Geology Reference
In-Depth Information
9.4 Practical Advice: How to Describe
Microbialites and Stromatolites, Bio-
genic Encrustations and Borings?
sponges). In contrast, low-energy carbonates of the
deep-water turbid facies dominated by bivalves exhibit
a low boring intensity of 0.03-0.06. A moderate to high
abundance of macroborers is found in Late Cretaceous
coral reefs (Coniacian, Bavaria: 0.18 - bivalves and
sponges dominate over worms; Turonian, France: 0.44
- worms dominating over bivalves). Factors influenc-
ing these patterns are apparently the existence of clear
or siliciclastic-influenced water and lagoonal or shal-
low/deep fore-reef settings. Microfacies analyses of
reef limestones but also of platform carbonates should
provide more quantitative data that can be used as mea-
sures of the changes in macroboring and bioerosional
intensity during earth history.
Box 9.5 summarizes the questions which should be kept
in mind when studying the biological aspects of the
formation and destruction of carbonate sediments.
Basics: Limestones are biological sediments
Microbial carbonates and stromatolites
Aitken, J.D. (1977): Classification and environmental sig-
nificance of cryptalgal limestones and dolomites. With il-
lustrations from the Cambrian and Ordovician of south-
western Alberta. - J. Sed. Petrol.,
14
, 405-441
Atlas, R.M., Bartha, T. (1981): Microbial ecology: Fundamen-
tals and application. - 569 pp., Reading (Adisson-Wessley)
Burne, R.V., Moore, I.S. (1987): Microbialites: organo-
sedimentary deposits of benthic microbial communities.
- Palaios,
2
, 241-254
Castanier, S., Le Metayer-Kevrel, G., Perthuisot, J.-P. (1999):
Ca-carbonates precipitation and limestone genesis - the
microbiologists point of view. - Sedimentary Geology,
126
, 9-23
Chavetz, H.S. and Buczynski, C. (1992): Bacterially induced
lithification of microbial mats. - Palaios,
7
, 277-293
Characklis, W.G., Marshall, K.C. (eds., 1990): Biofilms. -
796 pp., New York (Wiley)
Cohen, Y., Castenholz, R.W., Halvorson, H.D. (eds., 1984):
Microbial mats: stromatolites. - MBL Lectures in Biol-
ogy,
3
, 498 pp., New York (Alan R. Cis)
Gerdes, G., Krumbein, W.E. (1987): Biolaminated deposits.
- Lecture Notes in Earth Sciences,
9
, 1-183
Grey, K. (1989): Handbook for the study of stromatolites and
associated structures. - Stromatolite Newsletter,
14
, 82-171
Grotzinger, J.P., Knoll, A.H. (1999): Stromatolites in Precam-
brian carbonates: Evolutionary mileposts or environmen-
tal dipsticks. - Annual Review of Earth and Planetary Sci-
ences,
27
, 313-358
Kalkowsky, E. (1908): Oolith und Stromatolith im nord-
deutschen Buntsandstein. - Zeitschrift der deutschen
geologischen Gesellschaft,
60
, 68-121
Kennard, M.M., James, N.P. (1986): Thrombolites and stro-
matolites: two distinct types of microbial structures. -
Palaios,
1
, 492-503
Logan, B.W., Rezak, R., Ginsburg, R.N. (1964): Classifica-
tion and environmental significance of algal stromatolites.
- Journal of Geology,
72
, 68-83
Monty, C. (ed., 1981): Phanerozoic stromatolites. Case his-
tories. - 249 pp., Berlin (Springer)
Paul, J., Peryt, T.M. (2000): Kalkowsky's stromatolites re-
visited (Lower Triassic Buntsandstein, Harz Mountains,
Germany). - Palaeogeography, Palaeoclimatology, Palaeo-
ecology,
161
, 435-458
Pratt, B.R. (1982): Stromatolitic framework of carbonate mud-
mounds. - J. Sed.Petrol.,
52
, 1203-1227
Reid, R.P., Visscher, P.T., Decho, A.W., Stolz, J.F., Bebout,
B.M., Dupraz, C., Macintyre, O.G., Paerl, H.W., Pinkney,
J.L., Prufert-Bebout, J.L., Steppe, T.F., DesMarals, D.J.
(2000): The role of microbes in accretion, lamination and
early lithification of modern marine stromatolites. - Na-
9.3.4 Microborer Associations are Proxies
for Paleo-Water Depths
The bathymetric distribution of modern endolithic
microborers depends predominantly on the intensity and
spectral composition of light. The association of micro-
borers is different in the eu-, dys- and aphotic zones.
Microborers exhibit strong water depth controls; the
association patterns therefore represent one of the best
paleobathymetric criterium (Vogel et al. 1999). This ap-
proach is based on the
•
SEM study of the composition and distribution of
modern shallow- to deep-marine microborers,
•
investigation of trace fossils of microborers from an-
cient environments that can be assigned to specific
paleo-water depths according to paleontological and
facies criteria,
•
morphological comparison of ancient and modern
microborings, which surprisingly exhibit a high de-
gree of correspondence, and
•
establishment of characteristic ichnocoenoses de-
fined by the relative dominance of variously light-
adapted groups (cyanobacteria, green algae, red al-
gae, fungi) and the occurrence of the most common
endoliths.
These studies resulted in bathymetric subdivisions
of ancient subtidal, slope and deeper basinal sequences.
The subdivisions correspond to bathymetric zones rec-
ognized in modern environments (see summary in
Glaub 1994) and identified in the Silurian (Glaub and
Bundschuh 1997), Devonian (Vogel et al. 1987), Per-
mian (Balog 1996) and Triassic (Schmidt 1990, 1992,
1993; Glaub and Schmidt 1994; Balog 1996), Jurassic
and Cretaceous (Glaub 1994; Hofmann 1996), and Ter-
tiary (Radtke 1991) The distribution patterns have a
high potential for estimating the water depths of an-
cient reefs (Fig. 9.16).
