611

Site number:

611

Authors:

IBC, GGGC, MRB

Date recorded:

1990/01/23

Reason Sampled:

Mineralogical and weathering examination

Description:

At the northern of Marble Point region, approximately 1.9km west of Gneiss Point; on an undulating surface 150m south of a dolerite knoll; an exposure of brown 'golden shale'

Altitude:

55 m

Aspect:

Nil

Slope:

0 °

Climate

Soil climate zone:

Coastal Antarctic

Estimated mean annual temperature:

-18 °C

Frozen ground depth:

0 cm

Frozen type:

Frozen comment:

Geology

Geological setting:

A deposit described as Golden Shale occurs over about 100ha and has scattered erratics on the surface; the deposit is not seen in situ but larger fresh fragments occur around an old explosion pit; the material has been determined to be phillipsite, thought to have originated from the deposition of volcanic ash into a saline lake, and is believed to be several million years old, possible of similar age to other phillipsite deposits recorded elsewhere in the Dry Valleys; this deposit is significant as it sets a minimum age for the uplift of Wright Valley Fiord; the material is extremely fissile, has a low density and is distinctly banded

Patterned ground:

Micro cryic features; many rock fragments lying vertically

Surface weathering or surface features:

Surface erratics indicate subsequent ice-sheet over-riding

Soil

Soil parent material:

sampled only for mineralogical examination

Previous disturbance:

Engineering examinations

Soil weathering stage:

6

Soil moisture status:

Biological activity:

Nil