Geology Reference
In-Depth Information
Box 15.2.
Selected case studies of ancient lacustrine and palustrine carbonates. Case studies on freshwater oncoids and
stromatolites are listed in Box 4.8. References dealing with salt and soda lakes are marked by
+
, those on palustrine
carbonates by *.
Sykora 1980; Monty and Mas 1981; Normati and Salomon
1989*; Platt 1989.
Jurassic:
Bell 1989
+
; Leinfelder 1985.
Triassic:
Carozzi 1964; Clemmensen 1978; Gore 1989;
Milroy and Wright 2000; Olsen 1986; Seegis and Goerigk
1992*; Tucker 1978; Wright and Mayall 1981.
Permian:
Clausing 1990, 1992; Clausing et al. 1992;
Freytet and Lebreton 1992; Gebhardt 1988; Gebhardt et
al. 2000; Guy-Ohlson and Lindström 1994; Schäfer and
Stapf 1978; Schneider and Gebhardt 1993; Stapf 1973,
1989; Warren 1983.
Carboniferous:
Buatois and Mangano 1994;
Driese
1985; Gebhardt 1988; Valero-Garcés et al. 1994*.
Devonian:
Blomeier et al. 2003
,
Demicco et al. 1987;
Donavan 1975; Duncan and Hamilton 1988.
Tertiary
: Alonso-Zarza and Calvo 2000*; Anodon and
Utrilla 1993; Anodon and Zamarreno 1981; Anodon et al.
2000; Arenas et al. 1992; Armenteros et al. 1997*; Arp
1995; Bellanca et al. 1992; Bradley 1929; Bustillo et al.
2002; Cabrera and Saez 1987*; Calvo et al. 1989, 1995,
2000; Fouch et al. 1976; Herbig 1988*, 1994*; Leinfelder
and Hartkopf-Froder 1990; Krylov 1982; Nickel 1983; Platt
1992
+
; Reggiani 1989; Riding 1979; Rouchy and Monty
1981
+
; Schweigert 1996; Stanley and Collinson 1979*;
Straccia et al. 1990; Surdam et al. 1975
+
; Surdam and Wray
1976; Szulc et al. 1991
+
; Szulc 1992; Trappe 1992
+
; Wells
1983*; Willems and Wuttke 1987; Wright 1990*.
Cretaceous:
Alonson et al. 1991; Bell 1989
+
; Buatois
et al. 2000; Carozzi 1989; Fouch 1979; Fregenal-Martinez
and Melendez 1994; Freytet 1984
+
; Freytet and Plaziat
1982*; Martin-Chivelet and Gimenez 1992*; Misik and
15.4.2 Palustrine Carbonates
tions, coated grains; Seegis 1993). The main difference,
however, is the close association of these features with
lacustrine sublittoral limestones. Palustrine carbonates
are paleosols reflecting pedogenic effects, such as the
repeated drying of the sediment in carbonate swamps
bordering lakes, or in episodically drying shallow lakes.
Examples are shown in Pl. 48/2, 3. The carbonate beds
are commonly associated with claystones, marls, sand-
stones, cherts and coals. Stable isotopes of the micritic
Palustrine limestones assist in recognizing seasonal
wetland environments in the geological record (Wright
and Platt 1995). These limestones (Sect. 2.4.1.2) ex-
hibit criteria that also occur in pedogenic carbonates
(pseudo-microkarst associated with fenestrae, circum-
granular cracks and peloidal fabrics; Plaziat and Freytet
1978) and caliche horizons (rhizolites, rhizoconcre-
Plate 131 Lacustrine Carbonates from the Early Permian (Rotliegend) of Germany
The plate displays the microfacies of lowermost Permian lacustrine limestones, formed in intracontinental ba-
sins filled predomiantly with fluviatile-deltaic and lacustrine siliciclastic sediments. Limestones are rare. Most
carbonates are of algal and microbial origin or formed by the accumulation of ostracods and mollusks. Sporadic
subaerial exposure is indicated by pedogenic horizons rich in caliche pisoids (Pl. 14/6) at the top of stromato-
lites. Other facies types are shown in Fig. 15.8.
Facies-diagnostic criteria of these carbonates are various types of biogenic laminations (-> 2), stromatolites
(-> 1, 3) and oncoids (-> 5) formed in shallow marginal parts of the lakes.
1
Lacustrine columnar stromatolites:
LMF 11. These structures occur in limestones and marls with a thickness of up to
several meters. The columns are distinctly laminated. Larger columns consist of small-scaled stromatolites (black arrow).
Early Permian (Lower Rotliegend): Altenglan, Saar-Nahe Basin, Southwestern Germany.
2
Irregularly laminated mudstone and peloid mudstone
. Note the small-scale alternations of syngenetically deformed lay-
ers. These limestones yield 'marine' algae (-> 4). Early Permian (Lower Rotliegend): Birkigt near Freital, Döhlen Basin,
Thuringia, Germany.
3
Stromatolite boundstone:
LMF 11. Note the infilling of micro-oncoids (arrows) between the columns, indicating a some-
times turbulent shoreline/nearshore environment. Early Permian (Upper Kusel Group): Saar-Nahe Basin, Germany.
4
'Marine' green and red algae
can occur in lacustrine sediments as seen in examples from Thuringia (Schneider and
Gebhardt 1992). The fossil was assigned to the dasyclad genus
Macroporella
. The occurrence of these algae has been
explained by wind drift of algal cysts or acinetes from marine environments to relatively saline lakes. Same locality as -> 2.
5
Lacustrine oncoid
with thrombolite (T) microstructure: LMF 10. Thrombolites are characterized by clotted structures and
the absence of conspicuous lamination. The clots are interpreted as being formed by coccoid and filamentous microbes.
Early Permian (Upper Rotliegend): Dannenfels, Saar-Nahe Basin, Germany.
-> 1, 5: Stapf 1989; 3: Clausing 1990; 2, 4: Courtesy of J. Schneider (Freiberg)
