scholarly journals Amino acid racemization in ostracodes from Bear Lake cores BL96-1 and BL96-2, Utah and Idaho

2005 ◽  
Author(s):  
Darrell S. Kaufmann
Keyword(s):  
Amino Acid ◽  
Amino Acid Racemization ◽  
Bear Lake ◽  
Lake Cores

scholarly journals A new method for enamel amino acid racemization dating: A closed system approach

2019 ◽  
Vol 50 ◽  
pp. 29-46 ◽  
Author(s):  
Marc R. Dickinson ◽  
Adrian M. Lister ◽  
Kirsty E.H. Penkman
Keyword(s):  
Amino Acid ◽  
Closed System ◽  
System Approach ◽  
New Method ◽  
Amino Acid Racemization

scholarly journals Effect of acid hydrolysis on the racemization method using amino acid racemization in teeth.

1988 ◽  
Vol 37 (9) ◽  
pp. 476-480 ◽  
Author(s):  
Tsuneko OGINO ◽  
Hideki OGIUCHI ◽  
Toshiyuki HOBO ◽  
Hiroshi OGINO
Keyword(s):  
Amino Acid ◽  
Acid Hydrolysis ◽  
Amino Acid Racemization

Mechanism of pyridoxal phosphate-dependent enzymatic amino-acid racemization

1983 ◽  
pp. 82 ◽  
Author(s):  
Shu-jane Shen ◽  
Heinz G. Floss ◽  
Hidehiko Kumagai ◽  
Hideaki Yamada ◽  
Nobuyoshi Esaki Kenji Soda ◽  
...  
Keyword(s):  
Amino Acid ◽  
Pyridoxal Phosphate ◽  
Amino Acid Racemization

Late Quaternary history of the Lake O'Hara region, British Columbia – an evaluation of sedimentation rates and bulk amino acid ratios in lacustrine records

1988 ◽  
Vol 25 (7) ◽  
pp. 1037-1048 ◽  
Author(s):  
Mel A. Reasoner ◽  
Nathaniel W. Rutter
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Sedimentation Rate ◽  
River Sediments ◽  
Sedimentation Rates ◽  
Rate Data ◽  
Radiocarbon Dates ◽  
Clastic Sediments ◽  
Lake Cores ◽  
Total Sedimentation

Lake O'Hara (subalpine) and Opabin Lake (alpine) are situated directly adjacent to a high section of the Continental Divide in the central Canadian Rocky Mountains. Core samples recovered from the lakes show a consistent stratigraphy comprising gyttja and underlying inorganic clastic sediments. The gyttja contains Bridge River (2350 years BP) and Mazama (6800 years BP) tephras and is separated from the lower clastic sediments by a sharp, conformable contact. Radiocarbon dates obtained from conifer needles, extracted from directly above the contact, indicate that deglaciation had proceeded upvalley from the O'Hara basin priorto ca. 10 100 years BP. Preliminary palaeobotanical and macrofossil data suggest that a Pinus–Abies forest with lesser Picea was established in the vicinity of Lake O'Hara by this time. Consequently, the minimum age of moraine systems situated downvalley from Lake O'Hara is Late Wisconsinan.Mean annual sedimentation rates were derived from sediment thickness data from 14 Lake O'Hara and 2 Opabin Lake cores. Averaged total sedimentation rate values from the Lake O'Hara cores are 0.13 mm/year (post-Bridge River), 0.13 mm/year (Mazama – Bridge River) and 0.05 mm/year (11 000 years BP – Mazama). Averaged total sedimentation rate values from the Opabin Lake cores are 0.19 mm/year (post-Bridge River), 0.07 mm/year (Mazama – Bridge River), and 0.06 mm/year (8530 years BP – Mazama). Higher total sedimentation rates in post-Bridge River sediments of Opabin Lake are presumably related to climatic conditions associated with more extensive upvalley ice during the last ca. 2300 years. Highly variable sedimentation rate data obtained from the Lake O'Hara cores suggest that the use of sedimentation rate data as a proxy record of upvalley glacial activity is inappropriate in the Lake O'Hara setting where inflowing glacial stream systems are interrupted by upvalley lake basins.Aspartic acid D/L ratios were derived from bulk gyttja samples of known age from seven Lake O'Hara and one Opabin Lake core. In all but two cases, aspartic acid D/L ratios increase consistently with respect to sediment age. The increasing downcore trends in the aspartic acid D/L ratios suggest the possibility of using amino acid data from bulk gyttja samples as a check for reworking in cases where chronostratigraphic markers are absent.

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