# Atmospheric CO2 20 Million Year Foraminiferal B/Ca Reconstruction
#-----------------------------------------------------------------------
#                World Data Center for Paleoclimatology, Boulder
#                                  and
#                     NOAA Paleoclimatology Program
#-----------------------------------------------------------------------
# NOTE: Please cite Publication, and Online_Resource and date accessed when using these data.
# If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed.
#
#
# Online_Resource: https://www.ncdc.noaa.gov/paleo/study/16154
#
# Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tripati2011/tripati2011bca-mgca.txt
#
# Description/Documentation lines begin with #
# Data lines have no #
#
# Archive: Paleoceanography
#--------------------
# Contribution_Date
#	Date: 2014-03-09
#--------------------
# Title
#	Study_Name: Atmospheric CO2 20 Million Year Foraminiferal B/Ca Reconstruction
#--------------------
# Investigators
#       Investigators: Tripati, A.K.; Roberts, C.D.; Eagle, R.A.; Li, G.
#--------------------
# Description_and_Notes
#	Description: Paleoatmospheric CO2 concentrations estimated from the boron/calcium ratio of planktonic foraminifera.
#       Samples from Deep Sea Drilling Project Site 588 and Ocean Drilling Program Site 806 were used to reconstruct pCO2
#       values from the Miocene through Holocene (~20 to 0 Ma). Average, maximum, and minimum pCO2 estimates are calculated
#       for each time.
#--------------------
# Publication
#       Authors: Aradhna K. Tripati, Christopher D. Roberts, Robert A. Eagle, Gaojun Li
#       Published_Date_or_Year: 2011-05-15
#       Published_Title: A 20 million year record of planktic foraminiferal B/Ca ratios: Systematics and uncertainties in pCO2 reconstructions
#       Journal_Name: Geochimica et Cosmochimica Acta
#       Volume: 75
#       Edition:
#       Issue: 10
#       Pages: 2582-2610
#       DOI: 10.1016/j.gca.2011.01.018
#       Online_Resource: http://www.sciencedirect.com/science/article/pii/S0016703711000263
#       Full_Citation:
#       Abstract: We use new and published data representing a 20 million long record to discuss the systematics of interpreting planktic foraminiferal B/Ca ratios. B/Ca-based reconstructions of seawater carbonate chemistry and atmospheric pCO2 assume that the incorporation of boron into foraminiferal tests can be empirically described by an apparent partition coefficient, KD=(B/CaCaCO3)/(BOH4-/HCO3- seawater) (Hemming and Hanson, 1992). It has also been proposed that there is a species-specific relationship between KD and temperature (Yu et al., 2007). As we discuss, although these relationships may be robust, there remain significant uncertainties over the controls on boron incorporation into foraminifera. It is difficult to be certain that the empirically defined correlation between temperature and KD is not simply a result of covariance of temperature and other hydrographic variables in the ocean, including carbonate system parameters. There is also some evidence that KD may be affected by solution [HCO3-]/[CO32-] ratios (i.e., pH), or by [CO32-]. In addition, the theoretical basis for the definition of KD and for a temperature control on KD is of debate. We also discuss the sensitivity of pCO2 reconstructions to different KD-temperature calibrations and seawater B/Ca. If a KD-temperature calibration is estimated using ice core pCO2 values between 0 and 200 ka, B/Ca ratios can be used to reasonably approximate atmospheric pCO2 between 200 and 800 ka; however, the absolute values of pCO2 calculated are sensitive to the choice of KD-temperature relationship. For older time periods, the absolute values of pCO2 are also dependent on the evolution of seawater B concentrations. However, we find that over the last 20 Ma, reconstructed changes in declining pCO2 across the Mid-Pleistocene Transition, Pliocene glacial intensification, and the Middle Miocene Climate Transition are supported by the B/Ca record even if a constant coretop KD is used, or different KD-temperature calibrations and models of seawater B evolution are applied to the data. The inferred influence of temperature on KD from coretop data therefore cannot itself explain the structure of a published pCO2 reconstruction (Tripati et al., 2009). We conclude the raw B/Ca data supports a coupling between pCO2 and climate over the past 20 Ma. Finally, we explore possible implications of B/Ca-based pCO2 estimates for the interpretation of other marine pCO2 proxies.
#------------------
# Funding_Agency
#       Funding_Agency_Name: National Environmental Research Council (UK)
#       Grant:
#------------------
# Funding_Agency
#       Funding_Agency_Name: University of California - Los Angeles (USA)
#       Grant:
#------------------
# Funding_Agency
#       Funding_Agency_Name: Magdalene College (UK)
#       Grant:
#------------------
# Site_Information
#       Site_Name: DSDP588
#       Location: Ocean>Pacific Ocean>South Pacific Ocean
#	Country:
#	Northernmost_Latitude: -26.1117
# 	Southernmost_Latitude: -26.1117
# 	Easternmost_Longitude: 161.2267
# 	Westernmost_Longitude: 161.2267
# 	Elevation: -1533 m
#------------------
# Site_Information
#       Site_Name: ODP806
#       Location: Ocean>Pacific Ocean>North Pacific Ocean
#	Country:
#	Northernmost_Latitude: 0.3187
# 	Southernmost_Latitude: 0.3187
# 	Easternmost_Longitude: 159.361
# 	Westernmost_Longitude: 159.361
# 	Elevation: -2521 m
#------------------
# Data_Collection
#	Collection_Name: Tripati2011BCa-MgCa
#	Earliest_Year: 20000000
#	Most_Recent_Year: 0
#	Time_Unit: Cal. Year BP
#	Core_Length: m
#	Notes:
#------------------
# Chronology:
#
#
#----------------
# Variables
#
# Data variables follow (have no #)
# Data line variables format:  Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data)
## depth_m	depth, , , meters, , , MBSF, ,N
## notes-species	Notes Species, , , , , , , ,C
## B/Ca	Boron/Calcium ratio, , , mmol/mol, , , , ,N
## Mg/Ca	Magnesium/Calcium ratio, , , mmol/mol, , , , ,N
#----------------
# Data:
# Data lines follow (have no #)
# Data line format - tab-delimited text, variable short name as header
# Missing Values:
depth_m	notes-species	B/Ca	Mg/Ca
0.09	G. ruber	119.1	4.4
0.09	G. sacculifer	70.5	4.1
0.4	G. ruber	119.8	3.7
0.4	G. ruber	114.7	3.8
0.4	G. sacculifer	77.2	3.4
0.8	G. ruber	114.4	3.5
0.8	G. sacculifer	76.6	3.3
0.95	G. ruber	119.5	3.6
0.95	G. sacculifer	74.5	3.5
1.2	G. ruber	114.5	3.7
1.2	G. sacculifer	78.1	3.4
1.9	G. ruber	109.9	3.9
1.9	G. sacculifer	73.3	3.6
1.92	G. ruber	104.5	4
1.92	G. sacculifer	70.5	3.7
2.3	G. ruber	117.1	4.6
2.3	G. sacculifer	76.3	4.2
2.4	G. ruber	112.1	4.6
2.4	G. sacculifer	83.6	4.4
2.7	G. ruber	109.3	3.8
2.7	G. sacculifer	72.1	3.6
3	G. ruber	108.1	3.5
3	G. sacculifer	73.5	3.3
3.37	G. ruber	111.7	3.5
3.37	G. ruber	109.7	3.7
3.37	G. sacculifer	71.7	3.3
4.2	G. ruber	124.8	4.1
4.2	G. sacculifer	71	3.6
4.5	G. ruber	112.6	4.2
4.5	G. ruber	113.4	4.2
4.9	G. sacculifer	74.1	3.4
5.16	G. ruber	122.6	3.6
5.16	G. ruber	113.4	3.6
5.16	G. sacculifer	73	3.6
5.3	G. ruber	133.2	3.8
5.3	G. sacculifer	76.2	3.5
5.6	G. ruber	111.2	3.9
5.6	G. ruber	108.9	3.9
5.6	G. sacculifer	72	3.8
5.7	G. ruber	134.9	3.6
5.7	G. sacculifer	74.1	3.7
5.85	G. sacculifer	72.1	3.7
6	G. ruber	118.4	3.6
6.42	G. ruber	115.5	3.9
6.42	G. ruber	109.6	3.7
6.42	G. sacculifer	70	3.7
6.66	G. ruber	123.5	4.7
6.66	G. ruber	121.1	4.5
6.66	G. sacculifer	75	4.3
6.8	G. ruber	125.8	4.4
7.35	G. ruber	113.9	3.4
7.35	G. ruber	118.2	3.5
7.35	G. sacculifer	74.1	3.6
7.57	G. ruber	99.5	3.4
7.57	G. ruber	112.3	3.3
7.57	G. sacculifer	68.2	3.6
7.7	G. ruber	110.5	4.5
7.79	G. ruber	109.2	3.5
7.79	G. ruber	96.9	3.7
7.79	G. sacculifer	74	3.5
8.9	G. ruber	91.7	3.6
8.97	G. ruber	106.1	3.4
8.97	G. sacculifer	71.8	3.5
11.03	G. ruber	106.3	4
11.03	G. sacculifer	77.6	3.9
11.34	G. ruber	105.6	3.6
11.34	G. sacculifer	72.9	3.6
12.39	G. ruber	103.7	4.2
12.63	G. ruber	106.5	4
12.63	G. sacculifer	77	3.6
13.28	G. ruber	103.3	3.9
13.38	G. ruber	107.5	4.2
13.38	G. ruber	104.9	4
13.84	G. ruber	112	3.6
13.84	G. sacculifer	79.6	3.6
14.58	G. ruber	104.6	3.5
14.58	G. ruber	101	3.7
15.18	G. ruber	108.4	4.1
15.38	G. ruber	110.8	4
15.58	G. ruber	102.2	3.6
15.58	G. sacculifer	79.2	3.6
15.74	G. ruber	102.7	3.6
15.74	G. sacculifer	74	3.5
16.03	G. ruber	118.3	4.1
16.43	G. ruber	99.2	3.5
17.08	G. ruber	99.2	4
17.34	G. ruber	104.4	4.1
17.43	G. ruber	106.1	4.3
17.61	G. ruber	105.5	4.6
17.88	G. ruber	101.5	3.5
18.24	G. ruber	104	3.5
18.24	G. sacculifer	88.6	3.3
18.63	G. ruber	103.4	3.8
18.83	G. ruber	94.9	3.4
19.03	G. ruber	101.3	3.9
19.24	G. ruber	99.3	3.9
19.36	G. ruber	110	3.9
19.64	G. ruber	100.4	4.3
19.93	G. ruber	97.9	3.8
20.29	G. ruber	102	3.9
21.14	G. ruber	99.3	3.5
21.14	G. sacculifer	78.1	3.7
21.64	G. ruber	97.5	4
22.23	G. ruber	86.4	3.4
22.73	G. ruber	103.6	4
23.03	G. ruber	98.5	3.9
23.33	G. ruber	94.9	3.7
23.43	G. ruber	106.8	4.1
23.89	G. ruber	95.4	3.8
24.28	G. ruber	108.1	4
24.28	G. sacculifer	77.2	4.1
24.58	G. ruber	101.3	3.9
24.83	G. ruber	104.3	4
25.58	G. ruber	104.4	4.4
25.93	G. ruber	104.6	4
26.17	G. ruber	103.5	4.2
26.94	G. ruber	103.9	3.9
26.94	G. sacculifer	74.3	3.8
27.25	G. ruber	104.8	3.8
27.81	G. ruber	108.3	4.2
28.34	G. ruber	101.6	3.6
28.34	G. sacculifer	75.6	3.7
28.5	G. ruber	114.4	4.2
28.69	G. ruber	103	4.2
28.88	G. ruber	100	4.1
29.1	G. ruber	95.6	3.5
29.28	G. ruber	101.1	4
29.48	G. ruber	95.6	4.2
29.73	G. ruber	94.8	4.2
29.89	G. ruber	96.9	4.1
30.03	G. ruber	99.5	4.1
30.03	G. ruber	101	3.6
30.03	G. sacculifer	75.1	3.8
30.19	G. ruber	96.1	3.9
30.41	G. ruber	89.7	4.1
30.6	G. ruber	96.3	4.3
30.8	G. ruber	97.5	4.5
30.8	G. sacculifer	76	4.5
30.98	G. ruber	89.7	3.7
31.2	G. ruber	88.3	3.9
31.4	G. ruber	106.9	4
31.4	G. sacculifer	77.2	3.9
31.5	G. ruber	124.7	4
31.5	G. sacculifer	73.1	4
31.69	G. ruber	92.4	4.4
31.9	G. ruber	107.5	4
32.08	G. ruber	93.9	3.8
32.31	G. ruber	93.7	4
32.5	G. ruber	100.3	4.2
32.7	G. ruber	90.2	3.6
32.9	G. ruber	89.6	3.5
33	G. ruber	93.8	3.6
33.18	G. ruber	104	3.9
33.39	G. ruber	96.5	3.9
33.63	G. ruber	100.5	3.6
33.79	G. ruber	93	3.7
34.03	G. ruber	99.6	3.8
34.23	G. ruber	95.7	3.8
34.43	G. ruber	97.4	3.8
34.52	G. ruber	110	3.7
34.52	G. sacculifer	76.8	3.5
34.74	G. ruber	98.5	3.9
34.93	G. ruber	98.9	4
35.03	G. ruber	95	3.8
35.08	G. ruber	104.6	4
35.23	G. ruber	118.7	3.6
35.43	G. ruber	103.6	3.9
35.64	G. ruber	83.6	3.5
35.78	G. ruber	104.6	3.9
36.04	G. ruber	98.3	3.6
36.04	G. sacculifer	67.4	3.1
36.19	G. ruber	102.8	3.7
36.19	G. sacculifer	69	3.2
36.43	G. ruber	101.9	4.1
36.5	G. ruber	115.1	4
36.69	G. ruber	109.8	3.8
36.69	G. sacculifer	73.9	3.4
37.08	G. ruber	99.6	3.6
37.29	G. ruber	102.7	3.7
37.48	G. ruber	97	3.9
37.69	G. ruber	102.6	3.9
37.93	G. ruber	100	3.5
38.19	G. ruber	94.9	3.8
38.39	G. ruber	100.1	3.8
38.63	G. ruber	105.4	3.7
38.63	G. sacculifer	73.5	3.5
38.83	G. ruber	107.9	3.9
38.83	G. sacculifer	68.8	3.6
39.03	G. ruber	100.9	3.8
39.03	G. sacculifer	66.7	3.4
39.23	G. ruber	103.5	4
39.43	G. ruber	105.7	4
39.5	G. ruber	113.9	3.9
39.73	G. ruber	104.8	3.5
39.93	G. ruber	103	3.9
40.13	G. ruber	104	3.5
40.33	G. ruber	102.5	3.9
40.53	G. ruber	106.4	4
40.74	G. ruber	104.7	3.8
41.23	G. ruber	106.3	3.8
41.43	G. ruber	107.8	4.1
42.93	G. ruber	104.8	4.2
42.93	G. ruber	112.7	4.1
42.93	G. sacculifer	64	3.6
43.53	G. ruber	104.9	4.1
44.23	G. ruber	108	3.7
44.23	G. sacculifer	63	3.3
47.03	G. ruber	110.6	3.6
47.03	G. sacculifer	75.7	3.5
48.04	G. ruber	116.7	3.6
48.04	G. sacculifer	68.5	3.1
48.29	G. ruber	111	3.9
48.29	G. sacculifer	64.1	3.5
48.92	G. ruber	115.1	3.8
48.92	G. sacculifer	68	3.2
49.43	G. ruber	107.4	4
49.43	G. sacculifer	80	3.7
49.83	G. ruber	100.7	3.9
49.83	G. sacculifer	63.7	3.4
50.54	G. ruber	107.6	3.9
50.54	G. sacculifer	77.2	3.7
50.73	G. ruber	104.3	4
50.73	G. sacculifer	82.1	3.6
50.94	G. ruber	112.8	4
50.94	G. ruber	115	4.1
50.94	G. sacculifer	73.9	3.7
51.34	G. ruber	109.3	3.9
51.34	G. sacculifer	73.7	3.2
51.74	G. ruber	108.4	4.1
51.74	G. ruber	112.5	3.8
51.74	G. sacculifer	67.7	3.5
51.94	G. ruber	113.1	3.8
51.94	G. sacculifer	79.5	3.6
52.04	G. ruber	111.3	4.1
52.04	G. sacculifer	83.5	3.8
52.18	G. ruber	112.3	3.7
52.18	G. sacculifer	74.1	3.6
52.64	G. ruber	107.1	4.1
52.64	G. sacculifer	64.2	3.5
52.78	G. ruber	120.6	3.9
52.78	G. sacculifer	67.5	3.6
53.38	G. ruber	107	4
53.38	G. sacculifer	66.1	3.5
53.54	G. ruber	109.6	3.3
53.54	G. sacculifer	70.7	3.2
53.74	G. ruber	99.9	3.6
53.74	G. sacculifer	72.2	3.3
54.15	G. ruber	112.8	3.6
54.15	G. sacculifer	69.1	3.4
54.35	G. ruber	105.9	3.8
54.35	G. sacculifer	75.2	3.4
54.59	G. ruber	103.3	4
54.59	G. sacculifer	81.4	3.4
57.98	G. ruber	113.4	3.9
57.98	G. sacculifer	86.5	3.5
62.55	G. ruber	111.8	3.9
62.55	G. sacculifer	79.6	3.5
64.75	G. ruber	118.6	3.8
64.75	G. sacculifer	84.3	3.4
68.49	G. ruber	107.1	3.7
68.49	G. ruber	109.1	3.9
68.49	G. sacculifer	107.1	3.7
72.92	G. ruber	117.8	3.9
72.92	G. sacculifer	83.9	3.7
73.78	G. ruber	112.5	4
73.78	G. sacculifer	79	3.8
78.9	G. ruber	115.3	3.9
78.9	G. sacculifer	76.6	3.8
80.7	G. ruber	126.8	3.9
80.7	G. sacculifer	81.1	3.8
82.53	G. ruber	103.7	3.9
82.72	G. ruber	102.2	4
82.9	G. ruber	113.6	3.9
82.9	G. sacculifer	80.3	3.7
83.29	G. ruber	106.2	3.9
83.49	G. ruber	107.4	4.1
83.67	G. ruber	115.3	4
83.88	G. ruber	117.9	4.2
84.2	G. ruber	105.7	4.2
84.39	G. ruber	104.4	4.1
84.59	G. ruber	103.3	4.3
84.98	G. ruber	100.9	4.4
85.18	G. ruber	100.9	4.2
85.38	G. ruber	99	4.2
85.5	G. ruber	104.1	4.1
85.7	G. ruber	109.3	4.1
85.9	G. ruber	113.3	4
85.9	G. sacculifer	65.9	3.7
86.09	G. ruber	108.1	4
86.28	G. ruber	109	3.9
86.47	G. ruber	104	4.1
87.58	G. ruber	103.7	3.9
87.58	G. sacculifer	67.8	3.8
93.5	G. sacculifer	68	3.8
95.37	G. sacculifer	73.8	3.9
101	G. sacculifer	81.7	3.5
106.79	G. sacculifer	79	3.7
109.38	G. sacculifer	75.9	3.7
113.86	G. sacculifer	73.6	3.3
114	G. sacculifer	76.9	3.5
114.18	G. sacculifer	72.1	3.5
114.39	G. sacculifer	85.9	3.5
114.59	G. sacculifer	72.2	3.7
114.8	G. sacculifer	69.4	3.7
114.99	G. sacculifer	72	3.9
115.18	G. sacculifer	77.1	3.8
115.39	G. sacculifer	70.1	3.3
115.5	G. sacculifer	76.1	3.6
115.67	G. sacculifer	77.9	3.5
115.9	G. sacculifer	80	3.7
116.1	G. sacculifer	78.1	3.8
116.3	G. sacculifer	76.9	3.6
116.5	G. sacculifer	75.9	3.4
116.7	G. sacculifer	77.8	3.6
116.9	G. sacculifer	75.7	3.7
117	G. sacculifer	76.9	3.6
117.2	G. sacculifer	77.3	3.5
117.4	G. sacculifer	75.7	3.6
117.6	G. sacculifer	75.1	3.5
117.8	G. sacculifer	71.2	3.6
118	G. sacculifer	71.5	3.7
118.2	G. sacculifer	72.6	3.3
118.36	G. sacculifer	75.1	3.3
118.5	G. sacculifer	76.8	3.5
118.7	G. sacculifer	72.4	3.4
118.9	G. sacculifer	75.8	3.2
119.1	G. sacculifer	70.5	3.3
119.3	G. sacculifer	74.1	3.2
119.5	G. sacculifer	76.8	3.4
119.7	G. sacculifer	71.8	3.4
119.9	G. sacculifer	73.6	3.4
120.04	G. sacculifer	70.4	3.3
120.04	G. sacculifer	69.2	3.3
120.2	G. sacculifer	71.6	3.4
120.2	G. sacculifer	76.7	3.5
120.4	G. sacculifer	78.3	3.3
120.62	G. sacculifer	67.5	3.3
120.8	G. sacculifer	70.5	3.4
155.59	G. sacculifer	60.8	3.8
156.38	G. sacculifer	62.4	3.7
158.8	G. sacculifer	74.6	3.6
168.39	G. sacculifer	67.6	3.9
177.89	G. sacculifer	70.5	3.3
187.35	G. sacculifer	73.3	3.4
196.82	G. sacculifer	83.1	4
206.25	G. sacculifer	75.8	3.7
215.87	G. sacculifer	73.6	3.5
225.37	G. sacculifer	75.4	3.6
251.5	G. ruber	98.3	4
269.29	G. ruber	106.9	4.7
297.72	G. ruber	80.8	4.1
307.35	G. ruber	100.7	4.6
310.72	G. ruber	95	4.3
319.18	G. ruber	87.8	4.2
327.76	G. ruber	92.6	4