Steps in lithospheric thickness within eastern Australia, evidence from surface wave tomography

Fishwick, Stewart; Heintz, Maggy; Kennett, B. L. N.; Reading, Anya M.; Yoshizawa, Kazunori

doi:10.1029/2007tc002116

Cited by 116 publications

(94 citation statements)

References 72 publications

(104 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relative variations in the thickness of the lithosphere should be reliable and useful for geodynamic interpretation, but the absolute values depend on exactly where the boundary is drawn in a gradational transition. The contrast between thick lithosphere in the centre and west and thinner lithosphere in the east is very clear, and the nature of the transition is consistent with the analysis of Fishwick et al (2008). The base of the lithosphere is somewhat irregular and this is likely to impose complex stress patterns from the relative motions of the thick continental lithosphere and the free-flowing asthenosphere.…”

Section: Transition To the Asthenospheresupporting

confidence: 64%

AuSREM: Australian Seismological Reference Model

Kennett

Salmon

2012

Australian Journal of Earth Sciences

Self Cite

View full text Add to dashboard Cite

Although Australia has been the subject of a wide range of seismological studies, these have concentrated on specific features of the continent at crustal scales and on the broad scale features in the mantle. The Australian Seismological Reference Model (AuSREM) is designed to bring together the existing information, and provide a synthesis in the form of a 3-D model that can provide the basis for future refinement from more detailed studies. The model is grid based with a 0.5 degree sampling in latitude and longitude and is designed to be fully interpolable, so that properties can be extracted at any point. The crustal component makes use of prior compilations of sediment thicknesses, with cross checks against recent reflection profiling, and provides P and S wavespeed distributions through the crust. The primary information for P wavespeed comes from refraction profiles, for S wavespeed from receiver function studies, and we are able to use the results of ambient noise tomography to link the point observations into national coverage. Density values are derived using results from gravity interpretations. AuSREM is able to build on a new map of depth to Moho, which has been created using all available information including Moho picks from over 10,000 km of full crustal profiling across the continent . In the upper mantle the primary source of information comes from seismic surface wave tomography and a representative model has been developed to capture the features of a range of studies. Body wave studies and regional tomography provide useful constraints on the relation between P and S wavespeeds. The mantle model extends beyond the continent and so covers a larger area than for the crust. Below 350 km and in the surrounding area AuSREM is linked to the S40RTS model (Ritsema et al., 2011). Potential applications of the AuSREM model come through the delineation of major structural features in the crust and mantle, and consequent improvements in, e.g., earthquake location within the continent and at the nearby plate boundaries.

show abstract

Section: Transition To the Asthenospheresupporting

confidence: 64%

AuSREM: Australian Seismological Reference Model

Kennett

Salmon

2012

Australian Journal of Earth Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…7E). This agrees with the trend seen in surface wave tomography (Fishwick et al, 2008). Their results suggest a lithosphere of 150-200 km in the west which is in good agreement with the results of this study, however they only have a ~100 km thick lithosphere in the east which is thinner than the 120 km used in the best fitting model.…”

Section: Eastern Australiasupporting

confidence: 82%

Basin formation by thermal subsidence of accretionary orogens

2015

View full text Add to dashboard Cite

Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Response to referees of Holt et al.We thank the three referees for their extremely helpful comments on the submitted paper, and appreciate the time that must have been needed. We have paid close attention to their suggestions, and feel that the revised paper greatly benefits from the constructive criticism. We take each referee's comments in turn, below, and offer a point-by-point account of how we have addressed them in the revised version. Our responses are preceded by the # symbol and are in italics.1. Five basins were chosen for the analysis. Why were these basins chosen? The main goal of this paper is to show that a lithosphere cooling model is a fundamental process in accretionary orogens. Therefore, the choice of the case studies needs to be carefully justified to show that these are 'typical' basins (i.e., there are no special conditions that could lead to a subsidence pattern similar to that of the cooling model). This is done in places in the manuscript, but it should be more explicit. At the moment, it isn't clear if the five basins are representative of accretionary orogens or if they were chosen because they fit the cooling model. 2. The cooling model is only vaguely described and no quantitative details are provided. Perhaps there should be a separate section with a conceptual description of the cooling model -why is it expected that accretionary crust has a thin initial lithosphere, what maintains the thin lithosphere, and what happens to cause the lithosphere to start to cool? It is stated that this model is different from a mantle delamination model (top of pg 4), but the 'alternate' mechanism for creating thin lithosphere is not clearly described. #Text has been added to explain the cooling model in section 2. There is also a longer description of why accretionary crust starts with thin mantle lithosphere in the Introduction. Both of these items were first described in Holt et al (2010): the only reason they were not originally given more length in this paper is that we thought readers would prefer a terse version of the material!In addition, the actual numerical values used in the cooling model need to be given. Readers are referred to the Holt et al. (2010) paper, but it isn't clear how this method was applied to the current study. For example: Do all regions start with a 20 km thick mantle lithosphere or does this vary (as implied on pg 15, line ~18: "an unusually thin initial lithosphere…is required")? How was crustal thickness var...

show abstract

“…Dyksterhuis and Müller (2008) explained intraplate orogenesis in the FRSZ as resulting from stress concentration due to a dramatic decrease in effective elastic thickness of the lithospherefrom 116 km in the Gawler craton to 49 km in the FRSZ (and 42 km in the Murray basin farther to the east). However, such a model appears difficult to reconcile with regional seismic tomography (Fishwick et al, 2008) and estimates of elastic thickness (Zuber et al, 2007) that suggest thicknesses of 150-200 km and 92 km, respectively, with a thinning of Proterozic to Phanerozoic lithosphere occurring not in the FRSZ itself but 100-300 km to the east. Rather than a sudden decrease in effective elastic thickness, our tomography results for the FRSZ suggest that the seismicity is associated with a crustal suture extending into the lower crust, with earthquakes clustering in or near low v p /v s anomalies beneath the axis of the Flinders Ranges.…”

Section: Discussionmentioning

confidence: 94%