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Copyright by Nysha Chaderton 2009 - The University of Texas at ...

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element number 6 has the mostly deeply eroded base <strong>at</strong> this loc<strong>at</strong>ion with approxim<strong>at</strong>ely<br />

5 m <strong>of</strong> scour (Figure 2.15). Together the eight stacked channel elements form a channel<br />

complex in the sense <strong>of</strong> Campion (2000) (Figure 2.8 and 2.15). <strong>The</strong> upper portion <strong>of</strong> the<br />

outcrop is characterized <strong>by</strong> 10 m <strong>of</strong> lamin<strong>at</strong>ed silts, muds and rare sand beds th<strong>at</strong><br />

comprise Facies 6. It is possible th<strong>at</strong> more <strong>of</strong> this facies existed <strong>at</strong> one, time but was<br />

eroded. Thin bedded turbidite deposits th<strong>at</strong> overlie a channel complex such as those <strong>of</strong><br />

Facies 6 <strong>at</strong> this loc<strong>at</strong>ion, record an abandonment <strong>of</strong> the channel complex in space or time<br />

(Schwarz and Arnott, 2007).<br />

Chalky Mount Lower (CML)<br />

This section is loc<strong>at</strong>ed <strong>at</strong> the base <strong>of</strong> the prominent Chalky Mount Ridge.<br />

Although the contact between the two areas is obscured <strong>by</strong> thick veget<strong>at</strong>ion, it is thought<br />

to be a fault due to the appearance th<strong>at</strong> the entire Chalky Mount Upper package seems to<br />

have been thrust into place with beds <strong>at</strong> the southern end <strong>of</strong> the outcrop as the beds are<br />

almost vertical. <strong>The</strong> Chalky Mount Upper package is nevertheless still interpreted to<br />

overlie the Chalky Mount Lower <strong>at</strong> this locality. However, one must bear in mind th<strong>at</strong><br />

the upper part has been displaced some unknown distance from its original loc<strong>at</strong>ion <strong>of</strong><br />

deposition.<br />

Description<br />

<strong>The</strong> Chalky Mount Lower (CML) section is a large thickness <strong>of</strong> finer-grained<br />

sediments geographically loc<strong>at</strong>ed bene<strong>at</strong>h the Chalky Mount Upper section. However,<br />

the exact str<strong>at</strong>igraphic rel<strong>at</strong>ionship to the CMU is not known due to separ<strong>at</strong>ion <strong>of</strong> the two<br />

intervals <strong>by</strong> a thrust fault.<br />

<strong>The</strong> CML consists <strong>of</strong> 50 meters <strong>of</strong> continuous section characterized <strong>at</strong> its base <strong>by</strong><br />

several thicker bedded (20-70 cm), sharp-based, coarse-grained sands (Figure 2.16a-c).<br />

11

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