A RECORD OF ENVIRONMENT CHANGE OF THE LAST 23000 YEARS AT BARROW, ARCTIC

We haved drilled a core from Elson lagoon at Barrow, Alaska, Arctic in Summer 1998. A total of 189 samples from the Core are analyzed for 25 grain size items and 44 geochemical items. The 14C age at 0.28m, 0.66m, 1.89m of the core is 6720 aBP, 7915 aBP, 2340 aBP, respectively. According as the variation of the mean grain size of the core, the sedimentation environment was similar from 0.23m to 0.98m of the core. Its time is about from 9000aBP to 6600aBP. If the sedimentation rate from 0m to 0.18m of the core was similar to the rate from 0.23m to 0.98m, Its time is about from 0aBP to 570aBP. Thus the sedimentation was almost stop from 6600aBP to 570aBP. There were 3 sedimentation stops from 23400aBP to 9000aBP. The lastest one may be Younger Dryas, the other 2 stops may be the Last Glacial Maximum (LGM). The sedimentation of the core is similar to Core PC17. K. E. Lee and N. C. Slowey (Nature (1999) 397, 512 - 514) have identified a shallow-water core that preserves a detailed history of SST variations since LGM. Core PC17 was collected from a moderately sloped portion of the submarine flank of Oahu, Hawaii, located 6 km off the island's southwestern shore (21.358°ã N, 158.190°ã W). Sedimentation rates in PC17 during the Holocene (>10 cm kyr-1) and the last glacial period (3¨C10 cm kyr-1) are higher than those of typical deep sea sediment cores from the central North Pacific. These results help to reconcile and should ultimately yield improved estimates of global climate sensitivity by providing important new constraints on climate of ice-age cycles during the last glacial.

Acknowledgment This research was financially supported by funding from National Natural Science Foundation of China (49971078), Chinese Academy of Sciences, and the Department of Wildilife Management, North Slope Borough, Alaska, U. S.. The authors would like to express their sincere gratitude to Dr. Thomas Albert for the arrangement of filedwork, Mr. Charie Brower and Mr. Harry Borower for their help in field investigation and samplin