Download The Quaternary of Colombia - Subcommission on Quaternary

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!"#$%&'()%*#%+#"#&,(%-.(+#/$'(')/"0&#/Henry Hooghiemstra (1), Vladimir Torres (1,2),
Raul Giovanni Bogotá-Angel (1,3), Mirella Groot (1), Lucas Lourens (4),
Juan-Carlos Berrio (1, 5) & Project members #
Bogot
áB
Long Records of Environmental and Climate Change
are crucial to document the series of ice ages that characterise the Pleistocene. While in the
northern hemisphere ice sheets expanded and shrunk periodically, in the tropical mountains
the altitudinal vegetation distribution shifted downslope during relatively cold glacials and
stadials and upslope during relatively warm interglacials and interstadials. This poster focus on
development age models for the sediments in the basins of Bogotá and Fúquene (Fig. 1), the
climate history of the northern Andes and the evolution of its high elevation biota.
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In the Bogotá basin (4°N, 2550 m elevation) 586 m of sediments have been cored. The 2200-sample record of grain size
distributions shows changes in sedimentary environments (1). The pollen record starts at 540 m core depth and samples at 20cm increments along the core provide a record of 2100-samples (1). The record of aquatic vegetation reflects changes in water
depth. The record of trees, shrubs and herbs shows changes in the vegetation that covered the mountains around the lake.
0
-20
Funza: Arboreal Pollen
excluding Alnus and Quercus (detrended)
0.5
1
2
4
8
16
32
64
128
~4m (23ky)
~8m (41ky)
~20m (100ky)
0
50
100
150
200
250
300
350
400
450
500
Depth (m)
The 357-m deep Funza-1 core (2) and the 586-m deep Funza-2 core (1) have
been coupled at the first appearance event of Alnus (Fig. 2). Changing
percentages of arboreal pollen (AP%) in the composite record Funza09 (5401.6 m) show altitudinal shifts of the upper forest line (UFL) (3). Using a lapse rate
of 0.6°C/100 m UFL displacement and a mean annual temperature (MAT) at
the UFL of ~9.5°C paleo-temperatures have been calculated.
20
0
m
0
20
40
60
80
100%
0
0
m
50
100
100
100
150
150
150
200
200
200
250
250
250
300
300
300
350
350
350
400
400
450
450
20
40
60
80
100%
Gap in Funza-2 core recovery
During warm interglacial conditions the tree Alnus mainly forms swamp forest
around the lake reflected as high peaks in the AP% record. The sequence
of Alnus-based interglacials have been matched with the marine record of
glacial-interglacial cycles as shown by the LR04 benthic ∂18O stack record
(Fig. 3) (4). The immigration event of Alnus has been dated 1.018 Ma. We used
Fig. 2
cyclostratigraphy to develop the
age model for the lower part of the
Funza09 record. Frequency analysis
in the depth domain shows peaks
of 9.5-m and 7.6-m (Fig. 4). Wavelet
analysis shows a stable presence of
the 9-m frequency band which could
be robustly linked obliquity as the
main driver of climate change. The
age model shows the Funza09 record
reflects the period from 2,250,000 to
Fig. 3
27,000 years BP (Fig. 5).
20
0
100
0
Subandean forest
Andean forest
180
Arboreal Pollen (AP)
-20
O-tuning: Arboreal Pollen excluding Alnus and Quercus (detrended)
Páramo
500
500
550
550
500
Many gaps and
low pollen recovery
0
100
280
200
600
4
8
16
32
64
128
256
512
-2
1200
1400
1600
1800
2000
400
2200
3.2
2
Hooghiemstra et al., 1993
Alnus
3
Depth (m)
3.6
4.4
4.8
ODP Sites 846 & 849
5.2
18
50
40
P-tuning
30
O-tuning
1600
1800
2000
2200
2400
0
0
1000
Age (ka)
2000
5.1
27
17
8.5
4.0
35
29
160
33
23
18.3
120
3
80
4.5
40
Alnus
0
200
400
600
Age (ka)
800
1000
1200
3000
Fig. 5
Basin development
The AP%-based temperature record reflects marine isotope stages (MIS) 85 to 3 (Fig. 6 lower panel). The record
of aquatics shows deep-water vs. shallow-water conditions reflecting climate change superimposed by effects of
basin evolution (Fig. 6 top panel). In the period of 2.25-1.47 Ma wetlands, fluvial channels and swamps prevailed.
The basin floor subsided rapidly between 1.47 and 1.23 Ma and a lake developed. Between 1.23 and 0.86 Ma
lacustrine sediments accumulated in waters up to 50 m deep. Water depth was lower during the last 860,000
years but fluctuated in conjunction with the 100-kyr dominated glacial-interglacial cycles of the middle and late
Pleistocene (3). Around 27,000 BP the lake disappeared probably because the Bogotá basin became overfilled with
sediments.
Biome evolution
13
9.1
25
21
19
15.5
10
Age (ka)
Fig. 4
15.1
The Bogotá basin record shows 5 stages in the evolution of montane forest and páramo vegetation (Fig. 6 middle
panels) (3).
(1) Period 2.25-2.02 Ma: vegetation above the UFL was poor in species (protopáramo). Aragoa occasionally reached
high abundance. In the Andean forest Podocarpus increased in abundance. Proper lake conditions had not yet
developed. In absence of Alnus, Morella (Myrica) formed swamp forest and thickets on the basin floor.
(2) From 2.02 Ma (MIS 75) onwards increasing proportions of Aragoa, Ericaceae and Hypericum indicate that shrub
vegetation developed as a structural transition zone between upper montane forest and herbaceous páramo.
Polylepis, originating from the southern Andes, started its presence 2.1 Ma (MIS 78).
(3) From 1.58 Ma (MIS 54) onwards Borreria had developed as an element of the upper montane forest and was no
longer an exclusive constituent of open vegetation. The páramo reached more closely its modern structure and
taxonomic composition. In the montane forest the share of Podocarpus decreased.
(4) After the closure of the Panamanian Isthmus several Holarctic trees immigrated into South America. Alnus
immigrated 1.01 Ma (MIS 29). In the swamp forest around the lake Alnus replaced Morella (Myrica). On the north
Andean slopes Alnus changed the composition of montane forests.
(5) At 430,000 yr BP (MIS 12) Quercus (oak) arrived in the northern Andes and changed forest composition
dramatically. At high elevations Quercus competed with Weinmannia and Podocarpus. Near the UFL Quercus
Fluctuation of lake levels closely
related to glacial/interglacial cycles
Development of
proper lake
Highest lake levels
Low water stands. Mainly fluvio-lacustrine and swamp deposits.
Ludwigia &
Myriophyllum
Hydrocotyle
0
20%
40%
Cyperaceae
60%
80%
100%
Isoëtes
Proper Páramo and Andean forest
with no Oak
Development of Oak forest
Andean forest with
no Alder and no Oak
Development of shrub Páramo
120
Protopáramo
Myrica
Podocarpus
Extrapolation
30
5
20
7
10
9
11
13
17
Borreria
Aragoa
Polylepis
Hypericum
Visual match
19 21
Astronomical tuning
37
25
80
40
40
80
120
49
47
15
160
120
0
80
-10
-20
64
Alnus
-30
5
11
40
78
70
0
31
9
15
7
13
25
19 21
35
29
47
49
37
51
39
63
55
87
77
91 93
81
73
59
33
23
0.0
1400
Quercus
1200
3.0
1000
3.5
800
7.3
7.1 7.5
4.0
600
1
9.3
4.5
400
72
64
5.0
200
31
11
0
Aquatic taxa indicating lake level
0
20
3.5
5.0
AP(%, detrended)excl. Alnus and Quercus
100ky
60
δ18 O ODP Sites 846 & 849
23ky
41ky
5.5
3.0
200
4
8
16
32
64
128
256
512
0
visual tiepoint
OODP Sites 846 & 849
4.0
40
Alnus (%)excl. Quercus
1000
excl. Alnus and Quercus
800
Selected taxa (%)
600
Alnus & Quercus (%)
400
80
δ18 O Mediterranean
200
120
1
-3.0
0
160
0
Alnus (%)excl. Quercus
O-tuning
18
P-tuning
12
6
0
200
400
78
22
600
800
1000
1200
Age (ka)
1400
1600
1800
2000
82
2200
3.0
100ky
-1
OMediterranean
23ky
41ky
Sed. rate (cm/kyr)
eccl. Alnus and Quercus
AP (%, detrended)
Period (ky)
18O (per mil)
100%
Subparamo
-40
Period (ky)
80
50
450
2.8
60
Funza09
50
400
40
40
Al
nu
s
0
0
m
Funza-2
Andean forest
Period (m)
-40
Funza-1
Subpáramo & Páramo
eccl. Alnus and Quercus
AP (%, detrended)
20
h
t
r
o
Fúquene Basin n
Fig. 1
Age model development
40
asi
n
in south
s
a
B
e
en
Fúquene
The 2,250,000-yr long record from the Bogotá basin
Funza
Taken from Funza-1
I B E D
Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Netherlands
(2)
current address Exxon Mobil, Houston, USA
(3)
current address Universidad Distrital Francisco José de Caldas, Bogotá, Colombia
(4)
Geosciences, University of Utrecht, Netherlands
(5)
current address Dept. of Geography, University of Leicester, UK
Taken from Funza-2
(1)
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Fig. 6
partially replaced Polylepis. However, Quercus expanded slowly and
reached as late as 240,000 yr BP (MIS 7) significant proportions.
Most of the Pleistocene vegetation assemblages have no modern
analogue. However, modern ecological constraints of suites of taxa
allow a robust reconstruction of environmental and climate change.
The 284,000-yr long record from the Fúquene basin
In Lake Fúquene (5°N, 2540 m), a colluvial damm blocked lake (5), the upper 60 m of sediments have been collected from a floating
raft in two parallel cores (Fig. 1). Downcore measurements at 1-cm increments revealed multiple 4768-points records. Pollen
and carbon content show biome changes in the area and grain size distributions and XRF-based geochemistry show the abiotic
changes in the basin. Downcore changes in lithology (5), Fe and Zr (6) in cores Fq-9 and Fq-10 allowed to develop the composite
record Fq-9C (7). Geochemical records show changes in erosion and sediment transport in the basin. Downcore grain size
distributions show changing sedimentary environments (Fig. 7). Downcore aquatic pollen show changes in water-levels (Fig. 7).
Downcore regional pollen show temperature-driven changes in the altitudinal vegetation distribution.
Age model development
Sediments centrally located in the lake contain low percentages of carbon preventing robust 14C-dating (8). Cyclostratigraphy is
a challenging alternative. Frequency analysis of the AP% record in the depth domain show peaks at 907 and 2265 cm. Wavelet
power spectra show that the strengths of these frequencies are stable throughout the core in depth and time. These frequencies
were explored and appear to be linked to the obliquity (41-kyr) and eccentricity (~100-kyr) cycles of orbital forcing of climate
change (Fig. 8). Remarkable is the absence of a clear imprint of the precession-related 21-kyr cycle (7). Fig. 8A shows the Fq-9C AP%
record as raw data and Fig. 8B as a detrended and interpolated depth series overlain by a ~9 m Gaussian filter. Fig. 8C shows the
LR04 benthic ∂18O stack record (4) overlain by a Gaussian filter centered at the 41-kyr cycle. We correlated the filtered 9-m signal
in Fq-9C to the filtered 41-kyr obliquity-related component of the LR04 benthic ∂18O stack record to develop the age model. The
4768-points Fq-9C record reflects the interval from 284,000 to 27,000 yr BP. The Fq-9C record was extended to late Holocene
time by adding part of the Fq-2 pollen record (9): the Fúquene Basin Composite (Fq-BC) record. The connection with modern
instrumental data allows to calculate mean annual temperatures (MAT) throughout the record.
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Fig. 7
For a comparison of temperature records we show Greenland ∂18O ice core record (10) for the past 180,000 years
and the record from Antarctic core Epica Dome C (11) and our near equatorial record Fq-BC (Fig. 9) (7). During the last
130,000 years ice cores show 28 millennial-scale climate oscillations (Fig. 9, bottom panel), known as DansgaardOeschger (DO) cycles. Most DO cycles are reflected in equatorially located Fq-BC pollen record (Fig. 9, top panel) The
clear signature of the Younger Dryas (constrained by 14C dates), and the interstadial DO cycles 8, 12, 14, 19 and 20 in
the reconstructed MAT record suggest an unprecedented North Atlantic-equatorial link.
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We revisited the age models of pollen records Fq-3 (12, 15) and Fq-7C (13) with the new approach of cyclostratigraphy
and we obtained a basin-wide biostratigraphy (15) constrained in time (Fig. 10). We recognised periods with distinct
sediment compositions (14) and abundance of geochemical elements (6).
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Tropical montane forest and tropical alpine grassland (páramo) ecosystems are sensitive to variations in global
ice volume and respond to global climate change with significant altitudinal migrations. A one-to-one coupling
between changes in tropical MAT and the North Atlantic climate variability at both orbital and millennial time scales
is shown. Century-scale changes of 2-3.5°C during MIS 3-4 (Pleniglacial) and during previous glacial MIS 6, and
extreme changes of up to 10±2°C at the major glacial Terminations are shown. Long continental records analysed at
sub-centennial resolution show the dynamic history of terrestrial biomes and allow to assess current and projected
future climate change in a Pleistocene framework. However, developing such records is still an academic challenge.
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Acknowledgements
We greatly acknowledge the contributions to the Funza and Fúquene Projects by A.
Betancourt, L. Contreras, S. Gaviria, C. Giraldo, N. González, J.H.F. Jansen, M. Konert, D.
Ortega, J.O. Rangel, C.A. Rodríguez-Fernandez, G. Sarmiento, E. Tuenter, P.C. Tzedakis, J.
Vandenberghe, T. Van der Hammen, M. Van der Linden, J. Van der Plicht, B. van Geel, M.
Vriend, S.L. Weber, W. Westerhoff and M. Ziegler. These Long Continental Record projects
were financially supported by NWO (The Hague), WOTRO, (The Hague), AlBan (Madrid),
NUFFIC (The Hague), IBED (University of Amsterdam), INGEOMINAS (Bogotá) and
COLCIENCIAS (Bogotá).
This poster was designed by Jan van Arkel/IBED/University ofAmsterdam
I B E D
Fig. 9
Selected References
(1) Torres V et al. Palaeogeography Palaeoclimatology Palaeoecology 226, 127-148 (2005);
(2) Hooghiemstra H. Dissertationes Botanicae 79 (1984);
(3) Torres V et al. Quaternary Science Reviews 63, 59-72 (2013);
(4) Lisiecki LE, Raymo ME, Paleoceanography 20 PA1003,doi:10.1029/2004PA001071 (2005);
(5) Sarmiento G et al., Geomorphology 100, 563-575 (2008);
(6) Bogotá-A RG et al. Ch. 5 in PhD thesis (2011b);
(7) Groot MHM et al., Climate of the Past 7, 299-316 (2011);
(8) Groot MHM et al., Quaternary Geochronology (2014). http://dx.doi.org/10.1016/j.quageo.2014.01.003;
(9) Van Geel B, Van der Hammen T, Palaeogeography Palaeoclimatology Palaeoecology 14, 9-92 (1973);
(10) GRIP-Members, Nature 364. 203-207 (1993);
(11) Jouzel J et al., Science 317, 793-797 (2007);
(12) Van der Hammen T, Hooghiemstra H, Global and Planetary Change 36, 181-199 (2003);
(13) Mommersteeg HJPM, PhD thesis, University of Amsterdam (1998);
(14) Vriend, M et al., Netherlands Journal of Geosciences 91, 199-214 (2012);
(15) Bogotá-A RG et al. Quaternary Science Reviews 30, 3321-3337 (2011a).