Virtueller Geocache
GAGA - Gau-Algesheimer Geologische Aussicht

 About the geology of the northern Rheinhessen

von GeoMops     Deutschland > Rheinland-Pfalz > Mainz-Bingen

N 49° 57.519' E 008° 01.710' (WGS84)

 andere Koordinatensysteme
 Größe: kein Behälter
Status: kann gesucht werden
 Zeitaufwand: 1:00 h   Strecke: 2.0 km
 Versteckt am: 24. September 2009
 Gelistet seit: 01. Oktober 2009
 Letzte Änderung: 01. Oktober 2009
 Listing: https://opencaching.de/OC9390
Auch gelistet auf: geocaching.com 

19 gefunden
0 nicht gefunden
0 Bemerkungen
0 Beobachter
1 Ignorierer
492 Aufrufe
15 Logbilder

große Karte


Benötigt Vorarbeit

Beschreibung    Deutsch  ·  English

A Spur of the Westerberg in northern Rheinhessen. Wide view over the Rhine valley to Taunus and Hunsrueck. A cabin with a geological information board is situated at the Location.


At the beginning of the Devonian about 416 MBP a flat sea extended the ocean Tethys to the south of a line from Cologne to Hannover. Temporarily an island string was lifted out this sea at the todays Hunsrueck and Taunus. This is proved by fossil Brachiopoda and Coral. From here you can see on top of the Hunsrueck, Taunus and Rochusberg the early Devonian rocks, which are classified into colored slate, gray phylite, Hermeskeil sandstone, Taunus quartzite and Hunsrueck slate. Hermeskeiler sandstone and the superposed Taunus quartzite were built of sand, that has been deposited near the coastline. These hard rocks are todays highest elevations around. The following depression caused their overlay by clay, which has been compressed to Hunsrueck slate. During the late Devonian and early Carboniferous about 360 MBP these mountains had been folded and long period of mainland began here.


During the following millions of years the Rhenish Slate Mountains stayed mainland and erosion processes dominated. Mesozoic sediments have not been proved yet here.


The substratum of the Mainz Basin is built from rocks that originate from the Tertiary. 38 to 12 MBP the area of todays Rheinhessen was covered by a sea. This tertiary sea basin was about 50m deep and is named Mainz Basin. It was the bay of an arm of the sea that connected the ancient North Sea ? a part of the opening North Atlantic Ocean ? with the Para-Tethys ? a part of the closing Tethys ? in Paleogene. The formation of this sea happened in two phases intermitted by a siltation.


38 to 25MBP the Oligocene sea and its coastline were similar to todays Caribbean. There were subtropical temperatures, the mean annual temperature was ca. 18°C (today 10,5°C).

On the sandy bay grew palm and bay trees. The water was populated by crocodiles, ocean turtles, sea cows, sharks, skates and a multitude of fishes. The land was populated by flamingos, pelicans, rhinos, apes and elephants.

Rupel formation and later with upcoming brackish water Cyrene marl were deposit on the sea bed and near the coastline sands. During the Late Oligocene the Mainz Basin was almost land.


25 to 12 MBP the Mainz Basin was part of a depression and a second sea phase took part. Unlike the sand and clay deposits during the Oligocene era lime sediments were then deposited. Todays plateaus and hills are built by them.

These strata are denoted from their type fossil, in chronology at first Cerithium stratum, then Corbicula stratum and at last Hydrobia lime stratum (Hydrobia elongata).

In all these Tertiary strata are up to 250m elevated. The border between Devonian and Tertiary rocks is located near the line Ruedesheim ? Marienthal ? northern Johannisberg. It marks the coastline of the Mainz Basin against the Rhenish Slate Mountains. Composite and bedding of the strata denote a cliff line, that is still there noticeable, where the ancient surge broke against the Taunus quartzite.


The land phase of Rheinhessen began when the sea withdraw 11 to 3 MBP. Since then the Rhenish Slate Mountains elevated about 240m. Erosion processes predominate with the exception of the Rhine Graben, that is still depressing and therefor an accumulation area.

In Pliocene the todays Rhine, Main and Nahe river systems arose. They meandered through a flat rippled landscape.

The sandy strata of this period are denoted Dinotherium sands. The type fossil is the elephant like Dinotherium giganteum, that achieved a shoulder height of 5m.


From the beginning of Quaternary the temperature sunk noticeably. Cold periods with permafrost and warm periods with climates like today, partly almost warmer, altered. The glacial rivers cutted the lime strata into plateaus and so the basic shape of todays Rheinhessen landscape arose.

During the glacial cycles the Rhine deposited gravel to terraces. The oldest terraces (Main Terrace) are located near the Taunus edge, the middle and lower terraces are attached to these down to the Rhine like stairs. The sands and gravel are covered by Loess deposits in varying thickness. Apart from rests of the former glacial cycles todays Loess deposits arose mostly during the Wuerm glacial.

The quaternary Rhine was dam up the Rhenish Slate Mountains. Therefor the relatively soft tertiary rocks were eroded in the bottom of the wide Rhine valley. The Rhine flowed branched in multiple channels through the softer parts of the bedrock. The tougher components remained as islands, the channels were filled with sand and gravel.


Tafeln des Geoökologischen Lehrpfades Gau-Algesheim
Rathaus, Marktplatz 1, D-55435 Gau-Algesheim.

Wikipedia, Stichwörter Mainzer Becken und Rheinhessisches Hügelland.

DLR - Dienstleistungszentrum Ländlicher Raum: Böden der Weinbergslagen Rheinhessens.


  1. In which height were the Dinitherien sands deposited (Illustration of Prof. Dr. Abele)?

  2. Which terraces were deposited during the last (Wuerm-) glacial?

  3. How wide was the oligocene connection between the North Sea and Para-Tethys at their widest area near Mainz?

  4. Where have the erosion products from the Rhenish Slate Mountains during Carboniferous and Permian been deported?

  5. Which of today's cities is positioned on the devonian subduction zone at the northern border of the 'Mitteldeutsche Schwelle'?

  6. Which two rivulets mainly drain northern Rheinhessen today?

  7. Where do todays deposits, which mainly build the groundwater along the Rhine, drain away?

Log validation:

  1. To claim this cache as found you have to write an email containing the subject 'GC1Z2QQ', a valid return address and as body text the answers to the questions to GeoMops@web.de. You will receive an answer with the permission to log if your answers are correct within a few days.

  2. Attach a picture of you at GAGA to your log.

Logs without permission and / or picture will be deleted.

I hope you will enjoy this cache ? have fun!


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Logeinträge für GAGA - Gau-Algesheimer Geologische Aussicht    gefunden 19x nicht gefunden 0x Hinweis 0x

gefunden 28. April 2016 Heinzybaby hat den Geocache gefunden

Diesen EC habe ich in zwei Etappen gemacht - denn erst nachdem ich vor rund einem 3/4-Jahr die Informationen an den Hauptkoordinaten studiert hatte, wurde mir klar, dass ja noch der Besuch der Zusatztafel notwendig ist, um alle Fragen ordentlich beantworten zu können. Man sollte Listings doch immer vorher ganz genau lesen!

Leider führte mich mein Weg damals nicht an der Zusatztafel vorbei, aber heute war ich zufällig in der Gegend und konnte die fehlenden Antworten dort vor Ort gut einsammeln. Der Ausblick auf Gau-Algesheim und das Rheintal von dieser Stelle hat mir heute Abend in der Dämmerung fast noch besser gefallen als an den Hauptkoordinaten.

Die Mail an den Owner ist schon raus - und in der Hoffnung, dass meine Antworten einigermaßen gut passen, traue ich mich jetzt schon mal zu loggen.



gefunden 03. Januar 2015 Litthard hat den Geocache gefunden

Mit Anis511 konnten wir bei nicht ganz so schönem Wetter über Gau-Algesheim diesen Earthcache finden.
Vielen Dank und ein schönes Neue Jahr!

zuletzt geändert am 17. Januar 2017

gefunden 08. April 2012 DieFalken hat den Geocache gefunden

So, heute ging es mit der Family zur "Tigerburg" (so nennen meine Kinder den Bismarkturm).
Ich bin unten ausgestiegen und hochgelaufen, und habe mal die Caches am Weg eingesammelt.
Oben angekommen, musste ich natürlich auch noch hier bei dem Earthcache vorbeischauen.
Leider habe ich das mit der Zusatztafel verpeilt. Vielen Dank an Geomops für die schnelle Logfreigabe und den tollen Earthcache.

Grüße von den Falken

Bilder für diesen Logeintrag:
GAGA - Geological view over Gau-AlgesheimGAGA - Geological view over Gau-Algesheim

gefunden 23. Mai 2011 Schatziputzi hat den Geocache gefunden

Zusammen mit Karlmoitroppe auch diese schöne Aufgabe gemeistert.
Hier sind wir immer wieder gerne. Vielen Dank für die schnelle Logfreigabe.

TFTC sagt Schatziputzi
# 1314

gefunden 23. Mai 2011 karlmoitroppe hat den Geocache gefunden

Ein wunderschön gemachter Earth-Cache. In einer Gegend wo wir auch früher schon öfters waren. Wirklich toll hier.
An den Owner vielen Dank für die superschnelle Logfreigabe .

# 2141