Geology Reference
In-Depth Information
Deloffre, R. (1988): Nouvelle taxonomie des algues dasy-
cladales. - Bull. Centres Rech. Explor.-Prod. Elf-
Aquitaine, 12 , 165-217
Deloffre, R. (1993): Inventaire critique des algues dasy-
cladales fossiles. 2. partie - Les algues dasycladales du
Jurassique et du Crétacé. -Revue de Paléobiologie, 12 ,
19-65
Deloffre, R., Genot, P. (1982): Les algues dasycladales du
Cénozoique. - Mem. Centres Rech. Explor. Prod. Elf-
Aquitaine, 4 , 247 pp.
Deloffre, R., Granier, B. (1992): Inventaire critique des algues
dasycladales fossiles. - Revue de Paléobiologie, 11 , 331-
356
Elliott, G.F. (1968): Permian to Paleocene calcareous algae
(Dasycladaceae) of the Middle East. - British Mus. Nat.
Hist. Bull., Geol. Suppl., 4 , 111 pp.
Elliott, G.F. (1978): Ecologic significance of post-Palaeozoic
green algae. - Geological Magazine, 115 , 437- 442
Elliott, G.F. (1981): The Tethyan dispersal of some chloro-
phyte algae subsequent to the Palaeozoic. - Palaeogeogr.,
Palaeoclimat., Palaeoecol., 32 , 341-358
Flügel, E. (1985): Diversity and environments of Permian
and Triassic dasycladacean algae. - In: Toomey, D.F.,
Nitecki, M.H. (eds.): Paleoalgology. - 344-351, Berlin
(Springer)
Genot, P. (1991): Cenozoic and recent dasycladales. - In:
Riding, R. (ed.): Calcareous algae and stromatolites. - 131-
145, Berlin (Springer)
Granier, B., Deloffre, R. (1993): Inventaire critique des algues
dasycladales fossiles. 2. partie - les algues dasycladales
du Jurassique et du Crétacé. - Revue de Paléobiologie,
12 , 19-65
Granier, B., Grgasovic, T. (2000): Les algues dasycladales
du Permien et du Trias. Nouvelle tentative d'inventaire
bibliographique, géographique et de stratigraphique. -
Geologica Croatica, 53 , 1-197
Jaffrezo, M. (1973): Essai d'inventaire bibliographique des
algues dasycladacées du Jurassique et du Cretacé inferieur.
- Geobios, 6 , 71-99
Pia, J. (1920): Die Siphoneae verticillatae vom Karbon bis
zur Kreide. - Abhandlungen der zoologisch-botanischen
Gesellschaft Wien, 11 , 1-263
Further reading: K 129. See also Basics for 10.2.1.
Similar to modern dasyclads, ancient dasyclads ex-
hibit recurrent species assemblages that preferred par-
ticular depositional environments on shallow, well-
lighted shelves. The distribution of these assemblages
follows regular patterns, at least for Mesozoic and Ceno-
zoic dasyclads, and can be successfully used in recog-
nizing and subdividing facies belts of platforms and
ramps. Fig. 10.19 shows an example from Early Creta-
ceous platforms.
Biozonations: Many dasyclad genera and species
have long stratigraphical ranges, comprising more than
one stage (Bucur 1999). However, notable exceptions
exist that allow platform carbonates to be dated and
subdivided. Platform carbonates are often poor in guide
fossils. The only abundant fossils in these limestones
are calcareous algae and foraminifera. Both groups are
prone to strong facies controls that reflect the change
of the major environmental constraints (e.g. sea-level
fluctuations, clastic input) over time. These changes
are recorded by vertical successions of rock units yield-
ing specific dasyclads and other thin-section fossils that
allow Mesozoic platform carbonates to be subdivided
into variously defined 'biozones'. These biozones are
valuable stratigraphic tools in regional correlations, but
their boundaries are often certainly not synchronous.
Dasyclads play an important role in defining biozones.
First recognized in 1920 by Julius Pia from Vienna,
species ranges of dasyclads allow relatively short strati-
graphic intervals to be differentiated for time intervals
characterized by high origination rates (e.g. Middle and
Late Triassic, parts of the Early Cretaceous, Paleocene
and Eocene).
Basics: Dasyclad green algae
Barattolo, F. (1991): Mesozoic and Cenozoic marine benthic
calcareous algae with particular regard to Mesozoic
Dasycladalenas. -In: Riding, R. (ed.): Calcareous algae
and stromatolites. - 504-540, Berlin (Springer)
Bassoullet, J.-P., Bernier, P., Deloffre, R., Genot, P., Jaffrezo,
M., Poignant, A.F., Segonzac, G. (1975): Réflexions sur
la systématique des Dasycladales fossiles - Étude critique
de la terminologie et importance relative des critères de
classification. - Geobios, 8 , 259-290
Bassoullet, J.P., Bernier, P., Conrad, M.A., Deloffre, R.,
Jaffrezo, M. (1978): Les algues dasycladales du Jurassique
et du Crétacé. - Geobios, Mem. Spec., 2 , 330 pp.
Berger, S., Kaever, M.J. (1992): Dasycladales: an illustrated
monograph of a fascinating algal order. - 274 pp., Stuttgart
(Thieme)
Bucur, I.I. (1999): Stratigraphic significance of some skel-
etal algae (Dasycladales, Caulerpales) of the Phanerozoic.
- Palaeopelagos Special Publication, 2 , 53-104
De Castro, P. (1997): Introduzione allo studio di sezioni sottili
delle Dasicladali fossili (An approach to thin-section study
of fossil Dasycladales). - Quaderni dell'Accademia Ponta-
niana Napoli, 22 , 261 pp.
10.2.1.8 Charophyta: FreshWater and
BrackishWater Algae
Definition and morphology: Modern charophytes are
regarded as a separate group of macrophytic algae or
as a group of green algae. They live submersed and
occur predominantly in shallow oligotrophic freshwa-
ter environments of lakes and rivers as well as in brack-
ish waters of marginal seas. The erect and branched
thallus is divided into a regular succession of nodes,
with whorls of small branches, and internodes. The only
calcified parts are the reproductive organs, developing
from the nodes during fertile stages of the plant, and
vegetative stem nodes and internodes. The female re-
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