marsh creek . A drainage channel developed on a salt marsh.
Subscribe via EMail to the GeoWord of the Day.
marine ecology . The study of the relationships between marine organisms and their environment, including associated organisms.
discrete spectrum . In harmonic analysis of time series, a plot of power or variance at discrete frequencies or harmonics.
tyrrellite (tyr-rell'-ite). A metallic bronze cubic selenospinel mineral of the linnaeite group: (Cu,Co,Ni)3Se4 .
chaméanite (cha-mé-an'-ite). A metallic gray cubic mineral occurring in intergrowths with giraudite: (Cu,Fe)4As(Se,S)4 .
flame test . A qualitative analysis of a mineral made by intensely heating a sample in a flame and observing the flame's color, which will be indicative of the element involved, e.g. green from copper.
lateral accretion . Sediment accumulation at the side of a channel or bank. Lateral accretion deposits or sidebars grow towards the channel axis whereas cross bedding dips parallel to channel axis. Cf: vertical accretion.
exchangeable anions . Negatively charged ions held on or near the surface of a solid particle by a positive surface charge and which may be easily replaced by other negatively charged ions, e.g., with a Cl- salt.
driven well (driv'-en). A shallow well, usually of small diameter (3-10 cm), constructed by driving a series of connected lengths of pipe into unconsolidated material to a water-bearing stratum, without the aid of any drilling, boring, or jetting device. Syn: tube well.
fusulinid (fu-su-lin'-id). Any foraminifer belonging to the suborder Fusulinina, family Fusulinidae, characterized by a multichambered elongate calcareous microgranular test, commonly resembling the shape of a grain of wheat. Range, Middle Pennsylvanian to Upper Permian. Syn: fusuline. See also: alveolinid.