Thrombolites of the lower devonian Manlius Formation of central New York

Abstract

The Manlius Formation of the Lower Devonian Helderberg Group in central New York State contains decimeter-scale thrombolites. Internally, thrombolites comprise centimeter-scale, digitate to irregularly-shaped clots surrounded by skeletal wackestone. The clots are composed of variable amounts of: 1) millimeter-scale hemispheroids with radial and concentric structure that resembleKeega; 2)Renalcis-like forms; 3) stromatolitic laminae of mudstone; 4) peloidal mudstone laminae with filament molds; and 5) rare fossils. The thrombolites themselves are interbedded with grainstones, mudstones, graded beds, and intraclastic conglomerates. A low diversity fauna is found in many of these associated rocks.