A Matter of Preservation

  title={A Matter of Preservation},
  author={Chris J. Hawkesworth and Peter A. Cawood and Tony I.S. Kemp and Craig D. Storey and Bruno Dhuime},
  pages={49 - 50}
Differences in the preservation potential of crustal rocks may explain peaks in crustal ages previously attributed to enhanced crust formation. 
Section 7. Episodic Growth of the Continental Crust
In the previous section I proposed that Archean granitoids, like those of the present day, formed mainly in subduction settings. Two questions can now be posed. First, was the tectonic process thatExpand
From orogenies to oxygen
Tectonic controls on atmospheric oxygenation are frequently invoked — but whether geochemical records support these ties is an unsettled question.
Applying Popperian falsifiability to geodynamic hypotheses: empirical testing of the episodic crustal/zircon production hypothesis and selective preservation hypothesis
Even though Earth scientists widely recognize the episodic distribution of zircon ages, the cause of the episodes remains unresolved. Two competing explanations have emerged. Some interpret zircon ...
The Evolution of Modern Continents
In Chapter 2, we looked at the formation of continental crust in the Hadean and Archaean eras. This most likely involved the ascent of hot mantle plumes. In the earliest Hadean era, these made thickExpand
Understanding the roles of crustal growth and preservation in the detrital zircon record
Abstract Crustal evolution studies using detrital minerals must consider the potential for bias introduced at the time of formation of the continental crust, through its preservation in subsequentExpand
Zircon age episodicity and growth of continental crust
Granites form when silica-rich magma intrudes into the crust and slowly crystallizes. Such intrusions are discontinuous in space and episodic in time, resulting in a mosaic of ages for granites fromExpand
Crustal thickening and clay: Controls on O isotope variation in global magmatism and siliciclastic sedimentary rocks
New compilations of global O isotope data from zircon and siliciclastic sedimentary rocks highlight an increasing range in δ18O values in both systems since the late Archean. This is consistent withExpand
Growth of continental crust: a balance between preservation and recycling
Abstract One of the major obstacles to our understanding of the growth of continental crust is that of estimating the balance between extraction rate of continental crust from the mantle and itsExpand
Detrital zircon record and tectonic setting
ABSTRACTDetrital zircon spectra refl ect the tectonic setting of the basin in which they are deposited. Convergent plate margins are charac-terized by a large proportion of zircon ages close to theExpand
The chemistry of fine-grained terrigenous sediments reveals a chemically evolved Paleoarchean emerged crust
Abstract The nature of the rocks exposed to weathering and erosion on continents exerts an important control on weathering feedbacks and the supply of nutrients to the oceans. It also reflects theExpand


Episodic growth of the Gondwana supercontinent from hafnium and oxygen isotopes in zircon
The first study that integrates hafnium and oxygen isotopes, all measured in situ on the same, precisely dated detrital zircon grains reveals that crust generation in part of Gondwana was limited to major pulses at 1.9 and 3.3 Gyr ago, and that the zircons crystallized during repeated reworking of crust formed at these times. Expand
Earth as an evolving planetary system
1. Earth Systems 2. The Crust 3. Tectonic Settings 4. The Mantle 5. The Core 6. The Atmosphere and Oceans 7. Living Systems 8. Crustal and Mantle Evolution 9. The Supercontinent Cycle and MantleExpand
Abstract Episodic growth of continental crust and supercontinents at 2.7, 1.9, and 1.2 Ga may be caused by superevents in the mantle as descending slabs pile up at the 660-km seismic discontinuityExpand
Nature of extensional accretionary orogens
Extensional accretionary orogens form by creation and destruction of large arc/back arc basin systems, generated by extension and sediment infilling during prolonged slab retreat, but episodicallyExpand
Formation of supercontinents linked to increases in atmospheric oxygen
Atmospheric oxygen concentrations in the Earth’s atmosphere rose from negligible levels in the Archaean Era to about 21% in the present day. This increase is thought to have occurred in six steps,Expand
Intrinsic versus extrinsic biases in the fossil record: contrasting the fossil record of echinoids in the Triassic and early Jurassic using sampling data, phylogenetic analysis, and molecular clocks
Abstract Four independent lines of evidence, (1) the quality of specimen preservation, (2) taxonomic collection curves, (3) molecular divergence estimates, and (4) ghost lineage analysis of aExpand