### substance | earth:

Moraine
* Most moraine is part of glaciers
  - moraines have young apparent exposure ages, with only a few older than the last glacial cycle
* Some moraines form under the ice, others form in front of the ice.
* appear as hill or ridges marking original glacial limits.
* are glacial depositional landforms
  - deposits laid down along the margins of glaciers
  - hummocky , hilly , and can be steep
  - mostly soil and rocks
  - ridges of drift formed by moving ice
* can also create moraine dammed lakes.
* is Norway's most common type of superficial deposit
  - dominated by mud-rich till and poorly sorted debris flows
  - in southwest location of Dayton metropolitan area
  - material transported by a glacier and then deposited
  - sites
  - till deposits which are made up of hills and depressions
* only show up in places that have, or used to have, glaciers.
* sometimes form natural dams so that lakes form upstream after the ice recedes.

### substance | earth | moraine:

Ground moraine
* are more extensive area-wise than are lateral moraines
  - pieces of rock the glaciers drop as they travel
  - the most common type of moraine and can be found on every continent
* is exposed as glaciers retreat.

Lateral moraine
* are deposits of debris such as gravel and sand along the side of a valley glacier.
* are formed by the rocks falling from the mountains upon the sides of the glacier
  - lines of pushed-up debris on the sides of glaciers
  - parallel ridges of debris deposited along the sides of a glacier
  - the mounds of till that are at the margins of outlet or valley glaciers
* form along the side of a glacier and curl into a terminal moraine
  - at the sides of flowing valley glaciers

Medial moraine
* are formed when two glaciers meet
  - indicative of multiple valley glaciers flowing in parallel
* form on top of existing glaciers.
* is formed from two lateral moraines.

Recessional moraine
* are simply terminal moraines from more than one advance.
* mark intermediate advances.

Terminal moraine
* are big mounds of earth pushed up in front of the glacier as it moves forwards
  - similar deposits at the end of a glacier
* mark the position of the ice where it was most extensive.

### substance:

Elastomer
* All elastomers have a high and low temperature limit
  - an upper and lower temperature limit
* Many elastomers are sensitive to ozone cracking.
* Most elastomers contain waxes designed to offer protection from ozone.
* are a special case of the wider group of materials known as polymers
  - also usually thermoplastics
  - generally easier to pigment and store
  - polymers with long flexible chains
  - poor conductors of heat
  - the most corrosion sensitive part of the seal
* are very sensitive to both temperature and pressure
* have a tendency to stretch out when the are exposed to a repetitive duty cycle
  - very low moduli
* positioned in the seal face are subject to the heat generated between the seal faces.

### substance:

Enamel
* Some enamel has mechanical properties
* Some enamel is part of fangs
  - incisors
  - molars
  - teeth
  - tusks
  - enamels use other glass producing substances, such as phosphates
* are easy to apply and come in a wide assortment of colors
  - especially tough and washable
  - generally smoother and dry to a harder surface than other interior paints
  - great on metal
  - oil varnishes with pigment added
  - oil-based paints and they require paint thinner to thin and clean up
  - petroleum-based paints
  - transparent
* give greater moisture resistance and are easier to clean.
* is coating
  - compounds
  - part of crowns

### substance | enamel:

Dental enamel
* eroded by stomach acid and lack of menstruation are other signs.
* is the hardest substance our bodies can produce, even harder than bone.