Scherreiks Rudolph, BouDagher-Fadel Marcelle
Geologische Staatssammlung of the Bayerische Staatssammlung für Palaeontologie und Geologie, Luisenstr. 37, 80333 Munich, Germany.
University College London, Office of the Vice-Provost (Research), 2 Taviton Street, WC1H OBT, London, UK.
UCL Open Environ. 2021 Sep 22;3:e024. doi: 10.14324/111.444/ucloe.000024. eCollection 2021.
Seismic tomographic images of the mantle below the Hellenides indicate that the Vardar Ocean probably had a composite width of over 3000 km. From surface geology we know that this ocean was initially located between two passive margins: Pelagonian Adria in the west and Serbo-Macedonian-Eurasia in the east. Pelagonia was covered by a carbonate platform that accumulated, during Late Triassic to Early Cretaceous time, where highly diversified carbonate sedimentary environments evolved and reacted to the adjacent, converging Vardar Ocean plate. We conceive that on the east side of the Vardar Ocean, a Cretaceous carbonate platform evolved from the Aptian to the Maastrichtian time in the forearc basin of the Vardar supra-subduction volcanic arc complex. The closure of the Vardar Ocean occurred in one episode of ophiolite obduction and in two episodes of intra-oceanic subduction. During the Middle Jurassic time a 1200-km slab of west Vardar lithosphere subducted beneath the supra-subduction, 'Eohellenic', arc, while a 200-km-wide slab obducted onto Pelagonia between the Callovian and Valanginian times. During the Late Jurassic through to the Cretaceous time a 1700-km-wide slab subducted beneath the evolving east Vardar-zone arc-complex. Pelagonia, the trailing edge of the subducting east-Vardar Ocean slab, crashed and underthrust the Vardar arc complex during the Paleocene time and ultimately crashed with Serbo-Macedonia. Since the late Early Jurassic time, the Hellenides have moved about 3000 km toward the northeast while the Atlantic Ocean spread.
希腊地盾下方地幔的地震层析成像图表明,瓦尔达尔洋的复合宽度可能超过3000千米。从地表地质情况我们了解到,这片海洋最初位于两个被动大陆边缘之间:西侧是伯罗奔尼撒亚得里亚,东侧是塞尔维亚-马其顿-欧亚大陆。伯罗奔尼撒半岛被一个碳酸盐台地覆盖,在晚三叠世至早白垩世期间,这里演化出高度多样化的碳酸盐沉积环境,并与相邻的、正在汇聚的瓦尔达尔洋板块相互作用。我们认为,在瓦尔达尔洋东侧,一个白垩纪碳酸盐台地在瓦尔达尔超俯冲火山弧复合体的弧前盆地中,从阿普第阶到马斯特里赫特阶逐渐演化形成。瓦尔达尔洋的闭合发生在一次蛇绿岩仰冲事件和两次洋内俯冲事件中。在中侏罗世时期,瓦尔达尔西部1200千米宽的岩石圈板块俯冲到超俯冲的“古希腊”弧之下,而在卡洛维阶和瓦朗吉阶之间,一个200千米宽的板块仰冲到伯罗奔尼撒半岛上。在晚侏罗世到白垩纪时期,一个1700千米宽的板块俯冲到不断演化的瓦尔达尔洋东部区域弧复合体之下。伯罗奔尼撒半岛作为俯冲到东部的瓦尔达尔洋洋板块的后缘,在古新世时期与瓦尔达尔弧复合体发生碰撞并逆冲,最终与塞尔维亚-马其顿碰撞。自早侏罗世晚期以来,随着大西洋扩张,希腊地盾向东北方向移动了约3000千米。