Geology Reference
In-Depth Information
tary environments. - Marine Geology,
5
, 327-567
Hottinger, L. (1984): Zur Tiefenverbreitung von Großfora-
miniferen - Paläontologische Kursbücher,
2
, 140-147
Kenter, J.A.M. (1990): Carbonate platform flanks: slope angle
and sediment fabric. - Sedimentology,
37
, 777-794
Liebau, A. (1980): Paläobathymetrie und Ökofaktoren: Flach-
meer-Zonierungen. - Neues Jahrbuch für Geologie und
Paläontologie, Abhandlungen,
160
, 173-216
Luterbacher, H.P. (ed., 1984): Paläobathymetrie: Konzepte,
Methoden, Möglichkeiten, Probleme. - Paläontologische
Kursbücher,
2
, 225 pp.
Luterbacher, H.P., Van Hinte, J.E. (eds., 1984): Deep-water
paleobathymetry. - Palaeogeography, Palaeoclimatology,
Palaeoecology, Special Issue,
48
Madi, A., Bourque, P.A., Mamet, B.I. (1996): Depth-related
ecological zonation of a Carboniferous carbonate ramp:
Upper Viséan of Béchar Basin, Western Algeria. - Facies,
35
,59-80
Oberhänsli, H. (1984): Stabile Isotopen: Hilfsmittel für die
Paläobathymetrie. - Paläontologische Kursbücher,
2
, 96-
103
Porrenga, D.H. (1967): Glauconite and chamosite as depth
indicators in marine sediments. - Marine Geology,
5
, 495-
501
Seilacher, A. (1984): Bathymetrie von Spurenfossilien. -
Paläontologische Kursbücher,
2
, 104-123
Vogel, K., Balog, S.-J., Bundschuh, M., Gektidis, M., Glaub,
I., Kutschinna, J., Radtke, G. (1999): Bathymetrical stud-
ies in fossil reefs, with microendoliths as paleoecological
indicators. - Profil,
16
, 181-191
Further reading:
K169
to earthquake activity. Interesting case studies interprete
Late Devonian intraclast carbonate parabreccias con-
sisting of protointraclasts as seismites (Spalleta and Vai
1984), and extended stratigraphic carbonate breccia
beds in the Triassic Muschelkalk as seismites (Rüffer
1996). Unusual intraclastic limestones in Early Triassic
carbonates formed after the end-Permian mass extinc-
tion have been explained as the result of tsunami waves
related to seismic catastrophes (Wignall and Twitchett
1999).
Small-scaled dewatering structures
possibly trig-
gered by submarine earthquakes have been described
from micritic limestones, and may be recorded by
•
patchily distributed very small spar-filled voids
within microbioclastic wackestones or mudstones.
These structures have been interpreted as result of
pore-water escape during partial sediment consoli-
dation,
•
spar- or sediment-filled flame structures (Plaziat et
al. 1990),
•
vertical, crinkled spar-filled micro-cracks, width
about 1 mm or less,
•
close-set parallel vertical micro-faults.
Most examples described deal with carbonates
formed on epeiric ramps, at platform-edges or on up-
per slopes.
12.4 Looking for Seismic Events
Basics: Paleoseismic events
Ettensohn, F.R., Rost, N., Brett, C.E. (eds., 2002): Ancient
seismites. - Geological Society of America, Special Pa-
per,
359
, 190 pp.
Kullberg, J.C.,Oloriz, F., Marques, B., Caetano, P.S., Rocha,
R.B. (2001): Flat-pebble conglomerates: a local marker
for Early Jurassic seismicity related to syn-rift tectonics
in the Sesimbracea (Lusitanian, Portugal). - Sedimentary
Geology,
139
, 49-70
Plaziat, J.-C., Purser, B.H., Philobbos, E. (1990): Seismic de-
formation structures (seismites) in the syn-rift sediments
of the NW Red Sea (Egypt). - Bull. Soc. Géol. France,
ser. 8,
6
, 419-434, Paris
Pratt, B.R. (2002): Tepees in peritidal carbonates: origin via
earthquake-induced deformation, with examples from the
Middle Cambrian of western Canada. - Sedimentary Ge-
ology,
153
, 57-64
Rüffer, T. (1996): Seismite im Unteren Muschelkalk west-
lich von Halle (Saale). - Hallesches Jahrbuch für Geo-
wissenschaften,
B18
, 119-130
Seilacher, A. (1984): Sedimentary structures tentatively at-
tributed to seismic events. - Marine Geology,
55
, 1-12
Shiki, T., Cita, D.S. (2000): Sedimentary features of seismites,
seismo-turbidites and tsunamiites - an introduction. - Sedi-
mentary Geology,
135
, 7-9
Spalleta, C., Vai, B. (1984): Upper Devonian intraclast para-
breccias interpreted as seismites. - Marine Geology,
55
,
133-144
Further reading:
K086
Earthquakes contribute to the destruction of carbonate
sequences, soft sediment deformation and dewatering,
and the redeposition of marine sediment (Shiki and Cita
2000). Seismic shocks provoke limited internal frac-
turing of semi-lithified limestone beds, resulting in
seismites
characterized by a progressively higher de-
gree of disruption and brecciation from the bottom to
the top of the bed (Seilacher 1984; Plaziat et al. 1990;
Martire 1996). Earthquakes can cause sediment defor-
mation, create water escape structures, sedimentary
dikes, sedimentary breccias, recumbent folds, ball-and-
pillow structures, and convolute bedding. But it must
be noted that many of these features also originate in
shallow-marine high-energy settings without earth-
quake-driven causes.
Criteria used in evaluating ancient seismic activity
in carbonate rocks are intraclast and breccia beds, and
micro-scale dewatering structures.
Intraclast limestones:
Laterally continuous lime-
stone beds composed of intraclast wackestones and
packstones, and associated with deformation structures,
intraformational conglomerates and breccias may point
