University of California, Riverside

Earth Sciences

Department of Earth Sciences

Peter M. Sadler

Peter M. Sadler


Ph.D., University of Bristol , U.K. , 1973
Research Scientist, Georg August University , Goettingen 1973-76
Crosby Lecturer, MIT, 2005

Specialty: Quantitative Stratigraphy

Phone: (951) 827-5616
Office: Pierce 2331

Research Interests:

Rates and scaling laws of geologic processes; completeness of the stratigraphic record; quantitative biostratigraphy.

Recent Projects:

CONOP software for stratigraphic correlation and seriation; Ordovician and Silurian time scales; graptolite and conodont macroevolution; scaling laws for progradation, aggradation, and volumes of siliciclastic passive margins; rates of accumulation during Snowball earth; loess accumulation rates

Sadler, P.M. and Strauss, D.J., 1990. Estimation of the completeness of stratigraphical sections using empirical data and theoretical models. Journal of the Geological Society of London , 147:471-485.

Sadler, P.M. 1993. The Santa Ana Basin of the Central San Bernardino Mountains : evidence of the timing of uplift and strike slip relative to the San Gabriel Mountains . In, Powell, R.E., Weldon, R.J., and Matti, J.C. (eds.), The San Andreas fault System; displacement, palinspastic reconstruction, and geologic evidence , GSA Memoir 178, p. 307-321.

Sadler, P.M. 1993. Models of time-averaging as a maturation process: How soon do sedimentary sections escape reworking? In Kidwell, S.M. and Behrensmeyer, A.K. (eds.), Taphonomic approaches to time resolution in fossil assemblage s, Paleontological Society Short Courses in Paleontology, 6:188-209.

Sadler, P.M., Osleger, D.A., and Montañez, I.P., 1993. On the labelling, length and objective basis of Fischer plots. Journal of Sedimentary Petrology, 63:360-368.

Sadler, P.M., 1994. The expected duration of upward-shallowing peritidal carbonate cycles and their terminal hiatuses. Geological Society of America Bulletin , 106:791-802.

Kemple, W.G., Sadler, P.M., and Strauss, D.J., 1995. Extending graphic correlation to many dimensions: stratigraphic correlation as constrained optimization. SEPM Special Publication 53:65-82.

Macleod, N., and Sadler, P.M., 1995. Estimating the line of correlation, SEPM Special Publication 53:51-64.

Sadler, P.M. 1999. The influence of hiatuses on sediment accumulation rates. In Bruns, P. and Hass, H.C. (eds.), On the Determination of Sediment Accumulation Rates. GeoResearch Forum, 5:15-40, Trans Tech Publications, Switzerland .

Cooper, R.A., J.S. Crampton, J.I. Raine, F.M. Gradstein, H.E.G. Morgans, P.M. Sadler, C.P. Strong, D. Waghorn and G.J. Wilson. 2001
. Quantitative biostratigraphy of the Taranaki Basin, New Zealand - a deterministic and probabilistic approach. Bulletin of the American Association of Petroleum Geologists , 85(8):1469-1498.

Sadler, P.M. and R.A. Cooper 2003
. Best-fit intervals and consensus sequences: a comparison of the resolving power of traditional biostratigraphy and computer assisted correlation. In P. Harries (ed.) High-Resolution Stratigraphic Approaches in Paleontology. Plenum Press Topics in Geobiology, 21:50-95.

Webster, M., P.M. Sadler, M.A. Kooser, and E. M. Fowler 2003. Combining stratigraphic sections and museum collections to increase biostratigraphic resolution. In P. Harries (ed.), High-Resolution Stratigraphic Approaches in Paleontology. Plenum Press Topics in Geobiology, 21:96-128.

SADLER, P.M., KEMPLE, W. G., and KOOSER, M.A., 2003, CONOP9 programs for solving the stratigraphic correlation and seriation problems as constrained optimization, in Harries P. (ed.), High Resolution Stratigraphic Approaches in Paleontology, Plenum Press, Topics in Geobiology, v. 21, p. 461-465 and CD.

SADLER, P.M., and COOPER, R.A., 2004, Calibration of the Ordovician Time Scale, in Webby, B., Paris, F., Droser, M.L., and. Percival, I. G. (eds.), The Great Ordovician Biodiversification Event, Columbia University Press p. 48-51 .

COOPER, R. A., and SADLER, P. M., 2004, Ordovician, in Cooper, R. A., (ed.) The New Zealand Geologic Timescale, New Zealand Crown Institute of Geological and Nuclear Sciences, Monograph 22, p. 43–53.

COOPER, R.A., and SADLER, P.M., 2004, The Ordovician System, Chapter 12 in Gradstein F., Ogg, J. and Smith, A. (eds.), A Geologic Time Scale, p. 165-187, Cambridge University Press.

MELCHIN, M., COOPER, R.A., and SADLER, P.M., 2004, The Silurian System, Chapter 13 in Gradstein F., Ogg, J., and Smith, A. (eds.), A Geologic Time Scale, p. 188-201, Cambridge University ( eds.), A Geologic Time Scale, p. 188-201, Cambridge University Press.

SADLER, P. M., 2004. Quantitative Biostratigraphy - achieving finer resolution in Global Correlation. Annual Reviews of Earth and Planetary Sciences, v. 32, p. 187-213.

SADLER, P.M. 2006. Composite Time Lines: a means to leverage resolving power from radioisotopic dates and biostratigraphy. The Paleontological Society Papers. v. 12. p. 145-170.

JEROLMACK, D.J., and SADLER, P.M. 2007. Transience and persistence in the depositional record of continental margins. Journal of Geophysical Research. v.112 (F3), 14p.

SADLER, P.M., and COOPER, R.A. 2008. Improved resolution and quantified uncertainty – time scales of the future. Newsletters on Stratigraphy. v. 43: 1 p.49-53.

SADLER, P.M. 2008. Dating – biostratigraphic methods. p. 237-239 in V. Gornitz (ed.). Springer Verlag Encyclopedia of Earth Science Series. Encyclopedia of Paleoclimatology and Ancient Environments.

CODY, R.A., LEVY, R.H., HARWOOD, D.M., and SADLER, P.M. 2008. Thinking outside the zone: high-resolution quantitative diatom biochronology for the Antarctic Neogene. Palaeogeography, Palaeoclimatology, Palaeoecology. v.260, p.92-121.

SADLER, P.M., COOPER, R.A., and MELCHIN, M. 2009. High-resolution early Paleozoic (Ordovician-Silurian) time scales. Geological Society of America Bulletin. v. 121(5/6), p.887-906. SADLER, P., and SABADO, J.A. 2009. Automated Correlation, Seriation, and the Treatment of Biotic Dissimilarity. Museum of Northern Arizona Bulletin. v. 65: p.21-35.

COOPER, R.A., and SADLER, P.M. 2010. Facies preference predicts extinction risk in graptolites. Paleobiology. v.36, p.167-187.

SADLER, P.M. 2010. Brute-force biochronology: sequencing paleobiologic first- and last-appearance events by trial-and-error. The Paleontological Society Papers, v.16, p.271-289.

SADLER, P.M., and CERVATO, C. 2011. Data and Tools for Geologic Timelines and Timescales. p. 145-165, in G.R. Keller and C. Baru (eds.) Geoinformatics: Cyberinfrastructure for the Solid Earth Sciences. Cambridge University Press.

SHEN, S., CROWLEY, J.L., WANG, Y., BOWRING, S.A., ERWIN, D.H., SADLER, P.M., CAO, C., ROTHMAN, D.H., HENDERSON, C.M., RAMEZANI, J., ZHAN, H., SHEN, Y., WANG, X., WANG, W., MU, L., LI, W., TANG, Y., LIU, X., LIU, L., ZENG, Y., JIANG, Y., and JIN, Y. 2011. Calibrating the End-Permian Mass Extinction. Science, v.334, no.6061, p.1367-1372.

SADLER, P.M., COOPER, R.A., and MELCHIN, M.J. 2011. Sequencing the graptoloid clade: Building a global diversity curve from local range-charts, regional composites and global time-lines. Proceedings of the Yorkshire Geological Society, v. 58(4), p.329-343.

SADLER, P.M. and COOPER, R.A. 2011, Graptoloid evolutionary rates; sharp contrast between Ordovician and Silurian, Cuadernos del Museo Geominero, v. 14, p.499-503.

COOPER, R.A., and SADLER, P.M., 2012, The Ordovician Period. Chapter 20, p. 500-534 in Gradstein, F., Ogg, J, G., Schmitz, M., and Ogg, G., (eds.) Geologic Time Scale 2012, volume 2, Elsevier.

MELCHIN, M.J., SADLER, P.M., and CRAMER, B.D. 2012, The Silurian Period. Chapter 21, p 536-569. in Gradstein, F., Ogg, J, G., Schmitz, M., and Ogg, G., (eds) Geologic Time Scale 2012, volume 2, Elsevier.

SADLER, P.M., 2012, Integrating carbon isotope excursions into automated stratigraphic correlation: an example from the Silurian of Baltica. Bulletin of Geosciences, v. 87(3), p. 681-694.

SADLER, P.M. 2013. Stratigraphic Completeness. Grzimek’s Animal Life Encyclopedia, Extinction v. 2, p. 51-62, Gale (Cengage), Farmington Mills, MI.

COOPER, R.A., SADLER, P.M., MUNNECKE, A., and CRAMPTON, J.S. 2013. Graptoloid evolutionary rates track Ordovician-Silurian climate change. Geological Magazine. V. 151(2), p.349-364.

MILLER, D.M., SADLER, P.M., SCHMIDT, K., and REYNOLDS, R.E. 2013. Raising questions in the central Mojave Desert: the field trip. Sunbelt Publications Inc. p. 5-30. 2013 Desert Symposium. Zyzxx, California. 04/20/2013. California State University Desert Studies Consortium.

WANG, Y., SADLER, P. M., SHEN, S., ERWIN, D.H., ZHANG, Y., WANG, X., WANG, W., CROWLEY, J., and HENDERSON, C.M. 2014. Quantifying the process and abruptness of the end-Permian mass extinction. Paleobiology. v. 41(1), p.113-129.

KEMP, D.B., and SADLER, P.M. 2014. Climatic and eustatic signals in a global compilation of shallow-marine carbonate accumulation rates. Sedimentology, v. 61(5), p. 1286-1297.

BOYLE, J.T., SHEETS, D.H., WU, S., GOLDMAN, D., MELCHIN, M., COOPER, R.A., SADLER, P., and MITCHELL, C.E. 2014. A re-examination of the contributions of biofacies and geographic range to extinction risk in graptolites. GFF, v. 136(1), p. 38-41.

SADLER, P.M., COOPER, R.A., and CRAMPTON, J.S., 2014. High-resolution geobiologic time-lines: progress and potential, fifty years after the advent of graphic correlation. The Sedimentary Record, v. 12(3), p. 4-9.

SADLER, P.M., and JEROLMACK, D.J. 2015. Scaling Laws for Aggradation, Denudation and Progradation Rates: The Case for Time-scale Invariance at Sediment Sources and Sinks. in Smith, D., Bailey, R.J., Burgess, P.M., and Fraser, A.J. (eds.), Strata and Time, The Geological Society (of London). Special Publications, v. 404, 21 p.

DAY, M.O., RAMEZANI, J., BOWRING, S.A., SADLER, P., ERWIN, D.H., ABDALA, F., and RUBIDGE, B.S. 2015. When and how did the terrestrial mid-Permian mass extinction occur? Evidence from the tetrapod record of the Karoo Basin, South Africa. Proceedings of the Royal Society B., v. 282: 8 pp.

BOYLE, J.T., SHEETS, D.H., WU, S., GOLDMAN, D., MELCHIN, M.J., COOPER, R.A., SADLER, P.M., and MITCHELL, C.E. 2016. The impact of geographic range, sampling, ecology, and time on extinction risk in the volatile clade Graptoloida. Paleobiology, v. 43(1), p.85-113.

CRAMPTON, J.S., COOPER, R.A., SADLER, P.M., and FOOTE, M. 2016. Greenhouse-icehouse transition in the Late Ordovician marks a step change in extinction regime in the marine plankton. Proceedings of the National Academy of Science, v. 113, p.1498-1503.

PARTIN, C.A., and SADLER, P.M. 2016. Slow net sediment accumulation sets snowball Earth apart from all younger glacial episodes. Geology. v. 44(12), p.1019-1022.

GLAZNER, A.F., and SADLER, P.M., 2017, Estimating the duration of geologic intervals from a small number of age determinations: A challenge common to petrology and paleobiology. Geochemistry, Geophysics, Geosystems, v. 17(12), p. 4892-4898.

DANESHIAN, J., RAMEZANI DANA, L., and SADLER, P., 2017. A composite foraminiferal biostratigraphic sequence for the Lower Miocene deposits in the type area of the Qom Formation, central Iran, developed by constrained optimization (CONOP). Journal of African Earth Sciences, v. 125, p. 214-229.

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