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land, Sweden). ( 英 文 ). Jeppsson L.
GFF, 2008, 130(1): 31-40
Conodont faunas solve the longstanding
problem regarding the relationships
between the Hogklint, Tofta, and
lower Slite. The name Hangvar Formation
is here formally introduced for the
strata identified between the Tofta Formation
and the Slite Group. The Hangvar
Fm. includes marls as far SW as near
Paviken (previously Slite Marl), argillaceous
limestones (seen only in the most
distal areas accessible) followed by reefs
and associated limestones SE and NE of
Visby (previously Slite Beds, mostly
units a and b) and northeastwards to
eastern Faro (from the area around Kappelshamnsviken
and NE-wards, previously
Hogklint Beds). The formation is
delimited below and above by prominent
discontinuities i.e. sequence boundaries.
These coincide with biostratigraphical
boundaries, i.e. they probably represent
relatively long time intervals. The
Hangvar formation includes two subzones,
hence lower and upper parts can
be distinguished. The upper Hangvar
reef generation is the third in the
Wenlock of Gotland.
2010010547
中 国 西 南 地 区 峨 眉 山 火 山 作 用 前 后 沉
积 与 岩 相 古 地 理 : 地 幔 柱 活 动 在 地 表
表 现 的 新 见 解 = Sedimentation and
lithofacies paleogeography in southwestern
China before and after the Emeishan
flood volcanism: New insights into
surface response to mantle plume activity.
( 英 文 ). He B; Xu Y G; Wang Y M;
Luo Z Y. Journal of Geology, 2006,
114(1): 117-132
Investigations into Permian sedimentation
and reconstruction of paleogeography
in SW China are aimed at
characterizing sedimentary responses to
the Emeishan mantle plume. In addition
to erosional features on the sediments
underlying the uplifted Emeishan basalts,
unusual depositions of Permian age are
also present in the Emeishan large igneous
province ( LIP). Specifically, carbonate
gravity flows and submarine incised
canyon fillings were developed in
the western margin of the postulated uplifted
area, and rifting trenches were developed
along the eastern margin; alluvial
fan deposits occur at the boundary
between the inner and intermediate
zones. These depositions all rest on the
Maokou Formation and are in turn covered
by the Emeishan basalts, implying
synchronism between crustal uplift and
depositional events. These deposits and
the associated extension and normal
faulting along the margin of and within
the LIP represent sedimentary features
resulting from dynamic behavior of
mantle plume. Comparison of lithofacies
paleogeography before and after the
Emeishan flood volcanism highlights the
determinant role of mantle plume activity
in the geological evolution in SW
China. The rapid, differential erosion of
the Maokou Formation was likely related
to plume-induced dynamic uplift.
This uplift was apparently followed by
subsidence, given deposition of the marine
clastic rocks sandwiched between
basalts and the Maokou Formation in the
east and submarine basalts along the
margins of the province. A second-phase
uplift, attributed to underplating of
plume-derived melts at the crust-mantle
boundary, was characterized by prolonged
(similar to 45 m.yr.), plateautype
uplift and was responsible for the
appearance of the "Chuandian old land.
Integration of these erosional and depositional
characteristics allows us to depict
how the surface geology responds to
mantle plume, which explains some
complex sedimentological problems in
SW China.
2010010548
阿 曼 山 脉 构 造 深 部 岩 层 的 年 龄 及 地 层
相 互 关 系 : 晚 石 炭 世 新 特 提 斯 断 裂 U-
Pb SHRIMP 证 据 = Age and stratigraphic
relationships of structurally
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