Basin Development in an Accretionary, Oceanic-Floored Fore-Arc Setting; Southern Coastal Ecuador During Late Cretaceous-Late Eocene Time

1995 ◽  
Author(s):  
Étienne Jaillard ◽  
Martha Ordoñez ◽  
Stalin Benitez ◽  
Gerardo Berrones ◽  
Nelson Jiménez ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Late Eocene ◽  
Basin Development ◽  
Arc Setting

scholarly journals Coal petrology analysis and implications in depositional environments from upper Cretaceous to Miocene: a study case in the Eastern Cordillera of Colombia

2021 ◽  
Author(s):  
Clara Guatame ◽  
Marco Rincón
Keyword(s):  
Late Cretaceous ◽  
Foreland Basin ◽  
Late Eocene ◽  
Depositional Environments ◽  
Estuarine System ◽  
Eastern Cordillera ◽  
Stratigraphic Position ◽  
San Fernando ◽  
Coal Facies ◽  
Oil Sector

AbstractThe Piedemonte Llanero Basin is located on the eastern side of the Eastern Cordillera of the Colombian Andes. It has been the subject of numerous geological studies carried out for the oil sector, mainly. This study presents the coal-petrographical features of 15 coal seams of four geological formations from Late Cretaceous to Middle Miocene (Chipaque formation, Palmichal group, Arcillas del Limbo formation, and San Fernando formation). Analysis of 33 samples indicates enrichment in vitrinite, while liptinite and inertinite concentrations vary according to the stratigraphic position. Reflectance indicates that the coal range gradually decreases from highly volatile bituminous C (Chipaque formation) to subbituminous C (San Fernando formation). The microlithotypes with the highest concentrations are clarite and vitrinertoliptite. Maceral composition and coal facies indicate changes in the depositional conditions of the sequence. The precursor peat from Late Cretaceous to Late Paleocene accumulated under limnic conditions followed by telmatic in Late Eocene–Early Miocene. The coal facies indices show wet conditions in forest swamps with variations in the flooding surface, influxes of brackish water and good tissue preservation. The tectonic conditions along the Piedemonte Llanero basin is evident, from post-rift to foreland basin, evidenced by oxic and anoxic periods reflected in the maceral composition and its morphology. The coal environment corresponds to an estuarine system started in the Chipaque formation evolving to the lacustrine conditions in the San Fernando formation.

scholarly journals A second peirosaurid crocodyliform from the Mid-Cretaceous Kem Kem Group of Morocco and the diversity of Gondwanan notosuchians outside South America

2021 ◽  
Vol 8 (10) ◽  
Author(s):  
Cecily S. C. Nicholl ◽  
Eloise S. E. Hunt ◽  
Driss Ouarhache ◽  
Philip D. Mannion
Keyword(s):  
South America ◽  
Late Cretaceous ◽  
North Africa ◽  
Lateral Surface ◽  
Middle Jurassic ◽  
Tooth Enamel ◽  
Phylogenetic Analyses ◽  
Late Eocene ◽  
South American ◽  
Early Late

Notosuchians are an extinct clade of terrestrial crocodyliforms with a particularly rich record in the late Early to Late Cretaceous (approx. 130–66 Ma) of Gondwana. Although much of this diversity comes from South America, Africa and Indo-Madagascar have also yielded numerous notosuchian remains. Three notosuchian species are currently recognized from the early Late Cretaceous (approx. 100 Ma) Kem Kem Group of Morocco, including the peirosaurid Hamadasuchus rebouli . Here, we describe two new specimens that demonstrate the presence of at least a fourth notosuchian species in this fauna. Antaeusuchus taouzensis n. gen. n. sp. is incorporated into one of the largest notosuchian-focused character-taxon matrices yet to be compiled, comprising 443 characters scored for 63 notosuchian species, with an increased sampling of African and peirosaurid species. Parsimony analyses run under equal and extended implied weighting consistently recover Antaeusuchus as a peirosaurid notosuchian, supported by the presence of two distinct waves on the dorsal dentary surface, a surangular which laterally overlaps the dentary above the mandibular fenestra, and a relatively broad mandibular symphysis. Within Peirosauridae, Antaeusuchus is recovered as the sister taxon of Hamadasuchus . However, it differs from Hamadasuchus with respect to several features, including the ornamentation of the lateral surface of the mandible, the angle of divergence of the mandibular rami, the texture of tooth enamel and the shape of the teeth, supporting their generic distinction. We present a critical reappraisal of the non-South American Gondwanan notosuchian record, which spans the Middle Jurassic–late Eocene. This review, as well as our phylogenetic analyses, indicate the existence of at least three approximately contemporaneous peirosaurid lineages within the Kem Kem Group, alongside other notosuchians, and support the peirosaurid affinities of the ‘trematochampsid’ Miadanasuchus oblita from the Maastrichtian of Madagascar. Furthermore, the Cretaceous record demonstrates the presence of multiple lineages of approximately contemporaneous notosuchians in several African and Madagascan faunas, and supports previous suggestions regarding an undocumented pre-Aptian radiation of Notosuchia. By contrast, the post-Cretaceous record is depauperate, comprising rare occurrences of sebecosuchians in north Africa prior to their extirpation.

Two-stage development of the Late Cretaceous to Late Eocene Darende Basin: implications for closure of Neotethys in central eastern Anatolia (Turkey)

2012 ◽  
Vol 372 (1) ◽  
pp. 385-419 ◽  
Author(s):  
Matthew G. Booth ◽  
Alastair H. F. Robertson ◽  
Kemal Tasli ◽  
Nurdan İnan ◽  
Ulvi Can Ünlügenç ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Late Eocene ◽  
Eastern Anatolia ◽  
Two Stage ◽  
Stage Development ◽  
Central Eastern

Pre-Priabonian Palaeogene formations in southwestern Bulgaria and northern Greece: stratigraphy and tectonic implications

1998 ◽  
Vol 135 (1) ◽  
pp. 101-119 ◽  
Author(s):  
IVAN S. ZAGORCHEV
Keyword(s):  
Late Cretaceous ◽  
Middle Eocene ◽  
Regional Metamorphism ◽  
Late Eocene ◽  
Thin Layers ◽  
The South ◽  
Northern Greece ◽  
The North ◽  
Early Oligocene ◽  
Metamorphic Core

The Paril Formation (South Pirin and Slavyanka Mountains, southwestern Bulgaria) and the Prodromos Formation (Orvilos and Menikion Mountains, northern Greece) consist of breccia and olistostrome built up predominantly of marble fragments from the Precambrian Dobrostan Marble Formation (Bulgaria) and its equivalent Bos-Dag Marble Formation (Greece). The breccia and olistostrome are interbedded with thin layers of calcarenites (with occasional marble pebbles), siltstones, sandstones and limestones. The Paril and Prodromos formations unconformably cover the Precambrian marbles, and are themselves covered unconformably by Miocene and Pliocene sediments (Nevrokop Formation). The rocks of the Paril Formation are intruded by the Palaeogene (Late Eocene–Early Oligocene) Teshovo granitoid pluton, and are deformed and preserved in the two limbs of a Palaeogene anticline cored by the Teshovo pluton (Teshovo anticline). The Palaeocene–Middle Eocene age of the formations is based on these contact relations, and on occasional finds of Tertiary pollen, as well as on correlations with similar formations of the Laki (Kroumovgrad) Group throughout the Rhodope region.The presence of Palaeogene sediments within the pre-Palaeogene Pirin–Pangaion structural zone invalidates the concept of a ‘Rhodope metamorphic core complex’ that supposedly has undergone Palaeogene amphibolite-facies regional metamorphism, and afterwards has been exhumed by rapid crustal extension in Late Oligocene–Miocene times along a regional detachment surface. Other Palaeogene formations of pre-Priabonian (Middle Eocene and/or Bartonian) or earliest Priabonian age occur at the base of the Palaeogene sections in the Mesta graben complex (Dobrinishka Formation) and the Padesh basin (Souhostrel and Komatinitsa formations). The deposition of coarse continental sediments grading into marine formations (Laki or Kroumovgrad Group) in the Rhodope region at the beginning of the Palaeogene Period marks the first intense fragmentation of the mid- to late Cretaceous orogen, in particular, of the thickened body of the Morava-Rhodope structural zone situated to the south of the Srednogorie zone. The Srednogorie zone itself was folded and uplifted in Late Cretaceous time, thus dividing Palaeocene–Middle Eocene flysch of the Louda Kamchiya trough to the north, from the newly formed East Rhodope–West Thrace depression to the south.

Hydrocarbon Reservoir Potential of the Taranaki Basin, Western New Zealand

1988 ◽  
Vol 6 (3) ◽  
pp. 248-262 ◽  
Author(s):  
P.H. Robinson ◽  
P.R. King
Keyword(s):  
New Zealand ◽  
Late Cretaceous ◽  
Late Eocene ◽  
Hydrocarbon Reservoir ◽  
Future Activity ◽  
Terrestrial Sediments ◽  
Potential Reservoir ◽  
Sandstone Reservoir ◽  
Reservoir Potential ◽  
Sand Bodies

Taranaki Basin is a proven petroleum producing region, with commercial quantities of hydrocarbons from late Eocene paralic and terrestrial sands, and Miocene-latest Pliocene shelf sands. Other sediments with sub-commercial hydrocarbon accumulations, shows or potential reservoir features have also been encountered. The paralic and terrestrial sediments were deposited during periodic shoreline fluctuations in the Paleogene and were capped by transgressive terrigenous and carbonate muds. Other sand bodies, generally of bathyal and shelf setting and representing increasing regional tectonism, are found throughout the late Eocene to Pliocene sequence. Paleogeographic reconstructions depicting the maximum sand development during the Paelocene to Pliocene provide potential sandstone reservoir maps. These highlight onshore Taranaki and the Eocene paleoshoreline trend as areas of greatest prospectivity. Future activity should also consider the potential of the relatively unexplored late Cretaceous-Paleocene and Pliocene sandstone sequences.

scholarly journals Giant Placers of the Victorian Gold Province

SEG Discovery ◽  
2004 ◽  
pp. 1-18
Author(s):  
Martin J. Hughes ◽  
G. Neil Phillips ◽  
Stephen P. Carey
Keyword(s):  
Late Cretaceous ◽  
Quartz Vein ◽  
Late Eocene ◽  
Gold Deposits ◽  
Gold Production ◽  
Placer Gold ◽  
High Rainfall ◽  
Hydrothermal Quartz ◽  
Alluvial Gold ◽  
Primary Gold

ABSTRACT The Victorian gold province has yielded 2500 tonnes (t) Au, nearly 2 percent of cumulative world gold production, mostly mined between 1851 and 1910. Fifty-five percent (1375 t) was placer gold from modern and paleostream systems, and from eluvial deposits, and the remainder came from primary quartz vein-related deposits. Most of the alluvial gold placers are in unconsolidated or weakly cemented quartz pebble conglomerate and gravel, dominated by hydrothermal quartz, although a few paleoplacers are within duricrusted conglomerate that required crushing. Large and abundant gold nuggets were common. Placer gold deposits formed in three intervals following uplift in the Late Cretaceous, Late Eocene, and Pliocene. An important factor in the preservation of the paleoplacers has been their burial by younger sediments and basalt flows, with consequent protection from erosion and dispersal. Factors in the formation of the giant gold placers of Victoria include the following: (1) the existence of a major primary gold province with several multimillion-ounce gold deposits; (2) uplift and reactivation of older faults; and (3) high rainfall and deep Paleogene weathering.

scholarly journals Late Cretaceous basin development of the southern Danish Central Graben

1969 ◽  
Vol 20 ◽  
pp. 15-18
Author(s):  
Finn Jakobsen ◽  
Claus Andersen
Keyword(s):  
Late Cretaceous ◽  
Oil And Gas ◽  
Seismic Inversion ◽  
Gas Production ◽  
Structural Development ◽  
Oil Accumulation ◽  
Oil And Gas Production ◽  
North West ◽  
The North ◽  
Basin Development

The Danish oil and gas production mainly comes from fields with chalk reservoirs of Late Cretaceous (Maastrichtian) and early Paleocene (Danian) ages located in the southern part of the Danish Central Graben in the North Sea. The area is mature with respect to exploration with most chalk fields located in structural traps known since the 1970s. However, the discovery by Mærsk Oil and Gas A/S of the large nonstructurally and dynamically trapped oil accumulation of the Halfdan Field in 1999 north-west of the Dan Field (e.g. Albrechtsen et al. 2001) triggered renewed exploration interest. This led to acquisition of new high quality 3-D seismic data that considerably enhanced imaging of different depositional features within the Chalk Group. Parallel to the endeavours by the operator to locate additional non-structural traps in porous chalk, the Geological Survey of Denmark and Greenland took advantage of the new data to unravel basin development by combining 3-D seismic interpretation of a large number of seismic markers, well log correlations and 2-D seismic inversion for prediction of the distribution of porous intervals in the Chalk Group. Part of this study is presented by Abramovitz et al. (in press). In the present paper we focus on aspects of the general structural development during the Late Cretaceous as illustrated by semi-regional time-isochore maps. The Chalk Group has been divided into two seismically mappable units (a Cenomanian–Campanian lower Chalk Unit and a Maastrichtian–Danian upper Chalk Unit) separated by a distinct basin-wide unconformity.

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