DOI: 10.25921/bwq7-b749
title: NOAA/WDS Paleoclimatology - Santa Barbara County California Marine Terrace Quaternary Aminostratigraphy

description: Uplifted marine terraces along the coast of California between 
Point Conception and Gaviota, Santa Barbara County are mapped 
and defined based on elevation, faunal characteristics, and amino 
acid racemization (AAR) data.  At least five distinct terraces 
are recognized, ranging in elevation up to ~100 m, with likely 
offsets along the South Branch of the Santa Ynez Fault. 
The lowest two terrace platforms are assigned ages of ~80 ka 
and ~ 120 ka based on AAR.
description: Extent of Racemization (D/L) data for mollusks from Pleistocene 
marine terrace deposits along the California coast between Point 
Conception and Gaviota. 

Samples collected by numerous investigators, primarily K.R. Lajoie 
(US Geological Survey), G.L. Kennedy (USGS and Los Angeles County 
Museum of Natural History), J.F. Wehmiller, and R.H. Patterson 
(Dames and Moore). Some samples from existing USGS collections 
also included.  Samples collected and prepared between 1975 and 1981.
Samples prepared and analyzed at the University of Delaware, Newark DE, 
Lab PI John F. Wehmiller.  Some samples shared also with P.E. Hare, 
Geophysical Lab, Carnegie Institution of Washington. 

Locality ID = formal or informal name used by collectors and maintained 
in U Delaware database 
Site name  =  similar to locality ID; refers to designations 
in Rockwell et al., 1992 
Terrace number: from Rockwell et al., 1992 and Kennedy et al., 1992 
All collection sites are located within the area of the Point Conception 
1:100,000 US Geological Survey Topographic Map. 

Pretreatment: Fragments cut from shell valves; surface cleaning 
with dental tools; dilute HCl and distilled water wash; air dry 
AA fraction="amino fraction" 
THAA = total hydrolyzable amino acids;  
FAA = free amino acids (zero hydrolysis time) 
Hydrolysis procedure: 6N HCl 22 hours 105 deg C (for THAA only) 
Bleach: No 
Instrumental programming: GC temperature program; HPLC buffer gradient 
Blank corrections: no 
Response factors: no  
D/L values reported as peak height ratios 
Lab Code UDEL= University of Delaware; GL CIW = Geophysical Laboratory, 
Carnegie Institution of Washington
Sample ID = identity of specific shell analyzed
Analytical method: GC = gas chromatography, used for multiple amino acids; 
HPLC used for determination of A/I values
Subsample ID =  usually the same as sample ID; repeat fragments of same 
shell will have unique identification
Ratio type = Peak Height ratios used for all results from GC; 
peak area ratios assumed for all results for HPLC

D/L values are reported as the means of multiple chromatograms, 
usually at least 3. For GC results, in most cases sample derivatives 
were analyzed using more than one GC column.

Samples selected for analysis were chosen because they appeared 
to be the most robust specimens among those available,  In most cases, 
samples were not whole valves.  Abraded, rounded, or chalky fragments 
were avoided where possible, and multiple shells from each collection 
were analyzed in almost all cases.

Sample quality:
1 = whole valve
2 = fragment >50%
3 = fragment < 50%
4 = chalky throughout the shell
5 = robust and mechanically strong
6 = good luster
A = articulated

Abbreviations:

A/I     D-alloisoleucine/L-isoleucine
Ala     Alanine
Asx     Aspartic acid and asparagine
Glx     Glutamic acid and glutamine
Leu     Leucine
Phe     Phenylalanine
Pro     Proline
Val     Valine

P = Protothaca
S = Saxidomus
M = Macoma

In the "Published data summaries", mean values and number of 
samples may not correspond exactly to the raw data reported 
in the "Individual sample results" because of the way results 
were grouped in Rockwell et al. (1992), or because of the way 
analytical results have been re-evaluated.  Conclusions in the 
original publication are not affected.