Second-order Sea-level Changes Research Articles

Controls and evolution of facies patterns in the Upper Barremian–Albian Levant Platform in North Sinai and North Israel

Abstract The Upper Barremian–Albian Levant Platform was studied in North Sinai and Israel (Galilee and Golan Heights) by bio- and lithostratigraphy, facies analyses, and sequence stratigraphy. Integrating shallow-marine benthic foraminifera (mainly orbitolines), ammonite, and stable isotope data resulted in a detailed stratigraphic chart. Transects across the shallow shelf in both regions are based on facies analysis and form the basis for depositional models. In both transects five platform stages (PS I–V) were identified, which differ significantly in their stratigraphic architecture, mainly controlled by local tectonics, climate and second-order sea-level changes. In North Sinai, a transition from a shallow-shelf that is structured by sub-basins through a homoclinal ramp into a flat toped platform is recognized, while the sections in North Israel show a transition from a homoclinal ramp into a fringing platform. Local normal faults influenced the depositional architecture of the Upper Barremian–Lower Aptian strata in North Sinai and were attributed to syn-rift extensional tectonics. Four second-order sequence boundaries were identified, bounding Mid-Cretaceous Levant depositional sequences. These well-dated second-order sequence boundaries are MCL-1 (Late Barremian), MCL-2 (earliest Late Aptian), MCL-3 (Lower Albian), and MCL-4 (Late Albian). The sea-level history of the Levant Platform reflects the Late Aptian–Albian global long-term transgression, while the second-order sea-level changes show good correlation with those described from the Arabian plate.

Carboniferous-Permian long-term sea-level change inferred from Panthalassan oceanic atoll stratigraphy

This paper traces late Palaeozoic second-order sea-level change based on the stratigraphy of the Akiyoshi Limestone, an accreted Carboniferous-Permian Panthalassan atoll carbonate succession in SW Japan. The estimated subsidence of a volcanic edifice and the variable rate of carbonate accumulation reveal the long-term sea-level history of the late Palaeozoic. During Bashkirian time, just after the lowstand stage at the mid-Carboniferous boundary, a slow progressive long-term sea-level rise began. This sea-level rise then increased greatly during Moscovian time. The following Kasimovian to Asselian interval represents a stable highstand stage. Beginning in the Sakmarian, sea level fell slowly and became stable in the Yakhtashian (= Artinskian). This stable sea level was maintained into the Midian (= Capitanian), although a small-scale sea-level rise of approximately 55–70 m is recognized in the Murgabian (= Wordian). The most noteworthy aspect of this change of sea level is the rapid sea-level rise during the Moscovian that created a very large accommodation space and resulted in accumulation of a thick carbonate succession. The eustatic rise from the earliest Bashkirian lowstand to the latest Moscovian highstand had an amplitude of approximately 230–240 m. Such a large-scale eustatic rise in the long-term sea-level change would most likely be caused by greater uplift of the ocean floor along the mid-oceanic ridges, as a result of an increase in the production of oceanic crust during that time.

Lower Cretaceous carbonate platform of the eastern Levant (Galilee and the Golan Heights): stratigraphy and second-order sea-level change

The marine succession of the late Early Cretaceous carbonate platform of the eastern Levant was located at the southern border of the Tethyan Ocean. The studied areas of Galilee and the Golan Heights represent a transect across the shallow inner platform. The investigations were focused on carbonate platform biostratigraphy and facies analysis. A precise stratigraphic interpretation of the Upper Barremian–Albian succession was compiled on the basis of the definition of larger benthic foraminifer biozones allowing subdivision of the succession into six well-dated intervals. Detailed analyses of facies and sedimentological parameters allow interpretation of platform development, in connection with platform geometry, as well as relative third-order and second-order sea-level changes. The observed facies patterns reflect a depositional geometry changing from a ramp to a flat-topped platform during Late Barremian–Middle Albian times. Three second-order depositional sequences were recorded in the studied mid-Cretaceous succession of the eastern Levant (MCEL-1 to MCEL-3). The facies analysis clearly indicates their origin in relative sea-level variations. The stratigraphic framework allows biochronostratigraphic calibration of these depositional sequences (MCEL-1: Upper Barremian–Lower Aptian, MCEL-2: uppermost Lower Aptian–middle Upper Aptian, MCEL-3: middle Upper Aptian–Middle Albian) and correlation with stratigraphic charts of local and regional sequences. The second-order sequence boundaries and maximum flooding surfaces correlate with basic sea-level variations recorded on the Arabian Plate, here interpreted as originally eustatically enhanced by subsidence. Tethyan signals are recorded around the Aptian/Albian boundary. A noticeable deepening in the upper Lower Aptian correlates with an extended platform drowning during the Selli Level (Oceanic Anoxic Event 1a: OAE 1a). Orbitolinid beds at this level suggest a deepening facies and a possible response to nutrient enhancement developing at the continental margin during OAE 1a. Eight third-order depositional sequences were observed in the Upper Barremian–Albian interval. They comprise successions of the inner ramp facies from open marine to restricted lagoons or tidal flats. The age and frequency of the Upper Barremian–Lower Aptian sequences correlate with those observed on the Pacific guyots or the Arabian Plate suggesting influence by regional sea-level cycles.

Drowning of the Upper Marble Falls carbonate platform (Pennsylvanian), central Texas: A case of conflicting “signals?”

Marble Falls and Smithwick Formation carbonates and shales were deposited on the western margin of the slowly subsiding Fort Worth Basin of central Texas during Early Pennsylvanian time. The Upper Marble Falls Member carbonate platform back-stepped towards the west–southwest as Smithwick outer shelf–slope black shales drowned platform margin areas to the east. The shelf-to-basin profile observed from subsurface data from the Fort Worth Basin and outcrops from the Llano Uplift area records platform drowning; however, the platform began to shoal upwards as it back-stepped towards the west–southwest, due to the presence of the Llano Uplift paleobathymetric high. The geometry of these facies tracts was controlled primarily by a combination of subsidence and second-order sea-level change, while the development of sequences and unconformities was controlled by third-order sea-level changes and environmental factors, and not subsidence. The termination of platform deposition in the Fort Worth Basin was caused by the interplay of third-order sea-level changes, environmental deterioration in advance of siliciclastic burial, and a lack of accommodation space. The depositional history of the Upper Marble Falls carbonate platform does not fit “classic” examples of drowned platforms described from other areas, but may be typical of platforms in slowly subsiding basins.

Sequence stratigraphy of the siliciclastic East Puolanka Group, the Palaeoproterozoic Kainuu Belt, Finland

The 2300–2600 m thick Palaeoproterozoic East Puolanka Group within the central Fennoscandian Shield records four major transgressions on the cratonic margin within the approximate time period 2.25–2.10 Ga. Stacking of siliciclastic facies in parasequences and parasequence sets provides data to evaluate oscillation of relative sea-level and subsidence on different temporal scales. The lowermost part of the passive margin prism is characterized by alluvial plain to shallow marine sediments deposited in incised valleys. The succeeding highstand period is recorded by ca. 250 m of progradational parasequence sets of predominantly rippled and horizontally laminated sandstones, representing stacked wave-dominated shoreline units in sequence 1, capped by a hiatus or, in some places, by a subaerial lava. As relative sea-level rose again, sand-rich barrier-beach complexes developed with microtidal lagoons and inlets, corresponding to a retrogradational parasequence set. This was followed by a highstand period, with aggradation and progradation of alluvial plain and coastal sediments grading up into wave-tide influenced shoreline deposits in sequence 2. In sequence 3, the succeeding mudstones represent tidal flat deposits in a back-barrier region. With continued transgression, the parasequences stacked retrogradationally, each flooding episode being recorded by increasingly deeper water deposits above low-angle cross-bedded sandstones of the swash zones. The succeeding highstand progradation is represented by alluvial plain deposits. The next transgressive systems tract, overlying an inferred erosional ravinement surface, is recorded by a retrogradational parasequence set dominated by low-angle cross-stratified swash zone deposits in sequence 4. The large-scale trough cross-bed sets in these parasequences represent sand shoals and sheets of the inner shelf system. The overall major transgression recorded in the lowermost part of the Palaeoproterozoic cratonic margin succession was related to first- to second-order sea-level changes, probably due to increasing regional thermal subsidence of the lithosphere following partial continental breakup. The stratigraphic evolution can be related to changes of relative sea-level with a frequency of ca. 25 million years, probably propagated by episodic thermal subsidence. The parasequences identified here are related to high-frequency cycles of relative sea-level change due to low-magnitude eustatic oscillations.

Timing of mid-Cretaceous carbonate platform depositional cycles, northern Sinai, Egypt

The northern Sinai Upper Aptian to Middle Cenomanian succession represents an example of a carbonate platform, where stratigraphic interpretations are mainly based on benthic foraminifera, ostracods and rudists. This paper presents a concept combining the stratigraphic study of benthic organisms with graphic correlation and sequence stratigraphy, at a scale that determines the timing of sequence boundaries and quantification of sediment-accumulation rates. Biostratigraphic analyses result in multibiostratigraphic zonations and contribute to a northern Sinai fossil range chart for benthic larger and smaller foraminifera, ostracods and rudists. The age interpretation results from the careful comparison of the ages given in the literature and the distribution patterns in the northern Sinai sections. The northern Sinai chart for many fossil ranges matches with other studies, but also indicates some exceptions. Ostracods were grouped into assemblages characterised by short local ranges, which enables the exact correlation of different sections. The use of graphic correlation techniques within this framework improves the stratigraphic resolution and results in timing of the sequence boundaries. These chronostratigraphic assignments allow comparison of the Sinai sequence boundaries with those described from other regions. Furthermore, graphic correlation measures long-term sediment-accumulation rates of the northern Sinai. Based on their variations, we calculate the relative sea-level changes, resulting in a detailed second-order sea-level curve. In the Upper Aptian to Middle Cenomanian succession, important changes in the long-term sediment-accumulation rate were measured. They reflect three second-order sea-level cycles, which subdivide a general relative sea-level rise. 18 sequences superimpose the second-order sea-level change: 3 sequences in the Upper Aptian, 11 sequences in the Albian, and 4 sequences in the Lower–Middle Cenomanian. Both sequence-stratigraphic patterns and long-term sea-level changes were compared with those from the Tethyan domain, the African/Arabian Plate and the western Pacific. Abundance and distribution of the Sinai sequence boundaries were similar to the patterns described from other regions. We distinguish between sequence boundaries with regional extent correlating with examples from the North African/Arabian Plate or the western Pacific, sequence boundaries of possibly global or Tethyan extent and the few sequence boundaries of local extent. The influence of the regional and global signals on the studied successions reflect the Sinai location between the southeastern and southwestern Tethyan realms. Local tectonics or changes in subsidence are only of subordinate importance for the creation of sequence boundaries. The comparison of the chronostratigraphic assignments of the second-order sea-level curve with other descriptions indicates a second-order relative sea-level history of its own for Sinai triggered by the interaction of subsidence, sediment supply and eustasy.

Permian reefs re-examined: extrinsic control mechanisms of gradual and abrupt changes during 40 my of reef evolution

The evolution of Permian reefs is characterized by the following sequence of events: (1) Late Carboniferous–Cisuralian radiation, (2) early Late Cisuralian (Artinskian–Kungurian) turnover, (3) Guadalupian radiation, (4) end-Guadalupian crisis, (5) Lopingian radiation, (6) end-Lopingian crisis at the PTB (Permian–Triassic boundary), and (7) the at least 7 my (million years) metazoan reef gap during the Early Triassic. The early Late Cisuralian turnover and the end-Guadalupian reef crisis are gradual changes, while the end-Lopingian reef crisis represents an abrupt event. Lopingian reefs occur in a zone from 40 °N to 15 °S, Guadalupian reefs in an extended equatorial zone from 35 °N to 35 °S, and Lopingian reefs in a narrow equatorial zone of 20 °N and 20 °S. This pattern resulted from a network of global and regional control mechanisms including the assemblage of Pangea, the northward drift of continents, the opening of Neo-Tethys, and second-order sea level changes. The mechanism of the extinction has been intensely debated and a combination of the above mentioned long-term changes and abrupt ocean anoxia or hypercapnia (CO 2-poisoning) for the end-Guadalupian reef crisis is considered.

Manganese in Pelagic carbonates: indication of major Tectonic events during the geodynamic evolution of a passive continental margin (the Jurassic European Margin of the Tethys–Ligurian Sea)

Mid-oceanic hydrothermal activity is the main source of manganese in the pelagic realm. Consequently, long-term fluctuations of manganese in bulk carbonates could represent the variations in the hydrothermal flow intensity through time depending on global tectonic activity. Within this scope, we analysed three Jurassic sedimentary series in the Southeastern Basin (France), thus providing valuable information for further palaeogeographic and geodynamic reconstructions of the European Tethyan passive margin. The long-term variations of the manganese curve can be correlated with second-order sea-level changes. The main transgressive phases (Early Toarcian, Late Aalenian to Bajocian and Late Bathonian to Callovian) are marked by a manganese content increase whereas the regressive phases (Late Pliensbachian, Late Toarcian to Middle Aalenian, Early Bathonian to Middle Bathonian, Oxfordian) are characterized by decreasing trends. Furthermore, some manganese positive anomalies can be superimposed on the global geochemical record of sea-level changes. These coincide with periods of increasing subsidence rate (Early Toarcian, Late Bajocian, Middle and Late Oxfordian) and also with phases of extension (Early Aalenian) of the European margin of the Ligurian Ocean. The major event is the very sharp increase of manganese content localised in the Athleta Zone (Late Callovian) and corresponds to the first occurrence of oceanic crust. Moreover, the manganese enrichments recorded in carbonates deposited before Callovian times, may have resulted from hydrothermal emanations during the first stages of rifting.

Paleomagnetic constraints on the Rodinia supercontinent: implications for its Neoproterozoic break-up and the formation of Gondwana : D'Agrella-Filho M.S., Trindade R.I.F., Siqueira R., Ponte-Neto C.F. & Pacca I.I.G., International Geology Review, 1998, 40/2 (171–188)

The northern Sinai Upper Aptian to Middle Cenomanian succession represents an example of a carbonate platform, where stratigraphic interpretations are mainly based on benthic foraminifera, ostracods and rudists. This paper presents a concept combining the stratigraphic study of benthic organisms with graphic correlation and sequence stratigraphy, at a scale that determines the timing of sequence boundaries and quantification of sediment-accumulation rates. Biostratigraphic analyses result in multibiostratigraphic zonations and contribute to a northern Sinai fossil range chart for benthic larger and smaller foraminifera, ostracods and rudists. The age interpretation results from the careful comparison of the ages given in the literature and the distribution patterns in the northern Sinai sections. The northern Sinai chart for many fossil ranges matches with other studies, but also indicates some exceptions. Ostracods were grouped into assemblages characterised by short local ranges, which enables the exact correlation of different sections. The use of graphic correlation techniques within this framework improves the stratigraphic resolution and results in timing of the sequence boundaries. These chronostratigraphic assignments allow comparison of the Sinai sequence boundaries with those described from other regions. Furthermore, graphic correlation measures long-term sediment-accumulation rates of the northern Sinai. Based on their variations, we calculate the relative sea-level changes, resulting in a detailed second-order sea-level curve. In the Upper Aptian to Middle Cenomanian succession, important changes in the long-term sediment-accumulation rate were measured. They reflect three second-order sea-level cycles, which subdivide a general relative sea-level rise. 18 sequences superimpose the second-order sea-level change: 3 sequences in the Upper Aptian, 11 sequences in the Albian, and 4 sequences in the Lower–Middle Cenomanian. Both sequence-stratigraphic patterns and long-term sea-level changes were compared with those from the Tethyan domain, the African/Arabian Plate and the western Pacific. Abundance and distribution of the Sinai sequence boundaries were similar to the patterns described from other regions. We distinguish between sequence boundaries with regional extent correlating with examples from the North African/Arabian Plate or the western Pacific, sequence boundaries of possibly global or Tethyan extent and the few sequence boundaries of local extent. The influence of the regional and global signals on the studied successions reflect the Sinai location between the southeastern and southwestern Tethyan realms. Local tectonics or changes in subsidence are only of subordinate importance for the creation of sequence boundaries. The comparison of the chronostratigraphic assignments of the second-order sea-level curve with other descriptions indicates a second-order relative sea-level history of its own for Sinai triggered by the interaction of subsidence, sediment supply and eustasy.

Evolution of a Callovian-Oxfordian carbonate margin in the Neuquén Basin of west-central Argentina: facies, architecture, depositional sequences and global sea-level changes

This paper reviews a detailed stratigraphic and sedimentologic study of a carbonate complex developed on the foreland side of the Neuquén Embayment, a protected shallow-water epicratonic site behind the active edge of the South American plate. Superb outcrops at the core of basement-involved Andean structures expose the shelf-to-basin transition and reveal with clarity the external and the internal architecture of the depositional sequences and component system tracts. Platform carbonates are largely represented by ooid and mainly rhodoid grainstones, with associated patches of coral framestone. The deeper platform and slope facies are composed of oncoidal and skeletal micritic limestones with scattered coral-sponge-algal build-ups. The overall composition and facies pattern bears resemblance to other Late Jurassic carbonate complexes form Europe and with the Smackover Formation from the Gulf Coast Basin of North America.Analysis based on mapping of the stratal patterns and facies associations in outcrops allowed the recognition of four depositional sequences. Timing provided by ammonite biochronology suggests that eustatic fluctuations were a major factor influencing the carbonate-margin architecture, and regulated episodes of condensed sedimentation, shifts of the depositional belts, and development of stratigraphic discontinuities. The onset and the end of carbonate sedimentation were associated with episodes of marine retreat and accumulation of evaporites and eolian-fluvial deposits at basin-centre locations. However, most of the marine fluctuations recorded within the carbonate complex were insufficient to expose the shelf break (Type 2), and accordingly lowstand system tracts are poorly represented. On the shelf the transgressive system tracts are represented by thin grain-supported carbonate blankets. These taper out downslope into omission surfaces or are replaced by patches of small sponge buildups. Highstand system-tract organization changes through time, reflecting changes in productivity and accomodation, presumably tied to second-order sea-level changes. Callovian highstand accumulation featured a catch-up carbonate system and produced a thin-aggradational ramp configuration, whereas conditions during middle-late Oxfordian allowed a keep-up system and produced outbuilding depositional geometries with steeper slopes.