Aalenian pulses of tectonic activity in the Iberian Basin, Spain

Abstract

Keywords: Condense d sequences Tectonic controls AalenianIn the northwest Iberian Range the Aalenian to Bajocian interval is represented by condensed, as well as more expanded marine carbonate s.trata deposited in a shallow epicontinental-sea setting. Precise biochronological data (successive ammonites assemblages) from 29 measured sections, along with a bed by-bed facies analysis, allowed a detailed correlation between sections, the definition of a number of successive transgressive-regressive cycles and of two distinct sedimentation areas, as. well as the compilation of isopach maps for short time intelVals (duration of ammonites Zone/Subzone) and the assessment of sediment accumulation rates. Iberian Basin SpainDifferences in facies and thickness in the studied interval, and the sequential organization, reveal significant changes in the depositional environment. A tectonically-controlled compartmentalization of the sedimenta.

The Middle Jurassic succession in the central sector of the Pieniny Klippen Belt (Sprzycne Creek): implications for the timing of the Czorsztyn Ridge development

“…From a broader paleogeographic perspective, we stress that facies changes at the Aalenian/Bajocian and Early/Late Bajocian boundaries, associated with early tectonic evolution of the Czorsztyn Ridge, coincide with episodes of the 'midCimmerian tectonic event' represented by unconformities, hiatuses and facies changeover in the Tethyan/north PeriTethyan realms and adjoining boreal areas, for example, in the Iberian Basin (García-Frank et al 2008), Paris Basin (Jacquin et al 1998, North Sea (Underhill & Partington 1994), basins of the Caucasus (Saintot et al 2006), Alborz & Kopet-Dagh (Fürsich et al 2009). …”

Iron-Coated Particles from Condensed Aalenian-Bajocian Deposits: Evolutionary Model (Iberian Basin, Spain)

“…1, 2). On the basis of facies, thickness, and fossil content of the uppermost Toarcian to lowermost Bajocian sediments, García-Frank et al (2008) distinguished four main areas (Fig. 2), informally noted as Demanda (NW), San Leonardo (SW), Madero-Moncayo (SE), and Cameros (NE).…”

“…2). Two main episodes of faulting affected both the IB domain and the BCB domain during the Early-Middle Jurassic transition (García-Frank et al 2008), caused by synsedimentary faulting due to extensional tectonics in this period. This faulting is associated with development of widespread unconformities in several Iberian and western European basins (e.g., Basque-Cantabrian and Asturias basins: Aurell et al 2003;Betic Cordillera: Azañó n et al 2002;Algarve Basin: Terrinha et al 2002;Lusitanian Basin: Wright and Wilson 1984;Aquitaine Basin: Lezin et al 2007; Swiss Jura and adjacent areas of SW Germany: Wetzel et al 2003;western Middle Atlas: El Hammichi et al 2002).…”

“…Facies characteristics in AalenianBajocian deposits from the NW Iberian Range suggest condensed sections (Goy and Ureta 1990), with low sedimentation rate and prolonged submarine exposure (García-Frank 2007;García-Frank et al 2008).…”

“…Ferruginous particles, and associated unconformities and condensed sections, may provide important information for analyzing the evolution of the particles and interpreting the source of iron and the causes of their formation, and moreover, they can record paleoceanographic information. In parts of the NW Iberian Range, the Aalenian to Bajocian (Jurassic) interval, which includes condensed marine carbonate strata characterized by the presence of hardgrounds, oolitic ironstones, and hiatuses of variable extent (Goy and Ureta 1990;García-Frank 2007;García-Frank et al 2006, provides a unique opportunity to examine the record and formative processes of ferruginous particles. Specifically, this succession can provide insights into three aspects of the genesis of oolitic ironstones that have been controversial topics for decades: (1) the source of iron; (2) the peculiar mineralogy of the particles, and (3) the sedimentary environment where the particles formed.…”