THE QUEENSLAND TROUGH: ITS PETROLEUM POTENTIAL BASED ON SOME RECENT GEOPHYSICAL RESULTS

1975 ◽  
Vol 15 (1) ◽  
pp. 21 ◽  
Author(s):  
J. Pinchin ◽  
J. W. Hudspeth
Keyword(s):  
Middle Eocene ◽  
Outer Edge ◽  
Early Eocene ◽  
Petroleum Potential ◽  
Shallow Marine ◽  
Coral Sea ◽  
Basement Faults ◽  
Seismic Sections ◽  
Basement Surface ◽  
Marginal Reef

The Queensland Trough, about 130 km wide, lies between Queensland and the Coral Sea Plateau. It runs from a water depth of 1000 m off Townsville to 3000 m opposite Cape Melville.The most extensive and systematic geophysical survey of the area to date is that conducted by the BMR during 1971 as part of the survey of the Australian continental margin.The BMR sparker seismic sections show a rugged and eroded basement surface. It is concluded that this represents the top of mildly metamorphosed Palaeozoic sediments of the Tasman Geosyncline which were uplifted, folded, and faulted during the Permian and were subsequently severely eroded. In places coral reefs have grown from this basement surface. Some are now buried and some, especially those atop basement highs, are still growing.The Eocene/Oligocene unconformity encountered in the DSPD hole 209 on the outer edge of the Coral Sea Plateau can be traced as an unconformity over the entire trough and as a conformable Eocene seismic horizon over most of the trough. This horizon lies close to the basement over much of the plateau and at least 1.5 km above the basement in the centre of the trough. It is overlain by about 0.5 km of sediments over both the trough and the plateau.It appears that the trough was low relative to the plateau and the mainland since the beginning of the Mesozoic and received terrestrial and shallow marine sediments.Regional subsidence of the trough and plateau probably began in the Early Eocene. Small basins on the trough's eastern margin and on the plateau were formed by differential subsidence along rejuvenated basement faults. These small basins contain lower to middle Eocene shallow marine sediments.Petroleum prospects appear favourable in the south of the trough, especially in the trough's marginal reef development and in the region of pre-Eocene pinch-out against Palaeozoic basement.

scholarly journals The Paleogene Tectonostratigraphy Of Northern Part Masalima Trench Basin

2016 ◽  
Vol 1 (1) ◽  
pp. 7
Author(s):  
Luhut Pardamean Siringoringo ◽  
Dardji Noeradi
Keyword(s):  
Depositional Environment ◽  
Middle Eocene ◽  
Normal Faults ◽  
Tectonic Structure ◽  
Shallow Marine ◽  
Early Oligocene ◽  
Basin Formation ◽  
Java Sea ◽  
Seismic Sections ◽  
Well Data

Northern part of Masalima Trench Basin is located in the southern part of the Strait of Makassar, which includes Masalima Trough and Massalima High. The area of research is an extension of the South Makassar Basin which extends from South Makassar Basin to the Northeast part of Java Sea. Subsurface data are used such as 2D seismic sections (21 lines) and data drilling wells (2 wells) to understand the tectonic structure in the basin formation and understand the stratigraphic order of basin. Based on well data can be known that Northern part Masalima Trench Basin is aborted rift because marked by post rift phase. Northern part Masalima Trench Basin was formed by normal faults which have trend northeast-southwest with  pre rift, early syn rift, late syn rift, and post rift sediment geometry. Early syn rift sediment was Middle Eocene, late syn rift sediment was Middle Eocene till Early Oligocene and post rift sediment was Early Oligocene till Early Miocene. The Depositional environment of early syn rift phase such as beach, shallow marine, and land. The Depositional environment of late syn rift phase such as beach till deep marine, and the depositional environment of post rift is deep marine.

The incidence of unusual test morphologies of Eocene Larger benthic foraminifera: An example of Paleogene Adriatic Carbonate Platform

2021 ◽  
Author(s):  
Vlasta Ćosović ◽  
Jelena Španiček ◽  
Katica Drobne ◽  
Ervin Mrinjek
Keyword(s):  
Benthic Foraminifera ◽  
Carbonate Platform ◽  
Middle Eocene ◽  
Morphological Diversity ◽  
Late Eocene ◽  
Early Eocene ◽  
Coralline Red Algae ◽  
Larger Benthic Foraminifera ◽  
Shallow Marine ◽  
Scientific Project

<p>The Paleogene Adriatic carbonate platform(s) existed within the Central NeoTethys (around 32 N paleolatitude) from the Danian to the late Eocene (Bartonian/Priabonian) and produced a succession of limestones up to 500 m thick, rich in larger benthic foraminifera (LBF). The Eocene sediments are widely distributed along the eastern Adriatic coast and have been studied for many years. Taking into account the climatic changes that took place within the Eocene (Early Eocene and Middle Eocene climatic optima, known as EECO, MECO), special attention was paid to the composition of shallow-marine foraminiferal assemblages. The studies reveal the following trends: (1) the alveolinid-dominated assemblages were replaced by nummulitid-dominated assemblages around the MECO; (2) the greater species and morphological diversity (spherical, ellipsoid, extremely elongated fusiform) of the alveolinid fauna was evident at the EECO; (3) the nummulitid-dominated fauna was characterized by less diversified assemblages compared to the alveolinid ones and by the co-occurrence of scleractinian corals, coralline red algae and aborescent foraminifera. The occurrence of twin embryos has been assigned to the early Eocene in the alveolinid populations, especially in Alveolina levantina and A. axiampla (in some sections, the frequency is greater than 5%), and these coalesced embryos have the same size as the single form (usually they are smaller). The LBF assemblages of Middle Eocene showed a greater frequency of doubled adult tests (Orbitolites sp., Nummulites sp.). The origin of these unusual morphologies is poorly known, usually described as the results of stressful conditions. Considering the timing of the appearance of such morphologies, temperature and associated changes in the shallow-marine environment could be the cause.</p><p>This study is carried out as part of the scientific project IP-2019-04-5775 BREEMECO, funded by Croatian Scientific Foundation.</p>

Early Tertiary thermotectonic history of the northern Yukon and adjacent Northwest Territories, Arctic Canada

1997 ◽  
Vol 34 (10) ◽  
pp. 1366-1378 ◽  
Author(s):  
Paul B. O'Sullivan ◽  
Larry S. Lane
Keyword(s):  
Northwest Territories ◽  
Fission Track ◽  
Middle Eocene ◽  
Geothermal Gradient ◽  
Crystalline Rock ◽  
Early Eocene ◽  
Channel Formation ◽  
Rapid Cooling ◽  
Early Tertiary ◽  
History Of

Apatite fission-track data from 16 sedimentary and crystalline rock samples indicate rapid regional Early Eocene denudation within the onshore Beaufort–Mackenzie region of northwestern Canada. Rocks exposed in the area of the Big Fish River, Northwest Territories, cooled rapidly from paleotemperatures of >80–110 °C to <6 0°C at ca. 56 ± 2 Ma, probably in response to kilometre-scale denudation associated with regional structuring. The data suggest the region experienced a geothermal gradient of ~28 °C/km prior to rapid cooling, with ~2.7 km of section having been removed from the top of the exposed section in the Moose Channel Formation and ~3.8 km from the top of the exposed Cuesta Creek Member. Farther to the west, rocks exposed in the headwaters of the Blow River in the Barn Mountains, Yukon Territories, were exposed to paleotemperatures above 110 °C in the Late Paleocene prior to rapid cooling from these elevated paleotemperatures due to kilometre-scale denudation at ca. 56 ± 2 Ma. Exposure of these samples at the surface today requires that a minimum of ~3.8 km of denudation occurred since they began cooling below ~110 °C. The apatite analyses indicate that rocks exposed in the northern Yukon and Northwest Territories experienced rapid cooling during the Early Eocene in response to kilometre-scale denudation, associated with early Tertiary folding and thrusting in the northern Cordillera. Early Eocene cooling–uplift ages for onshore sections are slightly older than the Middle Eocene ages previously documented for the adjacent offshore foldbelt and suggest that the deformation progressed toward the foreland of the foldbelt through time.

scholarly journals Maastrichtian–Rupelian paleoclimates in the southwest Pacific – a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172

2021 ◽  
Vol 17 (6) ◽  
pp. 2393-2425
Author(s):  
Peter K. Bijl ◽  
Joost Frieling ◽  
Margot J. Cramwinckel ◽  
Christine Boschman ◽  
Appy Sluijs ◽  
...  
Keyword(s):  
Marine Sediments ◽  
State Of The Art ◽  
Middle Eocene ◽  
Potential Temperature ◽  
Critical Evaluation ◽  
Marine Biodiversity ◽  
Early Eocene ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Sw Pacific

Abstract. Sea surface temperature (SST) reconstructions based on isoprenoid glycerol dialkyl glycerol tetraether (isoGDGT) distributions from the Eocene southwest (SW) Pacific Ocean are unequivocally warmer than can be reconciled with state-of-the-art fully coupled climate models. However, the SST signal preserved in sedimentary archives can be affected by contributions of additional isoGDGT sources. Methods now exist to identify and possibly correct for overprinting effects on the isoGDGT distribution in marine sediments. Here, we use the current proxy insights to (re-)assess the reliability of the isoGDGT-based SST signal in 69 newly analyzed and 242 reanalyzed sediments at Ocean Drilling Program (ODP) Site 1172 (East Tasman Plateau, Australia) following state-of-the-art chromatographic techniques. We compare our results with paleoenvironmental and paleoclimatologic reconstructions based on dinoflagellate cysts. The resulting ∼ 130 kyr resolution Maastrichtian–Oligocene SST record based on the TetraEther indeX of tetraethers with 86 carbon atoms (TEX86) confirms previous conclusions of anomalous warmth in the early Eocene SW Pacific and remarkably cool conditions during the mid-Paleocene. Dinocyst diversity and assemblages show a strong response to the local SST evolution, supporting the robustness of the TEX86 record. Soil-derived branched GDGTs stored in the same sediments are used to reconstruct mean annual air temperature (MAAT) of the nearby land using the Methylation index of Branched Tetraethers with 5-methyl bonds (MBT'5me) proxy. MAAT is consistently lower than SST during the early Eocene, independent of the calibration chosen. General trends in SST and MAAT are similar, except for (1) an enigmatic absence of MAAT rise during the Paleocene–Eocene Thermal Maximum and Middle Eocene Climatic Optimum, and (2) a subdued middle–late Eocene MAAT cooling relative to SST. Both dinocysts and GDGT signals suggest a mid-shelf depositional environment with strong river runoff during the Paleocene–early Eocene progressively becoming more marine thereafter. This trend reflects gradual subsidence and more pronounced wet/dry seasons in the northward-drifting Australian hinterland, which may also explain the subdued middle Eocene MAAT cooling relative to that of SST. The overall correlation between dinocyst assemblages, marine biodiversity and SST changes suggests that temperature exerted a strong influence on the surface-water ecosystem. Finally, we find support for a potential temperature control on compositional changes of branched glycerol monoalkyl glycerol tetraethers (brGMGTs) in marine sediments. It is encouraging that a critical evaluation of the GDGT signals confirms that most of the generated data are reliable. However, this also implies that the high TEX86-based SSTs for the Eocene SW Pacific and the systematic offset between absolute TEX86-based SST and MBT'5me-based MAAT estimates remain without definitive explanation.

New Uintasoricine (?Primates, Plesiadapiformes) From the Earliest Bridgerian, Latest Early Eocene of Wyoming

2012 ◽  
Vol 86 (6) ◽  
pp. 973-978 ◽  
Author(s):  
Gregg F. Gunnell
Keyword(s):  
North America ◽  
New Genus ◽  
Middle Eocene ◽  
Field Work ◽  
Biodiversity Hotspot ◽  
Individual Species ◽  
Early Eocene ◽  
New Genus And Species ◽  
Body Weights ◽  
New Form

Uintasoricines are diminutive plesiadapiforms that are found in the latest Paleocene through middle Eocene, predominantly in North America. They are not a diverse group but individual species may be locally abundant and they are a persistent element of the plesiadapiform radiation in North America surviving over a span of approximately 16 million years. Recent field work in southern Wyoming at South Pass has led to the discovery of a new genus and species of uintasoricine. The new form is smaller in tooth dimensions compared to other known uintasoricines, being slightly smaller thanUintasorex montezumicusfrom California. Both the newly described taxon andU. montezumicusare among the smallest plesiadapiforms yet known with body weights estimated to be 20 to 25 g. The sediments of the Cathedral Bluffs Tongue of the Wasatch Formation at South Pass contain a unique upland fauna—the presence of a distinctive uintasoricine in this assemblage adds further evidence to support the notion that this upland environment was a biodiversity hotspot during the latest early Eocene.

PETROLEUM GEOLOGY OF WESTERN NEW SOUTH WALES

1977 ◽  
Vol 17 (1) ◽  
pp. 42 ◽  
Author(s):  
P. R. Evans
Keyword(s):  
Middle Devonian ◽  
New South ◽  
New South Wales ◽  
Early Carboniferous ◽  
Strike Slip ◽  
Petroleum Potential ◽  
Shallow Marine ◽  
Marine Deposits ◽  
South Wales ◽  
Petroleum Generation

The only area of Western New South Wales considered to have petroleum potential is the intracratonic, fault-bounded Darling Basin, which evolved during Late Silurian to Early Carboniferous time and which contains up to 7000 m of sediments. Initially deposition was controlled by a shallow marine transgression from the east. Regression during the Middle Devonian was followed by basin-wide extension of alluvial sedimentation, which prevailed until the Early Carboniferous. Strike slip movements during Late Devonian time along old basement trends fragmented the basin into distinct troughs. Movements along the same trends during the Carboniferous modified the troughs' configuration. Permian, Mesozoic and Cenozoic sag-like downwarps in various parts of the region had negligible effect on bedding attitudes.The only play of the Basin thought to have a chance for significant petroleum generation and entrapment lies in the Lower and (?) Middle Devonian, where marginal marine deposits flank highs created by strike slip movements. This play is regarded as one of high risk for modest returns, but its continued exploration seems warranted in view of proximity to markets and to the Moomba-Sydney pipeline.

The ant genus Tapinoma Förster (Formicidae: Dolichoderinae) in Miocene amber of Peru

2019 ◽  
Vol 2 (6) ◽  
pp. 585-590
Author(s):  
VINCENT PERRICHOT ◽  
RODOLFO SALAS-GISMONDI ◽  
PIERRE-OLIVIER ANTOINE
Keyword(s):  
Invasive Species ◽  
Middle Eocene ◽  
Argentine Ant ◽  
Early Eocene ◽  
Crown Group ◽  
Phylogenetic Studies ◽  
Major Species ◽  
Group Evolution ◽  
Molecular Phylogenetic ◽  
India And China

On the 17 extant subfamilies of ants, Dolichoderinae is one of the four major species-rich clades (with Formicinae, Ponerinae, and Myrmicinae), and a cosmopolitan group including some of the world’s most invasive species such as the Argentine ant and white-footed ant. It comprises currently 846 species in 28 extant and 20 extinct genera (Bolton, 2019). Most of the fossils are Cenozoic in age, which accords with the timeline of the Dolichoderinae as proposed by molecular phylogenetic studies (Ward et al., 2010; Moreau & Bell, 2013; Borowiec et al., 2019). According to these studies, crown-group dolichoderines arose sometime between 66 and 53 million years ago. Thus, around or after the Cretaceous–Paleogene transition, although this would have been preceded by approximately 30 million years of stem group evolution. Cretaceous dolichoderines are exceedingly rare indeed, and the only two known genera—Eotapinoma Dlussky, and Chronomyrmex McKellar, Glasier & Engel, from Canadian Campanian amber (79–78 Ma)—although originally placed in the Tapinomini and Leptomyrmecini, respectively, have been suggested to be stem dolichoderines (Dlussky, 1999; McKellar et al., 2013; Boudinot et al., 2016). Another fossil dolichoderine was reported from “Cretaceous amber” of Ethiopia (LaPolla et al., 2013: suppl. fig. 5) but this amber is now known to be much younger in age, likely Miocene (Perrichot et al., 2016, 2018). The first definitive crown-group dolichoderines are thus currently from the middle Eocene (50–45 Ma) of Europe and North America, belonging to various extinct species of the genera Dolichoderus, Iridomyrmex, Liometopum, and Tapinoma (see Barden, 2017). Some earlier crown-group dolichoderines may be present in early Eocene (55–52 Ma) ambers from France, India, and China (Perrichot, pers. observ.), but these have yet to be formally described.

The oldest long-legged fly of the subfamily Medeterinae (Diptera: Dolichopodidae) from the Early Eocene of France

2020 ◽  
Vol 3 (2) ◽  
pp. 173-179
Author(s):  
VALERIE NGÔ-MULLER ◽  
ROMAIN GARROUSTE ◽  
ANDRÉ NEL
Keyword(s):  
Middle Eocene ◽  
Baltic Amber ◽  
Early Eocene

We describe Paleothrypticus eocenicus gen. et sp. nov., oldest and first Medeterinae from the Early Eocene Oise amber (France). Representatives of the tribes Medeterini and Systenini are recorded in the Middle Eocene Baltic amber and the Miocene amber of Mexico. These fossils show that this subfamily was already well diversified at the beginning of the Eocene.

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