The Holzmaar lies in the

Volcanic Eifel The Volcanic Eifel or Vulkan Eifel (german: Vulkaneifel) is a region in the Eifel Mountains in Germany that is defined to a large extent by its volcanic geological history. Characteristic of this volcanic field are its typical explosion crater la ...

in the German state of

Rhineland-Palatinate Rhineland-Palatinate ( , ; german: link=no, Rheinland-Pfalz ; lb, Rheinland-Pfalz ; pfl, Rhoilond-Palz) is a western state of Germany. It covers and has about 4.05 million residents. It is the ninth largest and sixth most populous of the ...

almost halfway between

Gillenfeld Gillenfeld is an ''Ortsgemeinde'' – a municipality belonging to a ''Verbandsgemeinde'', a kind of collective municipality – in the Vulkaneifel district in Rhineland-Palatinate, Germany. It belongs to the ''Verbandsgemeinde'' of Daun, whose se ...

(2.5 km away to the southwest) and

Eckfeld Eckfeld is an ''Ortsgemeinde'' – a municipality belonging to a ''Verbandsgemeinde'', a kind of collective municipality – in the Bernkastel-Wittlich district in Rhineland-Palatinate, Germany. Geography Eckfeld lies in the middle of the Vulka ...

. The

maar A maar is a broad, low-relief volcanic crater caused by a phreatomagmatic eruption (an explosion which occurs when groundwater comes into contact with hot lava or magma). A maar characteristically fills with water to form a relatively shallow ...

has an area of about , a diameter of and a depth of and lies within a

nature reserve A nature reserve (also known as a wildlife refuge, wildlife sanctuary, biosphere reserve or bioreserve, natural or nature preserve, or nature conservation area) is a protected area of importance for flora, fauna, or features of geological or ...

, almost completely surrounded by woods. It is one of the two maars making up the Gillenfeld Maars, the other being the

Pulvermaar The Pulvermaar is a water-filled maar that lies southeast of Daun in the German state of Rhineland-Palatinate. Together with the Holzmaar it is one of the Gillenfeld maars. Description A tuff site in the bog formations of the neighbouring Stro ...

. The Holzmaar is fed by a headstream of the Sammetbach which crosses the maar. In the immediate vicinity is another maar, the

Dürres Maar __NOTOC__ The Dürres Maar is a maar located in the vicinity of the village of Gillenfeld, Germany in the West Eifel mountains about 400 metres northwest of the Holzmaar. The Dürres Maar ist a dry maar, the original maar lake has silted u ...

. On its south and southwest shores, the maar has silted up with

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

core sample A core sample is a cylindrical section of (usually) a naturally-occurring substance. Most core samples are obtained by drilling with special drills into the substance, such as sediment or rock, with a hollow steel tube, called a core drill. The h ...

s from which give a comprehensive picture of the climate going back to the last cold period. The sediments of the Holzmaar go back 23,200 years. This assessment was made possible by comparing the sequence and

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

obtained in the maar basin with that of the

Meerfelder Maar The Meerfelder Maar is a maar by the village of Meerfeld not far from the town of Manderscheid in the Eifel in the German state of Rhineland-Palatinate. Formation The maar is at least 30,000 years old and, according to the more recent i ...

. The time of the maximum of the last glaciation derived from

varve A varve is an annual layer of sediment or sedimentary rock. The word 'varve' derives from the Swedish word ''varv'' whose meanings and connotations include 'revolution', 'in layers', and 'circle'. The term first appeared as ''Hvarfig lera'' (var ...

chronology is in close agreement with data from the

Greenland Ice Sheet Project The Greenland Ice Sheet Project (GISP) was a decade-long project to drill ice cores in Greenland that involved scientists and funding agencies from Denmark, Switzerland and the United States. Besides the U.S. National Science Foundation (NSF), f ...

(GISP2), but are somewhat at odds with those of the

Greenland Ice Core Project The Greenland Ice Core Project (GRIP) was a research project organised through the European Science Foundation (ESF). The project ran from 1989 to 1995, with drilling seasons from 1990 to 1992. In 1988, the project was accepted as an ESF-associa ...

(GRIP). In the sequence of sediments three zones of strata were found, when the most dust was deposited in the crater lake. If these dust-laden layers correspond to the ice advances of the northern German inland ice sheet, by comparing them with the exact chronological sequence of the dust layers in the Maar sediments an equally accurate age for local terminal moraines may be possible at suitable locations in northern Germany.

References

Literature

* Werner D´hein: ''Natur- und Kulturführer Vulkanlandeifel. Mit 26 Stationen der "Deutschen Vulkanstraße".'' Gaasterland-Verlag, Düsseldorf. 2006, * H. Wolfgang Wagner et al., 2012: ''Trier und Umgebung, Sammlung geologischer Führer'', Bd. 60, 3. Auflage, Bornträger, , (see:) http://www.schweizerbart.de/publications/detail/artno/011006040 * Bernd Zolitschka, ''Paläoklimatische Bedeutung laminierter Sedimente: Holzmaar (Eifel, Deutschland), Lake C2 (Nordwest-Territorien, Kanada) und Lago Grande di Monticchio (Basilicata, Italien)''. Relief Boden Palaeoklima, Vol. 13, 1998.

External links

Rezension zum Forschungsbericht ''Paläoklimatische Bedeutung laminierter Sedimente – Holzmaar (Eifel, Deutschland), Lake C2 (Nordwest-Territorien, Kanada) und Lago Grande di Monticchio (Basilicata, Italien).'' 1998
Bogs of Rhineland-Palatinate Maars of the Eifel Nature reserves in Rhineland-Palatinate Vulkaneifel