Shell
beds
are
commonly preserved in modern and ancient lacustrine rift
settings and their taphonomy is well understood, but the accumulation
of disarticulated fish parts in strandline settings is poorly
understood. Hence, the Salton Sea shorelines are important modern
analogs for the buildup of disarticulated fish parts. The Salton Sea
accumulations are compared, contrasted and integrated into an
interpretation of fish-part beds of the Triassic Newark basin in
Pennsylvania.
Salton Sea shorelines consist of beach ridge surface morphology and
normal grading from the beach to the backshore. The most common clast
components in core samples are barnacles and disarticulated fish parts.
The cored deposits are characterized by normal graded beds, but are
doubly graded with two clast types within a single depositional bed:
First, the barnacles form a normally graded base of each bed, followed
near the top of the bed by smaller comingled barnacles and the
hydrodynamicly equivalent largest fish parts. Second, the bed top
consists of normally graded fish parts, with isolated partially
articulated fish fragments present across the beach surface at the
Salton Sea.
The composition and structure of the deposits of the modern Salton Sea
are comparable to fish kill beds from rare shoreline deposits of the
Triassic lacustrine Lockatong Formation. After death, decomposition and
bloating of the fish led to flotation. Fish carcasses were driven
shoreward by waves, probably storm-generated. The remains were
disarticulated and reworked as lag concentrations that are recorded in
the double normal grading of the intraformational clasts (barnacle
equivalent) and fish-parts. The graded beds record the impact of the
storm on the strandline and coeval washover into the associated fluvial
systems. Late partially articulated fish fragments found at the top of
the Triassic beds and Salton Sea had not degassed and thus settled last.
Strandline
deposits of the Salton Sea, California: An integrated analogue for
Triassic fish-part conglomerates of the Newark Basin
Shell
beds
are
commonly preserved in modern and ancient lacustrine rift
settings and their taphonomy is well understood, but the accumulation
of disarticulated fish parts in strandline settings is poorly
understood. Hence, the Salton Sea shorelines are important modern
analogs for the buildup of disarticulated fish parts. The Salton Sea
accumulations are compared, contrasted and integrated into an
interpretation of fish-part beds of the Triassic Newark basin in
Pennsylvania.