The Westernmost Tethys Blog

11/12/2019

Field trip to Granada

Filed under: Betics — Tags: , — messinianalicante @ 3:03 PM

Students of the third course of Geology of the Alicante University within the subject of Mapping 2: visit Benalúa in the Guadix basin.

The visit took place from October 23th until 26th of 2019 and the professor in charge was Manuel Martín-Martín.

 

10/29/2019

Regional geology field trip to Teruel

Filed under: Iberian range,Paleozoic — Tags: , , — messinianalicante @ 6:36 PM

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.

10/25/2019

Tectonic breakup in the Eastern Betic zone

Six Paleogene-Aquitanian successions have been reconstructed in the Alicante area (eastern External Betic Zone). The lithofacies association evidences “catastrophic” syn-sedimentary tectonic processes consisting of slumps, mega-olisthostromes, “pillow-beds” and turbiditic deposits  (Figure 1).

Figure 1. Field photos of the main macro-tectofacies found in the study area (see text for details). (A) A typical Lower Eocene sequence of the Villafranqueza section. (B) Calcarenite turbidite with convolute bedding (Lower Eocene, Villafranqueza). (C) Two Oligocene carbonate turbiditic channelized bodies (Busot). (D) Oligocene conglomeratic bed with erosional base and reverse grading of clasts, typical of debris flow deposits (Busot). (E) Oligocene slumped level and pillow-beds (Busot). (F) Oligocene mega-flute casts indicating a northwestwards-directed paleocurrents (Relleu). (G) Oligocene pillow-beds (Relleu). (H) Oligocene mega-olisthostrome with huge blocks (Playa Nudista). (I) Slumped megabed (Playa Nudista).

This kind of sedimentation is related to unconformity surfaces delimiting sequence and para-sequence cycles in the stratigraphic record (Figure 2).

Figure 2. Unconformities, associated gaps of the Eocene and Oligocene-Miocene depositional sequences compared with the sedimentary cycles of (Vera, 2000). The figure shows a basement tectonic interpreted as folding during the Eocene and blind thrust during the Oligocene-Aquitanian. The different evolutionary trends are discussed in the text.

The data compiled have enabled the reconstruction of the Paleogene-Aquitanian paleogeographic and geodynamic evolution of this sector of the External Betics. During the Eocene the sedimentary basin is interpreted as a narrow trough affected by (growth) folding related to blind thrust faulting with a source area from the north-western margin, while the southeastern margin remained inactive. During the Oligocene-Aquitanian, the sourcing margin became the southeastern margin of the basin affected by a catastrophic tectonic (Figure 3).

Figure 3. Paleogeographic-geodynamic model of the Alicante Trough during Eocene and Oligocene-Miocene times.

The activity of the margins is identified from specific sediment sources area for the platform-slope-troughsystem and from tectofacies analysis. The southeastern South Iberian Margin is thought to be closer to the Internal Betic Zone, which was tectonically pushing towards the South Iberian Margin. This pushing could generate a lateral progressive elimination of subbetic paleogeographic domains in the eastern Betics (Figure 4).

Figure 4. Synthetic Oligocene-Aquitanian paleogeographic-geodynamic model proposed for the western.

This geodynamic frame could explain the development of such “catastrophic” tectono-sedimentary processes during the Late Oligocene-Early Miocene.

Cite as: Guerrera, F. and Martín-Martín, M. (2014): Paleogene-Aquitanian tectonic breakup in the Eastern External Betic Zone (Alicante, SE Spain). Revista de la Sociedad Geológica de España, 27(1): 271-285.

 

10/07/2019

Nearshore Mid-Triassic Zoophycos

Filed under: Iberian range,Tethys — Tags: , , — messinianalicante @ 12:53 PM

 Zoophycos is a well-known trace fossil common throughout the Phanerozoic. Paleozoic forms show important differences in morphology and habitat distribution with respect to the Jurassic, Cretaceous, and Cenozoic ones. Therefore, Early–Middle Triassic is considered a crucial time-span for the understanding of the evolution of this trace fossil. So far, Early Triassic  Zoophycos is unknown and Middle Triassic forms were recorded only in deposits from Thuringia. The morphology and paleoenvironment of  Zoophycos from the middle–upper Muschelkalk of the Iberian Range is herein described.

Zoophycos ichnoassemblage. Note the very small dimensions and poor vertical development of the trace fossils. Top view of a well-preserved Zoophycos. The flower-shaped outline is well visible as is the apex in the central part of the structure.

 

The best-preserved trace fossils occur in a dolomicritic bed Ladinian in age, and are represented by small forms with a subcircular, slightly lobed outline and very little penetration depth. They were deposited in a very shallow, quiet-water environment with transition to supratidal/emerged areas. The low diversity of both trace fossils and skeletal remains point to stressful conditions related to strong salinity variations and/or poor water circulation. A comparison was made with  Zoophycos from Anisian deposits of the Muschelkalk in Germany. This showed that both forms are quite simple and penetrate only the shallowest tiers, although they are different in whorl outline and lobe shape.

Reconstruction of the most common Zoophycos form of the Jarafuel section. W lobe width, L lobe length, H height of the whole structure.

This confirms that, notwithstanding the morphological variability of this group,  Zoophycos still maintained a quite simple structure in the Triassic. A shallow-water environment was deduced for both localities, confirming that at least until the Early Jurassic  Zoophycos had not definitively migrated toward deep-water areas.

Cite as: Giannetti, A., Tent-Manclús, J. E. y Baeza-Carratalá, J. F. (2017): New evidence of nearshore Mid-Triassic Zoophycos: morphological and paleoenvironmental characterization. Facies, 63,16: 1-12. DOI : 10.1007/s10347-017-0498-8

09/23/2019

Jiménez de Cisneros course field trip to the Crevillente Sierra

Filed under: Betics — Tags: , , — messinianalicante @ 11:03 AM

The field trip of the he summer school course of the University Miguel Hernandez  entitled “Jimenez de Cisneros, pioneer in the geological and paleontological investigation in the Southern Alicante” took place on september 5th, 2019.

The participants visit the Los Molinos educative center and then waked along the dirt road to the Pouet de la Mel spring.

The fist photography show the conductor of this field trip will be our collegue José Enrique Tent-Manclús teaching the finimessinian transgressive surface on the background of the picture.

The second fotography show the all participants in the field trip near the Pouet the la Mel spring with the Sierra de Crevillente Jurassic at the back.

More information about the Crevillente course here.

09/01/2019

Tethyan to Mediterranean Evolution

Filed under: Betics,Tethys — Tags: — messinianalicante @ 5:49 PM

Message from the Guest Editor

Dear Colleagues,

Several geological modeling studies on the geodynamic and paleogeographic Alpine (Eo-Alpine during the Cretaceous–Paleogene; Neo-Alpine during the Oligocene– Miocene) evolution of the Mediterranean have been published without consensus in the last four decades. Therefore, a Special Issue dedicated to “Tethayan to Mediterranean evolution” seems justified. Studies that consider the geodynamic and/or paleogeographic evolution of the entire Mediterranean area or a part of this area will be welcome. The proposal can be focused on stratigraphic, sedimentological, petrographic, or tectonic data, or geophysical interpretations and reconstructions based on principles of Plate Tectonics using GPlates or similar software. The papers that are published in this Special Issue can contribute to clarifying and updating the state of our knowledge about this controversial theme.

Message from the Editorial Board

T h e Journal of Marine Science and Engineering (JMSE; ISSN 2077-1312) is an international peer-reviewed open access journal which provides an advanced forum for studies related to marine science and engineering. The journal aims to provide scholarly research on a range of topics, including ocean engineering, chemical oceanography, physical oceanography, marine biology and marine geosciences. We invite you to publish in our journal sharing your important research findings with the global ocean community.

Open Access: free for readers, with article processing charges (APC) paid by authors or their institutions.

High visibility: Indexed in the Science Citation Index Expanded in Web of Science, in Inspec (IET) and in Scopus.

CiteScore (2018 Scopus data): 1.76, which equals rank 30/92 in ‘Ocean Engineering’, rank 105/288 in ‘Civil and Structural Engineering’ and rank 77/203 in ‘Water Science and Technology’.

 

Guest Editor:

Prof. Dr. Manuel Martín-Martín

Earth sciences and environment

Department (University of Alicante). Campus Universitario del San Vicente del Raspeig, AP- 99, 03080 Alicante, Spain

manuel.martin.m3@gmail.com

Deadline for manuscript submissions:

10 March 2020

08/28/2019

Jiménez de Cisneros tribute in Crevillente

Filed under: Sin categoría — messinianalicante @ 2:22 PM

On september 5th of 2019 there will be a field trip (17:30 to 21:00)  organized under the summer school course of the University Miguel Hernandez  entitled “Jimenez de Cisneros, pioneer in the geological and paleontological investigation in the Southern Alicante”.

More information about the Crevillente course here.

The participant will see the southern section of the Crevillente Sierra from Los Molinos educative center to the Pouet de la Mel spring. Visiting the neogene cover, the Els Pontets diapir, and the Mesozoic carbonatic rocks of the Crevillente Sierra.

The conductor of this field trip will be our collegue José Enrique Tent Manclús.

Landscape of the Crevillente Sierra taken at the early XXth century by Daniel Jiménez de Cisneros. The mountain, “el Frare” viewed from the southern side of the Moeixa.

08/27/2019

Paleogene sedimentary evolution of the Alicante Trough

Filed under: Betics — Tags: , , , , — messinianalicante @ 7:52 AM

A new work to illustrate a changes in the evolution of the Alicante Trough located to the southeastern part of the sudiberian paleomargin and north to the supposed elevated sea floor forming a marine platform.  Here the link to the work in Repository of the UA.

The Paleogene Alicante Trough of the South-Iberian Margin (External Betic Zone) consists of a narrow sedimentary basin that has active margins  located to the north-northwest (active mainly during the Eocene) and to the south-southeast (active during the Oligocene). Both margins, consisting of shallow unstable platforms, were the source areas for the external-platform slope (in the opposite margins) and deep-basin (in the middle) depositional realms. The southern margin, lost under the Mediterranean Sea, is recognized only by the reconstructed Oligocene slope sediments.

Geological sketch map of the Alicante region of the study area (External Betic Zone) within the Internal Prebetic (North-Northeast sector) and Intermediate sub-Domains (south-southwest sector).

The eight successions studied, on opposites external-platform-slope margins and the deep within the central part of the basin, lead us to divide the basin into two depositional realms: the subsident Western Depositional Area (WDA) and the not subsident Eastern Depositional Area (EDA). This study has also enabled us to divide the infilling of the basin into two depositional sequences: Eocene p.p. (EDS) and Oligocene p.p. (ODS) in age, respectively, bound by two sequence boundaries (unconformities) at the Early Eocene (P6 zone) and Early Oligocene (P19 zone). The EDSand ODSare comprised of turbiditic and olisthostromic deposits and frequently slumps, evidencing an active tectonic in the margin-basin system.

Stratigraphy, correlation, sampling localization and main sedimentary cycles recognized (Eocene p.p. and Oligocene p.p.) of the studied successions in the Western (WDA) and Eastern EDA) Depositional Areas.

 

Chronostragraphy of the studied successions.

The correlation of the Paleogene sedimentary reconstructed in the Alicante Trough with other four synthetic successions throughout the External (three in the Subbetic Domain) and one in the Internal Betic Zone indicate a Paleogene generalised deformational framework.

Main Eocene and Oligocene sedimentary realms and location of the studied successions in the Internal Prebetic and Intermediate sub-Domains.

Sedimentary record and new sequential stratigraphy in the study area.

In addition, this evolution is contemporaneous to the Pyrenean, Iberian and the Nevado-Filabride Alpine deformation. The Paleogene tectonic recognised in the External Betic Zone is younger since the main orogenic deformation took place in the late Burdigalian to early Tortonian.

Correlation among synthetic Paleogene successions and main unconformities in the Betic Chain. Key: ALI, Alicante succession (Internal Prebetic-Intermediate sub-Domains); SB, Bullas succession, (Murcia province, Middle Subbetic sub-Domain); SPM, Piñar-Moreda succession, (Granada province, Middle Subbetic sub-Domain); SHC, Malaga succession (High Chain, Internal Subbetic sub-Domain); MSE, Sierra Espuña succession (Murcia province, Internal Betic Zones, Malaguide Complex).

The origin of these early tectonics is discussed in relation to the Nevado-Filabride Alpine deformation.

Palaeogeography and geodynamic model of the Western Tethys during Late Cretaceous and Late Oligocene. Numbers 1 to 5 indicate the location of the correlated successions.

Cite as: Guerrera, F., Estévez, A., López-Arcos, M., Martín-Martín, M., Martín-Pérez, J.A., Serrano, F. (2006): Paleogene tectono-sedimentary evolution of the Alicante Trough (External Betic Zone, SE Spain) and its bearing on the timing of the deformation of the South-Iberian Margin. Geodinamica Acta, 19 (2): 87-101. doi: 10.3166/ga.19.87-101

07/31/2019

8th International Brachiopod Congress

Filed under: Betics — Tags: , , — messinianalicante @ 8:34 PM

The 8th International Brachiopod Congress was held at the University of Milan (Università deli Studi di Milano) and organized by a committee chaired by Lucia Angiolini from Milan and Renato Posenato from Ferrara.

A four-day pre-congress fieldtrip was proposed to Spain with a detailed guidebook published by García Joral et al., (2018). The fieldtrip to Spain started on 6th September 2018 in Madrid, from where participants headed northwards to Aragon, where in the Iberian Ranges two days were devoted to Jurassic and one to the Palaeozoic (Ordovician, Silurian, and Devonian). The last day took the participants to the Betic Mountains near Alicante, where we admired the Liassic faunas of the Mediterranean province.

Pictures of the congress and the fieldtrips can be seen in:

Halamski A. T., 2019. Eighth International Brachiopod Congress Milan, Italy, 11th-14th September, 2018. http://paleopolis.rediris.es/BrachNet/REF/Pub/halamski-2019.html, 9 p

Fieldtrip to Spain, 9th September, 2018. José Enrique Tent-Manclús explaining the geology of the Betic Mountains. Liassic, Cerro de la Cruz section, Reclot Mountain Range near Alicante. Photo by A.T. Halamski.

Reference:

García-Joral F., Villas E. & Baeza-Carratalá J.F. (eds), 2018. 8th International Brachiopod Congress Field Guide. E1: Paleozoic and Mesozoic brachiopods of East Spain, ii + 76 pp. Workcenter Servicios Globales de Documentación, Madrid.

07/26/2019

Source areas in the Agost Basin (Betic Cordillera)

Filed under: Betics,Tectonosedimentary model — Tags: , , , — messinianalicante @ 7:52 AM

A new work to illustrate a changes in source areas related with pull-apart basin  in the Betics. Here the link to the work in researchgate.

Sedimentary and mineralogical analyses were performed in the Neogene Agost Basin (External Domain, Betic Cordillera) to reconstruct relationships between tectonics and sedimentation, and source areas evolution over time.

Geological Setting

Figure 1) A: Index map; B: Geological sketch showing the main zones and units of the Betic Cordillera; C: Geological map based on the main sedimentary cycles proposed by Vera (2004).

 

The sedimentary analysis allowed defining two sedimentary sequences: (1) Lower Stratigraphic Unit, Serravallian p.p. and (2) Upper Stratigraphic Unit, post Lower Tortonian (Upper Miocene p.p.)separated by an angular unconformity. They consist of marine (lithofacies L-1to L-3) and continental (lithofacies L-5to L-8) deposits respectively (Figure 2).

Figure 2. Lithostratigraphic record and correlations of four representative successions (logs 1 to 4) of the Agost Basin. The two main sequences (Lower Stratigraphic Unit, LSU and Upper Stratigraphic Unit, USU) separated by an angular unconformity are evidenced. Depositional environments, supplies and the isochronous lines T1-T5 are also indicated.

 

The analysis of mineralogical assemblages and some XRD parameters of the sedimentary sequences (Figure 3) and older formations (Figure 4) allowed recognizing a sedimentary evolution controlled by the activation of different source areas over time.

Figure 3. Mineralogical results of the Neogene sedimentary record of the Agost Basin (LSU and USU, given as the average value from the set of samples (n) in each lithofacies L-1 to L-8 included in tab. 2 for the whole rock and the <2 µm grain-size fraction (in wt. %). Ranges and average values of the intensities ratio of the Qtz(001)/Qtz(101) peak areas of quartz, and Sme(003)/Sme(002) peak areas of smectite and Ill(002)/Ill(001) peak areas of illite under ethylene glycol solvation are included.

 

Figure 4. Mineralogical results concerning the source areas given as the average value from the set of samples (n) in each Sedimentary Cycle included in tab. 1 for the whole rock and the <2 µm grain-size fraction (in wt. %). Ranges and average values of the intensities ratio of the Qtz(001)/Qtz(101) peak areas of quartz, and Sme(003)/Sme(002) peak areas of smectite and Ill(002)/Ill(001) peak areas of illite under ethylene glycol solvation are included.

 

In particular, the Ill+Kln±Sme+Chl clay-mineral association characterizes the supply from Triassic formations; the Ill+Kln+Sme association from Albian formations; the Sme+Ill±Kln+(I-S) and Sme+Ill±Kln associations from Upper Cretaceous p.p.formations; and the Sme+Ill±Kln+(I-S) association from Paleogene formations, testifying a tectonic mobility of the basin margins differentiated over time (Figure 5).

 

Figure 5. (A) Comparative plots of XRD parameters, traceable mineral phases, and clay-mineral associations of the Neogene sedimentary record of the Agost Basin (LSU and USU, including the lithofacies L-1 to L-8) and source areas (Sedimentary Cycles I to VI as Triassic p.p., CI; Albian p.p., CIV; Cenomanian-Turonian p.p., CV-CT; Upper Cretaceous p.p., CV-S; and Paleogene p.p., CVI); purple, green, and orange dotted lines identify supplies from predominant Triassic, Cretaceous, and Upper Cretaceous-Paleogene source areas, respectively. The ternary plots for the whole-rock (B) and the <2 µm grain-size fraction (C) mineralogy, given as the average value (in wt. %) from the set of samples in each Sedimentary Cycle (tab. 1, fig. 4) and lithofacies (tab. 2, fig. 5), show three compositional fields corresponding to predominant Triassic like (TR), Albian like (AL), and Upper Cretaceous-Paleogene like (CP) mineralogical associations mixing in variable proportions to determine the mineralogical associations from L-1 to L-8. Samples with gypsum and chloride as typical Triassic mineral phases to identify the Triassic influence in F-1 to F-8 are indicated.

 

This reconstruction leads to propose detailed relationships between types of deposits and provenance and not a classic “unroofing”, as follows: (i) the lithofacies L-1 (lithofacies L-2 and L-3 were not analysed) is characterized by the Ill+Kln+Sme mineralogical association indicating an origin from the Albian formations; (ii) the lithofacies L-4 shows a mixture of Ill+Kln+Sme and Sme+Ill+Kln associations sourced from the Albian and Upper Cretaceous formations; (iii) the lithofacies L-5 is characterized by the Sme+Ill±Kln+(I-S) association indicating a provenance from the Upper Cretaceous and Paleogene formations; (iv) the lithofacies L-6 to L-8 are characterized by the Ill+Kln±Sme+Chl association indicating a supply mainly from Triassic deposits. The evolutionary sedimentary model reconstructed for the Agost Basin, which improves a previous contribution about the same area, has been correlated with those reported in other intramontane Neogene basins in the Betic-Rifian Arc studied with similar resolution, so obtaining useful information for regional reconstructions.

Figure 6. Tectono-sedimentary evolutionary model with location of source areas of the Agost Basin and surrounding areas. A: Middle Miocene stage (Lower Stratigraphic Unit); B: Late Miocene stage (Upper Stratigraphic Unit).

 

 

Cite as: Martín-Martín, M., Guerrera, F., Alcalá, F. J., Serrano, F., Tramontana, M. (2018): Source areas evolution in the Neogene Agost Basin (Betic Cordillera): implications for regional reconstructions. Italian Journal of Geoscience. 2018, 137(3): 433-451. doi:10.3301/IJG.2018.14

 

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