Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)
Ductile nappe stacking and refolding in the Cycladic Blueschist Unit: insights from Sifnos Island (south Aegean Sea)
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基克拉迪蓝片岩单元中的延性推覆层堆积和重折叠：来自锡夫诺斯岛（南爱琴海）的见解
DOI：
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发表时间：
2016
影响因子：
2.3
通讯作者：
N. Gerogiannis
中科院分区：
文献类型：
--
作者：
E. Aravadinou;P. Xypolias;V. Chatzaras;I. Iliopoulos;N. Gerogiannis
利用新的地质和构造填图，结合运动学和角闪石化学分析，研究了西夫诺斯岛(爱琴海旋回)上旋回蓝片岩单元(CBU)的变形历史。我们集中在北Sifnos，这是一个以保存异常完好的榴辉岩和蓝片岩为特征的地区。我们的数据表明，CBU韧性变形的早期主相(D2)与从逆行到接近峰值的逆行条件的转变同步发生。这个变形阶段发生在始新世中期，与ESE向的逆冲作用有关，该逆冲作用使变质火山沉积亚单位侵位在大理岩亚单位之上。随后的折返相关(D3)变形以平缓的NE向俯冲褶皱和平行于褶皱轴面形成的NE向收缩剪切带为特征。晚始新世-渐新世，在蓝片岩和过渡的蓝片岩/绿片岩相条件下发生了北东向的剪切作用，导致早期推覆体的重新堆积。我们认为，在净挤压的构造背景下，CBU的韧性挤压机制比同造山和造山后伸展机制更能解释记录的与折返相关的变形。我们新的运动学结果结合前人在Cyclade地区的工作，揭示了区域尺度的构造运移方向从晚白垩世-中始新世(W)NW-(E)SE到晚始新世-渐新世(E)NE-(W)SW的区域尺度变化。观察到的运移方向的变化可能受阿尔卑斯山造山过程中非洲相对于欧洲的相对运动所支配。
New geological and structural mapping combined with kinematic and amphibole chemistry analyses is used to investigate the deformation history of the Cycladic Blueschist Unit (CBU) on Sifnos Island (Cyclades, Aegean Sea). We concentrate on north Sifnos, an area characterized by exceptionally well-preserved eclogites and blueschists. Our data show that the early, main phase (D2) of ductile deformation in the CBU occurred synchronous with the transition from prograde to close-to-peak retrograde conditions. This deformation phase took place at middle Eocene and is related to ESE-directed thrusting that emplaced the metavolcano-sedimentary subunit over the Marble subunit. The subsequent exhumation-related (D3) deformation is characterized by gently NE-plunging folds and NE-directed contractional shear zones that formed parallel to the axial planes of folds. NE-directed shearing occurred under blueschist and transitional blueschist-/greenschist-facies conditions during late Eocene–Oligocene and caused the restacking of the early nappe pile. We suggest that a mechanism of ductile extrusion of the CBU in a tectonic setting of net compression could explain better the recorded exhumation-related deformation than a mechanism of syn- and post-orogenic extension. Our new kinematic results in combination with previous works in the Cyclades area reveal a regional scale change in tectonic transport direction from (W)NW–(E)SE at Late Cretaceous–middle Eocene to (E)NE–(W)SW at late Eocene–Oligocene times. The observed change in transport direction may be governed by the relative motion of Africa with respect to Europe during Alpine orogeny.
影响因子：
2.9
作者：
L. Jolivet;C. Faccenna;B. Huet;L. Labrousse;L. Pourhiet;O. Lacombe;E. Lecomte;E. Burov;Y. Denèle
通讯作者：
L. Jolivet;C. Faccenna;B. Huet;L. Labrousse;L. Pourhiet;O. Lacombe;E. Lecomte;E. Burov;Y. Denèle
锡罗斯岛（希腊爱琴海）的新地质图：对基克拉迪蓝片岩单元的岩石地层学和结构历史的影响
DOI：
10.1130/2011.2481
发表时间：
2011
期刊：
影响因子：
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作者：
Keiter;Ballhaus;Tomaschek
通讯作者：
Tomaschek