<![CDATA[1A Collections]]>

<![CDATA[1A Collections]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/browse?sort_field=added&page=11&sort_dir=d&output=rss2 Tue, 09 Apr 2024 21:23:31 +0100 p1acollections@esc.cam.ac.uk (1A Collections) Zend_Feed http://blogs.law.harvard.edu/tech/rss <![CDATA[Lamellar twinning]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/169

Title

Lamellar twinning

Subject

Many parallel twins can be produced within one mineral grain by multiple parallel twin planes. This is known as lamellar twinning. It is a diagnostic characteristic of plagioclase feldspar, and is sometimes referred to as albite twinning.

]]> Fri, 21 Jun 2019 14:16:10 +0100 <![CDATA[Albite twinning]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/168

Title

Albite twinning

Subject

Named after albite (Na-plagioclase) twinning on the (010) crystallographic plane.
See lamellar twinning.

]]> Fri, 21 Jun 2019 14:15:20 +0100 <![CDATA[Aeolian]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/167

Title

Aeolian

Subject

Relating to or arising from the action of the wind; aeolian sediments are wind-blown. Also spelt eolian.

Description

Have a look at the ferruginous arenite sandstone (L326) in the 1A Reference Series.

]]> Fri, 21 Jun 2019 14:14:55 +0100 <![CDATA[Adamantine [lustre]]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/166

Title

Adamantine [lustre]

Subject

Minerals displaying a diamond-like lustre are described as adamantine. These minerals are transparent or translucent and have very high refractive indices, producing the high degree of lustre. Zeolites, for example, have adamantine lustre.

]]> Fri, 21 Jun 2019 14:13:18 +0100 <![CDATA[Acicular]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/165

Title

Acicular

Subject

Acicular means needle-shaped. The term is usually applied to crystal form.

]]> Fri, 21 Jun 2019 14:11:34 +0100 <![CDATA[TF0625 Acaste downingiae]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/164

Title

TF0625

Acaste downingiae

Description

Species

Acaste downingiae

Stratigraphic Range

Silurian to Devonian

Taxonomy

Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Family: Acastidae
Genus: Acaste

Distinctive Features

Glabella (with ridges)
Eyes
Cephalon
Thorax
Pygidium

Preservation

External mould (manmade cast)

]]> Fri, 21 Jun 2019 12:31:53 +0100 <![CDATA[TF0624 Homalonotus delphinocephalus]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/163

Title

TF0624

Homalonotus delphinocephalus

Description

Species

Homalonotus delphinocephalus

Stratigraphic Range

Silurian

Taxonomy

Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Genus: Homalonotus

Distinctive Features

Cephalon
Thorax
Pygidium
Eyes (holochroal)

Preservation

External mould (manmade cast)

]]> Fri, 21 Jun 2019 12:30:41 +0100 <![CDATA[TF0623 Dalmanites]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/162

Title

TF0623

Dalmanites

Subject

Specimen Age

Silurian

Description

Stratigraphic Range

Silurian to Devonian

Taxonomy

Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Genus: Dalmanites

Distinctive Features

Schizochroal eyes
Thorax
Cephalon
Pygidium

Preservation

External mould (manmade cast)

Advanced notes

Dalmanites always has 11 segments in the thorax

]]> Fri, 21 Jun 2019 12:29:15 +0100 <![CDATA[TF0622 Calymene blumenbachi]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/161

Title

TF0622

Calymene blumenbachi

Description

Species

Calymene blumenbachi

Stratigraphic Range

Silurian

Taxonomy

Phylum: Arthropoda
Class: Trilobita
Order: Phacopida
Genus: Calymene

Distinctive Features

Cephalon
Thorax
Pygidium
Eyes

Preservation

External mould

Advanced notes

Calymene blumenbachi likely lived as a predatory or scavenging animal in shallow waters. Its good vision would have allowed it to identify suitable prey/food.

]]> Fri, 21 Jun 2019 12:25:38 +0100 <![CDATA[TF0614 Odontopleurid]]> https://wserv3.esc.cam.ac.uk/p1acollections/items/show/160

Title

TF0614

Odontopleurid

Description

Stratigraphic Range

Ordovician to Silurian

Taxonomy

Phylum: Arthropoda
Class: Trilobita
Order: Odontopleurida
Family: Odontopleuridae

Distinctive Features

Cephalon
Thorax
Pygidium
Spines

Preservation

External mould (manmade cast)

]]> Fri, 21 Jun 2019 12:23:54 +0100