scholarly journals The evolution of submarine slope-channel systems: Timing of incision, bypass, and aggradation in Late Cretaceous Nanaimo Group channel-system strata, British Columbia, Canada

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 281-296 ◽  
Author(s):  
R.G. Englert ◽  
S.M. Hubbard ◽  
W.A. Matthews ◽  
D.S. Coutts ◽  
J.A. Covault
Keyword(s):  
British Columbia ◽  
Phase 1 ◽  
Vertical Channel ◽  
Rapid Phase ◽  
Channel System ◽  
Submarine Slope ◽  
Submarine Fans ◽  
Submarine Channel ◽  
Composite Deposits ◽  
Channel Systems

Abstract Submarine channel systems convey terrestrially derived detritus from shallow-marine environments to some of the largest sediment accumulations on Earth, submarine fans. The stratigraphic record of submarine slope channels includes heterogeneous, composite deposits that provide evidence for erosion, sediment bypass, and deposition. However, the timing and duration of these processes is poorly constrained over geologic time scales. We integrate geochronology with detailed stratigraphic characterization to temporally constrain the stratigraphic evolution recorded by horizontally to vertically aligned channel-fill stacking patterns in a Nanaimo Group channel system exposed on Hornby and Denman Islands, British Columbia, Canada. Twelve detrital zircon samples (n = 300/sample) were used to calculate maximum depositional ages, which identified a new age range for the succession from ca. 79 to 63 Ma. We document five phases of submarine-channel evolution over 16.0 ± 1.7 m.y. including: an initial phase dominated by incision, sediment bypass, and limited deposition (phase 1); followed by increasingly shorter and more rapid phases of deposition on the slope by laterally migrating (phase 2) and aggrading channels (phase 3); a long period of deep incision (phase 4); and a final rapid phase of vertical channel aggradation (phase 5). Our results suggest that ∼60% of the evolutionary history of the submarine channel system is captured in an incomplete, poorly preserved record of incision and sediment bypass, which makes up <20% of outcropping stratigraphy. Our findings are applicable to interpreting submarine channel-system evolution in ancient and modern settings worldwide and fundamentally important to understanding long-term sediment dispersal in the deep sea.

Application of four-dimensional monitoring to understand reservoir heterogeneity controls on fluid flow during the development of a submarine channel system

AAPG Bulletin ◽  
2018 ◽  
Vol 102 (10) ◽  
pp. 2017-2044
Author(s):  
Jiajia Zhang ◽  
Shenghe Wu ◽  
Guangyi Hu ◽  
Ting-en Fan ◽  
Yu Lin ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Channel System ◽  
Reservoir Heterogeneity ◽  
Submarine Channel

Evolution of the Slocan Syncline in south-central British Columbia

1968 ◽  
Vol 5 (4) ◽  
pp. 851-872 ◽  
Author(s):  
John V. Ross ◽  
P. Kellerhals
Keyword(s):  
British Columbia ◽  
Phase 1 ◽  
Granite Gneiss ◽  
Phase 2 ◽  
Phase 3 ◽  
The Core ◽  
South Central ◽  
Deformation Phase ◽  
Facies Metamorphism ◽  
The One

The Slocan Syncline, located in the center of the Kootenay Arc, south-central British Columbia, is outlined in its core by deformed Triassic sediments—the Slocan Group. These deformed sediments were originally deposited unconformably into a synform developed on the upward-facing limb of a recumbent, eastward-closing anticline, comprising Paleozoic and older rocks.The first phase of deformation resulted in the development of a recumbent anticline closing to the east. This anticline involved a sequence of rocks ranging in age from Windermere (late Precambrian—Horsethief Creek Group) up to Permian (Milford Group) and was originally developed along almost horizontal axes contained in an axial-plane having a shallow westerly dip. The core of this anticline contains granite gneiss, having a history pre-dating the deposition of the Horsethief Creek Group, which is in imbricate relation with the gneiss.Later, phase 2 deformation refolded this recumbent anticline into a synform and a westerly complementary antiform along shallow southeasterly axes contained within axial planes dipping southwesterly at about 45 degrees. Amphibolite-facies metamorphism (the "Shuswap Metamorphism") accompanied these phases of deformation and culminated in phase 2 time. Phase 1 and phase 2 deformation and metamorphism ate dated at post-Milford Group (Permian) and pre-Slocan Group (Triassic).Slocan Group (Triassic) sediments were deposited into the phase 2 synform, whose limbs consist of variable older rocks. A later non-metamorphic deformation, phase 3, along southeasterly striking axial planes dipping steeply to the northeast tightened the earlier phase 1 anticline and the phase 2 synform, and produced the Slocan Syncline. The Triassic sediments exhibit only phase 3 structures and are cut by the Nelson batholith dated at 171 × 106 years (Early Jurassic). Phase 3 deformation is then dated at post-Triassic and pre-Early Jurassic.Structural and stratigraphic evidence suggests that the phase 1 recumbent anticline herein described is but one of a set of nappes disposed structurally above and below the one presently described, and that the Kootenay Arc is an old structure perhaps resulting from interference of phase 1 and phase 2 deformations.

Multiattribute analysis for channel element discrimination in the Taranaki Basin, offshore New Zealand

2019 ◽  
Vol 7 (2) ◽  
pp. SC45-SC61 ◽  
Author(s):  
Phinphorn Amonpantang ◽  
Heather Bedle ◽  
Jonny Wu
Keyword(s):  
Small Scale ◽  
Root Mean Square Amplitude ◽  
Small Individual ◽  
Data Set ◽  
Channel System ◽  
Lithology Identification ◽  
Structure Channel ◽  
Multiattribute Analysis ◽  
Insight Into ◽  
Channel Systems

A detailed study of Pliocene channel systems within the Taranaki Basin was undertaken from the Parihaka 3D seismic volume to improve our understanding of the Plio-Pleistocene channel elements in terms of structure, channel evolution, and lithology. Seismic picking parameters were chosen based on the lateral resolution for optimal mapping of the channels. Individual and multiattribute studies were performed on single, combined, and complex channel systems with the goal of identifying channel features and discriminating between shale- and sand-rich regions of the channels. For this target and data set, the variance attribute provided key insights into channel features, such as the edge of the channel, meander scrolls, and point bars. Root-mean-square amplitude and sweetness performed equally well in lithology identification, and, combined with variance, it aided in identifying sand-rich channels, as well as small individual channels that could provide sediment pathways into the deepwater Taranaki Basin. Depending on the complexity of the channel system, different attribute analyses had varying success with each system. Therefore, it is important to combine various attributes to discriminate channel elements as fully as possible. The lithologies of individual channels and their elements can be determined using seismic attributes, although it becomes increasingly difficult to discriminate small-scale features within the channel as the complexity of the channel system increases. Chronostratigraphic studies using stratal slicing techniques provided insight into the evolution of the channel system through time, demonstrating an overall sand-rich base of the channel, with a shallower shale-rich lithology at the top of the channel fill.

Reduction of the transient outward potassium current in a canine model of Chagas' disease

1995 ◽  
Vol 268 (3) ◽  
pp. H1258-H1264 ◽  
Author(s):  
L. M. Pacioretty ◽  
S. C. Barr ◽  
W. P. Han ◽  
R. F. Gilmour
Keyword(s):  
Chagas Disease ◽  
Phase 1 ◽  
Outward Current ◽  
Canine Model ◽  
Transient Outward Current ◽  
Rapid Phase ◽  
Normal Cells ◽  
Current Decay ◽  
Recovery From Inactivation ◽  
Steady State Inactivation

The effects of Chagas' disease, an important cause of cardiac arrhythmias and cardiomyopathy, on cellular electrical properties were determined in epicardial tissue from normal dogs and dogs infected with Trypanosoma cruzi for 20–25 days (25 DPI), at the time of maximum parasitemia, and for 125–140 days (140 DPI) after the parasitemia had subsided. At 25 DPI, phase 1 repolarization of the action potential was attenuated and the transient outward current (Ito) was reduced from 10.2 +/- 0.5 to 5.5 +/- 0.6 pA/pF. No differences were apparent between infected and normal cells in the time constants of current decay (25.6 +/- 4.0 and 22.8 +/- 1.3 ms, respectively) or in the steady-state inactivation parameters (V1/2 = -34.1 +/- 3.6 and -34.6 +/- 1.4 mV and k = 6.3 +/- 1.8 and 4.0 +/- 0.3, respectively). The rapid phase of recovery from inactivation was nearly eliminated in infected myocytes, whereas the slower phase was unaffected. Phase 1 repolarization and Ito density at 140 DPI were not significantly different from normal cells. Thus T. cruzi acutely inhibited Ito in epicardial myocytes, an effect that was reversed with abatement of the parasitemia.

Geotechnical aspects of a submarine slope failure, Kitimat Fjord, British Columbia

1986 ◽  
Vol 6 (3) ◽  
pp. 243-279 ◽  
Author(s):  
M. W. Johns ◽  
D. B. Prior ◽  
B. D. Bornhold ◽  
J. M. Coleman ◽  
W. R. Bryant
Keyword(s):  
British Columbia ◽  
Slope Failure ◽  
Submarine Slope

Plasma and renal clearance of exogenous erythropoietin in the dog

1964 ◽  
Vol 207 (3) ◽  
pp. 523-529 ◽  
Author(s):  
Arthur H. Weintraub ◽  
Albert S. Gordon ◽  
E. Lovell Becker ◽  
James F. Camiscoli ◽  
Joseph F. Contrera
Keyword(s):  
Renal Clearance ◽  
Filtration Rate ◽  
Excretion Rate ◽  
Phase 1 ◽  
Urinary Recovery ◽  
Rapid Phase ◽  
Phase 0 ◽  
Pah Clearance ◽  
Excretion Rates ◽  
Plasma Compartment

The pattern of plasma and renal clearance of purified sheep erythropoietin (ESF) was studied in unanesthetized dogs given a single intravenous injection of the hormone. Creatinine and PAH clearance measurements were also made up to 5 hr after ESF administration. Plasma clearance of ESF was found to be essentially biphasic: half-times for an initial rapid phase (0–1 hr) ranged from 20–45 min while those for the slower phase (1–24 hr) were of the order of 9–10.5 hr. Despite the loss from the plasma compartment of up to 70% of the injected dose of ESF within 3.5 hr, urinary recovery of the factor was quite low: about 2% of the injected dose in two experiments where 1,600 units were given and about 5% in a third experiment in which a dose of 3,200 units was employed. Excretion rates of the factor were found to be uniformly low and ESF clearance ranged from 0.1 to 0.6 ml/min. Some correlation between plasma levels and excretion rate of ESF was obtained. ESF clearance represented only a small fraction (0.1–1.4%) of the glomerular filtration rate. Injection of the hormone did not markedly influence creatinine or PAH clearance.

Sign in / Sign up

Export Citation Format

Share Document