To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Outcrop, borehole, seismic, paleontologic and paleomagnetic data have been combined in order to define the geometric evolution of the eastern and central Pyrenean fold-and-thrust belt and its adjacent foreland basin during Eocene and Oligocene times. Restoration of balanced sections within a concise temporal framework forms the basis for more reliable and detailed palinspastic reconstructions than previously attained for this part of the Pyrenean orogeny.
The eastern and central part of the southern Pyrenees and related foreland Ebro basin display an unusually well-preserved geological record of the tectonic evolution of the chain. Numerous aspects of the compressional history of the south-eastern and southcentral Pyrenees have been recently delineated and provided an initial basis for detailed reconstructions of the kinematic development of the range. Within the adjacent foreland and piggyback basins, extensive paleomagnetostratigraphic sections provide good age control for the syntectonic sediments of the foreland basins.
The goal of this chapter is the construction of palinspastic maps ranging in age from the Early Eocene to the Early Oligocene showing the tectonic evolution of the eastern and central southern Pyrenees. These maps are constrained by both structural and temporal data sets. Two balanced and restored cross-sections extending from the undeformed foreland strata to the inner part of the chain provide the main structural framework. The cross-sections are constructed using geological surface information and the available subsurface data, including seismic lines, oil-well data and potash-well data.
From Late Lutetian times through to the Oligocene, the Jaca Basin evolved as a piggyback basin transported to the south by the San Felices thrust sheet. During the Oligocene, emergence, imbrication, and erosion of the frontal parts of this thrust sheet created the External Sierras and re-organized the pre-existing drainage systems. We describe here new magnetostratigraphic dates for stratigraphic sections within both the Jaca and northern Ebro basins. The resultant chronologies provide a temporal framework for quantifying and synthesizing the mid-Tertiary depositional and structural evolution of the western Pyrenees.
The Jaca Basin represents the westernmost structurally partitioned basin of the South Pyrenean foreland (Fig. 1). Previous studies (Puigdefabregas, 1975) have delineated the detachment of the basin as a sole thrust propagated beneath it during late Eocene times, after which it survived as a long-lived piggyback basin accumulating detrital sediments at least until the mid Oligocene. During this interval, the External Sierra emerged as an important structural and topographic range defining the southern margin of the Jaca Basin. Because most of the piggyback strata, as well as those fronting the External Sierra in the northern Ebro Basin, were deposited subaerially and have only yielded a sparse faunal record, previous temporal controls on the evolution of the basin and bounding ranges have been imprecise. We describe here the results of recent magnetostratigraphic studies within the Jaca Basin and the northern Ebro Basin.
Recently developed magnetic polarity stratigraphies in the western South–Central Unit provide a more-precise temporal database for the analysis of the depositional and deformational history of the southern Pyrenean foreland basin. When combined with lithostratigraphic and structural data, the eight new magnetic sections along the Isabena and Esera valleys and in the Ainsa Basin help define the early stages of development of the Eocene foreland and illustrate the important role played by growing structures, such as the Mediano Anticline, in controlling depositional environments and patterns of subsidence.
In an attempt to develop more precise chronological control for the depositional and deformational history of the central part of the South Pyrenean fold-and-thrust belt and its related foreland-basin deposits, several new magnetic polarity stratigraphies have been developed within the syntectonic sedimentary succession. The temporal information derived from these studies permits more detailed correlation between sections and more reliable analysis of the timing, sequencing and rates of sedimentary and tectonic processes. This work has been focused on the western part of the South–Central Unit (Séguret, 1972) and encompasses the western Tremp–Graus and Ainsa basins (Fig. 1). Whereas the majority of these studies has been concerned with late Eocene and Oligocene deposition, part of the studied record begins in the early Eocene. We report here the data and the location of each magnetostratigraphic section, the nature of the magnetic record from these sites, the chronologic significance of each section, and some of the geologic conclusions drawn from these chronologic data.
Email your librarian or administrator to recommend adding this to your organisation's collection.