Beaufort Formation (Late Tertiary) as Seen from Prince Patrick Island, Arctic Canada

The Beaufort Formation, in its type area on Prince Patrick Island, is a single lithostratigraphic unit, a few tens of metres thick, consisting of unlithified sandy deposits of braided rivers. Organic beds in the sand have yielded more than 200 species of plants and insects and probably originated during the Pliocene, when the area supported coniferous forest. This Beaufort unit forms the thin eastern edge of a northwest-thickening wedge of sand and gravel beneath the western part of the island. These largely unexposed beds, up to several hundred metres thick, include the Beaufort unit and perhaps other older or younger deposits. On the islands northeast and southwest of Prince Patrick Island (Meighen Island to Banks Island), the name Beaufort Formation has been applied to similar deposits of late Tertiary age. Most recorded Beaufort beds on these islands are stratigraphically and paleontologically equivalent to the "type" Beaufort, but a few sites that have been called Beaufort (such as Duck Hawk Bluffs and the lower unit at Ballast Brook, on Banks Island) differ stratigraphically and paleontologically from the "type" Beaufort. This paper recommends that these deposits (probably middle Miocene) and others like them be assigned new stratigraphic names and not be included in the Beaufort Formation as now defined. Informal names Mary Sachs gravel (Duck Hawk Bluffs) and Ballast Brook beds are proposed as an initial step. Formal use of the name Beaufort Formation should be restricted to the western Arctic Islands.

Late Quaternary Sea Level Changes on Brock and Prince Patrick Islands, Western Canadian Arctic Archipelago

Emerged shorelines are few and poorly defined on Prince Patrick and Brock islands. The sparse radiocarbon dates show emergence of only 10 m through the Holocene on the Arctic Ocean coast, increasing to 20 m 100 km to the east. Hence, from Brock Island, representative of westernmost coasts, the sea level curve since the latest Pleistocene has a very low gradient, whereas on eastern Prince Patrick Island the curve takes the more typical exponential form. A decline in isobases towards the west is thus registered. Drowned estuaries, breached lakes, and coastal barriers, particularly in southwest Prince Patrick Island, suggest that the sea is now transgressing at a rate that decreases towards the north end of the island, hence there is also a component of tilt to the south. Delevelling is assumed to result from undefined ice loads, but may have a tectonic component. The sole prominent raised marine deposit is a ridge probably built in a period of more mobile sea ice, possibly at a time of stable or slightly rising sea level in the middle or early Holocene. It winds discontinuously along several hundred of kilometres of the shores of the Arctic Ocean and connecting channels, declining to the south.Les rivages émergés sont peu nombreux et mal définis dans les îles Brock et du Prince-Patrick. Les rares datations au radiocarbone n'indiquent qu'une émergence de 10 m des côtes de l'océan Arctique, au cours de l'Holocène, s'accroissant à 20 m, à 100 km vers l'est. Ainsi, à partir des côtes de l'île Brock, représentatives de la partie la plus occidentale, le niveau marin depuis le Pléistocène supérieur a un très faible gradient; par contre, dans la partie est de l'île du Prince-Patrick, la courbe du niveau marin a un caractère nettement exponentiel. On enregistre donc un abaissement des isobases vers l'ouest. Les estuaires submergés, les lacs ébréchés et les barrières littorales, surtout dans le sud-ouest de l'île du Prince-Patrick, semblent indiquer qu'il y a actuellement transgression marine à un taux qui décroît vers le nord de l'île; il y a donc aussi inclinaison vers le sud. On présume que le dénivelé découle de charges glaciaires indéterminées, mais peut aussi avoir une composante tectonique. Le seul dépôt marin soulevé d'importance est une crête probablement édifiée alors que la glace de mer était plus mobile, pendant que le niveau marin était stable ou légèrement en hausse, au début ou au milieu de l'Holocène. La crête serpente de façon irrégulière sur plusieurs centaines de kilomètres de côtes de l'océan Arctique et de chenaux adjacents, tout en s'abaissant vers le sud.Auf-getauchte Uferlinien sind rar und kaum festgelegt auf den Insein Prince Patrick und Brock. Die spàrlichen Radiokarbondaten zeigen im Holozàn ein Auftauchen an der arktischen Ozeankùste von nur 10 m, das 100 km ostlich auf > 20 m ansteigt. So hat die Meeresniveaukurve von der lnsel Brock ausgehend, welche fur die am westlichsten gelegenen Kùsten reprâsentativ ist, seit dem spàtesten Pleistozàn ein sehr niedriges Gefàlle, wohingegen die Kurve im ôstlichen Teil der Insel Prince Patrick die mehr typische exponentielle Form hat. Man registriert also eine Senkung der Isobasen nach Westen hin. Ùberflutete Gezeitenmûndungen, geschartete Seen und Kùstendamme, besonders im Westen der Prince Patrick-lnsel, lassen vermuten, dassjetztdie horizontale Verlagerungsrate des Meeres zum Nordende der Insel hin abnimmt, folglich gibt es auch eine Neigung nach Sùden hin. Man fùhrt die Verstellung auf unbes-timmte Eisfrachten zurùck, doch kônnte sie eine tektonische Komponente haben. Die einzige herausragende marine Auftauchablagerung ist eine Schwelle, die wohl in einer Période mobileren Meereises gebaut wurde, môglicherweise in einer Zeit mit sta-bilem oder gering ansteigendem Meeresniveau im mittleren oderfrùhen Holozàn. Sie windet sich diskontinuierlich ùber mehrere hundert Kilometer an den Kùsten des arktischen Ozeans und der angrenzenden Kanàle entlang und senkt sich nach Sùden

Hypoxia Markers in Human Osteosarcoma: An Exploratory Study

Neoplastic cells growing under hypoxic conditions exhibit a more aggressive phenotype by activating a cascade of molecular events partly mediated by hypoxia-inducible transcription factor (HIF-1α) and vascular endothelial growth factor (VEGF). The roles of these markers have been studied previously in several cancer lines. We ascertained the frequency of HIF-1α expression, VEGF expression, the degree of neovascularization, and cell proliferation in osteosarcoma samples. Samples from osteosarcoma patients were assessed for HIF-1α and VEGF protein expression using immunohistochemistry, neovascularization using antibodies for Factor VIII, and cell proliferation using the Ki-67 labeling index. Associations between these parameters and clinical features were examined. HIF-1α staining was positive in 35% of patients and metastases were present in 61% of these HIF-1α-positive patients. VEGF protein expression was detected in 69% of patients, 92% of whom were female. We observed an insignificant trend for a higher frequency of VEGF expression in the high-grade as compared to low-grade osteosarcoma. We observed no association between vascular density and proliferation index and any clinical parameters. We found an association between HIF-1α expression and metastatic disease and between VEGF expression and female gender