|Title||Paleoenvironmental investigations of early Paleozoic seas from the northern Canadian Atlantic Margin: results from core analyses of the southeastern Baffin Island Shelf and Hopedale Basin|
|Source||The fossil week: abstract book, 5th International Palaeontological Congress; 2018 p. 513|
|Alt Series||Natural Resources Canada, Contribution Series 20180097|
|Publisher||5th International Palaeontological Congress|
|Meeting||5th International Palaeontological Congress; Paris; FR; July 9-13 2018|
|Province||Eastern offshore region; Northern offshore region; Nunavut; Newfoundland and Labrador|
|NTS||13I; 13N; 13O; 13P; 14; 15; 16; 27; 28; 37H; 38A; 38D; 38E; 38H|
|Area||Labrador-Baffin Seaway; Baffin Island; Labrador|
|Lat/Long WENS|| -76.0000 -48.0000 76.0000 54.0000|
|Subjects||marine geology; sedimentology; paleontology; continental margins; continental shelf; basins; paleoenvironment; depositional environment; marine environments; burial history; core samples; wells; core
analysis; thin section microscopy; bedrock geology; lithology; sedimentary rocks; mudstones; dolomites; carbonates; limestones; fossils; diagenesis; alteration; dolomitization; fractures; stylolites; Canadian Atlantic Margin; Labrador Margin; Baffin
Island Shelf; Hopedale Basin; Iapetus Ocean; Phanerozoic; Paleozoic|
|Program||Baffin Region Atlas, GEM2: Geo-mapping for Energy and Minerals|
|Links||Online - En ligne (complete volume - volume complet, pdf, 9.35
|Released||2018 07 01|
|Abstract||Preceding development of the Mesozoic, Labrador-Baffin Seaway rift succession, Paleozoic basins of the Iapetus Ocean existed along what is now the northern Canadian Atlantic Margin. These Paleozoic
basins are discontinuous and poorly understood in the offshore. Limited lower Paleozoic subsurface bedrock samples recovered from the margin offer unique glimpses into paleoenvironments that characterized the Iapetus Ocean prior to its closing.
Shallow seabed drill cores from the southeastern Baffin Island Shelf and conventional cores from industry wells in the Hopedale Basin, offshore Labrador, were described with a focus on lithology and biological components. Results from core and thin
section analyses were used to interpret the paleoenvironments of the regions, with dissimilarities reflecting variations in local depositional conditions and burial history.|
Lower Paleozoic seabed drill cores from the southeastern Baffin Island
Shelf are primarily composed of fine-grained lime mudstone with rare dolomite observed in all but one core. A high diversity of fossil content reflects a range of normal marine depositional settings spanning shallow water environments within the
photic zone, to deeper water domains. Seven exploration wells in Hopedale Basin intersect Paleozoic strata. Paleozoic cores recovered from the Labrador Margin are primarily fine-grained, lack macro-fossils, and typically represent deposition in deep
water, foreslope environments. All carbonate cores contain fractures and stylolites but only one of the cores has been moderately to pervasively dolomitized. The higher degree of alteration observed in the Hopedale Basin carbonate cores can be
attributed, in large part, to burial depths exceeding two kilometers.
The lower Paleozoic sediments located on the southeastern Baffin Island Shelf and in the Hopedale Basin are thought to be approximately syndepositional, but accumulated within
independent depositional centers along the western margin of the Iapetus Ocean. The highly variable and fossiliferous Paleozoic limestone deposits on the southeastern Baffin Island Shelf differ from the dolomitized Paleozoic strata of the Hopedale
Basin which are more diagenetically altered and represent deposition in deeper water environments. Understanding depositional paleoenvironments in both regions provides valuable insights into the reconstruction of the Iapetus Ocean.
|Summary||(Plain Language Summary, not published)|
Lower Paleozoic strata from the southeastern Baffin Island shelf and the Labrador margin were studied via core and thin section analysis. The drill cores
from offshore Baffin Island are composed primarily of lime mudstone and contain a wide variety of fossil fragments indicating that these rocks were deposited under normal marine conditions in shallow to deep water environments. The Labrador margin
cores, on the other hand, have undergone varying degrees of diagenesis with 2 of the 4 being composed entirely of dolomite. These two areas were not directly connected during the deposition of the sediments and therefore offer unique regional
insights into the paleoenvironmental conditions that existed along the western margin of the Iapetus Ocean.