this
marker horizon is pre-Neoproterozoic.
On the basis of newly reported zircon
ages of Ma from the basal part of the
Vindhyan Basin and accepting the consensus
that all 1631 +/- 5 virtually undeformed
and unmetamorphosed cratoninterior
Proterozoic sedimentary basins
in peninsular India are approximately
coeval, we conclude that these basins are
approximately Mesoproterozoic (1600-
1000 Ma) in age. The reassigned age for
these rocks (1650 to 900 or possibly
similar to 1000 Ma), up to 500 Ma in
variance with the current notion (similar
to 1100 to similar to 518 Ma; Naqvi
2005), calls for a thorough rethinking of
contemporary models concerning tectonics,
sedimentation, and other geological
activity that affected the Indian shield in
the Proterozoic Era.
2010010519
赞 比 亚 南 部 Zambezi 外 壳 岩 层 序 的 地
质 年 代 学 : 沿 刚 果 克 拉 通 南 缘 新 元 古
代 离 散 过 程 的 记 录 = Geochronology of
the Zambezi supracrustal sequence,
southern Zambia: A record of Neoproterozoic
divergent processes along the
southern margin of the Congo Craton.
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