136 research outputs found
Isotope records in vertebrate fossils: from Cretaceous seas to Quarternary Sundaland
Full text linkReijmer, J.J.G. [Promotor]Vonhof, H.B. [Copromotor]Joordens, J.C.A. [Copromotor
The Mid-Pleistocene to Holocene evolution of the Maldives carbonate platform
Full text linkReijmer, J.J.G. [Promotor]Betzler, C. [Promotor
Impact of diagenesis on carbonate mound formation
Full text linkWeering, T.C.E. van [Promotor]Reijmer, J.J.G. [Promotor]Mienis, F. [Copromotor
Physical and mechanical properties of carbonate sedimentary systems
Full text linkReijmer, J.J.G. [Promotor]Bertotti, G.V. [Copromotor
Lithofacies and depositional processes on a high, steep-margined Carboniferous (Bashkirian-Moscovian) carbonate platform slope, Sierra del Cuera, NW Spain
No full textThe depositional slope of the Sierra del Cuera, a Carboniferous (Bashkirian–Moscovian), high, steep-margined carbonate platform, provides excellent cross-sections of lithofacies zonations and associated stratal geometries. The steep (30–40°) and nearly planar upper slope is dominated by massive sheet-like layers of microbial, cement-rich boundstone, which alternate with intercalations of red-stained bryozoan cementstone with crinoids and brachiopods. The slightly gentler (20–26°) and concave-upward lower slope is characterized by clast-supported resedimented deposits. The upper slope extended from platform break to ca. 300 m water depth, whereas lower slope sediments were deposited in water depths up to 600–700 m, at which level the slope beds flatten to a few degrees (toe-of-slope) and interfinger with spiculitic and argillaceous basinal sediments. Between 250 and 450 m water depth, boundstones and breccias alternated in a transitional zone. The lower slope sediments include clast-supported breccias with radiaxial fibrous cement in interparticle space, mud- to clast-supported breccias with red-stained carbonate mud matrix and packstone to grainstone and rudstone beds. Most of the clasts comprise boundstone reworked from an upper slope setting and smaller grains are platform and slope derived. A pervasive submarine cementation occurs along the upper two-thirds of the flank and this stabilized the slope.
Slope deposition is interpreted as follows. During active boundstone accretion, microbial boundstone layers slid off and formed breccia tongues extending from the lower upper slope down to the toe-of-slope. Rock falls and avalanches were generated whenever the shear strength of the substrate of loose (or partly lithified) sediment was exceeded. Upper-slope boundstone accretion and shedding, independent of the depth of light penetration, controlled most of the depositional processes on the slope. Cement-dominated intervals are considered to be related to early highstand (and/or flooding) phases. Relative sea-level fluctuations and/or associated changes in the water conditions are believed to be responsible for intervals of low boundstone production or cement precipitation. Whether the in situ boundstone and breccia are preferentially related to lowstand or highstand periods is, as yet, unclear
The catching up of European money markets: The degree vs. the speed of integration
Full text linkFinancial Markets;EMS;European Integration;430;210;420;Interest
Carbonate-siliciclastic facies patterns related to the closure of the Central American Seaway: A comparison between the Pliocene of Costa Rica and the present-day Gulf of Panama and Gulf of Chiriqui
Full text linkAfter the closure of the Central American Seaway around 3.6 Ma, the benthic carbonate ecosystems developed differently in the Caribbean and on the Pacific side of the Isthmus of Panama. In this thesis, fossil and recent carbonate systems were studied and a comparison was made between fossil and present-day carbonate ecosystems from the same paleolatitude. This opens up the possibility to document the evolution of these sedimentation systems through time
Synchroneity of major late Neogene sea level fluctuations and paleoceanographically controlled changes as recorded by two carbonate platforms
Full text linkShallow-water carbonate systems are reliable recorders of sea level fluctuations and changes in ambient seawater conditions. Drilling results from Ocean Drilling Program (ODP) Legs 133 and 166 indicate that the timing of late Neogene sedimentary breaks triggered by sea level lowerings is synchronous in the sedimentary successions of the Queensland Plateau and the Great Bahama Bank. This synchrony indicates that these sea level changes were eustatic in origin. The carbonate platforms were also affected by contemporary, paleoceanographically controlled fluctuations in carbonate production. Paleoceanographic changes are recorded at 10.7, 3.6, and 1.7–2.0 Ma. At the Queensland Plateau, sea surface temperature shifts are documented by shifts from tropical to temperate carbonates (10.7 Ma) and vice versa (3.6 Ma); the modern tropical platform was established at 2.0–1.8 Ma. At Great Bahama Bank, changes were registered in compositional variations of platform-derived sediment, such as major occurrence of peloids (3.6 Ma) and higher rates of neritic carbonate input (1.7 Ma). The synchroneity of these changes attests to the far-field effects of modifications in the oceanographic circulation on shallow-water, low-latitude carbonate production
Report and preliminary results of R/V Meteor cruise M95 CICARB - Current Impact on the Facies and Stratigraphy of the Bahamas Carbonate Platform
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