Versteinerte Rippelmarken im Langfigtal, Altenahr, Rheinland-Pfalz, Germany
Posted by: 
argus1972
N 50° 30.453 E 006° 59.737
32U E 357875 N 5596983
A big rock slab with fossilized ripple marks in the Langfigtal.
Waymark Code: WMWT63
Location: Rheinland-Pfalz, Germany
Date Posted: 10/10/2017
Views: 5
In the Langfigtal one finds a large rock slab of slate stone with ripple marks next the footpath. It concerns a piece of fossilized seabed.
In contrast to the surrounding slate rock of the region the slab is aimed almost horizontally.
Slate stones are from marine sediments from the Lower Devonian (~ before 410 million years) emerged. Slate stone is a pellitic sedimentary rock and consists mostly of clay minerals (eg, montmorillonite, illite and smectite). Other parts are quartz, feldspar, and carbonates. As a sedimentäry rock this rock slab was part of soft seabed 400 million years ago.
When seafloor comes close to the surface, the small grains of the sediment get into the effect of surface flow. With a function of flow velocity and grain sizes particles are torn from the ground and transported by the water. Where the flow drops (eg behind obstacles) the grains sink to the bottom again. This causes wavy patterns in the sand ground.
Experts distinguish two different types of ripple marks:
1) Current ripples are formed by flows coming from a constant direction. They form more or less parallel wave pattern with unsymmetrical peaks: the flow-facing side forms gently sloping hillside. The other side drops significantly steeper. The mean height of the peaks are found today about 3-5 cm. The distance from crest to-valley (the wavelength) is between 4 and 60 cm.
This slab shows current ripples.
2) Oszillation ripples arise when the causing flow oscillates, ie periodically changes direction. Are the two directions real opposite directions (tides, ebb and flood) the ripples form intricate wave pattern with symmetrical peaks.
Sometimes the sandy patterns petrify and the structures in the beach floor remain. This must have happened here a long time ago.
Waymark is confirmed to be publicly accessible: yes
Requires a high clearance vehicle to visit.: no
Requires 4x4 vehicle to visit.: no
Public Transport available: no
Parking Coordinates: Not Listed
Access fee (In local currency): Not Listed
Website reference: Not listed
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Visit Instructions:
No specific requirements, just have fun visiting the waymark.