"Table 4. Distribution of modeled chemometric families by each sample type with percentages of sample types represented in each family. The data set includes samples from this study and from Lorenson and others (2009). The distribution reveals that the tribe 3 tarballs have no known produced oil source. The most frequent tarball family (22) occurs in 55.6 percent of the samples and in 16.5 percent of all seeps and from 17.5 percent of produced oils from Southern California. The most frequent produced oil family (13) comprises almost 40 percent of the produced oils, but only 7.0 percent of all seeps and 0.4 percent of the tarballs, indicating that produced oil spillage is not contributing to tarball deposition. Of the total seep samples, 36.7 percent could not be classified by our model due to typically extreme biodegradation. "																				
[ Southern California oils: SC oils]																				
																				
	Sample Type							Percentage of Sample Type within each Family												
Family	All Oils	SC Oils	Seeps	Unlocated seep oil	All Seeps	Tarballs	Total no. smpls.	% All Oils	%SC Oils	% Seeps	% Unlocated Seeps	% All Seeps	% Tarballs							
0	8	0	56	2	58	18	84	7.5	0.0	46.3	5.4	36.7	3.4							
Tribe 1																				
11	5	5	8	5	13	4	22	4.7	6.3	6.6	13.5	8.2	0.8							
12	13	7	4	3	7	5	25	12.3	8.8	3.3	8.1	4.4	1.0							
13	42	31	11	0	11	2	55	39.6	38.8	9.1	0	7.0	0.4							
14	2	2	3	4	7	28	37	1.9	2.5	2.5	10.8	4.4	5.4							
Tribe 2																				
22	15	14	18	8	26	291	84	14.2	17.5	14.9	21.6	16.5	55.6							
211	2	2	11	11	22	32	56	1.9	2.5	9.1	29.7	13.9	6.1							
212	5	5	5	3	8	20	33	4.7	6.3	4.1	8.1	5.1	3.8							
213	14	14	0	0	0	1	15	13.2	17.5	0	0	0	0.2							
Tribe 3																				
31	0	0	4	0	4	8	12	0	0	3.3	0	2.5	1.5							
32	0	0	1	1	2	12	14	0	0	0.8	2.7	1.3	2.3							
33	0	0	0	0	0	54	54	0	0	0	0	0	10.3							
34	0	0	0	0	0	27	27	0	0	0	0	0	5.2							
35	0	0	0	0	0	21	21	0	0	0	0	0	4.0							
Total no. type	106	80	121	37	158	523	787