Table 11. Distribution and relative abundances of diatoms, Hole 1020C.

Table 11. Distribution and relative abundances of diatoms, Hole 1020C.

Geologic

age

North Pacific diatom zone
Numeric age (Ma)*
Core,
section

Sample depth (mbsf)

Offset (m)
Composite depth (mcd) Group abundance Preservation Environment, type of upwelling Actinocyclus curvatulus Actinocyclus cf. curvatulus Actinocyclus oculatus Actinocyclus cf. oculatus Actinoptychus senarius Aulacoseira granulata Aulacoseira cf. italica Biddulphia aurita Fragilariopsis doliola Cocconeis scutellum Coscinodiscus marginatus Coscinodiscus radiatus Cymbella sp. Grammatophora sp. Hemidiscus cuneiformis Neodenticula kamtschatica Neodenticula koizumii Neodenticula cf. koizumii Neodenticula seminae N. sp. A sensu Akiba and Yanagisawa Nitzschia marina Nitzschia reinholdii Paralia sulcata Proboscia barboi Proboscia curvirostris P. cf. curvirostris Rhaphoneis sp. Rhaphoneis surirella Rhopalodia gibba Stephanopyxis dimorpha and S. turris Thalassionema nitzschioides Thalassiosira convexa Thalassiosira cf. convexa Thalassiosira eccentrica Thalassiosira leptopus Thalassiosira oestrupii Thalassiothrix longissima Diatom fragments (girdle bands) Resting spores

Quaternary
167-1020C-

1H-CC 4.30 0.00 4.30 R P/M Clay T

T

T
T T

T

T

F T

2H-CC 13.80 1.30 15.10 T P Clay

T

C

NPD 12
3H-CC 23.30 1.16 24.46 T P Clay

T

F

4H-CC 32.80 2.72 35.52 T P Clay

T

T

C

0.30 5H-CC 42.30 3.82 46.12 T P Clay

T

T

T

6H-CC 51.80 4.82 56.62 C M Clay

C

C

A

R

7H-CC 61.30 4.68 65.98 R P Dissolution

R

F

8H-CC 70.80 4.29 75.09 F P Clay

R R

C

C

C C

9H-CC 80.30 4.91 85.21 C P Clay

F

R
F

C

F F

NPD 11
10H-CC 89.80 4.55 94.35 F P Clay

F

R R

C

11H-CC 99.30 5.71 105.01 F P Clay

R

R

R

12H-CC 108.80 6.35 115.15 F P Clay

R

T

R

C

13H-CC 118.30 7.88 126.18 R P Clay

T

R
R R

R

T F

1.00 14H-CC 127.80 7.88 135.68 C P Dissolution R R

R

T

R

R

R
F

C

15H-CC 137.30 10.21 147.51 F P Clay
R R

R

R

R

R

F F

16H-CC 146.80 11.92 158.72 C P Dissolution R

R

R

R
R

R

R

A

NPD 10
17X-CC 156.30 13.67 169.97 R P

R R R

R

R
R

R

R R

R

18X-CC 165.90 14.37 180.27 R P Clay

R

R

R

R
R

R

1.90 19X-CC 175.50 14.37 189.87 A P Clay

R

R

R

R R R R R

R

R

R A

late Pliocene
2.00 20X-CC 185.10 15.99 201.09 A P Clay R
R

T T
R

R

A A

21X-CC 194.70 15.99 210.69 A P Coastal

R

C

R
R R
R R A

C

NPD 9
22X-CC 204.30 17.91 222.21 C P Coastal

R

C

R

R

C

C

2.35 23X-CC 213.90 18.45 232.35 R P Coastal R

C

R

C

C
R

R

24X-CC 223.50 19.01 242.51 F P Coastal

C

R

C

C

25X-CC 233.20 19.01 252.21 A M Coastal

A

R R

R

C

F

R

Notes: * = Cande and Kent (1995). Abundance: A = abundant, C = common, F = few, R = rare, and T = trace. Preservation: M = moderate, and P = poor. For complete definition of terms, see "Techniques" section of this chapter.

Geologic age	North Pacific diatom zone	Numeric age (Ma)*	Core, section	Sample depth (mbsf)	Offset (m)	Composite depth (mcd)	Group abundance	Preservation	Environment, type of upwelling	Actinocyclus curvatulus	Actinocyclus cf. curvatulus	Actinocyclus oculatus	Actinocyclus cf. oculatus	Actinoptychus senarius	Aulacoseira granulata	Aulacoseira cf. italica	Biddulphia aurita	Fragilariopsis doliola	Cocconeis scutellum	Coscinodiscus marginatus	Coscinodiscus radiatus	Cymbella sp.	Grammatophora sp.	Hemidiscus cuneiformis	Neodenticula kamtschatica	Neodenticula koizumii	Neodenticula cf. koizumii	Neodenticula seminae	N. sp. A sensu Akiba and Yanagisawa	Nitzschia marina	Nitzschia reinholdii	Paralia sulcata	Proboscia barboi	Proboscia curvirostris	P. cf. curvirostris	Rhaphoneis sp.	Rhaphoneis surirella	Rhopalodia gibba	Stephanopyxis dimorpha and S. turris	Thalassionema nitzschioides	Thalassiosira convexa	Thalassiosira cf. convexa	Thalassiosira eccentrica	Thalassiosira leptopus	Thalassiosira oestrupii	Thalassiothrix longissima	Diatom fragments (girdle bands)	Resting spores
Quaternary			167-1020C-
			1H-CC	4.30	0.00	4.30	R	P/M	Clay	T					T			T		T	T							T								T			F	T
			2H-CC	13.80	1.30	15.10	T	P	Clay																														T								C
	NPD 12		3H-CC	23.30	1.16	24.46	T	P	Clay																			T											F
			4H-CC	32.80	2.72	35.52	T	P	Clay																			T				T															C
		0.30	5H-CC	42.30	3.82	46.12	T	P	Clay							T							T																T
			6H-CC	51.80	4.82	56.62	C	M	Clay																			C						C					A				R
			7H-CC	61.30	4.68	65.98	R	P	Dissolution																			R											F
			8H-CC	70.80	4.29	75.09	F	P	Clay										R	R								C											C								C	C
			9H-CC	80.30	4.91	85.21	C	P	Clay																			F				R		F					C								F	F
	NPD 11		10H-CC	89.80	4.55	94.35	F	P	Clay																			F					R	R					C
			11H-CC	99.30	5.71	105.01	F	P	Clay																			R											R								R
			12H-CC	108.80	6.35	115.15	F	P	Clay																			R						T					R								C
			13H-CC	118.30	7.88	126.18	R	P	Clay						T													R		R	R								R							T	F
		1.00	14H-CC	127.80	7.88	135.68	C	P	Dissolution	R	R			R								T						R						R			R		F								C
			15H-CC	137.30	10.21	147.51	F	P	Clay		R	R											R					R					R						R								F	F
			16H-CC	146.80	11.92	158.72	C	P	Dissolution	R							R											R			R		R						R					R			A
	NPD 10		17X-CC	156.30	13.67	169.97	R	P					R	R	R					R								R		R			R					R	R						R
			18X-CC	165.90	14.37	180.27	R	P	Clay			R												R				R					R		R								R
		1.90	19X-CC	175.50	14.37	189.87	A	P	Clay			R						R						R			R	R	R	R	R				R							R				R	A
late Pliocene		2.00	20X-CC	185.10	15.99	201.09	A	P	Clay	R		R													T	T		R					R														A	A
			21X-CC	194.70	15.99	210.69	A	P	Coastal			R								C						R		R	R		R	R	A						C
	NPD 9		22X-CC	204.30	17.91	222.21	C	P	Coastal					R						C						R			R				C						C
		2.35	23X-CC	213.90	18.45	232.35	R	P	Coastal	R										C						R							C						C		R					R
			24X-CC	223.50	19.01	242.51	F	P	Coastal											C									R				C						C
			25X-CC	233.20	19.01	252.21	A	M	Coastal											A					R	R			R				C						F							R