May 13, 2009

18th International Sedimentological Congress


On behalf of the Organising Committee, we are pleased to invite you to the 18thInternational Sedimentological Congress 2010 in Mendoza, Argentina. Firstconvened in Belgium 60 years ago, this next event will be held in the Argentineancity of Mendoza and for the second time in South America, after the 14th ISC inRecife (Brazil) in 1994.

More information please click here

I hope to have the honor of participating in this event!!

May 12, 2009

Fossil-sponge or bryozoan?


In my field work, I found many fossils that I could not know! Here is a beautiful one in limestone from Permian, looks like an earthworm, maybe some bryozoan. Any one who knows this fossil, please leaves me a message, thanks!
The tag is about 1 centimeter.

Here is a great web site about bryozoans. Recent and Fossil Bryozoa.

May 7, 2009

Perspectives in Carbonate Geology: A Tribute to the Career of Robert Nathan Ginsburg


"Perspectives in Carbonate Geology", is a new book for carbonate sedimentology. It will be another great work, it includes 22 chapters, some new models of comparative sedimentology are proposed! Here is the tables of contents, from WILEY!


Perspectives in Carbonate Geology
Professor Peter K Swart (Editor), Gregor Eberli (Editor), Judith A McKenzie (Editor)
ISBN: 978-1-4051-9380-1
Hardcover
384 pages
April 2009, Wiley-Blackwell


1. Depth and species-related patterns of Holocene reef accretion in the Caribbean and western Atlantic: a critical assessment of existing models.
2. The mystique of beachrock.
3. A reevaluation of facies on Great Bahama Bank I: new facies maps of western Great Bahama Bank.
4. A reevaluation of facies on Great Bahama Bank II: variations in the δ13C, δ18O and mineralogy of surface sediments.
5. Stable isotopes of carbon and oxygen in modern sediments of carbonate platforms, barrier reefs, atolls and ramps: patterns and implications.
6. A tale of two storms: an integrated field, remote sensing, and modelling study examining the impact of hurricanes Frances and Jeanne on carbonate systems, Bahamas.
7. Rapid recycling and deposition of organic-rich carbonates within the coastal complex of southwest Florida.
8. The paradoxical occurrence of oolitic limestone on the eastern islands of Great Bahama Bank: where do the ooids come from?.
9. Calcareous epiphyte production in cool-water carbonate depositional environments, southern Australia.
10. Microbes versus metazoans as dominant reef builders: insights from modern marine environments in Exuma Cays, Bahamas.
11. Microbial dolomite precipitation under aerobic conditions: results from Brejo do Espinho Lagoon (Brazil) and culture experiments.
12. Karst subbasins and their relationship to cross-Florida Platform transport of Tertiary siliciclastics.
13. Controls on facies mosaics of carbonate platforms: a case study from the Oxfordian of the Swiss Jura.
14. On the allocyclic interpretation of the ‘Latemar Cycles’ (Middle Triassic, the Dolomites, Italy) and implications for high-frequency cyclostratigraphic forcing.
15. Phylloid algal mounds in the Paradox Basin, southwestern USA: an alternative to the in situ constructional growth model?.
16. The Cincinnati Arch: a stationary peripheral bulge during the Late Ordovician.
17. Reinterpreting a Proterozoic enigma: Conophyton - Jacutophyton stromatolite reefs of the Mesoproterozoic Atar Group, Mauritania.
18. Layering - What does it mean?.
19. Falling-stage systems tracts in tropical carbonate rocks.
20. Early load-induced fracturing in a prograding carbonate margin.
21. Markov models for linking environments and facies in space and time.
22. Evaluating validity and reliability in high-resolution stratigraphic analysis

May 2, 2009

Ooid and oolites


Ooid is one of the coated grains, is usually composed of calcium carbonate. It is commonly from shallow tropical seas, for example GBB. They can be cementde together to form carbonate rocks, named oolite.

Whether the primary mineral is of ooid is aragonite or calcite is determined by the Mg/Ca of the seawater. And there is a long secular variation in seawater, called aragonite sea and calcite sea.

In Lower Triassic of South China there are many Oolitic banks, which now are good oil and gas reservoir.

The picture is from my good friend, Feinan Li, who is interested in oolits.

May 1, 2009

Differential diagenesis



Differential diagenesis is proposed to interpret the alternating cemented and uncemented, fine-grained layers from Pliocene periplatform carbonates of the Great Bahama Bank (Westphal H, Head M J, Munnecke A. 2000).


There are also limestone-marl alternations in Phanerozoic eons, for example, Silurian of Gotland, Sweden(Munnecke A, Samtleben C. 1996). I find a analogous alternation in south China, and I want to find its origin. The difficulty is that the geochemical model. where does dissolusion take place? where does the reprecipitation occur?



More information about the topic:

  1. Munnecke A, Samtleben C. 1996. The formation of micritic limestones and the development of limestone-marl alternations in the Silurian of Gotland, Sweden. Facies, 34(1): 159-176.
  2. Westphal H, Head M J, Munnecke A. 2000. Differential Diagenesis of Rhythmic Limestone Alternations Supported by Palynological Evidence. Journal of Sedimentary Research, 70(3): 715-725.

Journals for Sedimentology


Journal of Sedimentary Petrology/Research
Sedimentology
Sedimentary Geology

沉积学报(in Chinese)
American Association of Petroleum Geologists Bulletin
Palaeogeography, Palaeoclimatology, Palaeoecology
Facies
Marine Geology
Palaios

Journal of Geology
Geological Society of America Bulletin
Geology
Journal of Geology
Acta Geologica Sinica
American Journal of Science
Earth Science Reviews

Apr 22, 2009

Carbonate Bible

Controls on Carbonate Platform and Reef Development
Edited by: Jeff Lukasik and J.A. (Toni) Simo

Carbonate Sedimentology and Sequence Stratigraphy‎
by Wolfgang Schlager

Microfacies of carbonate rocks: analysis, interpretation and application‎
by Erik Flügel

A color guide to the petrography of carbonate rocks: grains, textures
by Dana S. Ulmer-Scholle

Carbonate Sedimentology‎
by Maurice E Tucker, V Paul Wright

Carbonate Diagenesis‎
by Maurice E. Tucker, Robin G. C. Bathurst

Carbonate diagenesis and porosity‎
by Clyde H. Moore, Clyde M. Moore

Carbonate Depositional Environments‎
by Peter A. Scholle, Don G. Bebout, Clyde H. Moore

Carbonate sediments and their diagenesis Developments in sedimentology‎
by Robin G. C. Bathurst

Carbonate Facies in Geological History‎
by James L. Wilson

Carbonate rocks‎
by George V. Chilingar

Pressure dissolution or chemical compaction







Pressure dissolution (Sorby 1908) is the petrologic process wherein minerals dissolve as the result of pressure applied externally to them. Because pressure dissolution leads to a reduction of volume of the rock in which it occurs, it is also called chemical compaction(Lloyed 1977). The product of chemical compaction as fellows:
fitted-fabric

dissolution seam

stylolite


In limestone-marl aternations, differential compaction happend, in limestone no or rare compaction, but it is common in marl. It is due to the stratified cementation, the more cemented strata resisted further compaction.

picture from Permian South China

Apr 18, 2009

My first blog here

Hello, I am glad to be here, for the first, I will introduce myself. I am a graduate student on carbonate sedimentology, and my English is very poor, I come here to learn English and exchange thoughts with others on carbonate sedimentology and diagenesis. Now, I am interested in limestone-marl alternations, to discover whether they origined from sedimentary or diagenetic process!