A. N. Ab-'saber, Espaços ocupados pela expansao dos climas secos ne America do Sul, por ocasiao dos periodos glaciais quaternarios, Paleoclimas, vol.3, pp.1-20, 1977.

P. Adam, Nouvelles structures organo-soufrées d'intérêt géochimique : Aspects moléculaires et macro-moléculaires, Thèse de doctorat, 1991.

J. M. Adams and H. Et-faure, A new estimate of changing carbon storage on land since the last glacial maximum, based on global land ecosystem reconstruction, Global and Planetary Change, vol.16, issue.17, pp.3-24, 1998.
DOI : 10.1016/S0921-8181(98)00003-4

S. K. Agarwal and R. P. Et-rastogi, Triterpenoid saponins and their genins, Phytochemistry, vol.13, issue.12, pp.2623-2645, 1974.
DOI : 10.1016/0031-9422(74)80217-7

H. Ageta, K. Shiojima, and K. Et-masuda, Fern constituent: colysanoxide, and onoceroid having a novel carbon skeleton, isolated from species, Tetrahedron Letters, vol.23, issue.42, pp.4349-4352, 1982.
DOI : 10.1016/S0040-4039(00)85597-5

H. Ageta, K. Shiojima, and K. Et-masuda, Fern constituents. Onoceroid,.ALPHA.-onoceradiene,serratene and onoceranoxide,isolated from Lemmaphyllum microphyllum varieties., CHEMICAL & PHARMACEUTICAL BULLETIN, vol.30, issue.6, pp.2272-2274, 1982.
DOI : 10.1248/cpb.30.2272

H. Ageta, K. Shiojima, and Y. Arai, Acid-induced rearrangement of triterpenoid hydrocarbons belonging to the hopane and migrated hopane series., CHEMICAL & PHARMACEUTICAL BULLETIN, vol.35, issue.7, pp.2705-2716, 1987.
DOI : 10.1248/cpb.35.2705

P. Albrecht and G. Et-ourisson, Triterpene Alcohol Isolation from Oil Shale, Science, vol.163, issue.3872, pp.1192-1193, 1969.
DOI : 10.1126/science.163.3872.1192

A. L. Albuquerque, Organic geochemistry in the Caço Lake (North-eastern Brazil): Paleoenvironmental implications for the last 21

S. Allard and G. Et-ourisson, Remarques sur la nomenclature des triterp??nes, Tetrahedron, vol.1, issue.4, pp.277-283, 1957.
DOI : 10.1016/0040-4020(57)88002-8

V. U. Atta-ur-rahman, Handbook of Natural Products Pentacyclic Triterpenoids, 1994.

. Babady-bila and K. R. Tandu, Triterpenoid constituents from Gardenia imperialis, Monatsh. Chem, vol.11810, pp.1195-1196, 1987.
DOI : 10.1007/bf00811292

D. H. Barton and K. H. Et-overton, Triterpenoids. Part XX. The constitution and stereochemistry of a novel tetracyclic triterpenoid, Journal of the Chemical Society (Resumed), pp.2639-2652, 1955.
DOI : 10.1039/jr9550002639

N. Basu and R. P. Et-rastogi, Triterpenoid saponins and sapogenins, Phytochemistry, vol.6, issue.9, pp.1249-1270, 1967.
DOI : 10.1016/S0031-9422(00)86088-4

H. Behling, H. W. Arz, J. Pätzold, and G. Et-wefer, Late Quaternary vegetational and climate dynamics in northeastern Brazil, inferences from marine core GeoB 3104-1, Quaternary Science Reviews, vol.19, issue.10, pp.981-994, 2000.
DOI : 10.1016/S0277-3791(99)00046-3

J. Bertaux, F. Frohlich, . Et-ildefonse, and . Ph, A new application of FTIR spectroscopy for the quantification of amorphous and crystallized mineral phases, 1998.

K. K. Bhutani, R. Kapoor, and C. K. Et-atal, Two unsymmetric tetracyclic triterpenoids from cissus quadrangularis, Phytochemistry, vol.23, issue.2, pp.407-410, 1984.
DOI : 10.1016/S0031-9422(00)80341-6

T. Blunier and E. J. Et-brook, Timing of millenial-scale climate change in Antarctica and Greenland during the last glacial period, Science, vol.290, pp.325-327, 2001.

P. Boiteau, B. Pasich, and A. R. Et-ratsimamanga, Triterpénoïdes en physiologie végétale et animale, 1964.

A. G. Borrego, C. G. Blanco, and W. Et-püttmann, Geochemical significance of the aromatic hydrocarbon distribution in the bituments of the Puertollano oil shales, Spain, Organic Geochemistry, vol.26, pp.3-4, 1997.

S. Bourdon, Approches micromorphologiques et moléculaires de la diagenèse précoce de la matière organique dans une tourbe à Cypéracées en milieu tropical (Tritrivakely, Madagascar). Implications paléoenvironnementales, Thèse de Doctorat, 1999.

S. Bourdon, F. Laggoun-défarge, J. R. Disnar, O. Maman, B. Guillet et al., Organic matter sources and early diagenetic degradation in a tropical peaty marsh (Tritrivakely, Madagascar). Implications for environmental reconstruction during the Sub-Atlantic, Organic Geochemistry, vol.31, issue.5, pp.421-438, 2000.
DOI : 10.1016/S0146-6380(00)00010-3

URL : https://hal.archives-ouvertes.fr/hal-00091221

P. A. Colinvaux, P. E. De-oliveira, J. E. Moreno, M. C. Miller, and M. C. Bush, A Long Pollen Record from Lowland Amazonia: Forest and Cooling in Glacial Times, Science, vol.13, issue.1-2, pp.85-88, 1996.
DOI : 10.1016/0031-0182(94)90178-3

P. A. Colinvaux, D. Oliveira, P. E. Bush, and M. B. , Amazonian and neotropical plant communities on glacial time-scales: The failure of the aridity and refuge hypotheses, Quaternary Science Reviews, vol.19, issue.1-5, pp.141-169, 2000.
DOI : 10.1016/S0277-3791(99)00059-1

J. D. Connoly and R. A. Hill, Triterpenoids, Natural Product Reports, vol.3, pp.421-442, 1986.
DOI : 10.1039/np9860300421

Y. Copard, Altération diagénétique et post diagénétique (thermicité, oxydation) des charbons carbonifères du Massif-Central français (Saint-Etienne, Graissessac et autres lieux, Thèse de Doctorat, 2002.

B. Corbet, Origine et transformation des triterpènes dans les sédiments récents, 1980.

E. J. Corey and J. J. Et-ursprung, The Stereochemistry of the ??-Amyrins, Journal of the American Chemical Society, vol.78, issue.1, pp.183-188, 1956.
DOI : 10.1021/ja01582a052

J. L. Courtney, R. M. Gascoigne, and A. Z. Et-szumer, Triterpenoids of the friedelane series. Part III. The course of friedelane-oleanane rearrangement, Journal of the Chemical Society, pp.881-886, 1958.

P. A. Cranwell, Organic geochemistry of lacustrine sediments: triterpenoids of higher plant origin reflecting post-glacial vegetational succession Lakes sediments and environmental History, pp.69-92, 1984.

A. Cronquist, On the Taxonomic Significance of Secondary Metabolites in Angiosperms, Plant Systematics and Evolution, vol.1, pp.179-189, 1977.
DOI : 10.1007/978-3-7091-7076-2_12

T. J. Crowley, Ice Age terrestrial carbon changes revisited, Global Biogeochemical Cycles, vol.1, issue.43, pp.377-389, 1995.
DOI : 10.1029/95GB01107

J. A. Curiale, Molecular genetic markers and maturity indicators in intermontane lacustrine facies: Kishenehn Formation, Montana Advances in Organic Geochemistry, Organic Geochem istry 13, pp.633-638, 1987.

W. Dansgaard, S. J. Johnsen, H. B. Clausen, D. Dahl-jensen, N. S. Gundestrup et al., Evidence for general instability of past climate from a 250-kyr ice-core record, Nature, vol.364, issue.6434, pp.218-220, 1993.
DOI : 10.1038/364218a0

URL : https://hal.archives-ouvertes.fr/hal-01103728

M. C. Das and S. B. Et-mahato, Triterpenoids, Phytochemistry, vol.22, issue.5, pp.1071-1095, 1983.
DOI : 10.1016/0031-9422(83)80198-8

F. X. De-las-heras, J. O. Grimalt, and J. Et-albaiges, Novel C-ring cleaved triterpenoid-derived aromatic hydrocarbons in Tertiary brown coals, Geochimica et Cosmochimica Acta, vol.55, issue.11, pp.3379-3385, 1991.
DOI : 10.1016/0016-7037(91)90495-Q

D. Oliveira, P. E. Bush, M. B. Miller, M. Et-colinvaux, and P. A. , A 40,000 year record from the Amazonian lowland forest of Brazil, 1995.

A. Debella, E. Haslinger, M. G. Schmid, F. Bucar, G. Michl et al., Triterpenoid saponins and sapogenin lactones from Albizia gummifera, Phytochemistry, vol.53, issue.8, pp.885-892, 2000.
DOI : 10.1016/S0031-9422(99)00464-1

S. S. Deshmane and S. Et-dev, Higher isoprenoids-II; Triterpenoids and steroids of Saccharum officinarum linn, Tetrahedron, vol.276, pp.1109-1118, 1971.

T. K. Devon and A. Scott, Handbook of Naturally Occurring Compounds 2, Terpenes, p.pp, 1972.

J. R. Disnar and J. Et-trichet, The influence of various divalent cations (UO22+, Cu2+, Pb2+, Co2+, Ni2+, Zn2+, Mn2+) on the thermally induced evolution of organic matter isolated from an algal mat, Organic Geochemistry, vol.6, pp.865-874, 1984.
DOI : 10.1016/0146-6380(84)90109-8

J. R. Disnar, B. Guillet, D. Kéravis, R. Massif, and C. Di-giovanni, Soil organic matter (SOM) characterization by Rock-Eval pyrolysis : main classical parametersEntering the Third Millenium with a common approach to humic substances and organic matter in water, soil and sediments, Proc. IHSS 10, pp.1211-1214, 2000.

J. R. Disnar, B. Guillet, D. Kéravis, C. Di-giovanni, and D. Et-sebag, Soil organic matter (SOM) characterisation by Rock-Eval pyrolysis: scope and limitations, Organic Geochemistry

R. Djennadi, Sédimentation organo-minérale d'une tourbière d'altitude (site de Sibéria, Bolivie) Marqueurs des changements d'environnements au cours des derniers 13, 2001.

C. Djerassi, H. Budzikiewicz, and J. M. Et-wilson, Mass spectroscopy in structural and stereochemical problems. Unsaturated pentacyclic triterpenoids, Tetrahedron Letters, vol.7, pp.263-270, 1962.

M. Foudi, Distribution et état de préservation de la matière organique sédimentaire des sédiments superficiels du Lac Caço, 2002.

L. M. François, Y. Goddéris, P. Warnant, G. Ramstein, N. De-noblet et al., Carbon stocks and isotopic budgets of the terrestrial biosphere at mid-Holocene and last glacial maximum times, Chemical Geology, vol.159, issue.1-4, pp.163-189, 1999.
DOI : 10.1016/S0009-2541(99)00039-X

J. Fu, . Sheng, . Guoying, and D. Liu, Dans Lacustrine Petroleum Source Rocks, pp.279-289, 1988.

S. Garcia, H. Heinzen, C. Hubbuch, R. Martinez, X. De-vries et al., Triterpene methyl ethers from palmae epicuticular waxes, Phytochemistry, vol.39, issue.6, pp.1381-1382, 1995.
DOI : 10.1016/0031-9422(95)00173-5

A. Georgakopolous, Contribution à l'analyse des sédiments récents par la pyrolyse de type Rock-Eval, Thèse de Doctorat, 1984.

L. Gerard-zaugg, Effets de la maturation thermique sur les processus d'oxydation des charbons, Thèse de Doctorat, 1994.

D. E. Giannasi and K. L. Et-niklas, Comparative Paleobiochemistry of Some Fossil and Extant Fagaceae, American Journal of Botany, vol.68, issue.6, pp.762-770, 1981.
DOI : 10.2307/2443180

D. E. Giannasi and K. L. Et-niklas, The paleobiochemistry of fossil angiosperm floras, 1985.

I. Part, Chemosystematic aspects, Late Cenozoic history of the Pacific Northwest, pp.161-174, 1985.

S. H. Goh, F. L. Lai, and P. T. Gee, Wax esters and triterpene methyl ethers from the exocarp of Elaeis guineensis, Phytochemistry, vol.27, issue.3, pp.877-880, 1988.
DOI : 10.1016/0031-9422(88)84111-6

A. Greiner, . Ch, C. Spyckerelle, and P. Et-albrecht, Aromatic hydrocarbons from geological sources???I, Tetrahedron, vol.32, issue.2, pp.257-260, 1976.
DOI : 10.1016/0040-4020(76)87011-1

A. Greiner, . Ch, C. Spyckerelle, P. Albrecht, and G. Et-ourisson, Hydrocarbures aromatiques d'origine géologique. V. Dérivés mono-et di-aromatiques du hopane, Journal of Chemical Research, pp.3829-3871, 1977.

M. Ledru, J. Bertaux, A. Sifeddine, and K. Suguio, Absence of Last Glacial Maximum Records in Lowland Tropical Forests, Quaternary Research, vol.165, issue.3, pp.233-237, 1998.
DOI : 10.1006/qres.1993.1011

M. P. Ledru, R. C. Cordeiro, J. M. Dominguez, L. Martin, P. Mourguiart et al., Abstract, Quaternary Research, vol.36, issue.44, pp.47-56, 2001.
DOI : 10.1006/qres.2000.2187

M. P. Ledru, P. Mourguiart, G. Ceccantini, B. Turcq, and A. Et-sifeddine, Tropical climates in the game of two hemispheres revealed by abrupt climatic change, Geology, vol.30, issue.3, pp.275-278, 2002.
DOI : 10.1130/0091-7613(2002)030<0275:TCITGO>2.0.CO;2

S. Lemoine, P. Adam, P. Albrecht, and J. Et-connan, Novel series of diaromatic 14-methyl steroids occurring in petroleum, Tetrahedron Letters, vol.37, issue.16, pp.2837-2840, 1996.
DOI : 10.1016/0040-4039(96)00400-5

B. W. Leyden, Evidence of the younger dryas in Central America, Quaternary Science Reviews, vol.14, issue.9, pp.833-839, 1995.
DOI : 10.1016/0277-3791(95)00065-8

G. A. Logan and G. Et-eglinton, Biogeochemistry of the Miocene lacustrine deposit, at Clarkia, northern Idaho, U.S.A., Organic Geochemistry, vol.21, issue.8-9, pp.857-870, 1994.
DOI : 10.1016/0146-6380(94)90045-0

F. Lohmann, Aromatisations microbiennes de triterpènes végétaux, Thèse de doctorat, 1988.

M. R. Loureiro and J. N. Et-cardoso, Identificacao de des-a-fernenos no xisto do Vale do Paraiba; novos marcadores biologicos tetracyclicos, Encontro Nacionales de Quimica Analytica" 4. Sociedad Brasilera de Quimica, 1987.

M. R. Loureiro and J. N. Et-cardoso, Aromatic hydrocarbons in the Paraiba Valley oil shale, Organic Geochemistry, vol.15, issue.4, pp.351-359, 1990.
DOI : 10.1016/0146-6380(90)90161-R

G. Lüniger and L. Et-schwark, Characterisation of sedimentary organic matter by bulk and molecular geochemical proxies: an example from Oligocene maar-type Lake Enspel, Germany, Sedimentary Geology, vol.148, issue.1-2, pp.275-288, 2002.
DOI : 10.1016/S0037-0738(01)00222-6

S. B. Mahato and S. Et-sen, Advances in triterpenoid research, 1990???1994, Phytochemistry, vol.44, issue.7, pp.1185-1236, 1997.
DOI : 10.1016/S0031-9422(96)00639-5

S. B. Mahato, S. K. Sarkar, and S. G. Et-poddar, Triterpenoid saponins, Phytochemistry, vol.27, issue.10, pp.3037-3067, 1988.
DOI : 10.1016/0031-9422(88)80001-3

O. Maman, F. Marseille, B. Guillet, J. R. Disnar, and P. Et-morin, Separation of phenolic aldehydes, ketones and acids from lignin degradation by capillary zone electrophoresis, Journal of Chromatography A, vol.755, issue.1, 1996.
DOI : 10.1016/S0021-9673(96)00583-3

M. Pearson and N. G. Et-obaje, Onocerane and other triterpenoids in Late Cretaceous sediments from the Upper Benue Trough, Nigeria: tectonic and palaeoenvironmental implications, Organic Geochemistry, vol.30, issue.7, pp.583-592, 1999.
DOI : 10.1016/S0146-6380(99)00069-8

G. M. Perkins, I. D. Bull, H. L. Ten-haven, J. Rullkötter, Z. E. Smith et al., First positive identification of triterpenes of the taraxastane family in petroleums and oil shales, pp.19-24, 1995.

K. E. Peters and J. M. Et-moldowan, The biomarker guide, 1993.

R. P. Philp, Fossil Fuel Biomarkers. Applications and Spectra, 1985.

J. Poinsot, P. Adam, J. M. Trendel, J. Connan, and P. Et-albrecht, Diagenesis of higher plant triterpenes in evaporitic sediments, Geochimica et Cosmochimica Acta, vol.59, issue.22, pp.4653-4661, 1992.
DOI : 10.1016/0016-7037(95)00307-X

T. Prartono and G. A. Et-wolff, Organic geochemistry of lacustrine sediments: a record of the changing trophic status of Rostherne Mere, U.K., Organic Geochemistry, vol.28, issue.11, pp.729-747, 1998.
DOI : 10.1016/S0146-6380(98)00016-3

A. W. Purdie and H. E. Connor, Triterpene methyl ethers of Cortaderia splendens, Phytochemistry, vol.12, issue.5, 1196.
DOI : 10.1016/0031-9422(73)85055-1

Z. A. Raffi, R. S. Dodd, and F. Et-fromard, Biogeographic variation in foliar waxes of mangrove species, Biochemical Systematics and Ecology, vol.24, issue.4, pp.7-8, 1996.
DOI : 10.1016/0305-1978(96)00029-4

M. Ries-kautt, Etude des lipides dans divers types de sols. Aspects Moléculaires, Thèse de Doctorat, p.152, 1986.

M. G. Rowan and P. D. Et-dean, ??-Onocerin and sterol content of twelve species of Ononis, Phytochemistry, vol.11, issue.11, pp.3263-3265, 1972.
DOI : 10.1016/S0031-9422(00)86384-0

D. D. Rowan and G. B. Et-russell, 3?-methoxy-hop-22(29)-ene from Chionochloa cheesmanii, Phytochemistry, vol.312, pp.702-703, 1992.

M. G. Rowan, P. D. Dean, and T. W. Et-goodwin, The enzymic conversion of squalene(23)-diepoxide to ?-onocerin by a cell-free extract of Ononis spinosa, FEBS Letters, vol.2, issue.12, pp.22-229, 1971.

J. W. Rowe and C. L. Et-bower, Triterpenes of pine barks: naturally occurring derivatives of serratenediol, Tetrahedron Letters, vol.6, issue.32, pp.2745-2750, 1965.
DOI : 10.1016/S0040-4039(01)83904-6

H. D. Ruan, R. L. Frost, J. T. Kloprogge, and L. Et-duong, Infrared spectroscopy of goethite dehydroxylation. II. Effect of aluminium substitution on the behaviour of hydroxyl units, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, vol.58, issue.3, pp.479-491, 2002.
DOI : 10.1016/S1386-1425(01)00556-X

J. Rullkötter, D. Leythaeuser, and D. Et-wendisch, 28-bisnorlupanes in Tertiary sediments-Widespread occurrence of nuclear demethylated triterpanes, Geochimica et Cosmochimica Acta, vol.23, issue.46, pp.2501-2509, 1982.

J. Rullkötter, T. M. Peakman, and H. L. Et-ten-haven, Early diagenesis of terrigenous triterpenoids and its implications for petroleum geochemistry, Organic Geochemistry, vol.21, issue.3-4, pp.215-233, 1994.
DOI : 10.1016/0146-6380(94)90186-4

G. B. Russell, H. E. Connor, and A. W. Et-purdie, Triterpene methyl ethers of Chionochloa (Gramineae), Phytochemistry, vol.15, issue.12, pp.1933-1935, 1976.
DOI : 10.1016/S0031-9422(00)88849-4

M. L. Salgado-labouriau, Late Quaternary palaeoclimate in the savannas of South America, Journal of Quaternary Science, vol.125, pp.371-379, 1997.

M. L. Salgado-labouriau, M. Barberi, K. R. Ferraz-vicentini, and M. G. Et-parizzi, A dry climatic event during the late Quaternary of tropical Brazil, Review of Palaeobotany and Palynology, vol.99, issue.2, pp.115-129, 1998.
DOI : 10.1016/S0034-6667(97)00045-6

U. Samaraweera, S. Subramaniam, M. Ubais, and S. Sult-anbawa, 3',5'- Pentahydroxyflavan and 3 ?-methoxyfriedelan from Humboldtia laurifolia, Phytochemistry, vol.222, pp.565-567, 1983.

P. Schaeffer, J. Trendel, and P. Et-albrecht, An unusual aromatization process of higher plant triterpenes in sediments, Organic Geochemistry, vol.23, issue.3, pp.273-275, 1995.
DOI : 10.1016/0146-6380(95)00026-B

E. Schefuss, G. J. Versteegh, J. H. Jansen, and J. S. Et-sinninghe-damsté, Marine and terrigenous lipids in southeast Atlantic sediments (Leg 175) as paleoenvironmental indicators: initial results, Proc. ODP, Sci. Results, p.175, 2001.
DOI : 10.2973/odp.proc.sr.175.228.2001

J. M. Schmitter, W. Sucrow, and P. J. Et-arpino, Occurrence of novel tetracyclic geochemical markers: 8,14-seco-hopanes in a Nigerian crude oil, Geochimica et Cosmochimica Acta, vol.46, issue.11, pp.2345-2350, 1982.
DOI : 10.1016/0016-7037(82)90206-X

H. Schulten and P. Et-leinweber, Characterization of humic and soil particles by analytical pyrolysis and computer modeling, Journal of Analytical and Applied Pyrolysis, vol.38, issue.1-2, pp.1-53, 1996.
DOI : 10.1016/S0165-2370(96)00954-0

D. Sebag, J. R. Disnar, B. Guillet, D. Giovanni, C. Verrecchia et al., Soil organic matter (SOM) characterization using Rock-Eval Pyrolysis: Preservation rates of main organic fractions by decomposition of the S2 peak

A. L. Sessions, T. W. Burgoyne, A. Schimmelmann, and J. Hayes, Fractionation of hydrogen isotopes in lipid biosynthesis, Organic Geochemistry, vol.30, issue.9, pp.1193-1200, 1999.
DOI : 10.1016/S0146-6380(99)00094-7

K. Shiojima, Y. Arai, K. Masuda, Y. Takase, T. Ageta et al., Mass Spectra of Pentacyclic Triterpenoids., CHEMICAL & PHARMACEUTICAL BULLETIN, vol.40, issue.7, pp.1683-1690, 1992.
DOI : 10.1248/cpb.40.1683

A. Sifeddine, P. Bertrand, E. Lallier-vergès, and A. Et-patience, The relationships between lacustrine organic sedimentatio n and palaeoclimatic variations, Quaternary Science Reviews, vol.15, pp.203-211, 1996.

A. Sifeddine, L. Martin, B. Turcq, C. Volkmer-ribeiro, F. Soubiès et al., Variations of the Amazonian rainforest environment: a sedimentological record covering 30,000 years, Palaeogeography, Palaeoclimatology, Palaeoecology, vol.168, issue.3-4, pp.221-235, 2001.
DOI : 10.1016/S0031-0182(00)00256-X

A. Sifeddine, A. L. Albuquerque, M. P. Ledru, B. Turcq, B. Knoppers et al., cal years paleoclimate change in Caço Lake Northern Brazil: evidence from sedimentary and pollen records, Palaeogeography, vol.21, p.0

B. Simoneit, A. Otto, and V. Et-wilde, Novel phenolic biomarker triterpenoids of fossil laticifers in Eocene brown coal from Geiseltal, Germany, Organic Geochemistry, vol.34, issue.1, 2003.
DOI : 10.1016/S0146-6380(02)00141-9

R. M. Smith and M. Et-martin-smith, Triterpene methyl ethers in leaf waxes of Saccharum and related genera, Phytochemistry, vol.17, issue.8, pp.1307-1312, 1978.
DOI : 10.1016/S0031-9422(00)94579-5

C. Spyckerelle, Constituants aromatiques de sediments, Thèse de doctorat, p.134, 1975.

S. Stout, Aliphatic and aromatic triterpenoid hydrocarbons in a Tertiary angiospermous lignite, Organic Geochemistry, vol.18, issue.1, pp.51-66, 1992.
DOI : 10.1016/0146-6380(92)90143-L

M. G. Strachan, R. Alexander, and R. I. Et-kagi, Trimethylnaphthalenes in crude oils and sediments: Effects of source and maturity, Geochimica et Cosmochimica Acta, vol.52, issue.5, pp.1255-1264, 1988.
DOI : 10.1016/0016-7037(88)90279-7

M. Stuiver and P. J. Et-reimer, Extended 14C Data Base and Revised CALIB 3.0 14C Age Calibration Program, Radiocarbon, vol.27, issue.01, pp.215-230, 1993.
DOI : 10.1007/BF02162161

M. Stuiver, P. J. Reimer, and T. F. Et-braziunas, High-Precision Radiocarbon Age Calibration for Terrestrial and Marine Samples, Radiocarbon, vol.37, issue.03, pp.1127-1151, 1998.
DOI : 10.1177/095968369300300401

M. Stute, M. Forster, H. Frischkorn, A. Serejo, J. F. Clark et al., Cooling of Tropical Brazil (5??C) During the Last Glacial Maximum, Science, vol.269, issue.5222, pp.379-383, 1995.
DOI : 10.1126/science.269.5222.379

M. R. Talbot and D. A. Et-livingstone, Hydrogen index and carbon isotopes of lacustrine organic matter as lake level indicators, Palaeogeography, Palaeoclimatology, Palaeoecology, vol.70, issue.1-3, pp.121-137, 1989.
DOI : 10.1016/0031-0182(89)90084-9

H. L. Ten-haven, T. M. Peakman, and J. Et-rullkötter, ??2-Triterpenes: Early intermediates in the diagenesis of terrigenous triterpenoids, Geochimica et Cosmochimica Acta, vol.56, issue.5, 1991.
DOI : 10.1016/0016-7037(92)90325-D

H. L. Ten-haven, J. Rullkötter, and R. Et-stein, Preliminary Analysis of Extractable Lipids in Sediments from the Eastern North Atlantic (Leg 108): Comparison of a Coastal Upwelling Area (Site 658) with a Nonupwelling Area (Site 659), 1992.
DOI : 10.2973/odp.proc.sr.108.142.1989

H. L. Ten-haven and J. Et-rullköetter, The diagenetic fate of taraxer-14-ene and oleanene isomers, Geochimica et Cosmochimica Acta, vol.52, issue.10, pp.2543-2548, 1988.
DOI : 10.1016/0016-7037(88)90312-2

L. G. Thompson, E. Mosley-thompson, and K. A. Et-henderson, Ice-core palaeoclimate records in tropical South America since the Last Glacial Maximum, Journal of Quaternary Science, vol.26, issue.4, pp.377-394, 2000.
DOI : 10.1002/1099-1417(200005)15:4<377::AID-JQS542>3.0.CO;2-L

L. G. Thompson, M. E. Davis, E. Mosley-thompson, T. A. Sowers, K. A. Henderson et al., A 25,000-Year Tropical Climate History from Bolivian Ice Cores, Science, vol.282, issue.5395, pp.0-1858, 1998.
DOI : 10.1126/science.282.5395.1858