Middle Miocene Transgression Research Articles

Marine facies differentiation along complex paleotopography: an example from the Middle Miocene (Serravallian) of Lower Austria

In the area of Bad Deutsch-Altenburg (Hainburg Mountains, Lower Austria) a Middle Miocene transgression over Mesozoic basement was explored in the course of the Danube power plant project “Hainburg”. The Mesozoic basement forms a narrow ridge dipping to the northeast towards the Vienna Basin, covered by various Miocene sediments. The ridge represents a specific paleotopography that required a detailed study with 78 shallow, fully cored drill holes in an area of c. 0.5 km2. Ten drillings were selected for this study based on sedimentary composition and position relative to the Mesozoic ridge. These 10 cores, ranging in drilling depth from 26.5 to 96.4 m, were studied in respect to sedimentology, corallinacean algae, calcareous nannoplankton, foraminifers and ostracodes to reconstruct sediment distribution and paleoenvironment. Sediment distribution clearly shows that the Mesozoic ridge formed a physical barrier with siliciclastics dominating in the SW of the ridge and carbonate sediments prevailing in the NE. Based on biostratigraphy (calcareous nannoplankton, foraminifera, ostracodes, dinoflagellates) the majority of the sediments can be dated to the late Badenian (early Serravallian) only in some drillholes lower Sarmatian (upper Serravallian) sediments were detected. In terms of sequence stratigraphy, the Badenian sediments represent the transgressive and highstand systems tract of 3rd order sequence TB 2.5 (bound by the lowstands Ser 2 and Ser 3), the lower Sarmatian sediments can be correlated to sequence TB 2.6. Carbonate sediments show a wide spectrum of 13 facies which are mostly dominated by coralline algae. According to the relative positions of the drill holes a water depth between 0 and about 50 m can be reconstructed what is supported by the occurrence of the benthic biota. This biota indicates that the sedimentary succession started from the very beginning under full marine conditions. Except of basal conglomerates/breccias water energy conditions were low and turbidity high. Close to the Sarmatian boundary a reduction in salinity and depth may have occurred which is also observed in the Sarmatian sediments. Carbonate sediments and, in particular, larger benthic foraminifers indicate tropical to warm-temperate conditions for the late Badenian of the studied sections. The siliciclastic sediments NW of the Mesozoic ridge reflect riverine input indicated by the occurrence of freshwater ostracodes and characean oogonias. Calcareous nannoplankton and dinoflagellates show a high share of reworking from Upper Cretaceaous and Paleogene sediments.

The biogeography of Dromiciops in southern South America: Middle Miocene transgressions, speciation and associations with Nothofagus

The current distribution of the flora and fauna of southern South America is the result of drastic geological events that occurred during the last 20 million years, including marine transgressions, glaciations and active vulcanism. All these have been associated with fragmentation, isolation and subsequent expansion of the biota, south of 35°S, such as the temperate rainforest. This forest is mostly dominated by Nothofagus trees and is the habitat of the relict marsupial monito del monte, genus Dromiciops, sole survivor of the order Microbiotheria. Preliminary analyses using mtDNA proposed the existence of three main Dromiciops lineages, distributed latitudinally, whose divergence was initially attributed to recent Pleistocene glaciations. Using fossil-calibrated dating on nuclear and mitochondrial genes, here we reevaluate this hypothesis and report an older (Miocene) biogeographic history for the genus. We performed phylogenetic reconstructions using sequences from two mitochondrial DNA and four nuclear DNA genes in 159 specimens from 31 sites across Chile and Argentina. Our phylogenetic analysis resolved three main clades with discrete geographic distributions. The oldest and most differentiated clade corresponds to that of the northern distribution (35.2°S to 39.3°S), which should be considered a distinct species (D. bozinovici, sensu D’Elía et al. 2016). According to our estimations, this species shared a common ancestor with D. gliroides (southern clades) about ~13 million years ago. Divergence time estimates for the southern clades (39.6°S to 42.0°S) ranged from 9.57 to 6.5 Mya. A strong genetic structure was also detected within and between clades. Demographic analyses suggest population size stability for the northern clade (D. bozinovici), and recent demographic expansions for the central and southern clades. All together, our results suggest that the diversification of Dromiciops were initiated by the Middle Miocene transgression (MMT), the massive marine flooding that covered several lowlands of the western face of Los Andes between 37 and 48°S. The MMT resulted from an increase in global sea levels at the Miocene climatic optimum, which shaped the biogeographic origin of several species, including Nothofagus forests, the habitat of Dromiciops.

Depositional Environments in the Eastern Paratethys during the Final Middle Miocene Transgression (Kura Basin, Eastern Georgia)

The mineral composition and depositional environments of the Konkian in eastern Georgia (Kura trough, eastern Paratethys) corresponding to the Kosovian (13.65–12.829 Ma) in the Central Paratethys and the final Middle Miocene marine transgression in Paratethys are considered. Jurassic and Cretaceous volcanic rocks of the Lesser Caucasus (Adzhar–Trialet and Artvin–Bolnisi zones) were identified as the main provenances for the terrigenous material. Eight lithofacies types distinguished for the studied rocks characterize depositional environments with significant wave or submarine-fluvial influence. The change of depositional environment was controlled by the phases of transgression, as well as by the progradation and lateral migration of the prodelta. The development of depositional environment corresponds to the Konkian stratigraphic beds and reflects the main stages of the final Middle Miocene transgression in the Eastern Paratethys.

APPLICATION OF 18O AND 13C STABLE ISOTOPES COMPOSITION OF THE CARBONATE ROCKS OF THE JERIBE FORMATION EASTERN IRAQ; AN APPROACH TO DEFINE THE PALEO TEMPERATURE AND PALEO DEPTH

Stable isotopes 18O/16O and 13C/12C in the carbonate rocks of the Jeribe Formation are examined here to define the depositional characters in the basin includes paleo temperatures and paleo depth. The Jeribe Formation comprises a transgressive unit belongs to the Latest Eocene-Recent Megasequence (Ap11). Complete sections of the formation were studied in the core of Himreen structure in eastern part of Iraq. The Himreen structure lies in the outer platform margin of unstable shelf of the Arabian plate. The stable isotope (18O/16O and 13C/12C) of Jeribe Formation provides the first records of paleotemperature for the Neogene (middle Miocene Transgression) of the Southern Teythes, which indicate cooling during deposition. Microfacies study imply that the skeletal grains are composed of green and red algae, stromatolite and verities of benthic foraminifera. The non-skeletal grains are pellets and intraclasts. Analysis of microfacies suggests lagoon, reef, shoal and open marine environments. The depletion of both 18O and 13 C indicated shallowing at the contact with overlying and underlying formations in the shoal and lagoonal facies respectively. While in the middle part in the coral reef facies reveals elevation of the sea surface temperature. These suggest that the enrichment of both 18O and 13 C at the cool water temperature associated with upwelling and arise of sea level represented by reef and open marine facies.

Homotryblium-dominated Eocene dinoflagellate cyst assemblages from Middle Miocene (Badenian) glauconitic sands at Lipowiec (Roztocze, SE Poland)

A section over 20 m thick of the basal Middle Miocene succession exposed at Lipowiec (Roztocze, SE Poland) was studied for palynology. Thirteen samples were collected from quartz and glauconitic-quartz sands and thin clay layers. Sand samples were barren but clay samples yielded dinoflagellate cysts. Their assemblages consist of reworked Paleogene specimens dominated by the Homotryblium floripes complex ( H. floripes and morphologically similar H. plectilum and H. vallum ). The presence of reworked Paleogene specimens indicates intense erosion of marine Paleogene strata during initial stages of the Middle Miocene transgression at Roztocze. Analysis of stratigraphical ranges of reworked dinoflagellate cysts and comparison with their occurrences in known epicontinental Paleogene sites of SE Poland suggest an Upper Eocene age of the washed-out strata. The taxonomic composition of the assemblages described suggests that the Upper Eocene deposits accumulated in a near-shore, lagoonal embayment characterized presumably by oligotrophic waters of slightly increased salinity. A high proportion of the Homotryblium floripes complex is also characteristic of reworked assemblages found in younger Miocene strata of neighbouring exposures in Roztocze, which indicates widespread Eocene lagoonal environments in this part of Roztocze. Coeval Eocene strata from the eastern part of Roztocze and from the Carpathian Foredeep show different taxonomic compositions suggesting varied sedimentary settings during Eocene transgression in this region. These differences reflect variable amounts of freshwater influence resulting in a range of environments that ranged from oligotrophic to brackish.

REEFS AND BIOACCUMULATIONS IN THE MIOCENE DEPOSITS OF THE NORTH CROATIAN BASIN – AMAZING DIVERSITY YET TO BE DESCRIBED

During the early stages of the Middle Miocene transgression marine biota invaded the newly formed Paratethys Sea. Reefs and reef-like structures particularly flourished with life, supported by the favourable climate conditions. Miocene biogene buildups show a variety of fossil assemblages and lithologic features. The main reef-builders were bryozoans, coralline algae, corals, oysters, vermetids, sponges and serpulids. Water turbidity and depth were major ecological factors controlling the reef biota. Lithofacies types at the studied localities in Northern Croatia show significant similarity with the Upper Langhian (Middle Badenian) of the Leitha Mountains in Austria, but can also be well compared with Miocene to recent reef structures in the Mediterranean. The Miocene reef-like buildups exhibit different porosity rates and other lithological characteristics.

Badenian (Middle Miocene) echinoids and starfish from western Ukraine, and their biogeographic and stratigraphic significance

Abstract Echinoderms from the Badenian (Middle Miocene) of the Fore-Carpathian Basin of western Ukraine are facies restricted. The Mykolaiv Beds, stratigraphically older, yielded the starfish Astropecten forbesi (complete skeletons), two genera of sand dollars (Parascutella, Parmulechinus), and numerous other echinoids of the genera Psammechinus , Echinocyamus, Spatangus, Hemipatagus, Echinocardium, Clypeaster, Echinolampas, and Conolampas. The stratigraphically younger, calcareous Ternopil Beds yielded Eucidaris (complete coronae, isolated spines), Arbacina , Brissus, and Rhabdobrissus. Sixteen species of echinoids are distinguished and/or commented. A new brissid, Rhabdobrissus tarnopolensis sp. nov., is established. A mass occurrence of some species (Psammechinus dubius and Hemipatagus ocellatus) contrasts with that of mass aggregations (sand dollars and Echinocardium leopolitanum) by dynamic events in selected layers of proximal tempestites. Of special note is the occurrence of very small specimens, interpreted as juveniles (‘babies’) having been swept out of their restricted biotopes (‘nurseries’). Some species hitherto regarded as of Early Miocene age, and the problem of their persistence beyond the Fore-Carpathian Basin and/or migration into that basin during the Middle Miocene transgression are discussed.

The Iváň Canyon, a large Miocene canyon in the Alpine-Carpathian Foredeep

During the latest Early Miocene a large drainage system developed in the Alpine-Carpathian Foreland transporting sediments through a prominent submarine canyon along the narrow corridor between the south-eastern Bohemian Massif and the Waschberg-Ždánice Unit. The canyon followed the Alpine-Carpathian Foredeep from Lower Austria towards the north and northeast into the Czech Republic. 3-D seismic data allow the mapping of this 600 m deep structure over a distance of 25 km and a width of 5 km. Despite its dimension, making it the largest submarine erosive and sedimentary structure of the Neogene Alpine-Carpathian Foredeep, this canyon has not been previously recognised. Herein, it is interpreted as shelf-indenting canyon that formed due to a combination of isostatic rebound along a terminating thrust front and sea-level change during the terminal Early Miocene.The canyon fill comprises reworked littoral deposits with a typical Early Miocene, tropical micro- and macrofauna. The exact timing of this refilling remains unclear. Smaller channel structures in surface outcrops, representing potential tributaries of the canyon, suggest a more or less synsedimentary filling soon after indention. Finally, the top part of the canyon was eroded around the Early/Middle Miocene boundary, probably related to a global 3rd order sea level drop, and caped by marine marls during the subsequent early Middle Miocene transgression. With the sudden onset of the subsidence of the Northern Vienna Basin during that time, the drainage system abruptly moved southward shedding its sediments into the newly opening Vienna Basin. This explains the rather abrupt abandonment of the huge canyon feature, whose fan deposits are unknown so far.

The Late Cretaceous-Cenozoic transgressions in Patagonia and the Fuegian Andes: foraminifera, palaeoecology, and palaeogeography

In southernmost South America, several ephemeral Atlantic transgressions flooded the Patagonian Platform: in the Maastrichtian-Danian, late Mid-Eocene, Late Oligocene-Early Miocene, and Middle Miocene; only in the Fuegian Andes did marine conditions remain continuously from the Maastrichtian up to the Middle Miocene. In the Maastrichtian, the calcareous foraminiferal benthic assemblages contain endemic species, and most of them disappear in the Cretaceous-Palaeogene transition. The Palaeocene carries the extinct cosmopolitan Midway type assemblage with few endemic taxa such as Buliminella isabelleana, and the genera Antarcticella and Boltovskoyella. The Palaeocene/Eocene turnover gives room to assemblages of modern and marked Austral aspect: Elphidiidae dominates in shallow environments, including genera endemic to high and mid-high southern latitudes such as Cribrorotalia. The Late Middle Eocene transgression is characterized by large nodosarids in the Fuegian area and the spreading of Elphidium saginatum. The Late Oligocene transgression is of limited extension and shallow waters, with abundant Buccella and the conspicuous genus Discorotalia. The Early Miocene transgression carries the extinct and typical Antarctic genus Ammoelphidiella and witnesses the origin of the modern Patagonian coastal assemblage, characterized by its pauperism and the dominance of the genus Buccella. The Middle Miocene transgression covers mainly northern Argentina. Considering that the late Middle Eocene and Middle Miocene transgressions are coeval with relative climatic optima, and in comparison with assemblages at similar palaeolatitudes elsewhere in the Southern Hemisphere, the absence of larger foraminifera or thermophilic forms in the Patagonian and Fuegian assemblages is outstanding.

The Early and Middle Miocene transgression at the southern border of the North Sea Basin (northern Belgium)

The Lower–Middle Miocene Berchem Formation of northern Belgium is an essentially sandy sequence with a varying glauconite content and often abundant shelly intervals. The formation was deposited in a shallow marine environment and rests unconformably on stiff Rupelian clays or Chattian sands. The lithological recognition of the four members (Edegem Sands, Kiel Sands, Antwerpen Sands and Zonderschot Sands members) of the Berchem Formation solely based on lithological criteria proved to be difficult, especially in boreholes. The geometry of the Formation in the subsurface of northern Belgium remained largely unknown. Diverse and well preserved dinoflagellate cyst associations have been recovered from the four members in seven boreholes and two outcrops, and allow a refinement of the biostratigraphy of these deposits. A Miocene biozonation defined in mid-latitude shallow marine deposits in the Atlantic Coastal Plain of the USA (Salisbury Embayment, Maryland) is readily applicable to this material, and has led to a detailed stratigraphic assessment of each member. Three detailed profiles depicting the distribution of the biozones in the subsurface of northern Belgium allow the reconstruction of the geometry and depositional history of the Berchem Formation. The oldest Miocene deposits are of early Burdigalian age and they testify to a transgression, which invaded Belgium from a north–northwestern direction. The maximum flooding took place during early Serravallian times. The upper boundary of the formation is a major erosional surface of late Serravallian or (slightly) younger age. Copyright © 2005 John Wiley & Sons, Ltd.

THE MIDDLE CRETACEOUS TO RECENT SEQUENCE STRATIGRAPHIC EVOLUTION OF THE EXMOUTH-BARROW MARGIN, WESTERN AUSTRALIA

Five supersequences have been revealed by a regional sequence stratigraphic study conducted in the Albian (109 Ma) to Recent section of the Exmouth-Barrow passive margin. The interpretation utilises a new sequence stratigraphic model developed for mixed siliciclasticcarbonate lithofacies. A high degree of resolution is brought to the study by identification of 37 regional sequence boundaries controlled by biostratigraphic, wireline and seismic data. Ditch cutting analysis, integrated into the new chronostratigraphic framework, provided detailed lithofacies maps.The five supersequences, named the Gallic, Senonian, Palaeogene, Middle Neogene and Pliocene, are based upon regional lowstand, transgressive and highstand phases. The Gallic Supersequence (late Tithonian–latest Cenomanian) represents a marine incursion of siliciclastic sediments coincident with the rifting and accelerated movement of India away from Australia. A Senonian Supersequence (latest Cenomanian–middle Maastrichtian) truncates the previous supersequence with incised canyons developed on the outer shelf. The evolution of the Senonian section corresponds to the Australian separation from Antarctica and the first appearance of carbonates.The Palaeogene Supersequence (middle Maastrichtian– late Early Miocene) dominates much of the Tertiary and is identified by a basinward shift of facies following a Maastrichtian–Paleocene sea level fall. Enhanced subsidence on the outer shelf during the Eocene created a forced transgression with carbonate mudstonesiltstone deposition. A highstand during the Oligocene– Early Miocene formed the distinctive prograding carbonate shelf recognised throughout the North West Shelf.A Middle Neogene Supersequence (late Early Miocene– Early Pliocene) is identified by an erosive base and the development of a thin lowstand fan on the outer shelf. The supersequence is largely characterised by backstepping reefs following a Middle Miocene transgression. A Late Miocene eustatic stillstand restricted reef development to the inner shelf, generating coarsegrained carbonate progrades from highstand-shedding. The final Pliocene Supersequence (Pliocene–Recent) was initiated by a eustatic fall during the Early Pliocene and was followed by the development of a transgressive, aggrading shelf.

Synthetic data on the paleogeographic history of Northeastern Atlantic and Betic-Rifian basin, during the Neogene (from Brittany, France, to Morocco)

This paper presents the results of a synthetic compilation of the studies of Neogene marine deposits recognized on the northeastern Atlantic coast from Morocco to northern France. The shoreline fluctuations as well as the tectonic and climatic events are discussed regarding the following time intervals and eustatic cycles: late Oligocene, TB1.4 cycle (ca 25–22.7 Ma); Aquitanian, TB1.5 cycle (22.7–20.7 Ma); Burdigalian, TB2.1–2 cycles (20.6–16.5 Ma); Langhian — Serravallian, TB2.3–6 cycles (16.5–10.4 Ma); Tortonian, TB3.1–2 cycles (10.4–6.4 Ma); Messinian, TB3.3–4 (pars) cycles (6.4–5.3 Ma) and Pliocene (5.3–1.8 Ma). Marine Upper Chattian is well represented in the Acquitaine Basin (France), with various facies formed in a tropical climate During the Acquitanian and the Burdigalian, the transgressions extended in wide neritic gulfs in France, Portugal, Spain and North of Morocco. The Middle Miocene transgression is well pronounced in the different areas. In the Betico-Rifian realm, overthrusts are established and the flysch resorption is concluded at the end of that time. During the Upper Miocene, the marine realm is locally back from the preceding one; outstanding events occured in the tectonic Betico-Rifian basin, the eastern part of which was affected by the Mediterranean salinity crisis during the Messinian. Finally, in the Pliocene, most of the features of the modern palaeogeography are evidenced, even when the coastal frontage of several areas is still affected by little transgressions.

System of the Neogene regional divisions of Kamchatka and Sakhalin: horizons, zones and beds

Discussions are made on the concepts of suites, horizons, zones, and beds which have been widely used in stratigraphic divisions in Kamchatka and Sakhalin. Horizons are defined as chronostratigraphic divisions reflecting geologic events. The Miocene sequence in Kamchatka can be distinguished by five or six horizons. Bed-by-bed analysis of the benthic groups yields recognition of smaller units — beds with fauna. The West Kamchatka Neogene has 17–18 molluscan beds. Fortipecten takahashii beds are traced in Japan, Sakhalin and Kamchatka. Panomya elongata beds correspond to the beginning of the middle Miocene transgression in Kamchatka, and the overlying Mytilus chejeleveemensis beds coincide with the onset of deposition of extensive diatomites.

Hydrocarbon potential of Philippie Basins

The history of oil exploration in the Philippines dates back to the late 1800s when the first exploratory well for Petroleum was drilled on the Island of Cebu, in the Visayan Region. Since 1896 over 367 exploratory wells have been drilled in twelve basins within the Philippine Archipelago. In early 1979, the first commercial oil field in the Philippines was brought into production offshore northwest Palawan, about three years after NIDO No. 1, the first significant wildcat discovery, was drilled by a consortium of companies headed by Cities Service, Inc. Although exploratory work, including drilling, has been carried out in other areas during the past 84 years, the success attained in northwest Palawan has not yet been repeated in other Philippine basins.Philippine sedimentary basins are located within a complexly deformed zone between the Philippine Sea Plate and the Eurasian Plate. The basins can be classified genetically as 1.(a)Archipelagic Basins2.(b)Continental Margin Basins, and3.(c)Marginal Sea Basins. Archipelagic Basins may in turn have either a forearc or an intervolcanic arc setting.The stratigraphy of most of these basins reflects the cyclicity of geologic events recognized on a regional scale in Southeast Asia, and gives further evidence of the interconnected nature of the basins from Late Paleogene to Neogene time. Multiplicity of sedimentary cycles is more evident in the central, west central and southern Philippines where island arcs are more complexly deformed.The important hydrocarbon plays pursued by current groups of explorationists are carbonate buildups on platforms associated with the late Oligocene to middle Miocene transgression. Clastic reservoir plays in structural traps have not been encouraging due to rapid lateral and vertical facies change, in addition to low permeabilities of the sands which are mostly derived from volcanic detritus.Of the three classes of basins, the Continental Margin Basins, i.e., those bordering microcontinental blocks, have the best potential, followed by Archipelagic Basins located between volcanic arcs. As in many forearc basins, the petroleum potential of Archipelagic Basins is only marginal because of the low maturation reached by the potential source rocks, and low organic content. Not much is known of the only marginal sea basin recognized within the Philippine Archipelago, the Inner Sulu Sea Basin. However, high heat flow values suggestive of back arc spreading have been recorded. The very deep waters over this basin preclude active exploration of this area at the present time.