#Squantum

As Seen From Buck Hillasseenfrombuckhill@c.im
2024-12-27

Spectacle Island of Boston Harbor Islands National Park and the Squantum section of Quincy MA photographed from Buck Hill. The landscape fools the eyes here as there are several miles of Boston Harbor which cannot be seen, making this appear as one continuous land mass. Squantum is a little over six miles from Buck Hill while Spectacle Island is over eleven miles. On Spectacle Island, the visitor center building can clearly be seen, as can the dock out in front (left in the photo) with light posts. The frame of a special event tent on the island can be seen to the upper left. At the top of the frame, some of the stone seawall for Deer Island can be seen.

I am including a second image that includes a key to the structures that I have identified in this post.

1 - Spectacle Island Visitor Center
2 - Spectacle Island dock
3 - Spectacle Island tent frame
4 - 132 Crabtree Rd, Quincy MA
5 - 124 Crabtree Rd, Quincy MA
6 - 94 Crabtree Rd, Quincy MA
7 - 25 Woodbriar Rd, Quincy MA
8 - 78 Knollwood Rd, Quincy MA
9 - 72 Knollwood Rd, Quincy MA
10 - 75 Knollwood Rd, Quincy MA
11 - 13 Hillcrest Rd, Quincy MA
12 - 84 Knollwood Dr, Quincy MA
13 - 49 Sonoma Rd, Quincy MA

#BuckHill #BlueHills #BlueHillsReservation #Boston #BostonMA #BostonHarborIslands #Quincy #QunicyMA #Squantum #SquantumMA #Spectacle #SpectacleIsland #Landscape #LandscapePhotography #Photography #LongDistanceObservations #OlympusEM5 #CanonFD #500mm

Spectacle Island of Boston Harbor Islands National Park and the Squantum section of Quincy MA photographed from Buck Hill.
2023-10-06

A bizarre #sedimentary feature

Some layers in the #Neoproterozoic #Squantum Member of the #Roxbury #Conglomerate have been rolled up like a pie crust, into a tube. If this were a #tillite, as it once was thought to be, then it could have been caused by the drag of a #Gaskiers #glacier over the till. These rocks are mostly interpreted as deposited by submarine debris flows these days, in which case they could’ve been deformed during a slump and flow. Site of a field trip for #UMassBoston.

The circular form at the center of this color digital photograph is a bit of rolled up sandstone, with relict layering expressed like the layers of an onion in this exposure.  Blue key ring usb drive and key at top right for scale.
2023-09-09

A small #outcrop of the #Squantum Member of the #Roxbury #Conglomerate

These #rocks are in the #BostonBay Group, which is currently dated to #Neoproterozoic. The Squantum Member was interpreted as a #tillite, possibly associated with the #Gaskiers #glaciation, although there a scant signs like scratched pebbles or faceted cobbles. It is currently commonly interpreted as a #debrite (debris flow). Details in captions.
#geology #glacier #turbidite #Quincy #Boston #Massachusetts #NewEngland

Google Eart view of Squantum, Quincy, immediately southeast of Boston, Massachusetts USA. The small outcrop examined here is near the red pin. The “classic” Squantum cliff and beach exposures are near the pin for Myles Standish Cairn.My photo of a pice of float, not attached to bedrock. I interpret depositional up is at the bottom of this photo, and it is reverse graded as a debris pulse flowed over fine-grained sediments deposited in quieter conditions. Cell phone for scale.My photo of a piece of float, probably Squantum Member. There is compressive metamorphic foliation expressed as squashed clasts; compression is perpendicular to the pencil.Abrupt change in grain size in Squantum Member, depositional up is interpreted to be top right.
Alisa BokulichAlisaBokulich
2023-07-23

Point Park at on tonight's walk

purple flowers kine walkway into sunsettree across green grass field silhouetted against pink sunset streaked sky
2023-07-02

View about eastward over #Quincy Bay, #Squantum on the left, just south of #Boston, #Massachusetts USA
#NewEngland #Fujifilm my #photo #landscape
18/2 @ 5.6 1/950 s ISO 200 X-H1

2023-06-03

Anomalous pebble in layered #sedimentary #rock

An angular pebble is conformably surrounded by argillaceous and sandy layers in this #photograph of the #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate. The wide range of clast sizes led to an interpretation as a #glacial #tillite thru the 1970s, but the Squantum Member is now mostly interpreted as a #debrisFlow (#debrite or #turbidite). My #photo.

#Boston #fieldTrip #UMassBoston

In this color photo, a greenish circa 2 centimeter pebble at the center is bounded by distorted quasi parallel bedding below and above. Image height is about 10 cm. White balance card at right has an inch scale visible. My photo.
2023-06-01

Deformed bedding in meta#sedimentary #rocks

The horizontal bedding of the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic, #Boston Bay Group) has been disturbed locally.

In the #glacial #tillite interpretation of the Squantum (favored through at least the 1970s), the distortion might be caused by glaciotectonic drag at the ice base. The current interpretation as a #debrite or #turbidite would probably attribute the deformations to synsedimentary slumping. My #photo. #fieldTrip

This color photo show a circa 12 cm vertical extent of sedimentary rocks. In the upper part of the image, beds are inclined upward to the left. Near the center of the image, a bed has been rolled over itself. These features could have been caused by sediment slumping leftward, possibly in a debris flow. There is a white balance card with inch and centimeter scales at the bottom left. My photo.
2023-05-30

Rapid changes in #clast size in #sedimentary #rocks

The #Neoproterozoic #Squantum Member of the #Roxbury Conglomerate (#Boston Bay Group) transitions from sandstone, to almost-clast-supported conglomerate, to laminated argillite…in about 25 cm. Fifty years ago, it was interpreted as a #glacial deposit and called the Squantum #Tillite, presumably associated with the #Gaskiers Glaciation. Paucity of evidence (e.g., few scratches or faceted clasts) suggests a debris flow. My #photo.

A circa 25 cm high image shows a sandstone at bottom, conglomerate with angular clasts in the middle, and laminate argillite at the top. A white balance card with cm and inch scales is at the bottom left. My photo.
2023-05-29

The #glacier went that-a-way

The #striations on this face of the #Ediacaran (ca. 560 Ma) #Squantum Member of the #Roxbury #Conglomerate were probably left by the #Pleistocene #Laurentide ice sheet, which retreated ca. 12 ka. The striations have the right orientation, from northwest to southeast.

The Squantum Member was once interpreted as a (#glacial) #tillite. The most common contemporary model is a peri-#Gondwana #debrite (#turbidite).

My #photo. #Boston #geology #NewEngland #fieldTrip

Shallow scratches extend roughly left to right across this image, which is about 20 cm tall. The compass at the left center of the image indicates the scratches are on a NW-SE axis, consistent with the movement of the Pleistocene ice sheet in this region. The cracks are from extensive deformation. There are scales on the sides of the compass. My photo.
2023-05-25

Interbedded argillaceous & tuffaceous #sediments

These photos are of #Cambridge #Argillite, exposed above the #Squantum Member of the #Roxbury Conglomerate (#Neoproterozoic). Prior to the 1970s or so, the Squantum Member was interpreted as #glacial sediments; it's now broadly interpreted as debris flows, with the Cambridge being distal turbidites overlying it. I lead a field trip here for #UMassBoston. See captions.

#outcrop #fieldTrip #photo #rocks #tuff #Fufjilm #Venus 65mm #macro #Quincy

This map shows the location of the outcrop (black pin near center), at the north boundary of Quincy, and across Dorchester Bay from the University of Massachusetts Boston; Boston is at the top center. OpenStreetMap in MyTracks.A close up of fine laminations in Cambridge Argillite. The light layers are probably volcanic ash or tuff, which have been highly altered. The magenta-hued layers are argillaceous: clay, silt, and fine sand. The tuffaceous layers are circa 1 cm thick; scale at bottom is blurred because of limited depth of field. The scene is about 5 cm tall. My photo.Photo showing altenration of fine argillaceous and conglomerate layers near the boundary between the Squantum Member and the Cambridge Argillite. Scale card at base has cm and inch scales, and is about 5 cm wide; the entire scene is perhaps 50 cm tall, and the conglomerate layers are circa 5 to 10 cm. My photo.This photograph (scene is about 60 cm tall) shows interbedded argillite (smoother, pinkish, laminated rock) and tuffaceous (volcanic ash) layers that have been altered and weathered back from the rock face. The scale at top is about 5 cm tall. My photo.

Client Info

Server: https://mastodon.social
Version: 2025.04
Repository: https://github.com/cyevgeniy/lmst