FTELD TRIP ACROSS THE APPALACHTAN OROGENIC BELT

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folds. PodF of ouart? and feldspar: there are large masses of quartz and feldspar in the rocks. I'm not sure what their origrin is, or why they're here Joints: find the long, straight, regularly spaced, nearly vertical fractures that cut all the rocks. These fractures are called joints. They formed later than the folding defornation, because they cut all the folds and are not affected by the folds.
STOP 3: G()LD 7 , N GREEN CIUARRY, PARKESBURG This stop is in a privately owned quarryrand ere are here by the good graces of the owners (one is a UD grad). please respect the property and its contents. DO. NOT ENTER THE DEEP PIT TO THE RE,AR RIGHT; STAY ON THE HIGHER GROUND TO THE REAR LEFT. The rocks here are stil-I within the PIEDIIOIIT province, because they show penetrative shear deformation (see Figure 3). They are on the margin of a large anticline that exposes Precanbrian basement rocks in the center. However, they are ;rart of the niogeosynclinal, passive-nargin wedge (Figure 3). They belong to the CHICKIES FORIIATIOI{, of latest Precambrian age. The Chickies is a quartzite and netagongl,olerate, a sequence of quartz sandstones and quartz-pebble conglomerates that have undergone high-grade metamorphism. The parents of quartzite clearly are sedinentary sandstones. Thls particular sandstone was clean, mature and well-sorted when deposited, with little clay matrix. During metamorphism there wasn't much in the rock besides quartz Lo make new metarnorphic minerals, and the quartzite has the same minerals as the original sandstone (although grain shapes are clearly metamorphic). The cleanness and maturity of the original sandstone suggests a cratonic tectonic setting of deposition, even though the rock came into an orogenic-subduction zone later in its history. The Chickies is the basal, lowest rock unit in the oassive uargin wedge of sedimentary rocks that developed on the eastern margin of North America during Late Precanbrian through Middle Ordovician time (see Figure 4). The sand was produced by weathering of craton and basement rocks to the north and northwest, in Canada and the US midwest. Remember the Taconic Orogeny laboratory? The Chickies is sinilar to the sandstone facies on the Upper Cambrian map of that exercise. This sequence of rocks developed on the trailing edge of what was the rrAmericantf plate of that time. After the plate motion reversed in ruiddle Ordovician tirne, this trailing edge became the leading edge, and the eastern parts of the passive-nargin wedge were partially subducted, metamorphosed and deformed. Thus the Chickies. Features to observe at this outcrop include: strong, parallg,Lbgkligg in the quartzites. made more parallel by the metamorphism. It was probably Look for eross-beddingr in the sandstones. It might be visible, might not be. took for truncation of bed contacts by other beds, Iook for T-junctions.
Page 1 and 2: GEOIOGY 106 FTELD TRIP ACROSS THE A
Page 3: REGTONAL GEOLOGTC SETT TNG The next
Page 7 and 8: . Varlicot atlta (hrtlcol .rogsroho
Page 9 and 10: C*;:;il 't {r ( i:$-*
Page 11 and 12: i'.iii :iii.'i:j l3 lz ll lo 1 ?_-J
Page 13 and 14: STOP 1: h,INDY HILLS BRIDGE Stop L,
Page 15: There were at these rocks. 5 least
Page 19 and 20: STOP 4: 9 THE BIKE STORE', MOHNTON
Page 21 and 22: 11 STOP 5: STONE CLIFF PARK, READ I
Page 23 and 24: 1_3 Work out a sequence of eyents i
Page 25 and 26: 15 Note the regularity of the beddi
Page 27 and 28: 17 sToP 7 - DEER LAKE This is an ab
Page 29 and 30: 18 as representing shallow, gently
Page 31 and 32: sroP 70: 20 LAVELLE I I This exposu
Page 33 and 34: 22 STOP 77: LAVELLE TTT . This is a
Page 35 and 36: t l+{ o OJ 0) .o r0 E F (n F.l fr U
Page 37 and 38: sToP 73: DTNNER STOP 25 BEAR VALLEY
Page 39 and 40: surface of the rocks just below the
Page 41: Pecopter:is sp. Annu,a.ria sp. lieu

FTELD TRIP ACROSS THE APPALACHTAN OROGENIC BELT

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