History of western Tethys Ocean and the birth of the circum-mediterranean orogeny as reflected by source-to-sink relations

A broad region of Mesozoic to Cenozoic tectonism along the western and central Circum-Mediterranean (CM) margins, from southern Spain (Betic Cordillera) to the northern Morocco (Rif) and Italy (Apennines), includes huge volumes of sedimentary record since the Late Paleozoic. These sediments are contemporaneous and related with the fragmentation of the Pangean supercontinent due to the rifting and progressive closure, as well as the following birth of the CM orogeny. The composition and stratigraphic relations of clastics in diverse sedimentary basins of the CM region reflect a complete record of provenance relations related to the progressive destruction of the Neotethyan Ocean and plate convergence between the two major plates of Europe and Africa, and Iberia, Adria and Mesomediterranean micrplates located between them. The changing nature of clastic wedges reflects the provenance relations from different source rocks involving obduction of the oceanic lithosphere, the uplifted Alpine-Mediterranean Chains, and the accreted previously deformed Mesomediterranean Microplate (AlKaPeCa), as well local neovolcanic sources, within the spatial and temporal evolving geo-puzzle terranes of the CM orogeny. The provenance evolution of sediment provides insights into how plate convergence and continental collision direct the sediment dispersal pathway in Cenozoic basins due to closure of eastern and southern Alpine-Tethyan remnant ocean basins and to the dual dispersal pathways from the previously born Alps and the nascent AlKaPeCa at the expenses of the previously deformed Mesomediterranean terranes. The source-to-sink relations testify episodic deformation events, diachronous Tethyan basin development, differentiate sediment provenance from exhumed and uplifted Alpine and CM orogens, and palaeogeographic rearrangement of crustal blocks along the nascent Mediterranean region.

环地中海（Circum-Mediterranean, CM）中西部边缘带存在一片覆盖中生代至新生代构造活动的广阔区域，其范围从西班牙南部的贝蒂科山脉（Betic Cordillera）延伸至摩洛哥北部的里夫山脉（Rif）与意大利的亚平宁山脉（Apennines），保存了自晚古生代以来的巨量沉积记录。这些沉积序列与泛超大陆（Pangean supercontinent）因裂谷作用与逐步闭合而发生裂解的过程同期，且与之相关，同时也与后续环地中海造山带（CM orogeny）的形成有关。环地中海区域各类沉积盆地中碎屑岩（clastics）的组分与地层关系，完整记录了与新特提斯洋（Neotethyan Ocean）逐步消亡、欧亚与非洲两大板块，以及夹于其间的伊比利亚、亚得里亚和中地中海微板块（Mesomediterranean microplates）之间的板块汇聚作用相关的物源关系。在环地中海造山带随时间与空间演化的地质拼图地体（geo-puzzle terranes）框架内，碎屑楔（clastic wedges）的性质变化反映了其物源来自不同母岩，包括大洋岩石圈的仰冲作用、抬升的阿尔卑斯-地中海造山带（Alpine-Mediterranean Chains）、拼贴就位的先期变形中地中海微板块（AlKaPeCa），以及局域的新火山物源。沉积物的物源演化过程，为理解板块汇聚与大陆碰撞如何控制新生代盆地的沉积物搬运路径提供了视角——这一过程伴随着阿尔卑斯-特提斯东部与南部残余洋盆的闭合，同时存在来自先期形成的阿尔卑斯造山带与新生的AlKaPeCa微板块的双重搬运路径，其物源供给来自先期变形的中地中海地体。该区域的源汇系统（source-to-sink）关系，佐证了幕式变形事件、穿时的特提斯盆地演化过程，区分了来自剥蚀抬升的阿尔卑斯及环地中海造山带的沉积物物源，同时记录了新生地中海区域地壳块体的古地理重组。