Burrow Types Research Articles

Biogenic Sedimentary Structures in Facies of Middle Ordovician Black River Group of New York State: ABSTRACT

This study is based on analysis of 450 large vertical slabs from eight stratigraphic sections in the Black River Group type area, the Black River valley, northwest New York State. The group is underlain by an irregular Precambrian surface, is 90-140 ft thick, and consists of three formations: the basal Pamelia, the Lowville, and the Chaumont. These represent a sequence of six nearshore sedimentologic facies. Superimposed on these are four biogenic sedimentary structure facies, each characterized by particular biogenic structures. The Pamelia Formation consists of buff, algally laminated, fine-scale-mudcracked, supratidal dolomite characterized by rare vertical burrows like those of the succeeding Lowville Formation, and a sparse euryhaline fauna. The lower Lowville consists of lithologic types representing two environments: (1) gray, mudcracked, ripple-marked, thin-bedded, intertidal limestone with a euryhaline fauna, and (2) dark gray, thick-bedded, laminated, subtidal limestone containing algally coated grains and a sparse stenohaline fauna. The intertidal Lowville is characterized by permanent, vertical, and U-shaped burrows which today are most common in intertidal environments. Filter feeders usually construct these burrows for protection in environments characterized by stress at the interface. The subtidal part of the lower Lowville Formation is characterized by complex, irregularly oriented, feeding burrows, and large, concentrically laminated burrows. Today these types of burrows are common in quiet subtidal environme ts where deposit feeders dominate. The upper Lowville Formation represents a wave baffle formed by compound colonies of the spindle-shaped coral Tetradium associated with marginal zones of fallen Tetradium. These rocks are characterized by absence of biogenic structures, probably caused by the mechanical difficulty of burrowing into sediment with such a felted texture. The Chaumont Formation consists of silt-size debris of a diverse stenohaline biota, and is unbedded because of thorough burrowing. It is characterized by small, horizontal, sediment-filled burrows, which today dominate in level-bottom marine environments where a thin oxidized zone favors deposit feeders which cover broad horizontal areas near the sediment surface. Thus, integration of faunal, sedimentologic, and stratigraphic data with information on recent biogenic structures allows ecologic interpretation of Ordovician structures. End_of_Article - Last_Page 554------------

Burrows and Burrowing Behavior of Onychomys leucogaster

A study of the shelter-seeking behavior of captive northern grasshopper mice was made in 15 × 15 × 3 ft sheet metal enclosures. Observations showed that grasshopper mice invariably dug their own burrows. The following types of burrows were recognized: nest burrows, retreat burrows, cache burrows and miscellaneous burrows, including those used for defecation and signposting. Records showed that the burrows provided the mouse with a refuge from extreme fluctuations of temperature. Nest burrows were dug by males with the help of females; individual mice did not dig nest burrows. The burrow entrances were not noticeably raised above the surface, and nest entrances to burrows were not in protected areas.

A Life History Study of Thirteen-Lined Ground Squirrels in Southern Wisconsin

A population of thirteen-lined ground squirrels in Madison, Wisconsin, was studied during the spring and summer of 1961 and 1962. Conception dates varied within and between years. Males moved greater distances than females. Spring seemed to be the period when longest movements took place. Adults had a 29% annual survival rate, juveniles, only 16%. Females had a higher survival rate than males. High mortality among juveniles mainly occurred prior to hibernation. Three distinct types of burrows were noted.

Natural History of Two Beach Hoppers of the Genus Orchestoidea (Crustacea: Amphipoda) with Reference to their Complemental Distribution

Natural History of Two Beach Hoppers of the Genus Orchestoidea (Crustacea: Amphipoda) with Reference to their Complemental Distribution

Changes in the chalk heart-urchinMicrasterInterpreted in relation to living forms

Changes in the chalk heart-urchin<i>Micraster</i>Interpreted in relation to living forms

The Nymph of the Mayfly Genus Tortopus (Ephemeroptera: Polymitarcidae)1

Immatures of this genus had not been taken prior to the discovery of large numbers of T. incertus nymphs during a biological survey of the Savannah River. The nymphs honeycomb the clay banks of the river with their burrows and follow the river level up or down, as evidenced by abandoned burrows 5 or 6 feet above low-water level. Apparently the insect requires 2 years to develop from egg to adult, and emergence of adults is restricted to the period from late July to early September. The similarity of the distribution of hairs on the legs, and the type of burrows occupied by the nymphs, suggest that the insect strains its food much as does its African relative Povilla. The nymph of T. incertus is described and figured.

Observations sur les traces des organismes fouisseurs dans l'Ordovicien normand

Abstract Ordovician sediments in cores from different borings in lower Normandy, France, show evidence of the activity of burrowing organisms. Several types of traces and burrows are described. They are indicative of slow and calm sedimentation, otherwise either the animals could not live or the traces would have been mechanically obliterated after formation. They can also be used to determine tops and bottoms of beds and to furnish information on compaction of sediments. They are not a good criterion of depth because they are found over a wide range.