Doctors Rocks is both a geographical feature and a district on the north-west coast of Tasmania between Somerset and Wynyard, approximately 62 kms west of Devonport.
Doctors Rocks is a geographical feature of a basalt outcrop on the beachfront, behind which an escarpment rises to the north west coast plateaux. The terrain forced early road builders to construct a narrow roadway behind the rocks that was the scene of many serious accidents before modern vehicular traffic forced major earth moving and resisting of the main road further away from the rocks.
In addition to basalt several trace minerals occur on site including gold, the presence of which has attracted gold panners for decades.
This formation contains quartzites and slates outcropping along the foreshore at West Burnie. It appears to outcrop from east of Howth to Doctor's Rocks, except where covered by a superficial layer of later material. The formation is probably several thousand feet thick and consists mostly of a monotonous repetition of thin slates and quartzites. The argillites are dark-grey to black siltstones or slates which show a cleavage which is strongly developed in some specimens but lacking in others. Some contain abundant clastic mica and others are graphitic. Many of the coarser siltstones exhibit cross-bedding, scouring and other intraformational structures. The quartzites are generally light-coloured, quartzose, and massive, flaggy or thinly bedded with occasional cross bed folding. Thin sections of many quartzites show that they contain angular quartz fragments and this fact, together with their association with some beds of sub-greywacke, indicate that they are not normal ortho-quartzites. Some arenite layers contain abundant angular slate fragments up to eight inches long. The lack of recognizable marker horizons, together with the close folding and faulting prevents the accurate measurement of the thickness of this formation. The beds generally dip to the west, but small folds are abundant and these are asymmetrical with the steeper limb either to the east or west, but with a general fiat plunge in a direction 230'. Faults are common and cause difficulty in interpreting the structure, and are frequently associated with zones of contortion.
At this location, Basalt columns can be seen containing Xenoliths of a mineral.
Xenolith
A xenolith is a rock fragment which becomes enveloped in a larger rock during the latter's development and hardening. In geology, the term xenolith is almost exclusively used to describe inclusions in igneous rock during magma emplacement and eruption. Xenoliths may be engulfed along the margins of a magma chamber, torn loose from the walls of an erupting lava conduit or explosive diatreme or picked up along the base of a flowing body of lava on the Earth's surface. A xenocryst is an individual foreign crystal included within an igneous body. Examples of xenocrysts are quartz crystals in a silica-deficient lava and diamonds within kimberlite diatremes. Although the term xenolith is most commonly associated with igneous inclusions, a broad definition could include rock fragments which have become encased in sedimentary rock. Xenoliths are sometimes found in recovered meteorites. To be considered a true xenolith, the included rock must be identifiably different from the rock in which it is enveloped; an included rock of similar type is called an autolith or a cognate inclusion.
Q1 The posted coordinates will bring you to parking area on the side of the road. Describe the the rock and the colours that you see here.
Q2 Which way do the beds generally dip?
Q3 How old are the sediments that lie here and what mineral is contained in the basalt?
Once you complete the EarthCache requirements you can post your find without delay, as per the EarthCache guidelines. You will also need to verify your find by sending me a message and provide your answers to the questions.
For a link to my profile, click here - Na'wal
Thanks for visiting this Earth Cache. Hope you enjoy it. Feel free to attached photos to your log (optional) 
.
References ~Department of Geology, University of Tasmania & wikipedia