Saturday, June 30, 2012

Reviewer comments

The editors greatly appreciate the time that our reviewers and Associate Editors spend on helping authors craft better manuscripts.  These folks make our jobs much easier, and we are grateful for their time and efforts.

Occasionally, we see some comments that are...well...rather frank, and help break up what can become rather tedious editorial task.  Two recent comments fall in this category:

“It can also be seen how the tooth fairy might deliver coins in return for teeth, but I'd like to see a more evidence-based explanation….”

“This one ain’t ever gonna be a barn-burner….”

And who says scientists are boring?

Monday, June 18, 2012


Validation of paleoclimate models and reconstructions requires detailed sedimentologic and stratigraphic analyses.  Poland and Sims characterize sediments, sedimentary structures, surface hierarchy, and stratigraphic patterns of the Rush Spring Sandstone, a Permian unit in the southern midcontinent (USA).  The analyses of styles of sedimentation highlight spatial and temporal changes in distribution of erg, erg-margin, and extradune deposits.  Collectively, these data are interpreted to suggest a monsoonal wind regime, consistent with atmospheric circulation models for the Guadalupian.

Saturday, June 9, 2012


The stratigraphy of fluvial systems in rift basins records the complex interactions of numerous internal and external forcing mechanisms.  To better understand the controls on alluvial architecture in rift basins, Connell et al. examine the relation between surface processes and stratigraphic variability using an experimental basin, varying subsidence and sediment flux and observing stratigraphic packaging and variability.  The results reveal the changes in sediment distribution in a setting with well-constrained external boundary conditions.  The data provide novel insights into how multiple sediment sources impact the stratigraphic position, size, and composition of axial-river deposits of rift basins.

Stratigraphic Architecture of An Experimental Basin With Interacting Drainages by Sean D. Connell, Wonsuck Kim, Gary A. Smith, and Chris Paola


Although it is widely recognized that intracontinental rift basins include basin axis systems and transverse systems, the means by which these deposits of are partitioned in space and time is poorly understood.   Connell et al. describe fluvial morphology and sedimentation in an experimental basin designed to explore processes in asymmetrical rift basins.  In the experimental setting that allowed for constant sediment supply, subsidence, and base level, results illustrate how the locations of axial and tributary systems were controlled by autogenic influences of changes in relative discharge, evolving topographic gradients and boundaries, and resultant sediment redistribution.  The dynamic, internal interactions of axial and transverse systems likely play an important role on geomorphic attributes of comparable real-world basins.  


The history of Earth surface systems includes stages of erosion, deposition, and stability (including pedogenesis).  To understand controls on landscape evolution, Zembo et al. examine the stratigraphy, sedimentology, and paleopedology of a tectonically active basin in the Southern Apennines.  They compare the stratigraphic record of the basin with well -constrained tectonic, geomorphological, and chronological data.  The results illustrate that regional climatic and local tectonic events of the last ~100 ka are well preserved in the paleosols and stratigraphy of the area. 

Thursday, June 7, 2012


The dynamics of ice sheets are markedly influenced by rapid flows of ice streams at their margins.  Cowan et al. use sediment micromorphology, stratigraphy, and geomorphology to unravel the history of Late Pleistocene glacial processes in the marine-based West Antarctic Ice Sheet.  The integrated results reveal the importance of “till pellets” that form in situ, within a deforming bed under an ice stream characterized by repeated cycles of bed freeze-thaw.  This understanding of the formation, deposition, and preservation of these sedimentary particles provides new insights into dynamics between the deformable bed and the ice stream and the stratigraphic record of ice-sheet dynamics.

Sedimentological Signature of A Deformable Bed Preserved Beneath An Ice Stream In A Late Pleistocene Glacial Sequence, Ross Sea, Antarctica by Ellen A. Cowan, Poul Christoffersen, and Ross D. Powell

A Look Back…75 years:

Seventy five years ago, systematic studies of sedimentary rocks were still in their infancy.  John Cedric Griffiths (1947) made the observation that “little advance in the application of sedimentary petrography to the oil industry has been made to date.”  Griffiths reviewed possible applications, including “thin slice analysis,” and “classification of sediments,” and that these could be used to understand “genesis, diagenesis, sedimentation, and palaeogeography.”  His review concluded with the optimistic suggestion that “investigations within this field [sedimentary petrography] could offer great assistance in exploration for new oil pools.”  (April 1947)

Sedimentary petrography and the oil industry by John Cedric Griffiths

A Look Back…50 years:

The origin of silica that forms the cement ubiquitous in many successions was a topic of debate fifty years ago.  Towe (1962) reviewed several studies and suggested that clay minerals present in shale might be transformed, releasing “a possible source of silica which may be of importance in some sedimentary rocks.”  (March 1962)

Clay mineral diagenesis as a possible source of silica cement in sedimentary rocks by Kenneth M. Towe

A Look Back…25 years

Sedimentary geologists have long recognized the importance of biota in generating of modifying sediments.  Nelson et al. (1987) used side-scan sonar to describe and evaluate the character of surface modification on the Bering Shelf.  The study illustrated that excavations made by whales and walrus were widespread across the shelf, and could be modified, enhanced, or enlarged by currents and waves.  The results suggested that “volumetrically the mammal feeding disturbance may be the most significant sedimentary process” in their study area. (May 1987)

Gray whale and walrus feeding excavation on the Bering Shelf, Alaska by C. Hans Nelson, Kirk R. Johnson, and John H. Barber


High-energy rocky coasts are shaped by low-frequency, high-magnitude events.  McKenna et al. describe a previously unrecognized deposit, storm swash terraces, formed by landward transport of sediment from cliffs, beach, and marine sources to the area with final dissipation of wave energy; between storms, these areas are stabilized by vegetation.  Coasts with these types of deposits may provide a unique historical record of high-energy storms.

Storm Swash Terraces: A Previously Overlooked Element of the Cliff-Shore Platform System by John McKenna, J. Andrew G. Cooper, and Derek W. T. Jackson


Inclined heterolithic stratification (IHS) is a common sedimentary structure.  Sisulak and Dashtgard point out that this sedimentary structure recently has been recognized in a variety of sedimentary environments, and document the sedimentological and ichnological character IHS in a tide-influenced, fluvially dominated portion of the Fraser River.  The results indicate that the sedimentologic style and bioturbation patterns of IHS are closely related to seasonal cycles of freshwater discharge.  These insights provide an actualistic example of IHS, and an enhanced conceptual model for its deposition and internal heterogeneity.

Seasonal Controls On the Development And Character of Inclined Heterolithic Stratification In A Tide-Influenced, Fluvially Dominated Channel: Fraser River, Canada by Chad F. Sisulak and Shahin E. Dashtgard


Although stratigraphy is inherently three-dimensional, the vast majority of stratigraphic data is collected normal to bedding; as such, lateral facies dimensions and transitions commonly are poorly contrained. Purkis et al. use Markov chain analysis to describe the quantitative relations between facies transition patterns in vertical and lateral directions.  They reveal that these transition probabilities are statistically similar, and utilize these data to create three-dimensional models of facies heterogeneity.  The results illustrate the how quantitative facies transition metrics can be used to build enhanced reservoir models.

Vertical-To-Lateral Transitions Among Cretaceous Carbonate Facies—A Means To 3-D Framework Construction Via Markov Analysis by Sam Purkis, Brigitte Vlaswinkel, and Nuno Gracias


Meter-scale lithologic cycles are a common motif in shallow-water carbonate and mixed carbonate siliciclastic systems.  Myrow et al. study stratigraphic patterns of contemporaneous Upper Cambrian carbonate and mixed carbonate-silcicilastic systems of the Laurentian paleocontinent.  They reveal that although both types of systems include cyclic strata, each records fundamentally distinct dynamics and processes.

Mixed Siliciclastic–Carbonate Upward-Deepening Cycles of the Upper Cambrian Inner Detrital Belt of Laurentia by Paul M. Myrow, John F. Taylor, Anthony C. Runkel and Robert L. Ripperdan

Tuesday, June 5, 2012


Cave pearls forming in a splash pool in an underground limestone mine. Experimental cave pearls placed in this pool for 8–22 months show rapid growth and recrystallization (see Melim and Spilde 2011). Photo by Kenneth Ingham.