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Geomorphology 151–152 (2012) 175–187

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Geomorphology

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Reconstruction of the Landeskrone Scoria Cone in the Lusatian Volcanic Field, Eastern Germany — Long-term degradation of volcanic edifices and implications for landscape evolution

Jörg Büchner ⁎, Olaf Tietz

Senckenberg Museum für Naturkunde Görlitz, PF 300154, 02806 Görlitz, Saxony, Germany article info abstract

Article history: Remnants of numerous monogenetic volcanoes are preserved in the Central European Volcanic Province Received 31 August 2011 (CEVP). The Landeskrone Hill, a monogenetic scoria cone in the Lusatian Volcanic Field, is reconstructed Received in revised form 25 January 2012 here. This was done using measurements of the dip of columnar jointing of lava lake basalts and the detailed Accepted 29 January 2012 mapping of the volcaniclastic rocks. The reconstruction implies a large scoria cone and a lava lake; filling the Available online 3 February 2012 crater with a thickness of more than 110 m. Volcanic activity was characterized by strombolian eruptions possibly after an opening phreatomagmatic phase. A scoria cone was developed in an initial maar-diatreme Keywords: fi Scoria cone volcano. A late phreatomagmatic phase could explain the unusual modi ed crater of the scoria cone. The con- Monogenetic volcano duit was emptied and so the crater was widened in this late eruption stage. An increased magma flux prob- Nephelinite ably induced a change in the eruptive style and, finally, the crater was filled in a single event by a lava lake. Lava lake This effusive phase completed the multi-stage volcano development. Landscape evolution The 34 Ma-old volcano is an excellent example for the persistence of relicts of monogenetic volcanoes over a Phreatomagmatic long period of time. There are some other remnants of monogenetic scoria cones that survived degradation processes in the area. With respect to the present surface, the reconstruction of the paleosurface implies low uplift and erosion rates of about 3 mm/ka since the Oligocene. These denudation values support and expand on the previously published fission track data (prior to the Upper Cretaceous) and glacial- sedimentological data on neotectonic movements since the Middle Pleistocene. The erosion rate estimated by physical volcanological data implies stagnation of tectonic uplift from the Upper Paleogene to the Middle Neogene and a reactivation of tectonic movement for the Lusatian Massif in the Middle Pleistocene. Thus, the reconstructed edifice provides a powerful tool for the study of landscape evolution by clearly defining the characteristics of the paleosurfaces at certain times. © 2012 Elsevier B.V. All rights reserved.

1. Introduction In many cases, scoria cone volcanic activity begins with magma/ water interaction creating an initial tephra ring as known from the Monogenetic basaltic volcanoes are the most common type of vol- Eifel Volcanic Field in Germany (e.g. Eppelsberg Volcano (Schmincke, canoes in continental areas and occur as scoria cones, tuff rings or 2004)). Such phreatomagmatic deposits are unsorted and mainly con- maars (e.g. Wood, 1980a; Cas and Wright, 1987; Schmincke, 2004; sist of country rock fragments with small amounts of juvenile pyroclasts Lorenz and Kurszlaukis, 2007). The constructs of scoria cones are pro- (Lorenz and Kurszlaukis, 2007). The initial phreatomagmatic phase is duced mostly by strombolian and violent strombolian eruptions (e.g. usually followed by strombolian or hawaiian activity because of declin- McGetchin et al., 1974; Vespermann and Schmincke, 2000; Valentine ing water supply (Lorenz and Büchel, 1980; Lorenz, 1986; Vespermann and Gregg, 2008) that are driven mainly by magmatic volatiles. Maars and Schmincke, 2000; Schmincke, 2004). Subsequent magmatic activi- and tuff rings are the phreatomagmatic equivalent of scoria cones and ty, driven by the continued rise of magma and associated degassing, the magma fragmentation is caused by magma/water interactions produces a scoria cone. A typical scoria cone consists of three pyroclastic (Lorenz, 1986; Wohletz, 1986; Lorenz and Kurszlaukis, 2007). Tuff facies (Head and Wilson, 1989; Keating et al., 2008). The volcanic edifice cones are created by eruptions due to magma contact with abundant is constructed of outwardly inclined, mostly non-welded scoria beds of surface water (Wohletz and Sheridan, 1983). the wall facies and the inwardly dipping partly welded beds of the crater facies (Head and Wilson, 1989; Valentine and Gregg, 2008). In the lower part, the crater facies grades into the vent breccias, which are observed in the sub-surface conduit. Sometimes, simultaneous ⁎ Corresponding author. phreatomagmatic and strombolian activities take place and alternated E-mail address: [email protected] (J. Büchner). (Ukinrek East Maar, Alaska, Kienle et al., 1980, Rothenberg in the Eifel

0169-555X/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.geomorph.2012.01.027 Author's personal copy

176 J. Büchner, O. Tietz / Geomorphology 151–152 (2012) 175–187 region, Houghton and Schmincke, 1986) or mixed deposits appear 1999; Schröder and Peterek, 2002; Martin and Németh, 2004). In ad- (Baruth in eastern Germany, Tietz et al., 2011a). Later ascending dition, the recognition of the existence of scoria cones in the geolog- magma is characterized by lower gas content. It is extruded out of the ical past as well as their distinction from their phreatomagmatic vent and in some cases fills the superficial crater or produces lava equivalents can give valuable information for estimating paleoclimat- flows by breaking through or overflowing the cone (Keating et al., ic and paleohydrologic characteristics of a broader region (Kereszturi 2008; Valentine and Gregg, 2008). et al., 2011). Morphometric characteristics of scoria cones are generally There is only a small number of papers dealing with the re- expressed in the so called PW-ratio according to Porter (1972) and construction of ancient scoria cones older than Pliocene age (e.g.

Wood (1980a):Wcr =0.40×Wco and Hco =0.18×Wco, where Wco is Awdankiewicz, 2005; Rapprich and Cajz, 2007; Rapprich et al., the basal diameter of the cone, Wcr is the diameter of the summit cra- 2007; Tietz et al., 2011a,b) However, these data give some informa- ter and Hco is the distance from the baseline to the top of the cone tion on scoria cone degradation, that modified former quantifications (Fig. 1a). These equations were determined and constantly recal- by e.g. Wood (1980a) or Hooper and Sheridan (1998). The degrada- culated on numerous recent and young scoria cones (e.g. Wood, tion of scoria cones has been modeled for edifices without apprecia- 1980b; Vespermann and Schmincke, 2000; Rodríguez et al., 2010). ble lava filling. Accordingly, the superficial successions of a scoria They are useful only for cones with a simple geometry without early cone are completely eroded after about 5 Ma and only the subsurface spatter mounds, pit craters or initial maar formation (Fig. 1b,c). The parts of the volcano remain (Wood, 1980b). latter three processes shift the modeled baseline of the cone in cross In this paper, we present the field relationships of remnants of a section and so the Wcr vs. Wco —ratios show lower values for a spatter monogenetic scoria cone of Oligocene age and the reconstruction of mound and for the two other cases higher values (Riedel et al., 2003). the volcanic edifice. We calculate the morphometric values of the an- Over long timescales, scoria cones can be strongly modified and cient monogenetic scoria cone. Additionally, we estimate the implica- eroded, thus in ancient volcanic successions they are scarcely pre- tions for landscape evolution in uplifted areas over the long term served as intact, recognizable landforms. Therefore, research on using volcanological data from adjacent volcanoes. The results of older and eroded scoria cones and their remnants is limited. Deeper this study provide contexts for understanding scoria cone eruptions, exposed volcanic assemblages can carry information essential to their growth and their long-lasting destruction. The Landeskrone Vol- understanding the magma generation, evolution, rise of magma and cano was chosen to test these applications for landscape evolution by its fragmentation through explosive eruption at a well-defined point older volcanic structures supplementary or alternative to the other in a landscape strongly modified since the time of volcanism (e.g. methods such as fission track dating. The Lusatian area is particularly Németh and Martin, 1999; Shaw, 2004). Moreover, there are wide suitable for such investigations because it has been uplifted over the implications for the landscape evolution itself (Németh and Martin, last 100 Ma jointly with many other nearby monogenetic volcano remnants with ages between 34 and 22 Ma.

2. Regional geological setting

The Landeskrone Volcano (14.93260 E, 51.12955 N) is a solitary volcano, situated in the northern part of the Lusatian (Lausitz) Volca- nic Field (Fig. 2 inset map). The Lusatian Volcanic Field (Tietz et al., 2011a) is part of the Central European Volcanic Province (CEVP), a volcanic belt in Central Europe distributed over a distance of about 300 km north of the Alps (Wedpohl and Baumann, 1999; Lustrino and Wilson, 2007). The volcanic rocks occurring in this belt are main-

ly SiO2-undersaturated mafic volcanic rocks such as nephelinites, basanites and alkaline basalts as well as their phonolitic and trachytic differentiates. The volcanism was active from the Upper Cretaceous to the latest Tertiary and again in the late Quaternary (e.g. Lustrino and Wilson, 2007) in the Eifel region as well as in the Ohře Rift (Eger Graben). The Lusatian Volcanic Field is characterized by a bimodal volca- nism from nephelinites to phonolithes (Tietz et al., 2011a). Ages of the Cenozoic volcanic rocks ranges from about 41 to 20 Ma (K/Ar- method), with a climax between 30 and 27 Ma (Pfeiffer et al., 1984; Panasiuk, 1986; Suhr and Goth, 2002; Lorenz et al., 2003). The basaltic rocks appear mostly in small bodies (diatremes, plugs) or in more widely distributed lava flows (e.g. Tietz et al., 2011b). In some cases, there are complex volcanoes created due to si- multaneous strombolian to hawaiian and phreatomagmatic eruptions (Tietz and Büchner, 2007; Tietz et al., 2011a). Normally the volcanic constructs are weathered and removed. However, pyroclastic rocks are commonly preserved in sheltered positions such as in sedimenta- ry basins or under thick lava flows. Primary bedding and structure have survived strong chemical weathering (Büchner et al., 2006). Therefore, also strongly weathered volcanic rocks like saprolite can be used for volcanological reconstructions (Büchner et al., 2006). Fig. 1. Schematic image of morphometric values of scoria cones and their modification Only an unpublished isotopic age (34±2 Ma K/Ar-method) is due to different eruption styles according to Riedel et al. (2003). a: morphology of a normal scoria cone, b: shape of a scoria cone, modified due to an initial spatter available for the Landeskrone Volcano (Pushkarev, 2000), which mount, and c: scoria cone, modified by pit crater creation due to e.g. a maar phase. would make this volcano one of the oldest in the Lusatian Volcanic Author's personal copy

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Fig. 2. Geological map of the Oligocene Landeskrone volcano. Large arrows symbolize the mean direction of columnar jointing of the lava lake basalts. Smaller arrows show mea- surements at the summit of the hill, which represent the upper part of lava lake — not used for geometrical reconstruction of volcano edifice. The inset maps show the position of the study area in the border area between Germany, Poland and the Czech Republic with the distribution of the Cenozoic volcanic rocks and volcanic fields. E: Eifel, H: Heldburg dyke swarm, HD: Hessian depression, K: Kaiserstuhl, L: Lusatia (Lausitz), LS: Lower Silesia, OP: Upper Palatinate (Oberpfalz), OR: Ohře rift, R: Rhön, U: Urach volcanic field, V: Vogelsberg and W: Westerwald. Coordinate system: GCS Deutsches Hauptdreiecksnetz (German Grid - Zone 5), Transverse Mercator/Bessel. Map source: TK10, No. 4855SO reproduced with the permission of GeoSN.

Field. Only Panasiuk (1986) reported one older K/Ar age (41.4 Ma) Cretaceous (Voigt, 2009). The Lusatian Massif (Fig. 3)consistsofthe from the Polish part of the Zittau Basin. Cadomian Lusatian Anticline Zone in the south and the Variscan The Landeskrone Volcano is situated in the central part of the Lusa- Görlitz Syncline Zone in the north (Katzung and Ehmke, 1993). Both tian (Lausitz) Massif — an area of continuous uplift since the Upper basement units are separated by the Intra-Lusatian Fault (Innerlausitzer Author's personal copy

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(DEM) and data from boreholes. The DEM had a primary resolution of 20 m and was modified by additional GPS data. In this work we systematically measured orientations of the co- lumnar jointing of massive basalt at 30 locations around the Lande- skrone Hill as reported by Koch et al. (1983). In this paper, the crater slope angle of the Landeskrone Volcano was extrapolated by determination of the inclination of columnar jointing as well as the measurement of the orientation and distribution of the recent contact of pyroclastic (cone) and effusive (lava lake) rocks similar to that shown in Fig. 4. We considered the lowest values of inclination of co- lumnar jointing in basaltic cliffs for the estimation of crater wall slope angle (Table 1, Fig. 5). The reconstruction of the volcanic edifice is calculated trigono- metrically and geometrically by scale drawing of W–E and S–N cross-sections at a scale of 1:5000. The construction was made in con- sidering all the field observations of estimated sizes and orientations of the volcanic remnants. Reconstruction of volcano edifices is a useful tool for the estima- tion of denudation and uplift rates for the post-volcanic time. There- fore, it is necessary to check the volcanic structures and classify them into relevant physical-volcanologic types, such as scoria cone Fig. 3. Geotectonic map of the Lusatian Massif (Eastern Germany). L.V. = Landeskrone fl Volcano, and Zg. = Zgorzelec. volcanoes, lava ows and dykes (analogous to Rapprich et al., 2007). These classes allow the determination of the syn-volcanic elevation of the landscape. The integration of adjacent volcanoes in Störung). The Lusatian Massif is bounded in the south by the Lusatian a broader area increases the significance of results. Thereby, it is Overthrust (Lausitzer Überschiebung) and in the north by the Main possible to estimate the vertical excavation between the volcano Lusatian Fault (Lausitzer Hauptabbruch). remnants. In this study, nine additional volcano-remnants were in- The greatest uplift took place at the southern boundary along the corporated into the determination of the denudation values. The Lusatian Overthrust. Uplifting differs along the fault; the maximum values ancient volcanic structures are situated within distances of 4.5 to reach500minthewesternpartbetweenDresdenandPirna(Alexowsky 13 km of the Landeskrone Volcano. A slightly younger example for et al., 1997; 2001), 700 m in the central part by the Saxon Switzerland Late Miocene to Pliocene intra-plate volcanoes is given in Németh (Sächsische Schweiz) near Hinterhermsdorf (Müller and Wächter, et al. (2003) and Martin and Németh (2004). 1970), and 1000 m for the eastern part of the Lusatian Overthrust in the JěštědareainNorthernBohemia(Adamovič and Coubal, 1999). 4. Field relations The uplift age of the Lusatian Massif is specified by 28 apatite fis- sion track ages by Lange et al. (2008). These ages show a pronounced The shape of the Landeskrone Hill in cross-section view reflects cooling and uplift event for the interval between 85 and 50 Ma, with the boundary between country rock and volcanic rocks by the change an uplift value of 3–3500 m and a denudation rate of 100 m·Ma− 1 in the slope angle (Fig. 6). The distribution of the dense basaltic rocks (100 mm/ka). The samples have been cooled down to surface tem- is elliptical in map view (Fig. 2). They are underlain by pyroclastic peratures since the early Cenozoic. Therefore, Cenozoic denudation rocks of a thickness of up to 10 m. The pyroclastic rocks were directly is negligible in comparison with complete Post-Variscan denudation deposited on the Lusatian Granodiorite which is the country rock, and according to Lange et al. (2008). Mean values of the denudation rate the base of the pyroclastic rocks is nearly horizontal (Figs. 2, 11). for the Central European low mountain ranges vary from 20 to Columnar jointing is developed in dense basaltic rocks in several 80 mm/ka for Upper Cretaceous time (Wagner and van den Haute, diameters and shapes. Columns are smaller (20 to 40 cm) and more 1992). Upper Cretaceous thermotectonic age dates are congruent irregular in contact with the pyroclastic rocks than those a few meters with the uplift age for the Lusatian Overthrust according to Krentz (2008), who deduces the main uplift time for this fault by synchro- nous magmatic dykes with an age between 79 and 48 Ma (mainly by 63 to 53 Ma). The dykes run from NE to SW perpendicular to the Lusatian Overthrust and were opened in connection with the activity of the fault. Krentz (2008) correlated the end of the uplift movements on the Lusatian Overthrust with Upper Eocene sediments in the Zittau Basin to ca. 45–34 Ma (Suhr, 2003). Präger (1964) envisaged younger local tectonic movements for the Middle Pleistocene (app. 400 ka) in the neighboring Berzdorf Basin (Fig. 3). The author estimated a subsi- dence value up to 100 m in the basin and an uplift value up to 50 m in the surrounding Lusatian Highlands (Lausitzer Bergland). Reports of younger neotectonic movements are rare; Präger (1964) supposed a10–15 m subsidence for the post-Saalian time and Tietz (2000) assumed a 3 m subsidence since the Late Glacial (Weichselian) time, both in the Berzdorf Basin (see also Tietz and Büchner, 2011). Fig. 4. Contact zone between scoria wall plane and the marginal remnant of a basaltic lava lake, Schwarzenberg quarry, German Rhön Mountains (E 3566030, N 5578907). 3. Methods The basaltic columns and their typical joints are exactly perpendicular to the cooling contact plane (with a thin cobblestone-like basaltic layer as an endocontact). It is pos- sible to reconstruct the orientation of the plane of the inner crater wall from the dip of The distribution of the volcanic products was mapped using the columnar joints. This uniquely outcrop supplies the analogy for the reconstruction GPS data, interpretations of records from a digital elevation model method for the scoria cone of the Landeskrone volcano. Author's personal copy

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Table 1 Measured dip of columnar jointing of basaltic lava lake remnants in the center of the Landeskrone Volcano and complementary (perpendicular cooling) planes.

Outcrop no. Locality ci sap sd n

1a Old quarry center 357/50 40° ±7.6° 7 1b Old quarry SW-c006Frner 340/57 33° ±8.0° 7 1c Old quarry NE-corner 350/38 52° ±0.0° 1 2 Cliff over cirkleway, northwestern slope 299/42 48° ±4.0° 5 3 Cliff over cirkleway, western slope 286/42 48° ±8.7° 4 4 Cliff over cirkleway, western slope 298/37 53° ±8.6° 4 5 Cliff over cirkleway, western slope 283/42 48° ±5.7° 4 6 Western cliff, northern base 259/59 31° ±5.9° 4 7 Western cliff, southern base 255/58 32° ±2.2° 4 8 Little cliff 242/65 25° ±5.7° 4 9 Little cliff on southern way 181/65 25° ±7.4° 4 10 Little cliff between southern way and road 189/81 09° ±4.6° 5 11 Road upper outcrop 165/75 15° ±5.0° 4 12 Road middle outcrop 151/80 10° ±5.6° 4 13 Road lower outcrop 146/83 07° ±3.2° 3 14 Cliff above Northway 072/62 28° ±5.7° 4 15 Slope above Northway 029/62 28° ±10.3° 4 16 Slope above Northway 017/68 22° ±7.0° 4 17 Northern Slope 020/68 22° ±5.6° 4 18 70 m east from observation tower 120/85 5° ±4.2° 6 19 50 m east from observation tower 150/86 4° ±0.8° 4 20 40 m east from observation tower 165/86 4° ±0.8° 4 21 40 m northeast from observation tower 045/82 8° ±5.6° 4 22 40 m northnortheast from observation tower 066/87 3° ±2.7° 4 23 40 m north from observation tower 300/85 5° ±0° 1 24 55 m northwest from hotel tower 317/88 2° ±1.4° 2 25 Northway, junction of road 200/77 13° ±2.1° 2 26 Road, 50 m southwest from hotel tower 245/86 4° ±0° 2 27 20 m south from Körner monument 036/83 7° ±2.6° 3 28 25 m southeast from observation tower 251/81 9° ±1.7° 3 29 20 m northwest from Bismark tower 165/83 7° ±4.2° 2 30 20 m southeast from Bismark tower 178/84 6° ±1.5° 3 ci: column inclination, sap: slope angle of perpendicular plane. sd: standard deviation, n: number of measurements. away from the contact. The dip direction of the columns corresponds vesicles up to 4 mm in diameter and a few mantle xenoliths are ob- with the slope of the present hill (Fig. 7). The inclination of the basal- served. The rock could be interpreted as an olivine nephelinite. In tic columnar joints transitions to vertical with increasing distance the upper part of the lava body the vesicle content increases (Fig. 9). from the pyroclastic rock contact, and the columns widen up to 1 m We found weakly weathered scoriae in situ in an abandoned quar- in diameter (Fig. 8). The lowest dip values are at the contact with ry on the northern slope of the Landeskrone Hill (Fig. 5). The particle the pyroclastic rocks at about 40° and the highest values rise to 90° size of scoriae could not be determined exactly because of alteration. at the summit of the Landeskrone Hill. The full range of the inclina- However, the pyroclastic rocks seem to be composed mainly of tions is given in Table 1. Altogether the columnar jointing shows a bombs and scoria lapilli; the latter can be observed in thin section 3D periclinal structure around the present hill (Fig. 2, Table 1). The (Fig. 10B). Bedding of the tephra is lacking. The vesicles are round basaltic columns are orientated more or less vertically in the center to flat in shape, partly filled with secondary minerals and appear in of the basalt at the summit of the hill. about 65 vol.% of the whole rock (Fig. 10A,B). In thin sections the sco- The dense basaltic rocks are microlitic. The partly glassy and ria shows a microcrystalline to glassy matrix and is rich in olivine and microcrystalline groundmass contains clinopyroxene, nepheline clinopyroxene phenocrysts up to 1 mm in length (Fig. 10B). The rocks (together 40%), sometimes ore minerals as well as analcim (up to could be interpreted as scoria agglomerates of the scoria cone (wall 10% respectively) and no plagioclase. Olivine (35%) and clinopyroxene facies). (15%) are the phenocrysts; they are partly altered. There are some 5. The volcano edifice

The distribution of volcanic rocks, the occurrence of scoria beds and the orientation of columnar jointing imply that the Landeskrone Hill represents a remnant of a lava lake which is nearly completely preserved in its original thickness. The increase in vesicularity at the summit of the hill coincides with the uppermost part of the lava body where the magmatic gases collected below the quenched lava surface, thus following the internal anatomy of a lava flow (e.g. Schmincke, 2004; Bondre and Hart, 2008) or of the Kilauea Iki Lava Lake, Hawaii (Stovall et al., 2009). Therefore, we assume that the recent height of the basaltic hilltop nearly fits the thickness of the original lava lake. There is a general agreement that columnar joints develop per- pendicularly to the plane of cooling (e.g. DeGraff and Aydin, 1987). Fig. 5. Schematic cross-section of the abandoned quarry on the northern slope of Land- eskrone Hill. Note the inclined basaltic columnar jointing in relation to the recon- The plane of cooling is, in this case, the surface of the scoria cone cra- structed crater surface. ter. Fig. 4 shows a similar situation of a scoria cone remnant in the Author's personal copy

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Fig. 6. The Landeskrone Hill viewed from south. The forest-covered part of the hill divides in two parts: the top with steep slopes represents the basaltic cover and lower down with gentler slopes is the granitic foot. The paleosurface cuts the intersection point between the two geological units.

German Rhön area (Schwarzenberg Hill (Hofbauer, 2004)). The con- our field observations exclude a lava flow from the Landeskrone tact zone between a scoria wall and the remnants of a basaltic lava Volcano. The estimated morphological values of the primordial volca- lake is clearly exposed in the outcrop. no yield a Wcr vs. Wco ratio of 0.63 and an Hco vs. Wco ratio of 0.14, The dip values of the contact between the basalts and the pyro- which are comparable with the modified scoria cone shown in Fig. 2c. clastic rocks reflect the slope angle of the crater wall, similar to the Sizes of primordial scoria cones determined in this way allow the outcrop seen in Fig. 4. Average values of inclination of the columnar estimation of the erupted volume of the original volcano including joints near the contact with the pyroclastic rocks imply a steep the lava lake. This amounts to about 0.1 km3. The lava lake volume ac- slope angle for the crater wall as found by Martin and Németh counts for at least 30% (0.03 km3) of the whole volcano. The recent (2006) for their ‘type 4’ scoria cones. On average we have quantified remnant of the scoria cone has a volume of approximately 0.01 km3. values of about 40 to 50° for the slope angle of the crater wall (Fig. 5, The base of the volcanic rocks is quite horizontal, which implies a Table 1). These values are calculated by using the mean value of the nearly flat pre-volcanic paleosurface. flattest columnar joint cluster (Table 1); all steeper dip values of ba- According to the deduced values above, the geometric construc- saltic columns represent occurrences further inside the lave lake tion of a section through the volcanic edifice suggests the existence

(Figs. 8, 11, Table 1). In reference to our field observations and geo- of a wide vent (Fig. 11). So the Wcr vs. Wco ratio exceeds the value metric construction, the Landeskrone Volcano had a basal cone diam- of 0.40 common for scoria cones (Wood, 1980a). This value and the eter (Wco) of at least 1180 m and a crater width (Wcr) of at least distribution of the country rock could be explained in our case and 750 m and a cone height (Hco) of about 160 m. These sizes were in relation to Fig. 2c by an intensive maar phase and a resulting pit determined under the assumption that the cone, according to the crater (cf. Riedel et al., 2003 and Fig. 11). The underlying diatreme Hawaiian Pu´u ´O´o Crater (Witham and Llewellin, 2006), should be would be 400 to 500 m in diameter corresponding approximately at least one third higher than the level of the lava lake. In our case, with the present outcrop of the massive nephelinite (Fig. 11). The dis- the lava filled the crater up to the height of about 110 m above the tribution of scoriaceous pyroclastic rocks related with the steep slope pre-volcanic paleosurface (Fig. 11). A lower cone would lead to the angle of the crater wall and a wide crater imply a ‘type 4’ scoria cone breaking out of the lava and to the creation of a lava flow. However, according to Martin and Németh (2006, and see below).

Fig. 7. Basaltic columns and their joints on the southern slope of the Landeskrone Hill Fig. 8. Basaltic columnar joints in the center of the lava lake. Outcrop on the road to the with the typical outward dipping present against the former crater wall surface. hotel on the Landeskrone summit. Author's personal copy

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remnants over a distance of 28 km in the vicinity of the Landeskrone Volcano to reconstruct the landscape evolution (Figs. 13, 14 and Table 2). The cross-section cuts different volcanic types. We could distin- guish scoria cone volcanoes (with and without an initial diatreme phase), lava flows and dykes as the chimney of eroded volcanoes (Fig. 14, Table 2). The rocks at Knorrberg and Steinberg Hill (No. 1 and 2 in Figs. 13, 14 and Table 2) represent remnants of basaltic lava flows (Grahmann and Ebert, 1939) and show a recent inversion of relief. The sources of these lava flows are unknown. However, in the case of the Steinberg (Fig. 14), the volcano which erupted these lavas was probably situat- ed at the eastern part of the basaltic rock distribution. We identified also a remnant of a lava lake smaller than that Fig. 9. Polished sample section from vesicular basalt indicates a position close to the at Landeskrone Volcano at Quärgelberg Hill (No. 3 in Fig. 14 and original lava lake surface. Sample from the southern summit of the Landeskrone Hill Table 2). It is situated about 10 km south of the Landeskrone Hill. about 405 m above the sea level. The outcrop shows a similar periclinal structure of basaltic columnar joints and the distribution of volcanic rocks is again elliptical in map 6. Adjacent volcanoes and implications for landscape evolution view. Only the size of the remnant of the volcano is smaller with about 190 m in diameter. Numerous other Cenozoic volcanoes occur in the vicinity of the Hutberg Hill near the village Schönau-Berzdorf (No. 4 in Fig. 14 monogenetic Landeskrone Volcano. The geological ages of these vol- and Table 2) is interpreted as a lava flow (Grahmann and Ebert, canoes are mostly unknown. However, many age determinations in 1939). The outcropping basaltic columns at Hutberg Hill are quite ho- the Lusatian Volcanic Field mainly spread between 30 and 27 Ma mogeneous in size and their inclination is almost vertical. This and (Pfeiffer et al., 1984; Panasiuk, 1986; Suhr and Goth, 2002). Thus, the elongated distribution of the volcanic rocks (Fig. 13) are typical the Landeskrone Scoria Cone represents one of the older Cenozoic for basaltic lava flows. Basaltic rocks on the slope into the Pließnitz volcanoes in eastern Saxony (Pushkarev, 2000). Therefore, we as- River Valley (No. 5 in Fig. 13 and Table 2) represent the continuation sume ages a little younger for the surrounding volcano-remnants. of the lava flow at Hutberg Hill. The associated volcano, which In a north–south cross-section, we used nine additional volcano erupted the lava flows is not known and lies possibly to the south of the Hutberg Hill. A basaltic dyke crops out at the summit of Schwarzer Berg Hill (No. 7 in Fig. 14 and Table 2). This dyke represents the feeder vent of a deeply eroded volcano (Büchner et al., 2006). A remnant of a lava flow, which originated from Schwarzer Berg Hill, can be observed in a small abandoned quarry at the southern slope of this hill (No. 6 in Fig. 13 and Table 2). The basaltic rocks of the two localities show sim- ilar geochemical signatures and originate from the same volcano (Büchner et al., 2006). The different erosion levels suggest tectonic movement on a fault between the two outcrops (Figs. 13 and 14). A further scoria cone-remnant is found in the town of Görlitz at the Hospital Hill (No. 9 in Fig. 14 and Table 2), 4.5 km northeast from the Landeskrone Volcano. In this locality the paleosurface was reconstructed according to boreholes (Berg, 1943 and recent unpub- lished data), more than 50 m below the modern surface. Preliminary studies suggest a large scoria cone which probably erupted in a paleo- valley, comparable in size with the Landeskrone Volcano. The actual Hospital Hill represents a remnant of a lava lake, which filled the cra- ter of this volcano. Post-volcanic tectonic movements cut the volcanic structure in two parts and the central and northern part of the volca- no was recently uplifted and eroded. The young tectonic subsidence conserved the whole south flank of the scoria wall, which is covered by Pleistocene sediments 15 m thick. Therefore, we assume a fault is located at the southern slope of the Hospital Hill (Figs. 13, 14). In addition, a crater-filling structure is observed at Siebenhufen (No. 10 in Fig. 12 and Table 2) about 8 km north of the Landeskrone Hill (Pietzsch, 1909). The estimation of the syngenetic paleosurface of reconstructed volcanoes implies a denudation value of up to 90 m, as shown in Table 2 and Fig. 14. This value could be estimated from the assump- tion that the landscape was flat in volcanic times. Today we find up to 90 m depressions between two adjacent volcano remnants Fig. 10. Volcanic scoriae from the northern foot of the basaltic hill top at 315 m above (Schwarzer Berg Hill, No. 6 and 7 in Figs. 13, 14). However, in the the sea level. a): Macro-photograph from a scoria from a historic sample (image sec- case of the Görlitz Hospital Hill, the scoria cone remnant is covered tion=6 cm) showing flattened and partly filled vesicles. b): Photomicrograph of a by up to 15 m of late Pleistocene sediments, due to local subsidence. thin section from a recent in-situ sample. The mircrophenocrysts are olivine and clin- opyroxene. Note the different shaped vesicles and the impregnation due to secondary The highest values of denudation we estimate at the so-called and ore minerals (plane polarized light). now defined Görlitz Horst (Figs. 13, 14). This uplifted block is Author's personal copy

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Fig. 11. Reconstructed cross-section of the Landeskrone Volcano. Note the virtual shifting of the scoria cone's baseline according to Fig. 1c. Possible high of the cone edifice one-third higher than thickness of the lava lake is shown. Reconstruction according to the geological mapping (Fig. 2) and the dip data of the basaltic columnar jointing (Table 1, Fig. 5). bounded by the already described faults at Schwarzer Berg Hill in the (Figs. 11, 12). The resulting morphometric parameters imply the de- south and Hospital Hill in the north (Figs. 13, 14). velopment of a ‘type 4’ scoria cone after Martin and Németh (2006). Such a volcano has a late phreatomagmatic activity which empties 7. Discussion the vent and creates a pit crater and a volcano edifice as shown in Fig. 12–2. The steep slope angle would be developed by downward 7.1. The Landeskrone Volcano — edifice and degradation movement of scoria cone material into the vent, producing a flat cra- ter floor (Fig. 12–2). In our case, the crater, modified in this way, was The reconstructed measures of the Landeskrone Volcano produce then filled by massive lava. Thus the observed remnant of Lande- a higher Wcr vs. Wco ratio and a lower Hco vs. Wco ratio compared to skrone Volcano is an ancient example of this kind of scoria cone. those of commonly measured ratios (Wood, 1980a; Rodríguez et al., The appearance and distribution of the observed scoria beds are 2010). This result is caused by the steep slope angle of the scoria common successions for scoria cones and exclude other possible in- cone crater wall recalculated from the inclination of the columnar terpretations of the volcanic structure as intrusive magma bodies or jointing of the lava lake basalts at the contact with the crater wall. remnant lava flows. Furthermore, the internal structures of the lava Moreover the geometrically constructed virtual shape of the lava body exclude an interpretation as a subsurface plug as referred by body seems to be extraordinary; according to this shape the lowest Keating et al. (2008) for the Grants Ridge (USA). The authors describe tip of the crater should reach deeply into the ground as shown in horizontal oriented columnar joints as evidence for the sub-volcanic Fig. 11 (see also Fig. 1c). This can only be explained by a pit crater cre- deposition of the lava. At Landeskrone Volcano we observed a 3D ated due to additional phreatomagmatic phases resulting in a maar periclinal structure of columnar jointing. The deposited volcanic diatreme of about 400 to 500 m in width. The sizes of the resulting rocks represent superficial remnants of the volcano and the deter- maar volcano are quite speculative and only shown schematically in mined paleosurface can be found at the contact between pyroclastics Figs. 11 and 12. Additionally, there is no direct evidence for this erup- and the granodioritic basement (Figs. 2, 5, 11). Additionally a pit cra- tion style and hydromagmatic tephra is missing. However, such vol- ter creation due to phreatomagmatic activity could more plausibly canic activity leads to a distortion of the morphometric properties explain the extraordinary shape of the crater itself (Houghton, et al., (Riedel et al., 2003) for example widening and deepening the crater 1999; Martin and Németh, 2006).

Table 2 Data collection for the N–S cross-section reconstruction of the Landeskrone volcano and other surrounding volcano remnants with the subsequently calculated post-volcanic de- nudation values.

No Locality Community Volcanology Reference Altitude Postvolcanic basement Highest Paleo land denutation elevation surface

1 Knorrberg Bernstadt Lava flow Grahmann and Ebert, 1939 378.9 m 325–343 m 10–45 m 2 Steinberg Ostritz Lava flow Grahmann and Ebert, 1939 320.5 m 300–320 m 0 m 3 Quärgelberg Schönau-Berzdorf Crater filling in ?scoria cone 302.4 m 287 m 0–50 m this study (mean 25 m) 4 Hutberg Schönau-Berzdorf Lava flow Grahmann and Ebert, 1939, 309.7 m 275 m 0–50 m this study 5 Pließnitz valley slope Schönau-Berzdorf Lava flow Grahmann and Ebert, 1939 225 m 220 m 0–10 m 6 Schwarzer Berg, southern slope Markersdorf Lava flow Büchner et al., 2006 315 m >315 m > 10–35 m 7 Schwarzer Berg, summit Markersdorf Dyke/initial crater filling Büchner et al., 2006 393.6 m ca 395 m 1–2 (up to 90) m 8 Landeskrone Görlitz Crater filling in scoria cone this study 419.4 m 315 m 0–90 m 9 Hospital Görlitz Scoria cone, lava flow Berg, 1943, this study 222 m 150 m/217 m −10 m 10 Siebenhufen Schöpstal Crater filling in ?scoria cone Pietzsch, 1909, this study 255 m 245 m 0–40 m Author's personal copy

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Fig. 12. Schematic view of the development of the Landeskrone Volcano (not to scale), deduced according to the morphometric reconstruction (Fig. 11). 1 — Strombolian eruptions created a scoria cone after a hypothetical initial hydrovolcanic phase. 2 — A second intensive phreatomagmatic phase produced a maar-diatreme below the scoria cone. The scoria cone has been modified due to excavating the central part of the cone and sliding of the cone material into the enlarged crater. The crater slope became steeper and the scoria cone covered by a tuff cone. 3 — Final effusive phase produced a lava lake.

In case of the Landeskrone Scoria Cone, the volcano edifice should water supply was cut off and strombolian activity produced a scoria be higher (at least 160 m) than ‘type 4’ scoria cones reported by cone over the diatreme (Fig. 12–1). Following Martin and Németh Martin and Németh (2006). Our estimated sizes correspond with (2006), additional phreatomagmatic phases took place and modified the measures of the Crater Elegante in the Pinacate Volcanic Field in the volcano edifice. The scoria cone was cut by hydrovolcanic explo- Sonora (Mexico), which has been described in Gutmann (2002) and sions and the central part of the volcano slid into the diatreme that by Martin and Németh (2006). This volcano had a similar eruption widened the crater in a final phase (Fig. 12–2). The combination of history as that proposed here for the Landeskrone scoria cone. How- scoria cone and maar diatreme volcano causes an unusual shape as ever, we assume initial and late (after scoria cone development) well as morphometric ratios not common for single volcano types. A phreatomagmatic phases at the Landeskrone Volcano. The erupted phreatomagmatic eruption style takes commonly place while the volume of the primordial volcano calculated from a reconstructed magma column is subsiding in the conduit, due to a decreased idealized cone, as shown in Fig. 11, also implies a large sized monoge- magma flux (Gutmann, 2002). This should have happened at Lande- netic scoria cone with a very wide crater filled by lava with a thick- skrone Volcano followed by a rapidly increased magma ascent rate. ness more than 100 m. Scoria cones commonly eject 104 to 109 m3 The wide and flat crater was filled by a lava lake in a single event of juvenile material (Vespermann and Schmincke, 2000). Our recon- (Fig. 12–3). The homogeneous 3D periclinal structure of columnar structed eruption volume amounts about 8.9×107 m3 for the Lande- jointing without any irregularities suggests a lack of later fluctuations skrone Volcano (see above). To our knowledge, there is no published in the lava lake. Due to a flat pre-volcanic surface the cone did not locality requiring such a huge lava lake fill (at least 3×107 m3)ina breach while massive degassed lava filled the cone and produced a monogenetic scoria cone. lava lake in the final stage. Otherwise a scoria cone, situated on an The large size and the amount of lava lake nephelinite could be the inclined surface, would have been broken by the ponded-back lava reason for the preservation of the volcano remnants over such a long (Valentine et al., 2006). period of time (34 Ma) even in an area of uplift and denudation The original height of the crater rim of the scoria cone is an enig- (Fig. 14). A similar situation occurs at Quärgelberg (Figs. 13, 14, ma, because a major part of the scoria cone has been eroded already Table 2) about 10 km south of the Landeskrone Hill. In contrast, scoria and, in addition, there are to our knowledge no references for such cones are often completely degraded and eroded down to the vent huge lava lakes in monogenetic scoria cones. The morphological char- after about five million years (e.g. Wood, 1980b; Hooper and acteristics for only partly welded pyroclastic cones that maintain such Sheridan, 1998). In our case, the remnants of a monogenetic volcano a large lava lake without breaching are unknown. Our assumption of have survived much longer. Further we assume that superficial rem- the cone altitude is defined empirically and is one third higher than nants of scoria cones with a lava lake resist complete degradation the lava level (Fig. 11), conforming to the highest lava lake level at over 30 Ma. Hawaiian Pu´u O´o crater (Witham and Llewellin, 2006). Furthermore, due to intense phretomagmatic eruptions the crater rim should have 7.2. Eruption history of the volcano been elevated and stabilized by deposition of hydrovolcanic tephra (Fig. 12). The eruption style of the monogenetic Landeskrone Volcano can only be supposed to be due to the reconstructed size and shape of 7.3. Landscape evolution the volcanic edifice and the scarcely outcropping pyroclastic rocks. The story perhaps started with an initial phreatomagmatic phase, Neo-volcanoes can add important information on uplift and deg- which probably developed in a weak morphological depression radation rates for old cratons that complement fission track results because the ascending magma came into contact with groundwater. (85–50 Ma for Lusatia area) and the fluvial/glacial sediment leveling Again, there is no direct evidence for this eruption style but in the data (1.5–0.4 Ma). These two methods cannot completely close the Eifel Volcanic Field an initial phreatomagmatic phase has been inter- data gap for the uplift and denudation history for large parts of the preted for nearly all scoria cones (Schmincke, 2004). Afterwards the low mountain ranges in Central Europe because the main uplift took Author's personal copy

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rates for modern uplift and erosion, based on in situ 10Be concentra- tions in fluvial sediments, are available, but data determined with that method have been published for the Central European block- faulted area with values between 15 and 101 mm/ka or between 47 and 65 mm/ka for the Rhenish Massif (Meyer et al., 2010). These high erosion rates indicate intensive neotectonic movement for the Holocene and disequilibrium between erosion and uplift for the uplifted areas in Central Europe. In comparison, very low erosion rates for the investigated part of the Lusatian Massif would imply a steady state since the Oligocene, during which the rock uplift is bal- anced by erosion (Hack, 1976; Willet and Brandon, 2002). At that time, some local tectonic subsidence in the Lusatian Massif occurred with the formation of lignite basins (Brause, 1989a,b; Tietz and Czaja, 2004). No tectonic movements have been recorded by sedi- mentation during Middle and Upper Miocene on the northern margin of the Lusatian Massif (Brause et al., 1964). Tectonic uplift is described for the Pliocene (Bergerat, 1987; Brause, 1989a) and for the syn- and post-Elsterian glacial time in the Middle Pleistocene (Präger, 1964; Wolf and Hirschmann, 1964). Furthermore, the N–S cross-section shows a fracturing within the Lusatian Massif. In addition to the well-established Altbernsdorf Graben, we identify a fault 5 km south of the Landeskrone Hill with a fault vertical displacement of at least 90 m. This fault generat- ed the main uplift of the Landeskrone Volcano since the eruption 34 Ma ago. Additionally, we assume reverse tectonic movement along a fault on the southern margin of Hospital Hill (Figs. 13, 14). Tectonic displacement is also observed on the north-western slope of the Hutberg Hill (No. 4 and 5 in Fig. 13). Here, a lava flow is cut and displaced vertically by about 55 m by the marginal fault of the Altbernsdorf Rift (Fig. 14). These movements indicate morphologic variation due to tectonic processes and that the syn-volcanic landscape was nearly level. Such a planar landscape was created due to the climatic conditions in Tertiary times (e.g. Liedtke and Marcinek, 2002; Suhr, 2003; Rapprich et al., 2007). For example, Suhr (2003) noted several fluvial connections between North Bohemia and East Germany over the recent Erzgebirge Mountains for eight time intervals between the Eocene and Miocene. Further, the absence of coarser sediments in the study area suggests a low re- lief for Upper Lusatia in Tertiary times (Suhr et al., 1992; Tietz and Czaja, 2004). Rapprich et al. (2007) got the same result for the pre- volcanic landscape of the Jičín Volcanic Field (NE Bohemia), 75 km south of the study area. The shapes of the Kozákov lava flow bodies imply a pre-volcanic landscape with “relatively flat relief with wide shallow valleys” (Rapprich et al., 2007, p. 177) for Pliocene times (prior to 5 Ma). The now defined “Görlitz horst”, reconstructed according to the post-volcanic uplift, is a further indication of local tectonic differenti- ation and movement inside the Lusatian Massif during and since the Cenozoic (for comparable indications see Steding and Brause, 1969; Fig. 13. Shaded relief map of eastern Lusatia with the cross-section line of Fig. 14. The Krentz, 2008). locations of main faults which separate the tectonic units are taken from Krentz et al. (2000) and this study. Remnants of volcanic structures selected in Fig. 14 are men- A peak of post-volcanic degradation rate would have occurred tioned with their number (compare Table 2). Coordinate system: see Fig. 2. during the Pleistocene. Basaltic scoria pebbles in glaciofluvial sedi- ments near the 33–27 Ma-old Baruth Scoria Cone Volcano Complex support such neotectonic movements (Tietz et al., 2011a). Today the scoria deposits are nearly completely eroded, but a higher amount place in the Mesozoic and there are no or only rare sediments from of non-weathered scoria pebbles was found in 200 ka-old Saalian-1- that time (Lange et al., 2008). glacial meltwater sediments. These discoveries provide a very long The amount of morphological denudation in this area can be quan- lifetime for the scoria cone and imply a young uplift and denudation tified with up to 90 m being removed since the volcanic activity. This of the northern and central part of the Lusatian Massif. This young value reflects the amount of tectonic uplift during the last 30–27 Ma. age for uplift has possibly prevented an early and complete destruc- Assuming a broad simultaneity between long-term uplift and denu- tion of the Landeskrone Volcano. Pleistocene tectonic movements dation rates in tectonically active areas (Hack, 1976; Willet and are also known from the Berzdorf Basin. The early Pleistocene river Brandon, 2002; Ahnert, 2003), the estimated erosion rate would be terrace shows here a tectonic subsidence from 25 m compared with about 3 mm/ka for the investigation area. In contrast, fission track cal- the basin surroundings. Additionally, a diagenetic compaction of culations provide a value of 100 mm/ka for the whole Lusatian Massif 8 m for the same time during the last 1.2 Ma can be assumed (Tietz in the time period between 85 and 50 Ma (Lange et al., 2008). No and Büchner, 2011). Author's personal copy

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Fig. 14. N–S cross-section through the area surrounding the Landeskrone Volcano remnant with the reconstructed paleosurface at the time of volcanism, approximately 30–27 Ma ago. Location of the cross-section is shown in Fig. 13.

Therefore, the long-lasting degradation of monogenetic scoria Nine volcanic remnants were used to estimate the degradation cones is not only controlled by the size and composition of primary values which closely correspond to the uplift values. The positions volcanic edifices but also by the morphological elevation. Lande- of the syn-volcanic land surface suggest a tectonic differentiation of skrone Hill was twice affected by glaciers in the Elsterian Glacial the study area and a tectonically controlled landscape evolution. (Tietz and Büchner, 2010). The main part of the movement took This preliminary study needs to be extended over the entire place probably immediately after these glaciations in upper Middle Lusatian Volcanic Field and combined with other methods for the re- Pleistocene. Otherwise, the Landeskrone Volcano would have been construction of the landscape evolution, as for example, the river destroyed completely by today. The final destruction of the volcanic development and glaciation history or the cosmogenic 10Be con- edifices was caused by periglacial erosion in the Saalian and Weichse- centration in stream sediments (e.g. Meyer et al., 2010). A 3D model- lian glaciations. ing for more clearly defined monogenetic volcano remnants may lead Furthermore, we assume no or minor uplift and degradation in the to further knowledge for interpreting landscape evolution in space Upper Paleogene and Early Neogene. The tectonic regime in the and time. investigation area is characterized by extensional strain during the Oligocene and Miocene, creating sedimentary basins (Bergerat, Acknowledgments 1987; Tietz and Czaja, 2004). The authors have to thank Károly Németh (Palmerston North, New Zealand) for his helpful preview on the manuscript and professional 8. Conclusions and outlook hints to the topic. Further we are grateful for the digitizing help of August Gummenscheimer (Görlitz, Germany). We thank Catherine This paper shows that reconstruction of the Cenozoic volcano Capellari (Winston-Salem, USA) and Sven Büchner (Friedersdorf, remnants provides a powerful tool for elucidating the uplift and Germany) for improving the language. We wish to thank especially denudation history. Reconstructed volcano edifices provide a well the reviewers Pjotr Migon (Wroclaw, Poland), Peter Suhr (Freiberg, defined landscape situation at given times. Further we show the pos- Germany), Volker Lorenz (Würzburg, Germany), Gregg A. Valentine sibility of reconstructing ancient volcano edifices such as the nephe- (Buffalo, USA) as well as the editors Andrew Plater (Liverpool, UK), linitic Landeskrone Volcano. The explosive phase of the Landeskrone Jean-Claude Thouret (Clermont-Ferrand, France) and Adrian M. Volcano starts and ends with phreatomagmatic eruptions while the Harvey (Liverpool, UK) for their fruitful comments and questions. main activity in between was characterized by strombolian eruptions. The combination of the two eruption styles in this manner created a large combined scoria cone-maar volcano with a wide and deep cra- References ter. This combination of eruption styles led to an extraordinary volca- no morphology — the ratio of the crater rim diameter versus cone Adamovič, J., Coubal, M., 1999. Intrusive geometries and Cenozoic stress history of the northern part of the Bohemian massif. GeoLines 9, 5–14. height does not correspond with that commonly estimated for both Ahnert, F., 2003. Einführung in die Geomorphologie. Ulmer, Stuttgart. (438 pp). end members of the monogenetic volcano types, respectively. The Alexowsky,W.,Wolf,L.,Kurze,M.,Tröger,K.-A.,1997.GeologischeKartedes crater finally was filled by massive lava in a single event. The resulting Freistaates Sachsen 1 : 25 000, Karte und Erläuterungen zu Blatt 5049 monogenetic volcano represents a large and strongly modified scoria Pirna.- 3. edition, Sächsisches Landesamt für Umwelt und Geologie, Freiberg. 118 pp. cone (Fig. 11). The huge lava body inside of the crater has prevented Alexowsky, W., Schneider, J.W., Tröger, K.-A., Wolf, L., 2001. Geologische Karte des the complete erosion of the volcano. In contradiction to Wood Freistaates Sachsen 1 : 25 000, Karte und Erläuterungen zu Blatt 4948 Dresden.- (1980b), the remnant of the volcanic edifice has survived for more 4. Edition, Sächsisches Landesamt für Umwelt und Geologie, Freiberg. 148 pp. Awdankiewicz, M., 2005. Reconstructing an eroded scoria cone: the Miocene Sośnica than 30 Ma. Hill volcano (Lower Silesia, SW Poland). Geological Quarterly 49, 439–448. This long-lasting degradation supports the likelihood of neotec- Berg, G., 1943. Erläuterungen zur Geologischen Karte des Deutschen Reiches im Maßstab tonic movements in the Middle Pleistocene after the affecting glacia- 1 : 25 000, Blatt 4855 Görlitz.- 1. Edition, Reichsamt für Bodenforschung, Berlin. 42 pp. (unpublished). tions. Otherwise, the Landeskrone Volcano would be destroyed Bergerat, F., 1987. Stress fields in the European platform at the time of Africa-Eurasia completely through the glaciation events. collision. Tectonics 6, 99–132. Author's personal copy

186 J. Büchner, O. Tietz / Geomorphology 151–152 (2012) 175–187

Bondre, N.R., Hart, W.K., 2008. Morphological and textural diversity of the Steens Basalt Meyer, H., Hetzel, R., Strauss, H., 2010. Erosion rates on different timescales derived lava flows, Southeastern Oregon, USA: implications for emplacement style and from cosmogenic 10Be and river loads: implications for landscape evolution in nature of eruptive episodes. Bulletin of Volcanology 70, 999–1019. the Rhenish Massif, Germany. International Journal of Earth Sciences (Geologische Brause, H., 1989a. Bewegungsschritte bei der Bildung des Berzdorfer Beckens. Freiberger Rundschau) 99, 395–412. Forschungshefte C434, 26–35. Müller, B., Wächter, K., 1970. Beiträge zur Tektonik der Elbtalzone unter besonderer Brause, H., 1989b. Miozäne tektonische Bewegungen in der SE- Lausitz. Wissenschaftlich- Berücksichtigung der Lausitzer Störung. Geodätische und Geophysikalische Veröf- technischer Informationsdienst (WTI) 30. Reihe A 31–34. fentlichungen, Reihe III 18, 1–51. Brause, H., Steding, D., Schubert, F., 1964. Tektonische Beziehungen zwischen Präter- Németh, K., Martin, U., 1999. Late Miocene paleo-geomorphology of the Bakony– tiär, Tertiär und Quartär in der nördlichen Oberlausitz. Geologie 13, 731–744. Balaton Highland Volcanic Field (Hungary) using physical volcanology data. Zeits- Büchner, J., Tietz, O., Heinisch, H., 2006. The tertiary volcanic rocks of the brown coal chrift für Geomorphologie 43, 417–438. basin of Berzdorf/Upper Lusatia (Saxony) and their siallitic weathering. Zeitschrift Németh, K., Martin, U., Csillag, G., 2003. Calculation of erosion rates based on remnants für geologische Wissenschaften 34, 121–141 (in German, with English abstract). of monogenetic alkaline basaltic volcanoes in the Bakony–Balaton Highland Volca- Cas, R.A.F., Wright, J.V., 1987. Volcanic Successions — Modern and Ancient. Allen & nic Field (western Hungary) of Mio/Pliocene age. GeoLines 15, 93–97. Unwin, London. (528 pp). Panasiuk, M., 1986. Wyniki datowania wieku bezwzglednego law wulkanicznych DeGraff, J.M., Aydin, A., 1987. Surface morphology of columnar joints and its signifi- rejonu Bogatyni metoda potasowo-argonowa. Przeglad Geologiczny 34, 149–152. cance to mechanics and direction of joint growth. Geological Society of America Pfeiffer, L., Kaiser, G., Pilot, J., 1984. K-Ar Datierungen von jungen Vulkaniten im Süden Bulletin 99, 605–617. der DDR. Freiberger Forschungshefte C389, 93–97. Grahmann, R., Ebert, H., 1939. Erläuterungen zur Geologischen Karte von Sachsen Pietzsch, K., 1909. Die geologischen Verhältnisse der Oberlausitz zwischen Görlitz, im Maßstab 1 : 25 000, Blatt 4955 Ostritz.- 2. Edition, Sächsisches geologisches Weissenberg und Niesky. Zeitschrift der deutschen geologischen Gesellschaft 61, Landesamt, Freiberg. 110 pp. 35–133. Gutmann, J.T., 2002. Strombolian and effusive activity as precursors to phreatomagma- Porter, S.C., 1972. Distribution, morphology and size frequency of cinder cones on tism: eruptive sequence at maars of the Pinacate volcanic field, Sonora, Mexico. Mauna Kea Volcano, Hawaii. Geological Society of America Bulletin 84, 382–403. Journal of Volcanology and Geothermal Research 113, 345–356. Präger, F., 1964. Beiträge zur Kenntnis pleistozäner Tektonik in der Oberlausitz. Jahr- Hack, J.T., 1976. Dynamic equilibrium and landscape evolution. In: Melhorn, W.N., buch des Staatlichen Museums für Mineralogie Geologie Dresden, pp. 337–342. Flemal, R.C. (Eds.), Theories of Landform Development. Publications in Geomor- Pushkarev, Y., 2000. Altersbestimmung. – In: Stanek, K. P., Renno, A. D., Jentsch, K., phology, State University of New York, Binghamton, pp. 87–102. Lindner, H., Käppler, R. (Eds.), Interdisziplinäre Auswertung der Forschungsboh- Head, J.W., Wilson, L., 1989. Basaltic pyroclastic eruptions: Influence of gas-release pat- rung Baruth. Abschlussbericht zu einem Forschungs- und Entwicklungsvorhaben terns and volume fluxes on fountain structure, and the formation of cinder cones, des LfUG, Geologisches Institut der TU BA Freiberg. 129 pp. (unpubl.). spatter cones, rootless flows, lava ponds, and lava flows. Journal of Volcanology Rapprich, V., Cajz, V., 2007. The nature of Cenozoic volcanic activity in northeastern and Geothermal Research 37, 261–271. Bohemia. Acta Musei Turnoviensis 2, 21–22. Hofbauer, G., 2004. Ein tertiärer Schlackenkegel in der Rhön. http://gdgh.de/berichte/ Rapprich, V., Cajz, V., Košťák, M., Pécskay, Z., Řídkošil, T., Raška, P., Radoň, M., 2007. Re- b01/b1.pdf2004(2011.08.23). construction of eroded monogenic Strombolian cones of Miocene age: a case study Hooper, D.M., Sheridan, M.F., 1998. Computer-simulation models of scoria cone degra- on character of volcanic activity of the Jičín Volcanic Field (NE Bohemia) and sub- dation. Journal of Volcanology and Geothermal Research 83, 241–267. sequent erosional rates estimation. Journal of Geosciences 52, 169–180. Houghton, B.F., Schmincke, H.-U., 1986. Mixed deposits of simultaneous strombolian Riedel, C., Ernst, G.G.J., Riley, M., 2003. Controls on the growth and geometry of pyro- and phreatomagmatic volcanism: Rothenberg volcano, East Eifel Volcanic Field. clastic constructs. Journal of Volcanology and Geothermal Research 127, 121–152. Journal of Volcanology and Geothermal Research 30, 117–130. Rodríguez, S.R., Morales-Barrera, W., Layer, P., González-Mercado, E., 2010. A quaterna- Houghton, B.F., Wilson, C.J.N., Smith, I.E.M., 1999. Shallow-seated controls on styles of ry monogenetic volcanic field in the Xalapa region, eastern Trans-Mexican volcanic explosive basaltic volcanism: a case study from New Zealand. Journal of Volcanol- belt: geology, distribution and morphology of the volcanic vents. Journal of Volca- ogy and Geothermal Research 91, 97–120. nology and Geothermal Research 197, 149–166. Katzung, G., Ehmke, G., 1993. Das Prätertiär in Ostdeutschland. S. v. Loga, Köln. (139 pp). Schmincke, H.-U., 2004. Volcanism. Springer, Berlin, Heidelberg, New York. (324 pp). Keating, G.N., Valentine, G.A., Krier, D.J., Perry, F.V., 2008. Shallow plumbing systems for Schröder, B., Peterek, A., 2002. Känozoische Landschaftsentwicklung in Südthüringen. small-volume basaltic volcanoes. Bulletin of Volcanology 70, 563–582. Beiträge der Geologie Thüringens, N.F. 9, 9–26. Kereszturi, G., Németh, K., Csillag, G., Kovács, J., Balogh, K., 2011. The role of external Shaw, C.S.J., 2004. The temporal evolution of three magmatic systems in the West Eifel environmental factors in changing eruption styles of monogenetic volcanoes in a volcanic field, Germany. Journal of Geophysical Research 131, 213–240. Pliocene continental volcanic field in western Hungary. Journal of Volcanology Steding, D., Brause, H., 1969. Beziehungen zwischen Grund- und Deckgebirge in der and Geothermal Research 201, 227–240. Oberlausitz. In: Hirschmann, G., Brause, H. (Eds.), Exkursionsführer Alt- und Vor- Kienle, J., Kyle, P.R., Self, S., Motyka, R., Lorenz, V., 1980. Ukinrek Maars, Alaska, 1.April paläozoikum des Görlitzer Schiefergebirges und der westlichsten Westsudeten 1977 eruption sequence, petrology and tectonic setting. Journal and Geothermal zum Treffen des Fachverbandes Geologie vom 7.-10.9.1969 in Görlitz. Deutsche Research 7, 11–37. Gesellschaft für Geologische Wissenschaften, Berlin, pp. 35–41. Koch, L., Pfeiffer, L., Stammler, L., Beeger, D., 1983. Der Basalt von Stolpen in der Lausitz. Stovall, W.K., Houghton, B.F., Harris, A.J.L., Swanson, D.A., 2009. Features of lava lake Abhandlungen des Staatlichen Museums für Mineralogie und Geologie Dresden 32, filling and draining and their implications for eruption dynamics. Bulletin of Volca- 1–144. nology 71, 767–780. Krentz, O., 2008. Postvariszische tektonische Entwicklung. In: Pälchen, W., Walter, H. Suhr, P., 2003. The Bohemian Massif as a catchment area for the NW European Tertiary (Eds.), Geologie von Sachsen – Geologischer Bau und Entwicklungsgeschichte. Basin. GeoLines 15, 147–159. Schweizerbart, Stuttgart, pp. 472–478. Suhr, P., Goth, K., 2002. Maare - eine lange Zeit unbekannte Erscheinungsform des ter- Krentz, O., Kozdrój, W., Opletal, M. (Eds.), 2000. Geological Map Lausitz-Jizera- tiären Vulkanismus in der Oberlausitz. Berichte der Naturforschenden Gesellschaft Karkonosze 1:100000 (without Cenozoic sediments). Freiberg, Warszawa, Praha, der Oberlausitz 10, 27–35. 3 sheets. Suhr, P., Schneider, W., Lange, J.-M., 1992. Facies relationships and depositional envi- Lange, J.-M., Tonk, Ch., Wagner, G.A., 2008. Apatitspaltspurdaten zur postvariszischen ronments of the Lausitzer (Lusatic) Tertiary. 13th IAS Regional Meeting on Sedi- thermotektonischen Entwicklung des sächsischen Grundgebirges – erste Ergeb- mentology, Jena, Excursion Guide-Book, pp. 229–260. nisse. Zeitschrift der deutschen Gesellschaft für Geowissenschaften 159, 123–132. Tietz, O., 2000. Der Schädelfund eines Urs (Bos primigenius Bojanus 1827) aus dem Liedtke, H., Marcinek, J., 2002. Physische Geographie Deutschlands. Justus Perthes Ver- Braunkohlentagebau Berzdorf in der Oberlausitz. Abhandlungen und Berichte des lag, Gotha. (786 pp). Naturkundemuseums Görlitz 72, 215–233. Lorenz, V., 1986. On the growth of maars and diatremes and its relevance to the forma- Tietz, O., Büchner, J., 2007. Abundant in-situ zircon megacrysts in Cenozoic basaltic tion of tuff rings. Bulletin of Volcanology 48, 265–290. rocks in Saxony, Germany. Zeitschrift der deutschen Gesellschaft für Geowis- Lorenz, V., Büchel, G., 1980. Zur Vulkanologie der Maare und Schlackenkegel der Wes- senschaften 158, 201–206. teifel. Mitteilungen der Pollichia 68, 29–100. Tietz, O., Büchner, J., 2010. Geologie: Ein Gneisgeschiebe auf der Landeskrone. In: Tietz, Lorenz, V., Kurszlaukis, S., 2007. Root zone processes in the phreatomagmatic pipe em- O., Dunger, W. (Eds.), Neues aus der Natur der Oberlausitz für 2009: Berichte der placement model and consequences for the evolution of maar-diatreme volcanoes. Naturforschenden Gesellschaft der Oberlausitz, 18, pp. 141–142. Journal of Volcanology and Geothermal Research 159, 4–32. Tietz, O., Büchner, J., 2011. Die Neiße-Hochterrasse in Hagenwerder – Ein temporärer Lorenz, V., Suhr, P., Goth, K., 2003. Maar-Diatrem-Vulkanismus – Ursachen und Folgen. Aufschluss mit Aussagen zur quartären Senkungsgeschichte des Berzdorfer Beck- Die Guttauer Vulkangruppe in Ostsachsen als Beispiel für die komplexen Zusam- ens. Berichte der Naturforschenden Gesellschaft der Oberlausitz 19, 117–121. menhänge. Zeitschrift für geologische Wissenschaften 31, 267–312. Tietz, O., Czaja, A., 2004. Die Braunkohlenlagerstätte Berzdorf – Geologie, geologische Lustrino, M., Wilson, M., 2007. The circum-Mediterranean anorogenic Cenozoic igne- Substrate und Paläobotanik. Berichte der Naturforschenden Gesellschaft der Ober- ous province. Earth Science Reviews 81, 1–65. lausitz 11, 57–76. Martin, U., Németh, K., 2004. Late Miocene to Pliocene palaeogeomorphology of the Tietz, O., Büchner, J., Suhr, P., Abratis, M., Goth, K., 2011a. Die Geologie des Baruther Schaf- western Pannonian Basin based on studies of volcanic erosion remnants of small- berges und der Dubrauker Horken – Aufbau und Entwicklung eines känozoischen volume intraplate volcanoes. Geologica Hungarica, series geologica 26, 57–72. Vulkankomplexes in Ostsachsen. Berichte der Naturforschenden Gesellschaft der Martin, U., Németh, K., 2006. How Strombolian is a “Strombolian” scoria cone? Some Oberlausitz Supplement to Vol. 18, 15–48 (in German, with English abstract). irregularities in scoria cone architecture from the Transmexican Volcanic Belt, Tietz, O., Gärtner, A., Büchner, J., 2011b. The monogenetic Sonnenberg scoria cone — near Volcán Ceboruco, (Mexico) and Al Haruj (Libya). Journal of Volcanology and implications for volcanic development and landscape evolution in the Zittauer Geothermal Research 155, 104–118. Gebirge Mountains since the Paleogene. Zeitschrift für Geologische Wissenschaf- McGetchin, T.R., Settle, M., Chouet, B.A., 1974. Cinder cone growth modeled after ten 39, 311–334. Northeast Crater, Mount Etna, Sicily. Journal of Geophysical Research 79, Valentine, G.A., Gregg, T.K.P., 2008. Continental basaltic volcanoes — processes and 3257–3272. problems. Journal of Volcanology and Geothermal Research 177, 857–873. Author's personal copy

J. Büchner, O. Tietz / Geomorphology 151–152 (2012) 175–187 187

Valentine, G.A., Perry, F.V., Krier, D., Keating, G.N., Kelley, R.E., Cogbill, A.H., 2006. Small- Willet, S.D., Brandon, M.T., 2002. On steady states in mountains belts. Geology 30, volume basaltic volcanoes: eruptive products and processes, and post-eruptive 175–178. geomorphic evolution in Crater Flat (Pleistocene), southern Nevada. Geological So- Witham, F., Llewellin, E.W., 2006. Stability of lava lakes. Journal of Volcanology and ciety of America Bulletin 118, 1313–1330. Geothermal Research 158, 321–332. Vespermann, D., Schmincke, H.-U., 2000. Scoria cones and tuff rings. In: Sigurdsson, H., Wohletz, K.H., 1986. Explosive magma-water interactions: thermodynamics, explosion Houghton, B.F., McNutt, S.R., Rymer, H., Stix, J. (Eds.), Encyclopedia of Volcanoes. mechanisms, and field studies. Bulletin of Volcanology 48, 245–264. Academic Press, San Diego, pp. 683–694. Wohletz, K.H., Sheridan, M.F., 1983. Hydrovolcanic explosions — 2. Evolution of basaltic Voigt, T., 2009. Die Lausitz-Riesengebirgs-Antiklinalzone als kreidezeitliche Inversions- tuff rings and tuff cones. American Journal of Science 283, 385–413. struktur: Geologische Hinweise aus den umgebenden Kreidebecken. Zeitschrift für Wolf, L., Hirschmann, G., 1964. Postume pleistozäne Bruchtektonik in der östlichen Geologische Wissenschaften 37, 15–39. Oberlausitz. Geologie 13, 1229–1234. Wagner, G.A., van den Haute, P., 1992. Fisson-track Dating. Enke, Stuttgart. (285 pp). Wood, C.A., 1980a. Morphometric evolution of cinder cones. Journal of Volcanology Wedpohl, K.H., Baumann, A., 1999. Central European Cenozoic plume volcanism with and Geothermal Research 7, 387–413. OIB characteristics and indications of a lower mantle source. Contributions to Min- Wood, C.A., 1980b. Morphometric analysis of cinder cone degradation. Journal of Vol- eralogy and Petrology 136, 225–239. canology and Geothermal Research 8, 137–160.