Abstract: The recently formed Canyon Lake Spillway Gorge in Comal County, Texas, U.S.A., exposes a continuous 63-m-thick section ofthe middle part of the Glen Rose Formation (Lower Albian). This part of the Lower and Upper Members of the Glen Rose consists of shallow-shelf carbonate rocks with depositional cycles on several scales. These strata can be grouped into sixty-two high-frequency cycles whosevertical succession defines two relative orders of asymmetric, intermediate-scale cycles. The lower-order cycles correspond to thelithostratigraphic units of Stricklin et al. (1971) . We propose that these widespread lithostratigraphic units of Stricklin et al. (1971) areregionally correlative because they are intermediate-scale sequences or significant portions of sequences (e.g., sequence sets). Intervals that historically have been used as stratigraphic markers are mainly transgressive units of the high-frequency sequences and are predicted to be extensive. The exception is the “Corbula” interval, which we interpret to occur in the lower highstand of a high-frequencysequence. The correlation of the “Corbula” interval has been based in part on the succession of the underlying Salenia Interval to theoverlying solution-collapse interval. We suggest that this is correlating on the scale of high-frequency sequences and not individual beds. Six postulated high-frequency sequences occur in the Gorge (Gorge-1 to Gorge-6). The lower three are characterized by highstandrestricted facies and relatively thin beds and cycles. The upper three are characterized by toucasid and Orbitolina texana limestones. It ispossible that these cycles are grouped into two larger-scale, lower-order sequences, one consisting of Gorge 1, 2, and 3, and the otherconsisting of at least Gorge 4, 5, and 6. The facies, the asymmetry of the intermediate-scale cycles, and the well-developed high-frequencycycles in the Upper Glen Rose are consistent with being in the highstand of both a supersequence and the composite sequence.

Abstract A Holocene carbonate beach to eolian-dune sequence is a significant geomorphic feature along the Isla Cancun barrier island. The dunes are low, coalescing, parabolic dunes forming a ridge parallel to the present shoreline. The dunes comprise the “Bianca eolianite” and the slightly older “Cancun eolianite.” The Blanca eolianite is similar in age to the modern beach system. The more lithified Cancun eolianite, which forms excellent outcrop sections, contains three stratification types: 57% of the dune system is climbing translatent stratification, 36% is grainfall lamination, and 7% is sandflow cross-stratification. Biogenic structures in the Cancun and Blanca eolianites include animal burrows and rhizoliths. The general lateral transition between the modern beach system and the adjacent Blanca eolian dune system appears to have a fair-weather equilibrium profile with no abrupt break between the back beach and toe of dune. The quantity of coarse shell material and animal burrows decreases significantly into the dunes, where eolian processes dominate over marine processes. Sediment sorting and plant-root traces increase dramatically in the area where eolian processes become dominant. During strong storms and hurricanes, marine processes may reach well into the eolian realm, removing the beach sediment in front of dune deposits and allowing the swash or surf to erode the dunes directly. During rare, exceptionally severe hurricanes, the dune complex can be truncated, as is evident in the Cancun eolianite. This interaction between marine and eolian processes forms a time-transient boundary (interfingering) in the beach-dune systems. Marine-produced features that punctuate eolian deposits are: (1) dune-front conglomerates produced during dune-front erosion and (2) intradune marine storm deposits laid down during dune truncation.

Abstract Miocene carbonates are a rich but largely untapped source for general models of carbonate stratigraphy, paleoecology, diagenesis and hydrocarbon exploration. Lower and Middle Miocene reef carbonates display an ample worldwide distribution (Fig. 1A), surpassing the modern reef belt (Fig. 1B). In contrast, Upper Miocene reefs are remarkably restricted (Fig. 1C), reflecting the well-known global-cooling trend during Miocene times. The Mediterranean regions, which we define to include the entire Mediterranean Sea plus the Paratethys, Red Sea and nearby Atlantic areas, include a wide variety of Miocene carbonates and some of the world's best outcrops. In terms of quality of outcrops and field control, Miocene carbonates of Mediterranean regions equal or surpass those of the Devonian of the Canning Basin of Australia, the Permian Capitan reef of Texas and New Mexico, the Triassic of the Dolomites of Italy or the Lower Cretaceous in the Vercors of France. In some aspects, Miocene carbonates in Mediterranean regions offer significant advantages over those world-famous examples currently used as stratigraphic models, because: 1. Mediterranean-region reef complexes occur in a wider variety of structural and depositional settings, with better potential to evaluate the relative influence of the different tectonic, sedimentologic, hydrographic, climatic, ecologie and eustatic controls on facies patterns and geometries. 2. Miocene carbonates of Mediterranean regions offer better stratigraphic resolution, a plus for the study of high-frequency stratigraphic cycles. 3. The similarity with modern carbonates facilitates detailed analysis of depositional facies and ecology. 4. At various times and places during Miocene deposition in Mediterranean regions, carbonates developed as tropical coral reefs, temperate ramps or variations in between the two. A wider variety of platform styles occurs including non-rimmed platforms, rimmed platforms some with deeper-water mounds and platforms consisting of oolite shoals and stromatolites.

Abstract Abstract: Miocene carbonates in the Mediterranean are dominated by organic buildups of rhodalgal and coral-reef facies with local stromatolitic mounds, ahermatypic coral mounds and oyster banks and occur in a wide variety of tectonic settings and substrates. Regional chronostratigraphic correlation is in a state of flux, but it appears that coral reef development was extensive during the climatic optimum of the Chattian-Aquitanian, Langhian and Late Tortonian-Messinian times corresponding to global 2nd-order highstands or supercycles of relative sea level. The coral reef provinces of the Mediterranean reflect the transition between Early Miocene open-oceanic, humid-tropical conditions and Late Miocene landlocked, semi-arid and marginally subtropical environments. This is interpreted as a reflection of the global cooling trend and the northward displacement of the European plate, but also the increasing involvement of the rising Alpine foldbelts in controlling the climatic trends. The evolution of the connecting seaways with the Atlantic and Indo-Pacific domains are critical in the development of the Mediterranean Miocene carbonates. Most facies models in the region are based on superb outcrops of Upper Miocene carbonate complexes, which are largely applicable to lesser known Lower and Middle Miocene carbonates. Narrow platforms with fringing reefs are predominant; lagoonal facies are poorly developed and commonly with variable amounts of terrigenous mixing. Extensive carbonate platforms with barrier reefs and lagoons occur in Oligocene-Lower Miocene carbonates but are very scarce or ephemeral in Upper Miocene platforms. The best outcrops show excellent preservation of depositional morphologies (platform slopes, reef buttresses and spur-and-grooves, reefal patches, skeletal sand bodies and lobes) and allow detailed paleogeographic reconstructions. Depositional sequences of different orders of magnitude display a basic stacking pattern consisting of vertical aggradation, progradation and offlaping (downstepping); faithfully reflecting inferred relative sea-level oscillations. Coral diversity decreased from Early to Late Miocene times; part of the Messinian coral reefs are essentially monogeneric ( Porites , one of the main reef builders in all Miocene times). There are also Messinian reefs with 3-5 coral species; variations in diversity reflect local conditions rather than age or basin-wide events. The largest Upper Miocene reef complexes tend to be monogeneric and show good vertical zonation in colonial morphologies. However, these vertical zonations cannot be generalized for an entire basin or even a single reef complex. Upper Miocene coral reefs developed before, during and after the repeated deposition of basinal evaporile units and marine marls, resulting in complex wedge-on-wedge geometries of difficult correlation. Some of the Messinian coral reefs in the western Mediterranean exhibit peculiar features: exuberant monogeneric coral branches coated by cyanobacterial crusts, locally associated with giant stromatolitic domes, algal blooms and diatomitic marls. The peculiar look of some Messinian reefs is interpreted to be a result of the influx of cold, nutrient-rich Atlantic waters and their interaction with dense, warmer Mediterranean waters with a tendency to eutrophic, stressed marine conditions. These features are considered part of the scenario referred to as the Messinian crises, leading to major salinity variations and evaporile deposition in the basin.

Abstract: The western Mediterranean region contains abundant examples of the different types of Lower, Middle and Upper Miocene reefs (hermatypic coral reefs, ahermatypic mounds, rhodalgal biostromes and stromatolitic reefs). Those corresponding to the Upper Tortonian-Messinian rock units are the ones that have attracted the most attention because of the extraordinary quality of the outcrops and their relation to the polemic Messinian events in the Mediterranean. This section is a general introduction to the region, with a review of the Lower-Middle Miocene rhodalgal biostromes and coral reefs of the Gulf of Valencia-Provençal Basin and the Middle-Upper Miocene reefs of southeastern Spain and northern Morocco. The emphasis in this paper will be on the complex Miocene stratigraphy and paleogeography of southeastern Spain (Betics) and northern Morocco (Rif). This part of the western Mediterranean is important in understanding the paleogeographic evolution of the entire Mediterranean and its connection with the Atlantic Ocean.

Abstract: A review of the distribution of Miocene coral bioherms and biostromes is presented for Italy, Malta, Libya and Tunisia. These can be grouped into three natural settings related respectively to stable forelands, Alpine fold belts and graben zones. Morphological development within each zone is controlled by such factors as water depth, exposure to water currents, tectonism and siliciclastic sedimentation rates. The more diverse reefs developed in clear seas within stable foreland settings. Three principal reef development episodes are recognised. The earliest reefs (Aquitanian) are modest developments and represent a continuation of Oligocene coral reef growth with a high species diversity. Middle Miocene reefs are dominated by non-coral faunas and coralline algal biostromes; many are related to ramp situations. Corals return in Late Tortonian time though with much lower diversities than their Aquitanian predecessors. Many low diversity coral reefs typically contain up to five species but are always dominated by Porites and Tarbellastraea together with abundant coralline algae. Quite distinct from these are the reefs containing only Porites and Tarbellastraea and even more peculiar, the monogeneric (Porites) reefs. The latter are particularly typical of the Early Messinian. The slender coral rods are never as long and thin as those from strata of similar age in Spain; however, they are similarly associated with stromatolites and abundant Halimeda plates, particularly in the highest beds. It is suggested that locally introduced toxin and nutrient imbalances may contribute significantly to such aberrant reef growth. The driving force for these fluctuations appears to be a combination of tectonic basin deformation and small-scale, intra-Mediterranean eustatic oscillations marking the onset of the principal desiccation event.

Abstract: Miocene carbonates of the eastern Mediterranean and Middle East areas are characterized by subtropical-temperate rhodalgal or foramol facies. The geological setting of most carbonate occurrences is of platforms or low-energy ramps, whereas reef buildups are usually subordinate. The convergence of Euro-Asian and the African-Arabian plates in Late Oligocene and Miocene times resulted in the narrowing of the Tethys seaway and eventual separation of the Mesopotamian basin from the eastern Mediterranean basin. In Early Miocene (Aquitanian) to early Middle Miocene (Langhian) times, the Mesopotamian basin was occupied by a shallow low-energy ramp. Carbonate sedimentation of locally dolomitized wackestones and packstones, with red algae, mollusks and benthic foraminifers, prevailed during sea-level highstands and evaporites prevailed during lowstands. Three carbonate evaporite cycles are distinguished: (1) Middle Asmari-Kalhur; (2) Euphrates-Dhiban, of Aquitanian Burdigalian age; and (3) Jeribe-Lower Fars of Langhian Serravalian age. Early Miocene carbonates are poorly developed along the southeastern Mediterranean coasts, probably due to terrigenous influx by the pre-Nile river system draining the northern part of the African continent. Low sea levels at the beginning of cycle TB2 may have enhanced land erosion and subsequently siliciclastic deposition in the southeastern Mediterranean. Early Miocene carbonate deposition was limited to Cyprus, southern Turkey and to the Suez-Red Sea basin. Ubiquitous and uniform carbonate deposition throughout the entire Middle East took place in early Middle Miocene (Langhian) times when highstand seas spilled over the barrier separating the eastern Mediterranean from the Mesopotamian basin, depositing the Jeribe Formation in the Mesopotamian basin, the Ziqlag and Terbol Formations in Israel, Lebanon and northwest Syria and the Marmarica Formation, west of the Nile River, in Egypt. Lowstand seas in the Serravalian, coupled by continuous plate convergence, resulted in evaporite deposition in the Mesopotamian basin (Lower Fars) and the Red Sea (Belayim Formation). Carbonate deposits were absent from the Mediterranean during most of the Serravalian because of a surface water salinity decrease and a cooling trend. Late Miocene (Tortonian early Messinian) carbonates are scarce in the Middle East because of widespread tectonic emergence. Continental sedimentation prevailed in the Mesopotamian basin, and evaporitic deposition prevailed in the Red Sea. Patchy development of coral reefs and rhodalgal carbonates took place along the coasts of Israel, northern Sinai, Cyprus and Crete until their demise during the Messinian salinity crisis.

Abstract: Following successive trasgressive events, two main reef episodes occurred during Miocene deposition in the Paratethys: the Badenian and Sarmatian. Small coral patch reefs and coral carpets are known from Austria, Hungary and Bulgaria from the Badenian. Algal-vermetid reefs form the main Badenian reef chain extending from Poland through the Ukraine to Moldavia. The Sarmatian reefs are composed of peloidal (thrombolitic) limestones with large amounts of early fibrous cement and varying admixture of serpulid tubes, sessile forams Nubecularia , monostromatic red algae and encrusting cheilostomatous bryozoans. The main Sarmatian reef chain occurs in the same paleogeographic position as the Badenian algal-vermetid reefs and follows the former shallow-water platform margin from Poland through the Ukraine, Moldavia to Bulgaria; these reefs occur also on the Crimea and in the Forecaucasian region. The development of the Badenian reefs had been controlled by sedimentation patterns (clastics supply) and climatic factors. The Sarmatian reefs composition had been controlled by the chemistry of the Sarmatian basin water.

Abstract: Chattian and Miocene coral reefs and faunas of the western France basins are reviewed within a paleogeographic context. Several new outcrops have been discovered, and extensive new and historic collections have been studied. Coral diversity was very high in the Aquitaine basin during the Chattian(1) (ca. 150 species) and a little less so during the Early Miocene (110 species); during these times, relatively small reefal buildups formed in a tropical climate. The Mid-Miocene coral faunas show a marked decrease in diversity (some 75 species in all), with "subreefal" facies in the Langhian of southwestern and northwestern France. The Upper Miocene fauna is even poorer (just about 20 species) and only known in northwestern France. Throughout the Miocene, the proportion of hermatypic taxa also decreased notably; in the coral assemblages, these species were strongly predominant from Chattian to Burdigalian. Afterwards, the ahermatypic taxa became progressively predominant. Other northeastern Atlantic areas (Portugal, Morocco) are also investigated. Some biogeographic data sketch the evolutionary trend of these coral communities. During the Chattian, an (eastern and western) Atlantic-Mediterranean bioprovince was differentiated. During the Early Miocene, this bioprovince was restricted to eastern Atlantic and Mediterranean. From the Mid-Miocene, the coral faunas were disconnected from the Mediterranean, and an impoverished eastern Atlantic bioprovince became established without real renewal. A comparison with Mediterranean reefs shows that maximum coral building took place within the Mid-Miocene in the Mediterranean realm (with continuation of reefs in the Late Miocene), instead of Chattian (and Early Burdigalian) as in the Atlantic areas.