Morozumi Range

In the next section, the geology of the Morozumi Range and of the Lanterman and Salamander Ranges will be discussed separately because their tectonic settings differ from that of the Daniels Range in the western province of the Wilson Terrane. 

The metasedimentary rocks were intruded by vein-like bodies of granitic rock. The outcrop pattern of one such body forms the light-colored arch in this picture (Adapted from Tessensohn et al. 1981, Fig. 5, p. 50) 

Age determinations by the whole-rock Rb-Sr method listed in Appendix 4.8.3.10 of granites in the Morozumi Range have yielded dates of 515 28 Ma ( Sr/ Sr) = 0.7136 0.0022 (Middle Cambrian) for the Adamellite Massif at the north end of the range and a lower date of 478 14 Ma ( Sr/ Sr). = 0.7092 0.0008 for granitic rocks in the Jupiter Amphitheater and in Unconformity Valley (Vetter et al. 1983 Kreuzer et al. 1987). The K-Ar dates of biotite and muscovite in the Granite Harbor Intrusives of the Morozumi Range in Fig. 4.16 

Granite Harbor Intrusives in the southern Daniels Range and elsewhere in northern Victoria Land. Therefore, the Granite Harbor pluton in the Morozumi Range formed from a sedimentary proto-liths without achieving complete homogenization of the isotopic composition of strontium. 

The Morozumi Range has preserved a record of past fluctuations of the volume of the ice in the Rennick Glacier in late Tertiary lime (Denton et al. 1986). The evidence presented by Mayewski (1975, 1976), Mayewski and Attig (1978), and by Mayewski et al. (1979) indicates that the Rennick Glacier covered all 

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Fig. 4.2 Northern Victoria Land consists of three terranes that are separated from each other by the Leap Year and Lanterman faults. Each terrane is composed of characteristic assemblages of metasedimentary and metavolcanic rocks of Neoproterozoic and Cambrian ages. These basement rocks were locally intruded by plutons of the Granite Harbor Intrusives and by the younger Admiralty Intrusives. Rocks of the Beacon Supergroup occur only in a few places in northern Victoria Land including in the Morozumi Range and HeUiwell HiUs, in the adjacent Freyberg Mountains, and in the Lichen HiUs. The Kukri Peneplain, which is so prominent in southern Victoria Land, is only preserved in these locations (Adapted from Stump 1995)...

Fig. 4.14 View of the northern end of the Morozumi Range where light-colored adamellite is in contact with black metased-imentary rocks that were assigned to the Robertson Bay Group by Gair et al. (1969) and by Tessensohn et al. (1981).

The comparison of the initial Sr/ Sr ratios in Fig. 4.17 supports the conclusion that the feldspar in the till of the Morozumi Range originated primarily from the Granite Harbor Intrusives (GHI) and not from the Rennick Schist (RS) and the Wilson Gneiss (WG) which are exposed in the Daniels Range and in the adjacent Lanterman and Salamander ranges in Fig. 4.14. 

Unconformity Valley 4.8.3.11 Granite Harbor Intrusives, Morozumi Range, K-Ar MOl Adamellite Adamellite Massif B 476 2 2... 

Figure 4.31 Wilson Gneiss, Daniels Range Figure 4.32 Turbidites, Robertson Bay Group Figure 4.33 Beacon Sandstone, Morozumi Range...

Engel S (1984) Petrogenesis of contact schists in the Morozumi Range, north Victoria Land. Geologisches Jahrbuch, B 60 167-186... 

Faure G (1986) Provenance of feldspar in till from the Morozumi Range, northern Victoria Land. In Stump E (ed) Geological investigations in Northern Victoria Land. Antarctic Research Series, vol. 46. American Geophysical Union, Washington, DC, pp 377-381... 

A second cluster of outcrops of Beacon rocks in Fig. 10.12 within the Rennick basin includes the Freyberg Mountains, the Morozumi Range, the HeUiwell Hills, as well as the Lanterman and Salamander ranges. The Beacon rocks of northern Victoria Land lie uncom-formably on the metasedimentary rocks of the basement... 

Each outcrop of Beacon rocks is unconformable to underlying pre-Permian basement rocks and the three formations identified in this table are not in contact with each other. The only exception is the basal breccia which grades into the overlying Takrouna Formation in the Neall Massif and at the DeGoes Cliff at the southern end of the Morozumi Range in Fig. 10.12. 

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