No description available.

No description available.

The Vera Basin is used as a case study to examine the structural evolution and sedimentary response of a basin undergoing uplift and inversion during the Plio-Pleistocene. Particular emphasis is placed on the drainage evolution during that period. Located within the Internal zone of the Betic Cordilleras, the Vera Basin is defined within a large left-lateral shear zone and has evolved as a reponse to isostatic uplift from nappe emplacement during the Oligocene, and by regional compressive tectonics. Since basin formation during the Seravallian, sedimentary fill has been dominantly marine. During the Plio-Pleistocene a switch from marine to continental conditions occurred. These sediments (Cuevas, Espiritu Santo and Salmerbn Formations) represent the final stages of basin fill and form the focus of this study. The Cuevas Formation represents an early Pliocene marine transgression within the Vera Basin. Early sedimentation mulled a pronounced submarine topography produced by a rapid late Miocene fall in sealevel. A broad, shallow shelf platform area existed which opened out to the Pliocene Mediterranean Sea towards the east. Along the northern and western basin margins, wave dominated shorelines were formed. Structural activity was confined to low amounts of basin subsidence and limited left lateral strike-slip movement along the Palomares Fault Zone. The Espiritu Santo Formation marks a major palaeogeographic reorganisation and the final marine phases of the Vera Basin during the mid to late Pliocene. Unsteady strike-slip movement along the Palomares fault zone on the eastern basin margin partially enclosed the Vera Basin by northwards movement of a structurally detached landmass. Gilbert-type fan-delta bodies prograded westwards from the landmass (Sierra Almagrera), infilling the central region of the basin. Early fan-delta sediments were reworked into shoreline areas along the western and northern basin margins. Western margin shorelines retreated northwards as a response to partial enclosure and a gradual lowering of sea-level. Late stages of the Espiritu Santo Formation, saw a fan-delta body prograde from the northern basin margins. Interaction between the basinal and marginal fan-delta bodies enclosed the northern region of the Vera Basin. A swamp/mangrove environment developed within the enclosed northern basin area suggesting a humid, sub-tropical climate. Continental conditions were established during Salmerön Formation times in the late Pliocene. Along the western and northern basin margins, the retreating Pliocene shorelines provided a topography onto which the primary consequent drainage network developed. Three separate drainage systems can be identified on the basis of clast assemblages, palaeocurrents, depositional style and morphological expression. Early deposition was characterised by the progradation of alluvial fans of two drainage systems (Cuevas & Jauro), sourced from the northern and western basin margins. Distal areas of the northern fan system intercalated with an evaporitic playa lake. A third drainage system in the northwest of the basin (Salmerbn) developed within a topographic low between the two fan systems. An increase in structural activity towards the end of the Salmerbn Formation was characterised by a basin wide phase of north-south compression. Uplift and extensional faulting lead to abandonment of the primary drainage network. Fan entrenchment and minor rerouting of sediment supplies marked the establishment of a new secondary consequent drainage network during the Pleistocene. The Pleistocene drainage network records the progressive dissection of the Vera Basin as a response to ongoing regional epeirogenic uplift. During this post-inversion phase the Rios Antas, Almanzora and Aguas developed respectively along the western, northern and southern basin margins as- a series of braided streams. Distal, coastal areas of this drainage network are recorded by a series of Pleistocene shoreline sequences which developed as a response to fluctuating sea-level during the Pleistocene glacial and interglacial periods. Early Pleistocene proximal parts of the drainage network are well preserved. Distal parts of the Pleistocene fluvial system display limited evidence for interaction between the drainage network and shoreline sequences. This lack of preservation relates to the high energy, wave dominated depositional setting of the Pleistocene shoreline areas which reworked fluvial sediment inputs into the shoreline environment. The Plio-Pleistocene evolution of the Vera Basin, and in particular the development of the fluvial during system this period has been highly complex. Despite the importance of sea-level and climatic controls, tectonic activity during this period of basin inversion has been the dominant control on the positioning of the drainage networks, depositional styles and sediment supply.

No description available.

Thesis (Ph. D.)--Illinois State University, 1995. / Title from title page screen, viewed May 8, 2006. Dissertation Committee: Hou Tak Cheung (chair), David W. Borst, Herman E. Brockman, Alan J. Katz, Anthony J. Otsuka. Includes bibliographical references (leaves 98-110) and abstract. Also available in print.

Hyperplasia was induced by physical and chemical means. The resulting goitres were examined by electron microscopy, and the basement membranes were analyzed by stereological methods. The basement membrane in experimental colloid goitre was found to be significantly thinner than its control. A consideration of the course of the various goitres and of the chemical nature of basement membranes leads to the conclusion that the thinning of the basement membrane was the result of stretching. / Science, Faculty of / Zoology, Department of / Graduate

No description available.

No description available.

No description available.

The dissertation examines the interaction between basement tectonics, salt tectonics and sedimentation during the Late Cretaceous basement reactivation in the center of the Santos Basin. The study area is a seismic volume 60 x 30 km² in area, augmented by 2D regional seismic lines. The results of seismic interpretation and structural restorations revealed important inversions in the Late Cretaceous, including inversion of an NNE-oriented aborted rift segment known as Merluza Graben. The following tectono-stratigraphic evolution was inferred. During the Albian, basin subsidence and differential loading by the overburden caused salt to flow basinwards. In the Late Turonian, intraplate compression resulted in uplift of the onshore and proximal areas of the Santos Basin and in a newly recognized basement inversion in deep water. ENE and NNE oriented structures were reactivated. The uplift exposed the Turonian shelf and a new shelf began to prograde. The first shelves were narrow (~25 km wide) but enlarged to 60 km in the Santonian. Salt influenced the position of the shelf break and the progradation pattern of the shelf margin. Because of the continuous accommodation space provided by salt withdrawal underneath the sedimentary wedge, the shelf margin aggraded until underlying salt welded, after which the shelf prograded to a position around 50 km to the east of the present-day shelf break. Deformation peaked in the Late Santonian when the shelf was widest, the rate of progradation of the shelf margin was anomalously high, and transtension along the borders of the Merluza Graben allowed Late Santonian magma to intrude. Salt acted as a partial seal, causing a large part of the magma to spread beneath it. Some magma formed sills inside the evaporitic layer, intruding zones of dilation in the salt. Magma also followed the top of the evaporitic layer and intruded salt-related faults as dikes. These dikes supplied sills in the overburden and extrusive flows emerged on the Late Santonian seafloor from ENE-striking transtensional zones. Right-lateral reactivation of the Merluza Graben borders slightly compressed the graben, which favored sill injection in Coniacian/Santonian strata. Tectonic activity diminished towards the end of the Cretaceous. / text