University of St Andrews
tel: +44 01334 462381
fax: +44 01334 463949
room: 410

Dr Tony Prave

Reader in Earth Sciences and Director of Research


Research Overview

My interest is reconstructing Earth history, specifically those times in Earth's past when the convergence of geological events drove major changes in ocean and atmosphere chemistry, climate and life. Unravelling that history is inextricably linked to geology and my reading of the rock record is dictated largely by a diligence to field geology. My aim is to obtain original observations and data that underpin and inform on the physical and chemical conditions at the time of deposition, as well as to unravel subsequent deformation and disruption of the rock record by processes of orogenesis.

My method is to develop geological and stratigraphic frameworks, supplemented with geochemical and stable isotope data, to interpret palaeoenvironments and define relative chronologies. Where possible I refine temporal calibrations with radioisotope geochronology to constrain timing, rates and durations of processes and events. My observational and analytical data begin at the outcrop and culminate at the level of inter-cratonal comparisons, and span scales from the textures seen in thin sections to the tectonic evolution of sedimentary basins.

My maxim is that if the geology is suspect then any interpretation or model of past natural processes, no matter how elegant or creative, is also suspect. In essence, my research is field based, curiosity driven, and has the goal of deliver underpinning geological constraints for creating and testing ideas about the co-evolution of Earth and life during key junctures in Earth history.

The Neoproterozoic and Palaeoproterozoic Time Slices

I am especially keen on two periods in Earth's past: the Neoproterozoic, with its exceptional climatic fluctuations and advent of animals, and the Palaeoproterozoic, when Earth's surface environments became oxygenated. For the former, I have studied key archives in western North America, Namibia and the Highlands of Scotland-Ireland, with sojourns into many other locations worldwide. For the latter it has been the metasedimentary rocks of the Fennoscandian Shield and Scotland's own wee record, the Loch Maree Group.

Rocks of these two time slices have enjoyed intense scrutiny by the international Earth science community. However, the interconnectedness and causal mechanisms of the biological and environmental changes that drove Earth System change during those two hallmark periods remain much debated and offer rich areas of study.

The Neoproterozoic was a time of unparalleled geological change: the extreme climatic states of Snowball Earth with global sea ice cover for millions of years followed by ultra-greenhouses; the reappearance of banded-iron formation (BIF) after a billion year hiatus; a rise in oxygen that resulted, perhaps for the first time ever, in the deep oceans becoming oxic; and the evolution of life from eukaryotes to animals.

Understanding the genesis of these and related events is one of my research foci. My efforts are centred on obtaining the critical geological data to address such key issues as determining the extent to which geochemical data record regional or worldwide and coeval or diachronous events, the timing, number and durations of global glaciations, the genesis of cap carbonates, the linkages, if any, between the repetitive climatic extremes and animal evolution, and what were the first animals.

Palaeoproterozoic Earth history archives arguably the single-most profound aspect of Earth System evolution other than the origin of life itself, the rise of free oxygen some 2.4 to 2.0 Gyr ago. This singularity, known as the Great Oxidation Event (GOE), makes Earth unique as a planet. As the late, great Preston Cloud showed more than a half a century ago, deeper in Earth's past free oxygen was essentially absent. The transition to an O-rich Earth is one of a series of intriguing geological events that mark Palaeoproterozoic time, such as the Lomagundi-Jatuli positive carbonate C isotopic excursion, the global Huronian glaciations, deposition of the first non-marine red beds, and termination of mass-independent fractionation of S isotopes.

My and my colleague's collective goal is to develop a self-consistent model of the GOE and related phenomena that led to the establishment of the aerobic Earth System. To begin to achieve this, we undertook the International Continental Drilling Program's Fennoscandia Arctic Russia – Drilling Early Earth Project (FAR-DEEP), an international, multidisciplinary effort utilising fresh drill core supplemented by outcrop exposures of Palaeoproterozoic rocks on the Kola Peninsula of NW Russia and adjacent Norway. My research is to help develop basin-scale depositional frameworks and put into context the wealth of geochemical, geobiological and isotopic data we are obtaining. Our 3-volume Treatise, Reading the Archive of Earth's Oxygenation, was published late in 2012 but that work has only scratched the surface---the how, why and when of the hallmark events of Palaeoproterozoic time remain variably unanswered and much remains to be done.


Recent Publications

Ohnemueller, F , Prave, AR , Fallick, AE & Kasemann, SA 2014, ' Ocean acidification in the aftermath of the Marinoan glaciation ' Geology , vol 42, no. 12, pp. 1103-1106.
Spencer, CJ, Roberts, NMW , Cawood, PA , Hawkesworth, CJ , Prave, AR , Antonini, ASM & Horstwood, MSA 2014, ' Intermontane basins and bimodal volcanism at the onset of the Sveconorwegian Orogeny, southern Norway ' Precambrian Research , vol 252, pp. 107-118.
Spencer, CJ , Prave, AR , Cawood, PA & Roberts, NMW 2014, ' Detrital zircon geochronology of the Grenville/Llano foreland and basal Sauk Sequence in west Texas, USA ' Geological Society of America Bulletin , vol 126, no. 7-8, pp. 1117-1128.
Spencer, CJ , Cawood, PA , Hawkesworth, CJ , Raub, TD , Prave, AR & Roberts, NMW 2014, ' Proterozoic onset of crustal reworking and collisional tectonics: Reappraisal of the zircon oxygen isotope record ' Geology , vol 42, no. 5, pp. 451-454.
Crne, AE, Melezhik, VA, Lepland, A , Fallick, AE , Prave, AR & Brasier, AT 2014, ' Petrography and geochemistry of carbonate rocks of the Paleoproterozoic Zaonega Formation, Russia: documentation of C-13-depleted non-primary calcite ' Precambrian Research , vol 240, pp. 79-93.
Oliver, G & Prave, A 2013, ' Palaeogeography of Late Triassic red-beds in Singapore and the Indosinian Orogeny ' Journal of Asian Earth Sciences , vol 76, pp. 214-224.
Martin, AP, Condon, DJ , Prave, T , Melezhik, VA, Lepland, A & Fallick, AE 2013, ' Dating the termination of the Palaeoproterozoic Lomagundi-Jatuli carbon isotopic event in the North Transfennoscandian Greenstone Belt ' Precambrian Research , vol 224, pp. 160-168.
Lepland, A, Joosu, L, Kirsimäe, K , Prave, T , Romashkin, A, Črne, AE, Martin, AP , Fallick, AE , Somelar, P, Üpraus, K, Mänd, K, Roberts , NMW, van Zuilen , MA, Wirth, R & Schreiber, A 2013, ' Potential influence of sulphur bacteria on Palaeoproterozoic phosphogenesis ' Nature Geoscience .
Brasier, AT, Martin, AP, Melezhik, VA , Prave, T , Condon, DJ & Fallick, AE 2013, ' Earth’s earliest global glaciation?: Carbonate geochemistry and geochronology of the Polisarka Sedimentary Formation, Kola Peninsula, Russia ' Precambrian Research , vol 235, pp. 278-294.
Macdonald, FA , Prave, T , Petterson, R, Smith, E, Pruss, SB, Oates, K, Waechter, F, Trotzuk, D & Fallick, AE 2013, ' The Laurentian record of Neoproterozoic glaciation, tectonism, and eukaryotic evolution in Death Valley, California ' Geological Society of America Bulletin , vol 125, no. 7-8, pp. 1203-1223.
Bonsor, HC, Strachan, RA , Prave, AR & Krabbendam, M 2012, ' Sedimentology of the early Neoproterozoic Morar Group in northern Scotland: implications for basin models and tectonic setting ' Journal of the Geological Society , vol 169, no. 1, pp. 53-65.
Brain, CKB , Prave, AR , Hoffmann, K-H , Fallick, AE , Botha, A, Herd, DA, Sturrock, C, Young, I, Condon, DJ & Allison, SG 2012, ' The first animals: ca. 760-million-year-old sponge-like fossils from Namibia ' South African Journal of Science , vol 108, no. 1/2, 658.
Melezhik, VA (ed.) , Prave, T (ed.) , Hanski, EJ (ed.), Fallick, AE (ed.), Lepland, A (ed.), Kump, LR (ed.) & Strauss, H 2012, Reading the Archive of Earth's Oxygenation: (3 volumes) . Frontiers in Earth Science, Springer.
Brasier, AT , Fallick, AE , Prave, AR , Melezhik, VA, Lepland, A & FAR-DEEP Scientists 2011, ' Coastal sabkha dolomites and calcitised sulphates preserving the Lomagundi-Jatuli carbon isotope signal ' Precambrian Research , vol 189, no. 1-2, pp. 193-211.
Osinski, GR, Preston, L, Ferriere, L , Prave, T , Parnell, J, Singleton, A & Pickersgill, AE 2011, ' THE STAC FADA "IMPACT EJECTA" LAYER: NOT WHAT IT SEEMS ' Meteoritics & planetary science , vol 46, pp. A181-A181.
Petterson, R , Prave, T , Wernicke, BP & Fallick, AE 2011, ' The Neoproterozoic Noonday Formation, Death Valley region, California ' Geological Society of America Bulletin , vol 123, no. 7-8, pp. 1317-1336.
Bonsor, HC, Strachan, RA , Prave, AR & Krabbendam, M 2010, ' Fluvial braidplain to shallow marine transition in the early Neoproterozoic Morar Group, Fannich Mountains, northern Scotland ' Precambrian Research , vol 183, no. 4, pp. 791-804.
Kasemann, SA , Prave, T , Fallick, AE , Hawkesworth, C & Hoffmann, K-H 2010, ' Neoproterozoic ice ages, boron isotopes, and ocean acidification: Implications for a snowball Earth ' Geology , vol 38, no. 9, pp. 775-778.
Batchelor, RA & Prave, T 2010, ' Crystal tuff in the Stoer Group, Torridonian Supergroup, NW Scotland ' Scottish Journal of Geology , vol 46, pp. 16.
Prave, T , Fallick, AE , Thomas, CW & Graham, CM 2009, ' A composite C-isotope profile for the Neoproterozoic Dalradian Supergroup of Scotland and Ireland ' Journal of the Geological Society , vol 166, pp. 845-857.