Geoscience Reference
In-Depth Information
Figure 9-5.
Thick brown coal (lignite) exposed in a surface mine at Lubstów near Konin, west-central Poland.
Excavating machines are working at multiple levels beneath a relatively thin cover of overburden. Photo by J.S. Aber.
Figure 9-6.
Schematic illustration of wetland types during the Miocene of central Europe (see Fig. 8-24A and Fig.
9-5). Coniferous trees are labeled; adapted from Greb, DiMichele and Gastaldo (2006, Fig. 19B).
varied widely through time and space. As an
example, the Miocene lignite of central Europe
was laid down in a complex succession of habi-
tats that included many types of eutrophic to
oligotrophic wetlands (Fig. 9-6).
species, and these fossils possess lifelike forms
in three dimensions with original textures and
color patterns (Poinar and Poinar 1999). Mil-
lions of years later, these exquisite inclusions
reveal geologic history and paleoenvironments.
Engel (2001) wrote that amber allows scientists
to “peer directly into past eons with far greater
clarity than is possible from other kinds of
fossils” (p. 161). Amber is also a beautiful gem-
stone; early gem use of amber amulets and
bead necklaces dates from the Stone Age.
Resin is a viscous, amorphous hydrocarbon
produced in specialized structures within plant
tissue. Although all woody plants produce resin,
not all tree resin becomes amber. Certain factors
favor the transformation such as chemical
composition, resistance to decay, ability to
polymerize (harden), and potential for burial.
9.3 Amber
Amber is a treasury of past l ora and fauna.
Amber is found primarily in Cretaceous and
Tertiary coal and lignite deposits and provides
further evidence for reconstructing wetland
paleohabitats. Resin oozes from trees primarily
as a defensive mechanism and upon death;
ancient tree resin was the sticky trap that
captured plant debris, small vertebrates, inver-
tebrates, and air. Amber preserves extinct
