Regional Sea-Level History of the Southern Cordilleran Passive Margin during Middle to Early Late Cambrian Time: Combined Sequence Stratigraphy and Subsidence Analysis: ABSTRACT

AAPG Bulletin ◽  
1996 ◽  
Vol 80 ◽  
Author(s):  
David A. Osleger, Javier Martin-Chi
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Passive Margin ◽  
Late Cambrian ◽  
Subsidence Analysis ◽  
History Of ◽  
Regional Sea Level ◽  
Early Late

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.

Stratigraphic framework for the Cambrian–Ordovician rift and passive margin successions from southern Quebec to western Newfoundland

2003 ◽  
Vol 40 (2) ◽  
pp. 177-205 ◽  
Author(s):  
Denis Lavoie ◽  
Elliott Burden ◽  
Daniel Lebel
Keyword(s):  
Sea Level ◽  
Continental Margin ◽  
Passive Margin ◽  
Early Cambrian ◽  
Sea Level Fluctuations ◽  
Late Cambrian ◽  
Head Groups ◽  
Stratigraphic Framework ◽  
Lower Ordovician ◽  
First Time

The Taconian Humber Zone stretches from western Newfoundland to southern Quebec. The Early Cambrian slope succession in Newfoundland is found in the Curling Group, whereas in Quebec, various units were deposited during that first time slice. Biostratigraphic data allow correlation of the Curling Group with the Labrador Group in Newfoundland and with the newly time-constrained slope succession in Quebec. The end of the rift–drift transition is marked by a sea-level lowstand at the end of the Early Cambrian. The Middle Cambrian to latest Early Ordovician passive margin history recorded five cyclic sea-level fluctuations. Three of these cycles are recorded in the shallow-marine Middle to Late Cambrian platform (Port au Port Group) and slope sediments preserved in the Cow Head and Northern Head groups in Newfoundland. The biostratigraphic information assists correlation with Cambrian passive margin units in Quebec. Major sea-level lowstands are recognized along the continental margin in early–middle Late Cambrian (Steptoan) and in late Late Cambrian (Sunwaptan). Even if the Quebec succession can be tied with its Newfoundland correlative, some significant differences in the nature of Upper Cambrian slope conglomerates argue for a tectonic control on the depth of erosion of the Cambrian continental margin. The Lower Ordovician record of the passive margin consists of two depositional cycles (Tremadocian–Arenigian) separated by a sea-level lowstand. This last event is well expressed in platform succession and is also recognized in conglomerate units found in the slope succession.

scholarly journals Deglacial sea-level history of the East Siberian Sea Margin

2017 ◽  
Author(s):  
Thomas M. Cronin ◽  
Matt O'Regan ◽  
Christof Pearce ◽  
Laura Gemery ◽  
Michael Toomey ◽  
...  
Keyword(s):  
Sea Level ◽  
Sediment Cores ◽  
Younger Dryas ◽  
Ice Shelves ◽  
Isostatic Adjustment ◽  
East Siberian Sea ◽  
History Of ◽  
Regional Sea Level ◽  
Core Depth ◽  
Younger Dryas Event

Abstract. Abstract. Deglacial (12.8–10.7 ka) sea-level history on the East Siberian continental shelf/upper continental slope was reconstructed using new geophysical records and sediment cores taken during Leg 2 of the 2014 SWERUS-C3 expedition. The focus of this study is two cores from Herald Canyon, piston core SWERUS-L2-4-PC1 (4-PC) and multicore SWERUS-L2-4-MC1 (4-MC1) and a gravity core from an East Siberian Sea Transect, SWERUS-L2-20-GC1 (20-GC). Cores 4-PC1 and 20-GC were taken at 120 m and 115 m modern water depth, respectively, only a few meters above the global last glacial maximum (LGM, ~ 24 kiloannum (ka)) minimum sea level of ~ 125–130 meters below sea level (mbsl). Using calibrated radiocarbon ages mainly on molluscs for chronology and the ecology of benthic foraminifera and ostracode species to estimate paleo-depths, the data reveal dominance of river-proximal species during the early part of the Younger Dryas event (YD, Greenland Stadial GS-1) followed by a rise in river-intermediate species in the late Younger Dryas or the early Holocene (Preboreal) period. A rapid relative sea-level rise beginning roughly 11.4 to 10.8 ka (~ 400 cm core depth) during is indicated by a sharp faunal change and unconformity or condensed zone of sedimentation. Regional sea level at this time was about 108 mbsl at the 4-PC1 site and 102 mbsl at 20-GC. Regional sea-level during the YD was about 40 to 50 meters lower than those predicted by geophysical models corrected for glacio-isostatic adjustment. This discrepancy could be explained by delayed isostatic adjustment caused by a greater volume and/or geographical extent of glacial-age land ice and/or ice shelves in the western Arctic Ocean and adjacent Siberian land areas.

scholarly journals Depositional environment of the Branch Sandstone and correlative sequences: Late Cretaceous changes in relative sea level in the East Coast Basin of New Zealand

2021 ◽  
Author(s):  
◽  
Lisa McCarthy
Keyword(s):  
Sea Level ◽  
East Coast ◽  
Depositional Environments ◽  
Passive Margin ◽  
Sea Level Changes ◽  
Relative Sea Level ◽  
Sea Level Fluctuations ◽  
The North ◽  
Tasman Sea ◽  
History Of

<p>The Branch Sandstone is located within an overall transgressive, marine sedimentary succession in Marlborough, on the East Coast of New Zealand’s South Island. It has previously been interpreted as an anomalous sedimentary unit that was inferred to indicate abrupt and dramatic shallowing. The development of a presumed short-lived regressive deposit was thought to reflect a change in relative sea level, which had significant implications for the geological history of the Marlborough region, and regionally for the East Coast Basin.  The distribution and lithology of Branch Sandstone is described in detail from outcrop studies at Branch Stream, and through the compilation of existing regional data. Two approximately correlative sections from the East Coast of the North Island (Tangaruhe Stream and Angora Stream) are also examined to provide regional context. Depositional environments were interpreted using sedimentology and palynology, and age control was developed from dinoflagellate biostratigraphy. Data derived from these methods were combined with the work of previous authors to establish depositional models for each section which were then interpreted in the context of relative sea level fluctuations.  At Branch Stream, Branch Sandstone is interpreted as a shelfal marine sandstone, that disconformably overlies Herring Formation. The Branch Sandstone is interpreted as a more distal deposit than uppermost Herring Formation, whilst the disconformity is suggested to have developed during a fall in relative sea level. At Branch Stream, higher frequency tectonic or eustatic sea-level changes can therefore be distinguished within a passive margin sedimentary sequence, where sedimentation broadly reflects subsidence following rifting of the Tasman Sea. Development of a long-lived disconformity at Tangaruhe Stream and deposition of sediment gravity flow deposits at Angora Stream occurred at similar times to the fall in relative sea level documented at the top of the Herring Formation at Branch Stream. These features may reflect a basin-wide relative sea-level event, that coincides with global records of eustatic sea level fall.</p>

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