Carboniferous to Cretaceous assembly and fragmentation of Mexico

Wr. Dickinson et Tf. Lawton, Carboniferous to Cretaceous assembly and fragmentation of Mexico, GEOL S AM B, 113(9), 2001, pp. 1142-1160
Citations number
Categorie Soggetti
Earth Sciences
Journal title
ISSN journal
0016-7606 → ACNP
Year of publication
1142 - 1160
SICI code
The geologic framework of Mexico evolved through the Phanerozoic assembly a nd fragmentation of crustal elements derived from Laurentia, Gondwana, and an intra-Pacific volcanogenic terrane. In middle Paleozoic time, an inactiv e south-facing Laurentian continental margin of transform origin passed thr ough northern Mexico to connect the miogeoclinal Cordilleran margin with th e passive continental margin formed by Cambrian rifting in Texas. Gondwanan blocks of eastern Mexico were accreted to Laurentia by juxtaposition along the Ouachita-Marathon suture belt in earliest Permian time. Subsequent Jur assic opening of the Gulf of Mexico by seafloor spreading displaced the Yuc atan-Chiapas block southward, as it rotated anticlockwise from edge-driven shear between Colombia and Florida, along a gulf-flank transform passing th rough the Isthmus of Tehuantepec. The continuity of a linear north-trending Permian-Triassic arc (now represented by a granite belt) in eastern Mexico precludes strike-slip slivering, of Mexico during gulf opening and implies that Colombia lay east of internally coherent Gondwanan crust of southeast ern Mexico, but south of Yucatan-Chiapas, prior to Pangean breakup. During subsequent intracontinental rifting, crustal elements of eastern Mexico wer e displaced southeastward, along a transform between basement blocks of pre sent northeastern and east-central Mexico, in the wake of Colombia's retrea t from Laurentia. The Chortis block of nuclear Central America also lay wit hin Pangea west of Colombia and remained attached to southern Mexico prior to its Cenozoic displacement eastward along the Cayman transform. The Cabor ca block of northwestern Mexico was displaced southeastward from the Cordil leran miogeocline by Permian-Triassic slip along a transform that linked th e convergent Sonoma orogen with the northern end of a subduction zone in ce ntral Mexico that paralleled the Permian-Triassic magmatic arc built on Gon dwanan crust of eastern Mexico. Subsequent post-MiddIe Triassic initiation of a west-facing continental-margin arc-trench system (i.e., with the subdu cting slab moving down to the east) along the structurally modified paleo-P acific flank of Pangea produced middle Mesozoic arc assemblages extending s outheastward from California and Arizona through east-central Mexico into C olombia. Beyond a compound suture belt lying outboard of the middle Mesozoi c continental margin, western Mexico is underlain by Mesozoic volcanogenic crust formed beneath an east-facing intraoceanic island arc that was accret ed to Laurentian and Gondwanan Mexico by arc-continent collision late in Ea rly Cretaceous time. The accreted are assemblage was overlapped by late Ear ly Cretaceous-early Late Cretaceous carbonate platforms linked depositional ly with comparable facies in eastern Mexico. As the offshore island arc app roached the continent, progressive consumption of the intervening oceanic p late induced slab rollback beneath the Jurassic magmatic arc on the mainlan d, terminating are magmatism and promoting development of associated rift t roughs that extend from northeastern Mexico to southeastern California. Fol lowing are collision and accretion, reversal of subduction polarity along t he expanded western flank of Mexico created a west-facing continental-margi n arc-trench system that was continuous with the Cordilleran arc and Franci scan trench of California. Subsequent subduction produced volcanic-plutonic arc assemblages on the mainland and in Baja California, which was contiguo us with the mainland prior to Neogene seafloor spreading that opened the Gu lf of California. A paired late Early Cretaceous subduction complex and late Mesozoic forearc basin occurred along the Pacific flank of Baja California.