scholarly journals A note on the status of Lower Jurassic ammonite biostratigraphy and paleontology of Queen Charlotte Islands, British Columbia

1988 ◽  
Author(s):  
H W Tipper ◽  
P L Smith ◽  
G Jakobs

1996 ◽  
Vol 33 (3) ◽  
pp. 444-451 ◽  
Author(s):  
Fabrice Cordey ◽  
Elizabeth S. Carter

New nassellarian radiolarians are described from the Insular and Intermontane belts of the Canadian Cordillera in British Columbia. Two new genera (Atalanta n.gen. and Nitrader n.gen.) and three new species (Atalanta emmela n.gen., n.sp., Atalanta epaphrodita n.gen., n.sp., and Nitrader montegufonensis n.gen., n.sp.) were found in Lower Jurassic carbonate concretions of the Sandilands Formation of the Queen Charlotte Islands and in a chert pebble extracted from a Cretaceous conglomerate of the Intermontane Belt possibly correlative with the Spences Bridge Group. The discovery of new taxa within two distinct belts of the Canadian Cordillera stresses their biostratigraphic significance.



1991 ◽  
Author(s):  
H W Tipper ◽  
P L Smith ◽  
B E B Cameron ◽  
E S Carter ◽  
G K Jakobs ◽  
...  


1992 ◽  
Vol 11 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Paul R. Bown

Abstract. Sediments of the Kunga and Maude groups (Early Norian-Aalenian) from the Queen Charlotte Islands, British Columbia, have yielded the first records of early Mesozoic calcareous nannofossils in North America. These occurrences are the only record of Triassic nannofossils away from the recent discoveries in the Tethyan area (Austria, Indonesia, and the northwestern Australian margin). The nannofossil assemblages from the Queen Charlotte Islands are generally poor to moderately preserved, with species diversities typical for this time interval (2–10 species). The assemblages are comparable to those from northwest Europe, for the Lower Jurassic, and to those from Austria, Indonesia, and the Australian margin, for the Upper Triassic. They show compatible stratigraphical ranges, allowing the application of existing biostratigraphical zonations. Palaeobiogeographical interpretations are inconclusive and fail to positively confirm a low latitude (Tethyan) position for the Queen Charlotte Islands, as indicated by macrofossil data. However, Triassic nannofossil assemblages have yet to be described from high palaeolatitude locations. In addition, certain features of the Lower Jurassic assemblages may indicate Tethyan affinities but also distinguish these assemblages from those which have been previously documented. These features include the absence of Schizosphaerella punctulata, which occurs abundantly in the circum-Mediterranean region and was previously thought to be “cosmopolitan” in distribution; and the absence of Mitrolithus jansae which characterizes “Tethyan” assemblages in the circum-Mediterranean area. The Queen Charlotte Islands results are compared with new nannofossil data from Argentina, Timor and North America.



2019 ◽  
Vol 66 (4) ◽  
pp. 501-508 ◽  
Author(s):  
Katalin Waga ◽  
Piotr Tompalski ◽  
Nicholas C Coops ◽  
Joanne C White ◽  
Michael A Wulder ◽  
...  

Abstract Forest roads allow access for silvicultural operations, harvesting, recreational activities, wildlife management, and fire suppression. In British Columbia, Canada, roads that are no longer required must be deactivated (temporarily, semipermanently, or permanently) in order to minimize the impact on the overall forested ecosystem. However, the remoteness and size of the road network present challenges for monitoring. Our aim was to examine the utility of airborne laser scanning data to assess the status and quality of forest roads across 52,000 hectares of coastal forest in British Columbia. Within the forest estate, roads can be active or deactivated, or have an unknown status. We classified road segments based on the vegetation growth on the road surface, and edges, by classifying the height distribution of airborne laser scanning returns within each road segment into four groups: no vegetation, minor vegetation, dense understory vegetation, and dense overstory vegetation. Validation indicated that 73 percent of roads were classified correctly when compared to independent field observations. The majority were classified as active roads with no vegetation or deactivated with dense vegetation. The approach presented herein can aid forest managers in verifying the status of the roads in their management area, especially in remote areas where field assessments are costly and time-consuming.



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