Bonebed amber as a new source of paleontological data: The case of the Pipestone Creek deposit (Upper Cretaceous), Alberta, Canada

Paleomagnetism of the Upper Cretaceous Nanaimo Group, southwestern Canadian Cordillera

Canadian Journal of Earth Sciences ◽

10.1139/e01-031 ◽

2001 ◽

Vol 38 (10) ◽

pp. 1403-1422 ◽

Cited By ~ 27

Author(s):

Randolph J Enkin ◽

Judith Baker ◽

Peter S Mustard

Keyword(s):

British Columbia ◽

North America ◽

Upper Cretaceous ◽

Vertical Axis ◽

Vancouver Island ◽

Canadian Cordillera ◽

Paleontological Data ◽

The Mean ◽

Prime Target

The Baja B.C. model has the Insular Superterrane and related entities of the Canadian Cordillera subject to >3000 km of northward displacement with respect to cratonic North America from ~90 to ~50 Ma. The Upper Cretaceous Nanaimo Group (on and about Vancouver Island, British Columbia) is a prime target to test the model paleomagnetically because of its locality and age. We have widely sampled the basin (67 sites from seven islands spread over 150 km, Santonian to Maastrichtian age). Most samples have low unblocking temperatures (<450°C) and coercivities (~10 mT) and strong present-field contamination, forcing us to reject three quarters of the collection. Beds are insufficiently tilted to provide a conclusive fold test, and we see evidence of relative vertical axis rotations. However, inclination-only analysis indicates pretilting remanence is preserved for many samples. Both polarities are observed, and reversals correlate well to paleontological data, proving that primary remanence is observed. The mean inclination, 55 ± 3°, is 13 ± 4° steeper than previously published results. Our new paleolatitude, 35.7 ± 2.6° is identical to that determined from the slightly older Silverquick and Powell Creek formations at Mount Tatlow, yet the inferred displacement is smaller (2300 ± 400 km versus 3000 ± 500 km) because North America was drifting southward starting around 90 Ma. The interpreted paleolatitude conflicts with sedimentologic and paleontologic evidence that the Nanaimo Basin was deposited near its present northern position.

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Dinosaur behavior and growth

The Paleontological Society Special Publications ◽

10.1017/s247526220000695x ◽

1992 ◽

Vol 6 ◽

pp. 135-135 ◽

Cited By ~ 2

Author(s):

John R. Horner

Keyword(s):

Upper Cretaceous ◽

Social Behaviors ◽

Mate Recognition ◽

Morphological Evidence ◽

First Year ◽

Adult Size ◽

Metabolic Rates ◽

Paleontological Data ◽

Sexual Display

Geological and paleontological data derived from the Upper Cretaceous Two Medicine Formation of Montana indicates that at least some dinosaur species exhibited complex social behaviors comparable to many living birds. Two species of duck-billed dinosaurs, a hypsilophodontid and a troodontid, nested in colonies and attended their respective young. Duckbilled dinosaurs had altricial young, whereas the hypsilophodontid and troodontid had precocial young. Morphological evidence indicates that several of the cranial elements of the nestling duckbills experienced retarded development, and a retention of juvenile features. Following their respective nesting periods duck-billed and horned dinosaurs aggregated into large herds, and apparently migrated seasonally. Cranial ornamentations possessed by duck-billed and horned dinosaurs were most likely used for sexual display and mate recognition.Osteohistological data indicates that the duck-billed dinosaurs hatched from their eggs at .50 to .75 meters in length, and exited their nests at 1.5 to 2 meters in length, at an age of about one month. These dinosaurs reached 3 to 4 meters in length their first year, and 7 to 8 meters in length after about 5 years. Growth and metabolic rates decreased substantially upon reaching adult size.

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Paleomagnetic characteristics of upper cretaceous sediments of North–East Western Siberia

Недропользование. Горное дело. Направления и технологии поиска, разведки и разработки месторождений полезных ископаемых. Экономика. Геоэкология: Материалы XVI международной конференции (20-24 апреля 2020, Новосибирск) ◽

10.18303/b978-5-4262-0102-6-2020-050 ◽

2020 ◽

Author(s):

Aleksandra Levicheva ◽

◽

Zinaida Gnibidenko ◽

Keyword(s):

Upper Cretaceous ◽

Western Siberia ◽

Facial Region ◽

Paleontological Data ◽

North East ◽

Deep Wells ◽

Cretaceous Deposits

Presents the results of complex paleomagnetic and geological–stratigraphical study of Upper Cretaceous deposits of the three deep wells (Tagul’skaya 21, Tagul’skaya 25) (south–east of Western Siberia, Kolpashevo facial region), drilled on the nord–east of Western Siberia (Enisei–Khatangskii megadeflection). All studies were complex and carried out based on paleomagnetic, geological– stratigraphic and paleontological data.

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