Stratigraphic record in the transition from basin floor to continental slope sedimentation in the ancient passive‐margin Windermere turbidite system

Sedimentology ◽  
2020 ◽  
Vol 67 (4) ◽  
pp. 1710-1749
Author(s):  
Lilian Navarro ◽  
Robert William (Bill) C. Arnott
Keyword(s):  
Continental Slope ◽  
Passive Margin ◽  
Stratigraphic Record ◽  
Basin Floor ◽  
Turbidite System

Anatomy and Stratigraphic Development of a Basin Floor Turbidite System in the Laingsburg Formation, Main Karoo Basin, South Africa

2004 ◽  
Vol 74 (2) ◽  
pp. 239-254 ◽  
Author(s):  
P.J. Sixsmith ◽  
S.S. Flint ◽  
H.DeV. Wickens ◽  
S.D. Johnson
Keyword(s):  
South Africa ◽  
Karoo Basin ◽  
Basin Floor ◽  
Turbidite System

Tribes Hill–Rochdale formations in east Laurentia: proxies for Early Ordovician (Tremadocian) eustasy on a tropical passive margin (New York and west Vermont)

2011 ◽  
Vol 149 (1) ◽  
pp. 93-123 ◽  
Author(s):  
ED LANDING ◽  
JONATHAN M. ADRAIN ◽  
STEPHEN R. WESTROP ◽  
BJÖRN KRÖGER
Keyword(s):  
New York ◽  
Sea Level ◽  
Continental Slope ◽  
Appalachian Mountains ◽  
Passive Margin ◽  
Depositional Sequence ◽  
Early Ordovician ◽  
Layer Cake ◽  
Low Diversity ◽  
Early Late

AbstractSlow subsidence and tectonic quiescence along the New York Promontory margin of Laurentia mean that the carbonate-dominated Tribes Hill and overlying Rochdale formations serve as proxies for the magnitude and timing of Tremadocian eustatic changes. Both formations are unconformity-bound, deepening–shoaling, depositional sequences that double in thickness from the craton into the parautochthonous, western Appalachian Mountains. A consistent, ‘layer cake’ succession of member-level units of the formations persists through this region. The Tribes Hill Formation (late early Tremadocian, late Skullrockian, late Fauna B–Rossodus manitouensis Chron) unconformably overlies the terminal Cambrian Little Falls Formation as the lowest Ordovician unit on the New York Promontory. It was deposited during the strong early Tremadocian, or Stonehenge, transgression that inundated Laurentia, brought dysoxic/anoxic (d/a) slope water onto the shelf and led to deposition of the Schaghticoke d/a interval (black mudstone and ‘ribbon limestone’) on the Laurentian continental slope. The uniform lithofacies succession of the Tribes Hill includes a lower sand-rich member; a middle, dark grey to black mudstone that records d/a in eastern exposures; and an upper, shoaling-up carbonate highstand facies. A widespread (12000+ km2) thrombolitic interval in the highstand carbonate suggests the New York Promontory was rimmed by thrombolites during deposition of the Tribes Hill. Offlap and erosion of the Tribes Hill was followed by the relatively feeble sea-level rise of the Rochdale transgression (new) in Laurentia, and deposition of the Rochdale Formation. The Rochdale transgression, correlated with the Kierograptus Drowning Interval in Baltica, marks a eustatic rise. The Rochdale Formation represents a short Early Ordovician interval (early late Tremadocian, middle–late Stairsian, Macerodus dianae Chron). It correlates with a depositional sequence that forms the middle Boat Harbour Formation in west Newfoundland and with the Rte 299 d/a interval on the east Laurentian slope. The Rochdale has a lower carbonate with abundant quartz silt (Comstock Member, new) and an upper, thrombolitic (Hawk Member, new) high-stand facies. Tribes Hill and Rochdale faunas are mollusc-rich, generally trilobite-poor, and have low diversity, Laurentian faunal province conodonts. Ulrichodina rutnika Landing n. sp. is rare in Rochdale conodont assemblages. Trilobites are also low in diversity, but locally form coquinas in the middle Tribes Hill. The poorly preserved Rochdale trilobites include the bathyurid Randaynia, at least two hystricurid species and Leiostegium.

Continental slope sedimentation in the Sheepbed Formation (Neoproterozoic, Windermere Supergroup), Mackenzie Mountains, N.W.T.

1996 ◽  
Vol 33 (6) ◽  
pp. 848-862 ◽  
Author(s):  
R. W. Dalrymple ◽  
G. M. Narbonne
Keyword(s):  
Sea Level ◽  
Continental Slope ◽  
Cold Water ◽  
Passive Margin ◽  
Slope Instability ◽  
Fine Grained ◽  
Windermere Supergroup ◽  
Mackenzie Mountains ◽  
Water Depths

The Sheepbed Formation (Ediacaran) is a 1 km thick, siliciclastic unit that overlies glacial deposits of the Ice Brook Formation and is overlain by carbonates of the Gametrail Formation. Observations in the Mackenzie Mountains indicate that the Sheepbed Formation accumulated in water depths of 1–1.5 km on a passive-margin, continental slope. The lower part of the formation consists predominately of dark mudstone. Fine-grained, turbiditic sandstone becomes more abundant upward, as does the scale and abundance of slope-instability indicators. Mesoscale facies successions (i.e., evidence of channels, lobes, and (or) compensation cycles) are developed in the upper half of the formation. The larger-scale changes are interpreted as reflecting a postglacial sea-level rise, followed by a relative fall and an increase in the rate of deposition. Contourites that may have been formed in response to the circulation of deep, cold water occur in the lowstand deposits. Their presence confirms previous speculation that the proto-Pacific Ocean was initiated at the beginning of Windermere deposition (ca. 780 Ma), not at the start of the Cambrian. The paleoflow direction toward the present-day northwest suggests that this part of Laurentia lay in the northern hemisphere. In situ Ediacaran megafossils are preserved on the soles of sandy turbidites; the deep-water setting indicates that these organisms were not photoautotrophs.

Slumps Mass-Transport Deposits in the Brazilian Continental Margin Deep Water: Offshore Potiguar Basin, NE Brazil.

2020 ◽  
Author(s):  
Yoe Perez ◽  
Julia Fonseca ◽  
Helenice Vital ◽  
Andre Silva ◽  
David Castro
Keyword(s):  
Mass Transport ◽  
Continental Slope ◽  
Continental Margin ◽  
Deep Water ◽  
Negative Impact ◽  
Water Area ◽  
Passive Margin ◽  
Rift System ◽  
Potiguar Basin ◽  
Mass Transport Deposits

<p>The Brazilian Continental Margin (BEM) deep-water regions contain important geological features that need advance in their characterization. Mass-transport deposits (MTD) are important not only by their significance in the sedimentary but also because of their negative impact economically. A slump is a coherent mass of sediment that moves on a concave-up glide plane and undergoes rotational movements causing internal deformation and one of the basic types of MTD. The study area comprises part of the offshore Potiguar Basin in NE Brazil, on the distal eastern portion of the Touros High and Fernando de Noronha Ridge. This portion of the Potiguar Basin comprises a transform rift system that has evolved into a continental passive margin. This basin represents an important location related to the breakup between South America and Africa. The database used in this work included 2D post-stack time-migrated seismic profiles from the Brazilian Agency of Petroleum, Natural Gas, and Biofuels (ANP). The slumps reflectors are identified on the continental shelf profiles in form of present clinoform configuration, medium to high continuity, high amplitudes, and medium to high frequencies, representing a sigmoidal oblique complex prograding reflector. The slump scars at the continental slope indicate that this is a gravitationally unstable area that will eventually collapse, resulting in erosional features on the continental slope and deposition on the continental rise. Our results provide some insights regarding MDT slumps sedimentary evolution in the BEM deep water area as well as their interrelation with other sedimentary deposits.</p>

Stratigraphic record of translation down ramps in a passive-margin salt detachment

2005 ◽  
Vol 27 (5) ◽  
pp. 889-911 ◽  
Author(s):  
Martin P.A. Jackson ◽  
Michael R. Hudec
Keyword(s):  
Passive Margin ◽  
Stratigraphic Record

A glacier-influenced turbidite system and associated landform assemblage in the Greenland Basin and adjacent continental slope

2016 ◽  
Vol 46 (1) ◽  
pp. 461-468 ◽  
Author(s):  
M. García ◽  
C. L. Batchelor ◽  
J. A. Dowdeswell ◽  
K. A. Hogan ◽  
C. Ó Cofaigh
Keyword(s):  
Continental Slope ◽  
Greenland Basin ◽  
Turbidite System
Sign in / Sign up

Export Citation Format

Share Document