Home » Posts tagged 'Internal Betic Zone'
Tag Archives: Internal Betic Zone
3D Visualization of geological structures using Python: the case study of the Palomeque sheets
The goal of this paper is the construction of computerized 3D visualization of geological structures. Several Python applications have been used to adapt the paper map-based geological classical information to numerical geological maps represented in HTML files. The models include a map with the stratigraphic and structural contacts and symbols, five serial vertical sections, and a geological block diagram, all with real topography. This block diagram made with 2D figures allows a 3D visualization. Palomeque area (Murcia region, southeastern Spain) has been used as a key-case. This area consists of a deformed Upper Cretaceous to Oligocene succession belonging to the Internal Zone Malaguide Complex. The main structure consists of two thrust-fold sheets forming an imbricate system, also affected by a set of strike-slip faults with a sinistral regime. The constructed maps show a good agreement with the published classical geological maps and cross-sections demonstrating the benefits of using these Python applications.
Cite as: Bullejos, M. and Martín-Martín, M. (2023): 3D Visualization of geological structures using Python: the case study of the Palomeque sheets (SE, Spain). Journal of Maps 19, NO. 1, 2282593 https://doi.org/10.1080/17445647.2023.2282593
Oligocene-Lower Miocene sandstones of Western Tethys
The changing nature of detrital signatures in clastic wedges of the Circum-Mediterranean orogenic systems reflect the provenance relations from different source rocks of evolving geo-puzzle terranes, including ophiolite bearing, uplifted continental crust (both shallow to deep crust terranes), volcanic and sedimentary source rocks. We selected here sandstone suites directly occurring over the Mesomediterranean Micropaleoplate during the final stages of closure of the western-southern Tethyan realm. They are unconformably over the internal domains of the Circum-Mediterranean thrust belts, and include Oligocene-to-lower Miocene siliciclastic formations of the Betic Cordillera (As, Bosque, Río Pliego, El Niño, Ciudad Granada, Fuente-Espejos, Alozaina and Viñuela fms), Rif Chain (Fnideq and Sidi Abdeslam fms), and Calabrian terranes (Paludi, Pignolo and Stilo Capo d’Orlando fms). All these sandstone suites range from quartzolitic to quartzofeldspathic detrital modes reflecting close relations with their Paleozoic metasedimentary and plutonic source rocks and their related Mesozoic sedimentary covers.
Marked differences have been recognized from western (Betic-Rif) to eastern (Calabria) portions in terms of detritic suites. Detrital suites of the Betic-Rif portions reflect a transition between a craton, transitional and recycled orogenic provenance type. Contrarily, detrital suites of the Calabria portions reflect their transition from transitional continental to basement uplift orogenic provenance reflecting deposition in wedge-top basins during final subduction of the Magrebian-Lucanian-Ionian Basin below the Mesomediterranean and the opening of the Mediterranean basin as a backarc.
Middle Eocene carbonate platforms of the westernmost Tethys
A study of the paleoenvironmental evolution of the middle Eocene platforms recognized in the westernmost Tethys has been carried out in the well exposed middle Eocene succession from Sierra Espuña-Mula basin (Betic Cordillera, S Spain). Eight microfacies (Mf1 to Mf8) have been recognized, based mainly on fossil assemblages (principally larger benthic foraminifera), and rock texture and fabric.
The fossiliferous assemblage can be asigned to the ‘subtropical’ heterozoan association or to the low-latitude ‘foralgal facies’ , which are dominated by non-framework building, light-dependent biota such as perforate larger benthic foraminifera, coralline algae, and sometimes green algae and solitary corals. Larger benthic foraminifer assemblages, corresponding from euphotic to oligophotic conditions and the large surface showed, suggest a progressive marine ramp under essentially oligotrophic conditions. Eventually, supply of detrital sediments from the continent and/or upwelling currents increasse the nutrients of marine waters. Comparision with other Tethyan sectors allows stating that coral-reef buildups (z-corals) were widespread on shallow platforms of the central and eastern Tethys Ocean, but that these were neither of great dimensions nor dominant because of the much more dominant presence of larger benthic foraminifera. Moreover, these coral constructions were completely absents in the westernmost Tethys. The dominance of larger benthic foraminifera and the absence of z-corals in the westernmost Tethys is explained by particular paleogeographic features due to the occurrence of a narrow and deep oceanic branch (i.e., the Maghrebian Flysch Basin) connecting the Tethys with the Atlantic Ocean.
The various issues regarding the morphological characters and evolution of larger benthic foraminifera in the study area, such as sizes of tests, specific diversity and/or intraspecific variability, number of appearances and last occurrences during the middle Eocene are analyzed and compared with those appearing in other Tethyan sectors. In addition, the early to late Bartonian boundary is recognized in the study area as critical for the biological change as in other shallow-marine environments along the Tethys margins.
Recent Comments