| Autor: |
Sutherland, R, Toy, V, Townend, J, Eccles, J, Prior, DJ, Norris, RJ, Mariani, E, Faulkner, DR, De Pascale, G, Carpenter, BM, Boulton, C, Menzies, CD, Cox, SC, Little, TA, Hasting, M, Cole-Baker, Langridge, RM, Scott, HR, Lindroos, ZR, Fleming, B, Wing, R |
| Rok vydání: |
2011 |
| DOI: |
10.21420/g2hc76 |
| Popis: |
The first phase of the Deep Fault Drilling Project (DFDP-1), Alpine Fault, was carried out in January and February 2011 at Gaunt Creek, South Westland, New Zealand. Two boreholes, DFDP-1A and DFDP-1B, were drilled to depths of 101 m and 151 m respectively. DFDP-1A cored a hangingwall mylonite sequence containing cataclasite zones that increase in frequency downward; 20–30 m of cemented and hydrothermally altered cataclasites; a >5 cm-thick principal slip surface of ultracatalasite and gouge at 90 m; and footwall fluvial gravels to a total depth of 100.6 m. DFDP-1B cored a similar hangingwall sequence; encountered a principal slip surface with a thickness of about 20 cm at depth of 128 m; penetrated a footwall sequence of quartz- and feldspar-rich, extensively altered and variably cataclased rock including a significant fault at 130 m; and reached a total depth of 151.4 m. A broad suite of downhole geophysical logs was collected using acoustic televiewer, neutron, full-waveform sonic, density, dipmeter, and electromagnetic flowmeter sondes. A fault zone observatory was installed in the DFDP-1B borehole, consisting of a seismometer near the base; a 25 mm internal diameter alkathene fluid sampling tube (perforated above the seismometer in the footwall); four vibrating-wire piezometers with inbuilt temperature sensors; 20 platinum RTD temperature sensors on two separate strings; and surface infrastructure providing security and housing the power supply and recording equipment. DFDP-1A was cased to 81 m depth and had a seismometer installed at the base of the casing, connected to the observatory equipment mounted above DFDP-1B. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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