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Alicante University geology students visit Ojos Negros quarry

Students of the third course of Geology of the Alicante University within the subject of Regional Geology: visit the abandon Ojos Negros quarry. This is an excellent Ordovician-Silurian section of the Hirnantian glaciation.

The picture shows the student at the quarry border.

Ojos Negros quarry

Malaguide Carboniferous culm cycle in the Betic Cordillera

Carboniferous sandstone within the Paleo-Mesomediterranean Domain (Malaguide Subdomain), in southern Spain, represents a key detrital mode within the sedimentary budget of convergent plate boundaries during the Variscan s.s. to Paleotethysian orogenic time span (≈420–300 Ma). This Carboniferous detritus corresponds with Culm lithostratigraphic depositional unit, and it covers an important gap of information (paleogeographic, paleotectonic, source areas) to the area located between the Iberian-French massifs and the African Paleo-Atlas, in the western Paleotethys. Sandstone composition is quartzolithic and records an important high-to-medium-low grade metamorphic content. The source area was a lithic and transitional recycled orogen with a signature of volcanic and ophiolitic detritus (≈330 Ma and/or older). These supplies seem to be derived from a mid-crustal deformed and thrusted pre-late Ordovician to Early Carboniferous terrane, involved in the plate convergence (the southern Europe Iberian-French massifs overriding the north African area) southeatwards of the Variscan s.s. orogenic system, rapidly exhumed and uplifted at mid-Late Carboniferoous time. Consequently, in the overriding hinterland (southern Europe: Iberian-French massifs), metamorphic basement should be already structured during middle Carboniferous when thrusting took place and deposition of Culm facies started in the Malaguide Complex, suggesting Proterozoic-Early Carboniferous (most probably, ≈420 to 330 Ma) metamorphic highlands. The presence of serpentinite-like detritus (≈330 Ma and/or older) seems to indicate a metamorphosed oceanic crust being dismantled at that time. Thus, sources from ophiolitic suture (most probably developed at ≈420–330 Ma) zones are tentatively proposed in other northern Gondwana of southwestern Europe. The occurrence of a synsedimentary volcanic activity (andesitic) should be related to a lost magmatic arc (most probably developed at ≈360–330 Ma), reinforcing the idea of a nearby subduction area. Therefore, the thick terrigenous Culm deposits (≈330–300 Ma) from the Malaguide Subdomain could be deposited in a complex foreland system basin connected northward with carbonate platforms and with a crystalline highland uplifted domain from the southern Europe Iberian-French massifs and southward with the African Paleo-Atlas Domain. The studied mid- to late Carboniferous sandstone petrofacies deeply contributes to paleogeographic reconstructions since block fragmentation and spreading, during the Paleotethysian and Alpine orogenies, rearranged the Paleozoic paleogeography now part of the Cenozoic Perimediterranean Chains. After the correlation with the Carboniferous from other western Paleotethys domains, new paleogeographic-paleotectonic constraints.

Paleogeographic-paleotectonic maps: A) global pre-Pangea situation (350 Ma, Early Carboniferous); B) global Pangea situation (310 Ma, Late Carboniferous); C) detail of the Pangea situation (310 Ma, Late Carboniferous) in the northern Gondwana area; D) nowadays situation; E) geological cross-section at 310 Ma,Late Carboniferous (located in Fig. 14C). A) and B) modified from Pérez-Estaún et al. (2004) and Vera (2004), C) modified from Arenas et al. (2016), D) modified from Vera (2004). In C appears the location of the studied sectors (1–4) in the Malaguide Subdomain from the Paleo-Mesomediterranean Domain, and the corelated sectors: Iberian (sectors 5–7) and Central French (sectors 8 and 9) Massifs, E Paleo-Mesomediterranean Domain (sector 10), Bohemian Massif (sector 11), Paleo- Atlas-Saharian Domain (sectors 12–14), and Arabian (sector 15)
Paleogeographic-paleotectonic maps: A) global pre-Pangea situation (350 Ma, Early Carboniferous); B) global Pangea situation (310 Ma, Late Carboniferous); C) detail of the Pangea situation (310 Ma, Late Carboniferous) in the northern Gondwana area; D) nowadays situation; E) geological cross-section at 310 Ma, Late Carboniferous (located in Fig. 14C). A) and B) modified from Pérez-Estaún et al. (2004) and Vera (2004), C) modified from Arenas et al. (2016), D) modified from Vera (2004). In C appears the location of the studied sectors (1–4) in the Malaguide Subdomain from the Paleo-Mesomediterranean Domain, and the corelated sectors: Iberian (sectors 5–7) and Central French (sectors 8 and 9) Massifs, E Paleo-Mesomediterranean Domain (sector 10), Bohemian Massif (sector 11), Paleo- Atlas-Saharian Domain (sectors 12–14), and Arabian (sector 15).

cite as: Criniti, S.; Martín-Martín, M.; Martín-Algarra, A. New Constraints for the Western Paleotethys Paleogeography-Paleotectonics Derived from Detrital Signatures: Malaguide Carboniferous Culm Cycle (Betic Cordillera, S Spain). Sediment. Geol. 2023, 458, 106534, doi: 10.1016/j.sedgeo.2023.106534.

 

Regional geology field trip to Teruel

Students of the third course of Geology of the Alicante University within the subject of Regional Geology: visit Jarafuel triassic section, Aguaton jurassic section, Murero paleontological site, Fombuena section, Santa Cruz Paleozoic Seas Museum, Ojos Negros Mine, and Orea-Checa road Hirnatian section.

Student in the Aguatón “tunnel” section

The visit took place from 16 to 19 October of 2019 and the professors in charge were Juan Alberto Pérez-Valera and José Enrique Tent-Manclús.

Zoophycos found in the Devonian Santa Cruz de Nogueras Formation, near the village of Santa Cruz de Nogueras. The specimen is now in the Paleozoic Seas Museum.