Red Crag formation, Bawdsey beach.

This specimen was collected in September 2021 on our annual weekend away. The location was Bawdsey beach in Suffolk, which has the most extensive outcrop of the Red Crag formation in South Eastern Sussex,  a formation that also has outcrops in North Eastern Essex. The Red Crag formation is sandwiched between the Norwich Crag formation and the Coralline Crag formation, a specimen of which is also on this website. The age is between Late Pliocene and Early Pleistocene, 3.3 - 2.5 Ma.  The Red Crag  is typically composed of a course grained shelly sand, the most common of the fossils being bivalves and gastrapods. This particular specimen is indurated Red Crag from the basement beds, and also has prominent phosphate rich mudstone pebbles, sometimes mistaken for coprolites, and some pieces of flint.

Serpentine, Anglesey.

The principle outcrop of serpentinite in Anglesey is near Rhoscolyn, from where I collected this specimen. The main component of the serpentinite is serpentine, which is  serpentin-ized gabbro. It is a brecciated rock with inclusions of calcite. When handled it has a very "soapy" feel.

Serpentinite. bastite serpentine.

This specimen of bastite serpentine is from Kynance cove in Cornwall. Serpentinite is a coarse grained  rock composed of one or more of the serpentine minerals. Heat and pressure was applied to peridotite as it moved upwards from the moho, the resulting metamorphic process creating  serpentinite. The primary serpentine mineral at Kynance cove is bastite sepentine, the other being tremolite.

Concretion - High detail. Mid Wales.

This concretion was collected a few days ago, August 2021. The location is a quarry at Bwlch-y-Sarnau in Powys. The detail in this cone in cone variety of concretion is outstanding, with high detail in the cross section, and very pronounced cone tops. It appears to be a broken section of a much larger rock. The detail is so clear that the specimen could be a helpful aid in understanding the formation and growth of concretions. This specimen is now in the possession of Tim Holt Wilson.

Mica schist. Ontario, Canada.

Schist is a medium grade crystalline metamorphic rock. It's metamorphism from mudstone, shale, or sometimes igneous rock, is the result of higher pressure and temperature, than that needed to form slate. The crystals are larger than those of slates, and are visible to the unaided eye. Several minerals can determine the type of schist, i.e. garnet schist, talc schist, graphite schist, chlorite schist, but the most common type of schist is mica schist. Mica schist contains quartz with biotite mica or muscovite mica as the dominant minerals. This specimen from Ontario in Canada displays the silvery appearance that is attributed to muscovite mica.