Paleoclimate Records and Young-Earth Creationism
Although YEC dogma states that the universe originated 7000 years ago, and that virtually the entire sedimentary record originated 4500 years ago, we have an annual to near-annual resolution paleoclimatological record extending back roughly 20 thousand years, and a decadal to millennial scale resolution record extending much further. This record is concordant, based on mutiple overlapping proxy records, and dated by several independent methods. Not only does this evidence allow us to test and refute the YEC "flood model," it also clearly demonstrates that even some of the most recent geological features on the earth's surface are far older than the entire YEC timescale will allow.
The European tree ring chronology gives and annual record extending from the present back about 11,000 years before the present (Becker 1993). The German Oak chronology extends back to 9971 yr bp, and the Pine ring chronology extends from 9800 yr bp to 11,597 yr bp. The two records overlap by 295 rings, and the correlation is also confirmed by radiocarbon dating (Kromer and Becker 1993).
The varve chronology in Europe extends back to about 14,000 yrs bp. For instance, the Lake Soppensee (Switzerland) and Lake Holzmaar (Germany) varve chronology extends back to 13,800 years (Hajdas 1993, 2000). Lake Van in Turkey preserves a continuous varve record extending back from the present to about 14,570 yr bp (Landmann et al. 1996). Together, these tree ring and varve chronologies give an extremely detailed and concordant annual-scale climatic record.
The varve-tree ring chronology from Europe can be extended back to about 45,000 yrs bp by correlation with the Japanese Lake Suigetsu clay/diatom varves. H. Kitagawa and van der Plicht write:
The combined AMS 14C and varve ages provide an extension of dendrocalibration range. The features in our data overlapping the absolute tree-ring record agree very well, and our varve chronology also supports the recent revision of the floating German pine chronology . . . Beyond the range of the dendrocalibration (~11,700 cal yr bp), there is also general agreement with the European sediments as well as with marine calibrations (1998, Science 279 (5354): 1187).
The illustration above shows the Suigetsu varve/14C data compared to the European tree ring/14C data (solid line). The correlation is excellent. In passing, the Suigetsu varves are interesting not only because they preserve an annual to century scale absolute chronology for the period 8830-37,930, but also because they allow atmospheric radiocarbon to be calibrated for essentially its entire useful range. Below is a graph comparing the 14C dates from Suigetsu varves to the expected absolute age based on varve count:
The article explains that the pattern of fluctuations in the production of 14C and other cosmogenic nuclides seen in other records - including those based on tree rings, Europeam varves, uranium series dated (!) speleotherms, 10Be levels in ice cores - are clearly seen in the Suigetsu varves also. The Suigetsu record overlaps and extends this record back to about 45,000 yr bp:
The detailed record in atmospheric D14C during the deglaciation shows millennium scale fluctuations superimposed on a long-term increasing trend, resulting from a decreasing geomagnetic intensity as reconstructed from geomagnetic records. Abrupt D14C drops correspond to radiocarbon plateaus in the calibration curve. Near (a few centuries after) the onset of the Younger Dryas (YD), the D14C value drops by 80 per mil from 10,800 to 9,800 BP (12.500 to 10,000 cal BP); the drop thus extends into the Preboreal (the earliest Holocene). This radiocarbon plateau has been well known in marine and terrestrial records, and is referred to as the YD plateau. . .
From the last Glacial Maximum to 31,000 cal BP, the long-term trend of D14C agrees well with reconstruction of cosmogenic isotope production rate deduced by 10Be deposition reconstruction and geomagnetic field intensity reconstruction. For this time span, we observe two pronounced peaks in D14C at 23,000 and 31,000 cal BP. The apparent D14C increases correspond to an increase in the concentration of another cosmogenic isotope, 10Be, at 23,000 and about 35,000 cal BP, respectively, observed in ice cores from the Antarctic and Greenland as well as in marine sediments. Furthermore a 14C anomaly at these times has been observed previously in speleothems, dated by both 14C and U-series (PE-04. A 45.000 YEAR VARVE CHRONOLOGY FROM JAPAN; see also fig 2 in Kitagawa and van der Plicht, 1998, Science 279 (5354): 1187).
Ice Cores: GISP2 and Vostok
The tree ring/varve chronology overlaps the much longer Greenland and Antarctic ice sheet chronologies. The ice sheets are dated by numerous methods (Mayewski and Bender, Dating GISP2).
The deepest GISP2 Greenland ice sheet core has a depth of about 3km. The ice at 2800m is estimated to be 110k years old. The ice below this is too distorted to be useful, but probably represents a considerable amount of time. This page shows a comparison of the gas and ice oxygen isotope ratios between the ARCSS/GISP2 and Vostok Ice Cores, again showing a fine correlation.
The Vostok record is much longer than the Greenland record, but where they overlap during the past 110k years, they are in excellent agreement. The thickest Vostok core is about 3623m, spanning an estimated 420,000 yrs. See Petit et al. (2000) Historical Isotopic Temperature Record from the Vostok Ice Core.
The Devil's Hole Calcite: A directly datable paleoclimate record
Summarizing from Cronin (Principles of Paleoclimatology, 1999): The DH calcite is a calcite vein which has grown via precipitation from ground water in a shallow fissure. Core DH 11 is 36cm long. The calcite has been dated by U series at approximately 1cm intervals, making the DH record "probably the best directly dated continuous stratigraphic record covering the past few hundred thousand years yet available" (Cronin, p.186). DH 11 covers the past 500k years.
Because the calcite has precipitated from groundwater, it preserves a record of the isotopic fluctuation as a result of glaciation and deglaciation. The O and C isotope ratios are sampled at 1.25mm intervals as well, for a total of 285 samples. Because of the excellent U series age control, the DH gives us a radiometrically-dated isotope curve. The actual data plus additional references can be found at the USGS. See: DH 11 core data More recently, Edwards et al (1997) applied 231Pa dating to the Devil's Hole record, which confirm the previous U-series dates.
What do you suppose we would find when we compare the 500k year DH calcite isotope record to the other records mentioned above, such as the Vostok and Greenland ice cores, or to the SPECMAP isotope curve derived from oceanic sediments? Remember that, whereas the SPECMAP curve was dated by correlation with the geomagnetic time scale, and the Vostok and Greenland cores are dated via layer counting, conductivity measurements, ice flow modeling, and correlation with SPECMAP, the DH core and other calcite records are directly dated by TIMS U-series.
As the graphs below shows, the fit between the curves is outstanding, especially the 18O isotope curve. This concordance strongly supports the accuracy of all the methods used. Cronin (1999) notes that "the similarity between the DH oxygen isotope curve and both the SPECMAP deep-sea oxygen isotope curve and the Vostok Antarctica ice core record of CO2, CH4, and the atmospheric temperature is startling. Especially noteworthy is how the rapid glacial terminations in the DH oxygen isotope curve have the same shape as those seen in deep-sea isotope curves" (p. 187).
Comparison of DH 11 and SPECMAP 180 Curves
Winograd 1997. Figure linked from Sean Mewhinney's "Minds in Ablations page.
Comparison of DH 11 and Vostok
Winograd 1997. Figure linked from Sean Mewhinney's "Minds in Ablations page.
Becker, B., 1993. A 11,000-year German Oak and Pine dendrochronology for radiocarbon calibration: Radiocarbon 35:201-213.
Edwards, R.L., Cheng, H., Murrell, M.T., Goldstein, S.J., 1997. Protactinium-231 Dating of Carbonates by Thermal Ionization Mass Spectrometry: Implications for Quaternary Climate Change, Science 276, 782
Hajdas, G. Bonani, and B. Zolitschka., 2000. Radiocarbon dating of varve chronologies: Soppensee and Holzmaar after Ten Years: Radiocarbon 42, 349-354.
Hajdas, I., Ivy, S.D., Beer, J., Bonani, G., Imboden, D., Lotter, A.F., Sturm, M. & Suter, M. 1993: AMS radiocarbon dating and varve chronology of lake Soppensee: 6000 to 12,000 14C years BP. Climate Dynamics 9, 107-116.
Kitagawa, H., and van der Plicht, J., 1998. Atmospheric Radiocarbon Calibration to 45,000 yr B.P.: Late Glacial Fluctuations and Cosmogenic Isotope Production, Science 279 (5354): 1187- 1190.
Kromer, B., and Becker, B., 1993, German Oak and Pine 14C calibration, 7200 BC - 9400 BC: Radiocarbon 35:125-135.
Landmann, G., Reimer, A., Lemcke, G. and Kempe, S., 1996. Dating Late Glacial abrupt climate changes in the 14,570 yr long continuous varve record of Lake Van, Turkey. Palaeogeography, Paleoclimatology, Palaeoecology, 122: 107-118.
Winograd, I.J., et al., 1997. Duration and Structure of the Past Four Interglaciations," Quaternary Research Vol. 48, pp. 141-154.