El Kimmeridgiense del Este de la Península Ibérica: Distribución de facies y evolución sedimentaria.

Abstract

A map showing the thickness distribution of the sedimentary units comprised from latest Oxfordian to earliest Tithonian in the Eastern part of the Iberian Plate, is presented in this work. We also shown four maps which display the facies distribution of Eastern Iberia along four successive stages. Base data for these maps were II well-logs and 171 measured sections. The thickness distribution map shows the existence of several furrows and sedimentary highs along the basin, which were originated during the tectonic extension of the onset of the Late Jurassic-Early Cretaceous Rift stage. The studied units are arranged in two depositional sequences: Sequence-l spans from latest Oxfordian (Planula Biozone pp.) to early Late Kimmeridgian; Sequence-2 reached the lower part of the Tithonian. In ocr work we describe the distribution of the litoestratigraphic units found in these sequences. At tbe onset of Sequence- 1, a transgressive episode involved the flooding of the marginal areas and the linking between the northern and southern sedimentary realms (Le., Basque-Cantabran basin aud Iberian basin). During Late Kimmeridgian-earliest Tithonian the progradation of the shallow reefal and oolitic facies over the outer ramp micritie facies took place. The four reconstructed palaeogeographical maps show tbe lateral reíationship between the outer ramp realms (dominated by marly and micritic facíes, deposited below storm wave base) and the oolitic, sandy and reefal facies located in marginal areas (i.e., western Iberian basin, Soria Seaway and East Basque-Cantabrian basin). Coralgal reef bad tbeir maximal geographical extend along the marginal areas of the Iberian basin at tbe end of the Kimmeridgian. The results reported in our work allows to discuss on the genetic relationship between the different sedimentary domains of the carbonate ramp, specially between the shallow areas that had high carbonate productivity, and the outer areas, which were the site of the carbonate mud accummul.ation.