INTRODUCTION 



Lately it has been realized that there exists, for 

 a number of reasons, a compelling need to pre- 

 serve both the continental and marine environ- 

 ments in as unpolluted a state as possible. How- 

 ever, to detect pollution in an environment it is 

 necessary to have in hand baseline ecological 

 data of that environment in its pristine or unpol- 

 luted state. The foregoing statement has special 

 relevance to the North Slope deltaic and shallow 

 marine environments of North Alaska. Although 

 these environments are now apparently free from 

 any appreciable pollution, potential problems 

 may arise in the future as a result of development 

 in that area of newly discovered large petroleum 

 reserves. Realizing this, several federal, state, 

 and private agencies have undertaken to further 

 our knowledge of north arctic Alaska. This report 

 presents preliminary results of baseline studies 

 on the size distributions, mineralogy, and 

 chemistry of bottom sediments of the continental 

 margin and the adjacent shallow marine regime of 

 this region. 



DESCRIPTION OF ENVIRONMENTS 



The deltaic region of north arctic Alaska is one 

 of the few transitional natural environments on 

 earth of which we have very limited knowledge. 

 The area under study extends from Harrison Bay 

 in the west to Maguire Island in the east, and from 

 the North Slope coast oceanward to approximately 

 the 18 meter line (Figure 1). 



The transitional environment between Cape 

 Halkett and Canning River mouths (Figure 1) 

 consists of a complex of several river estuaries, 

 distributary channels, bays, lagoons, barriers, 

 bars, coastal beaches and deltaic plain consisting 

 of tundra. Several large rivers (e.g. Colville, 

 Kuparuk, Sagavanirktok and Canning) have built 

 deltas which coalesce laterally to form a complex 

 of deltas. The most prominent of the deltas in this 

 region is that of the Colville River, and it greatly 

 influences sedimentation in the nearshore. As 

 such it merits special mention. 



The Colville River has a course of approxi- 

 mately 600 km, and has built a 560 km^ delta at 



the mouth. Several distributaries break off from 

 the main channel at the delta head, and as a result 

 several lobate islands have formed in the far 

 downstream end. Most of these islands in the 

 estuary are elongated parallel to the distributary 

 channels. All river channels of the North Slope 

 are highly braided, presumably because of the 

 great seasonal variations in sediment and water 

 discharge. Arnborg et al. (1962) have calculated 

 that the most striking feature of the arctic rivers is 

 the great concentration of activity in a short 

 period of time. For example, in 1962 43% of the 

 annual discharge (16 X lO^m^) and 73% of the 

 total inorganic suspended load (5.8 X 10^ tons) 

 were discharged from the Colville River during a 

 three-week period around the spring breakup 

 (Arnborg et al., 1962). The bulk of this 

 sediment-laden fluvial discharge initially flows 

 oceanward over sea ice situated off the river 

 mouths, and settles on the ice as.a deposit ranging 

 from 2.5 to 24 centimeters in thickness. Finally 

 this sediment finds its way to the bottom through 

 drain holes in sea ice (Walker, 1972) and/or by 

 melting of the ice. According to Reimnitz and 

 Bruder (1972), most of this fluvial sediment out- 

 fall is deposited on the steeper slopes seaward of 

 the 2 m depth contour off the Colville River 

 mouth; this area represents the delta front. 



Some detailed morphological and hydro- 

 graphical attributes of the North Slope river 

 deltas — especially that of Colville River — were 

 recently presented by Walker and McCloy 

 (1969), Lewellen (1972), Kinney et al. (1972)1 

 and Walker (1972), and; therefore, particulars of 

 these attributes will not be enumerated here. 

 However, it should be noted that the mor- 

 phologies of the North Slope deltas do not exactly 

 conform to any of the delta prototypes mentioned 

 in the literature; the closest resemblance, at best, 

 is probably to the arcuate delta type. All North 

 Slope rivers are truly arctic rivers inasmuch as 

 they arise, flow and discharge in arctic Alaska, 

 which is charaterized by permafrost terrain. All 

 these rivers are partly or wholly frozen almost 

 eight months of the year. 



The mean lunar tidal range in the north Alas- 

 kan arctic coast is comparatively very low, 

 roughly .3 meters (Matthews, 1970). Kinney et 

 al. (1972) have reported that in the lagoons and 



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