The Tertiary Geological Record of the Bureba Area, Western Ebro Basin, Spain

Escavy, Jose I.¹; Herrero, Maria J.¹
(1) Petrology and Geochemistry, Fac. CC: Geologicas, Univerity Complutense Madrid, Madrid, Spain.

During the Tertiary, from the Late Eocene to the Miocene, the Ebro Basin, situated at the northeastern part of Spain, became a non-marine basin where diverse lacustrine evaporitic systems developed. Diverse alluvial and fluvial systems were originated in the marginal areas (Iberian chain to the south and Cantabrian Mountains and Pyrenees to the north). These systems advanced towards the center of the basin. The excellent preservation and outcrop continuity from the northern to the southern margins permit to literally walk along the lateral contact and facies changes from the alluvial and/or fluvial systems into the lacustrine evaporitic deposits. Bed-by bed sections measurements, petrographic and geochemical analyses of samples as well as the establishment of the depositional framework of the different architectural elements permit to determine that the main factors that controlled the vertical and lateral facies arrangements appear to be the paleoclimatic conditions and lithologic composition of the source area, among other factors such as the slope of the depositional surfaces and the size of the catchment area have a less important impact.

The study is focused in the western part of the Ebro basin, in the area called La Bureba Corridor that connects the Ebro and Duero basins. The detailed analyses of the interrelationships permit to develop a model of the geologic evolution of this part of the Ebro Basin in Tertiary times. The resultant dataset permits to establish an outcrop analogue model as well as characterize geometry and architectural arrangements of lacustrine facies associations and their correlative marginal detrital deposits.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.