Building the regional understanding of the deep-water geology and benthic ecology of the Great Australian Bight

2017 ◽  
Vol 57 (2) ◽  
pp. 798 ◽  
Author(s):  
Andrew Ross ◽  
Alan Williams ◽  
Asrar Talukder ◽  
Joanna Parr ◽  
Christine Trefry ◽  
...  
Keyword(s):  
Deep Water ◽  
Autonomous Underwater Vehicle ◽  
Sedimentary Environment ◽  
Hydrocarbon Exploration ◽  
Benthic Ecology ◽  
Geological Processes ◽  
Recent Collection ◽  
Biological Sampling ◽  
Great Australian Bight ◽  
First Time

The Great Australian Bight (GAB) represents one of Australia’s most prospective frontier hydrocarbon exploration regions. Its largest subregion – the Ceduna sub-basin – is a deep (slope to abyss) area of 126 300 km2 with a 15-km deep sedimentary sequence that remains effectively untested. Knowledge of the Ceduna sub-basin’s geology is rapidly evolving following recent collection of 3D seismic datasets, but many questions remain about its geological evolution. The composition of the seabed biota and its ecology in the deep GAB was virtually unknown. To address a range of geological and biological questions, the multidisciplinary Great Australian Bight Deepwater Marine Program aims to build a more comprehensive regional understanding of the geology of the deep (~700–5437 m) GAB, with a focus on rocky outcrops, segif and volcanic seamounts, and to document aspects of the biota and benthic ecology for the first time. A field campaign of 63 days in 2015 aboard the RV Investigator and a second support vessel for an Autonomous Underwater Vehicle completed a detailed mapping of 10 225 km2 of seabed. In addition, physical geological and biological sampling collected 1.3 tonnes of volcanic and sedimentary rocks and over 25 553 biological specimens. A surprisingly complex deep-water sedimentary environment was revealed, including several previously unmapped deep-water canyons and 10 previously unmapped volcanic seamounts. A total of 430 species were collected, of which nearly half appeared to be unknown to science. This paper uses results from this survey to provide insights into the geological processes that have shaped the GAB, and briefly describes the makeup of biological assemblages present on the seabed.

Insights into the Great Australian Bight gained through marine geology and benthic ecology studies

2018 ◽  
Vol 58 (2) ◽  
pp. 845 ◽  
Author(s):  
Andrew Ross ◽  
Alan Williams ◽  
Asrar Talukder ◽  
Joanna Parr ◽  
Christine Trefry ◽  
...  
Keyword(s):  
Deep Water ◽  
Research Program ◽  
Marine Geology ◽  
Benthic Ecology ◽  
Geological Samples ◽  
Multidisciplinary Research ◽  
Mapping Data ◽  
Biological Communities ◽  
Sedimentary Sequences ◽  
Great Australian Bight

While the Great Australian Bight (GAB) represents one of the most prospective deep water basins in Australia, its vast geographic extent and deep sedimentary sequences remain poorly characterised. Recently, multidisciplinary research has been conducted to better characterise the continental and abyssal slope of the Ceduna Sub-basin. The Great Australian Bight Deepwater Marine Program (GABDMP) aimed to build a regional understanding of the deep water GAB marine geology and benthic ecology. This three-year research program encompassed four research voyages that aimed to sample and characterise deep water outcropping facies, volcanic seamounts, potential seeps and their associated biological communities. These voyages used a variety of equipment to achieve the research goals and included the deployment of autonomous underwater and remotely operated vehicles and a seafloor coring system. Numerous sites across the Ceduna Sub-basin from 700 to 5501 m water depth were studied. Sampling operations collected over 2.8 tons of rocks, 148 m of core, 55 698 biological specimens and 48 097 km2 of mapping data. Nearly 4000 geological samples have been analysed to date. This paper will summarise the key findings from the GABDMP and the geological and biological insights that have been revealed through this multidisciplinary research program.

ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF

2017 ◽  
Author(s):  
Svetlana Rubtsova ◽  
Svetlana Rubtsova ◽  
Natalya Lyamina ◽  
Natalya Lyamina ◽  
Aleksey Lyamin ◽  
...  
Keyword(s):  
Black Sea ◽  
Field Intensity ◽  
Deep Water ◽  
Coastal Waters ◽  
Integrated Management ◽  
Abiotic Factors ◽  
Environmental Safety ◽  
The Black Sea ◽  
Intensity Increase ◽  
First Time

The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.

Cyathea gigantea (Wall. ex Hook.) Holttum, A New Record to Andaman & Nicobar Islands

2016 ◽  
Vol 39 (1) ◽  
pp. 77-78
Author(s):  
Bhupendra Kholia ◽  
Lal Singh ◽  
S. Srivastava
Keyword(s):  
New Record ◽  
Andaman And Nicobar Islands ◽  
Tree Fern ◽  
Recent Collection ◽  
Nicobar Islands ◽  
First Time

Based on the recent collection a tree fern Cyathea gigantea (Wall. ex Hook.) Holttum is reported here for the first time from Andaman and Nicobar Islands, India.

Lithology and sedimentary heterogeneity of the Longmaxi Shale in the southern Sichuan Basin, China

2021 ◽  
pp. 1-49
Author(s):  
Boling Pu ◽  
Dazhong Dong ◽  
Ning Xin-jun ◽  
Shufang Wang ◽  
Yuman Wang ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Sedimentary Environment ◽  
Gas Production ◽  
Carbonaceous Shale ◽  
Gas Wells ◽  
Longmaxi Shale ◽  
Siliceous Shale

Producers have always been eager to know the reasons for the difference in the production of different shale gas wells. The Southern Sichuan Basin in China is one of the main production zones of Longmaxi shale gas, while the shale gas production is quite different in different shale gas wells. The Longmaxi formation was deposited in a deep water shelf that had poor circulation with the open ocean, and is composed of a variety of facies that are dominated by fine-grained (clay- to silt-size) particles with a varied organic matter distribution, causing heterogeneity of the shale gas concentration. According to the different mother debris and sedimentary environment, we recognized three general sedimentary subfacies and seven lithofacies on the basis of mineralogy, sedimentary texture and structures, biota and the logging response: (1) there are graptolite-rich shale facies, siliceous shale facies, calcareous shale facies, and a small amount of argillaceous limestone facies in the deep - water shelf in the Weiyuan area and graptolite-rich shale facies and carbonaceous shale facies in the Changning area; (2) there are argillaceous shale facies and argillaceous limestone facies in the semi - deep - water continental shelf of the Weiyuan area and silty shale facies in the Changning area; (3) argillaceous shale facies are mainly developed in the shallow muddy continental shelf in the Weiyuan area, while silty shale facies mainly developed in the shallow shelf in the Changning area. Judging from the biostratigraphy of graptolite, the sedimentary environment was different in different stages.

Deep Water Scientific Drilling in Lake Malawi, Africa

2006 ◽  
Vol 40 (1) ◽  
pp. 29-35
Author(s):  
K. Moran ◽  
M. Paulson ◽  
M. Lengkeek ◽  
P. Jeffery ◽  
A. Frazer
Keyword(s):  
Deep Water ◽  
Lake Malawi ◽  
Design Work ◽  
Scientific Drilling ◽  
Drilling Rig ◽  
Core Recovery ◽  
Lake Floor ◽  
Drilling System ◽  
Rift Valley Lakes ◽  
First Time

A new deep water drilling system was developed and applied to recover deeply buried sediments for scientific analyses in one of the deep rift valley lakes of Africa—Malawi. This approach overcame the difficulty of maintaining position over a drill site in a remotely located, large, deep lake. Environmental conditions in Lake Malawi are similar to deep water marine settings and, as such, a marine approach was adopted for the Lake Malawi Drilling Project (LMDP). In February and March 2005, the modified pontoon, Viphya, successfully completed a scientific drilling expedition in Lake Malawi. This expedition recovered core at depths greater than 380 m below lake-floor in water depths as great as 600 m. The major refit of Viphya included installation of a moonpool, bridge, crew accommodations, mess, washroom, power system, dynamic positioning, and a drilling system. These major modifications required early pontoon surveys and naval architectural analyses and design work prior to their commencement. The expedition also used modified scientific coring tools with a marine geotechnical drilling rig for the first time, resulting in excellent core recovery and quality.

The sequence and correlation of Early Ordovician (Arenig) graptolite faunas in the Richardson Trough and Misty Creek Embayment, Yukon Territory and District of Mackenzie, Canada

2006 ◽  
Vol 43 (12) ◽  
pp. 1791-1820 ◽  
Author(s):  
D E Jackson ◽  
A C Lenz
Keyword(s):  
Northwest Territories ◽  
Deep Water ◽  
Yukon Territory ◽  
Early Ordovician ◽  
The Road ◽  
Bedded Chert ◽  
First Occurrence ◽  
Mackenzie Mountains ◽  
First Time

Four graptolite biozones are recorded from the Arenig portion of the Road River Group in the Richardson and Mackenzie mountains in the Yukon and Northwest Territories. In ascending order, these zones are Tetragraptus approximatus, Pendeograptus fruticosus, Didymograptus bifidus, and Parisograptus caduceus australis (new). The Castlemainian stage may be represented by nongraptolitic massive bedded chert. The Arenig–Llanvirn boundary is drawn below the first occurrence of Undulograptus austrodentatus. Fifty-four graptolite taxa are present, and 16 of these species and subspecies are recorded for the first time in this deep-water biotope, namely, Didymograptus? cf. adamantinus, D. asperus, D. dilatans, D. cf. kurcki, D. validus communis, Holmograptus aff. leptograptoides, H. sp. A, Isograptus? sp. nov. A, I. ? dilemma, Keblograptus geminus, Pseudisograptus manubriatus harrisi, Ps. m. koi, Ps. m. janus, Ps. cf. tau, Xiphograptus lofuensis, and Zygograptus cf. abnormis.

scholarly journals Zeiform mouthbrooding in the deepsea – dispelling a myth

2020 ◽  
Author(s):  
Ralf ◽  
G. David Johnson ◽  
Kevin Conway
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
Developmental Stages ◽  
Extended Period ◽  
Marine Fishes ◽  
Early Developmental Stages ◽  
Water Fish ◽  
First Time ◽  
Early Developmental ◽  
Deep Sea Fauna

Mouthbrooding or oral incubation, the retention of early developmental stages inside of the mouth for an extended period of time, has evolved multiple times in bony fishes1,2. Though uncommon, this form of parental care has been documented and well-studied in several groups of freshwater fishes but is also known to occur in a small number of marine fishes, all inhabiting coastal waters1,2. A recent paper3, reported for the first time mouthbrooding in a deep-water fish species, the zeiform Parazen pacificus, which according to the authors “fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.”

Ordovician Formations and Faunas, Southern Mackenzie Mountains

1975 ◽  
Vol 12 (4) ◽  
pp. 663-697 ◽  
Author(s):  
Rolf Ludvigsen
Keyword(s):  
Deep Water ◽  
Carbonate Facies ◽  
Northern Canada ◽  
Northeastern Part ◽  
Early Ordovician ◽  
The Road ◽  
Carbonate Sedimentation ◽  
Skull Formation ◽  
Tectonic Features ◽  
First Time

Ordovician strata of the South Nahanni River area occur as a western fine clastic facies with graptolitic faunas (Road River Formation) and an eastern carbonate facies with shelly faunas (Broken Skull, Sunblood, Esbataottine, and Whittaker Formations). The lithofacies are controlled by major tectonic features. In the early Ordovician the Selwyn Basin received fine clastic sedimentation (Road River) while carbonate sedimentation (Broken Skull, Sunblood, Esbataottine) was confined to the Root Basin and the fringes of the emergent Redstone Arch. Later in the Ordovician a pronounced transgression caused a marked eastwardly shift of facies belts and resulted in the flooding of the Arch and deposition of a widespread carbonate sheet (Whittaker) in the northeastern part of the study area.The carbonate facies of the Root Basin and south of the Redstone Arch contains a complete record of shelly faunas of Canadian to, probably, Maysvillian age. The Broken Skull Formation consists of craggy weathering, variably sandy carbonates and contains, in its highest parts, the Hesperonomia fauna (Canadian). The Sunblood Formation consists of generally resistant, red-orange-buff weathering limestones and minor dolostones and contains two faunas; the Orthidiella-'Goniotelina' fauna (Whiterockian) and the Bathyurus sp. 1 fauna (?Chazyan). The Esbataottine Formation (proposed) comprises moderately recessive, grey-buff weathering limestones and contains two faunas; the Mimella fauna (Chazyan) and the Doleroides fauna (Blackriveran). The lower Whittaker Formation (Trentonian to ?Maysvillian) comprises three lithosomes containing discrete faunas which appear to represent coeval communities: The Strophomena-Ceraurus fauna in thinly bedded, argillaceous limestones; the Bighornia-Thaerodonta fauna in well bedded, nonargillaceous limestones; and the Hesperorthis-Oepikina fauna in well bedded dolostones. A unique fauna of deep water aspect, the Cryptolithus-Anataphrus fauna, occurs in shales and black limestones of the Road River Formation and is, in part, equivalent to the faunas of the lower Whittaker Formation. The Sunblood, Esbataottine, and Whittaker Formations contain abundant and well preserved silicified trilobites; many of which are reported for the first time from western and northern Canada.

Halimeda incrassata (Bryopsidales, Chlorophyta) reaches the Canary Islands: mid- and deep-water meadows in the eastern subtropical Atlantic Ocean

2018 ◽  
Vol 61 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Carlos Sangil ◽  
Laura Martín-García ◽  
Julio Afonso-Carrillo ◽  
Jacinto Barquín ◽  
Marta Sansón
Keyword(s):  
Atlantic Ocean ◽  
Canary Islands ◽  
Deep Water ◽  
Population Coverage ◽  
Isolated Populations ◽  
La Palma ◽  
Soft Bottoms ◽  
The Caribbean ◽  
Marine Flora ◽  
First Time

AbstractExtensive offshore meadows ofHalimeda incrassataare documented for the first time in sandy bottoms of La Palma, Canary Islands.Halimeda incrassataforms dense sublittoral assemblages between 20 and 55 m, but isolated populations occur down to 65 m depth. This species currently spreads over an area of 9.14 ha. Population coverage varies with depth, with the highest values at 35–40 m and an average cover of 62.34%. The calcified segments ofH. incrassataact as a stable substratum in these soft bottoms for the growth of other macroalgae, such as the rhodophytesLophocladia trichocladosandCottoniella filamentosa. Specimens reach lengths of up to 10 cm, shorter than individuals from the Caribbean. Although it is difficult to ascertain whether this species is a recent introduction, there is evidence of a correlation between the increase in population coverage and recent ocean warming, constituting another example of the tropicalization of the marine flora of this region.

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